Genetics of Psoriatic Arthritis – an update
Main Article Content
Abstract
Psoriatic arthritis (PsA) is an inflammatory arthritis that commonly occurs with psoriasis and is attributed to genetic, immunologic and environmental factors. It shares skin involvement with psoriasis, articular involvement particularly with spondyloarthritis, bowel involvement with Crohn’s disease and eye involvement with uveitis, suggesting the existence of some common pathways. The Th-17 pathway and the IL-23/IL-17 axis have become prominent players in PsA and have considerably increased our understanding of disease pathogenesis. In this review article, we will focus on the genetic, epigenetic, and pharmacogenetic information with respect to PsA. Prominent genes identified in PsA via GWAS include HLA-A, HLA-B, HLA-C, IL-12B, IL-23R, IL-23A, TNIP1, TRAF3IP2, CSF2/P4HA2, FBXL19, REL, TYK2, NOS2, PTPN22, TNFAIP3, IFNLR1, IFIH1, and NFKBIA. These genetic markers have also illuminated key signaling pathways involved in PsA pathogenesis which can be broadly classified into those involved in epidermal differentiation, innate immunity, antigen presentation and processing, and acquired/adaptive immunity. With respect to PsA pathogenesis, the most consistent and predominant genetic effect is located on chromosome 6p21.3 within the major histocompatibility complex (MHC) region. The most significant association for increased PsA risk was with asparagine or serine residue at amino acid position 97 of HLA-B, where asparagine at position 97 of HLA-B represents the HLA-B*27 allele. Moreover, specific HLA alleles have been associated with disease susceptibility, expression and progression in PsA. The prominent emerging role of the Th-17 signaling pathway in PsA pathogenesis will be highlighted. The lack of identified PsA genetic susceptibility loci is largely attributed to the much smaller number of patients, classification criteria used, and the greater clinical heterogeneity of PsA compared with psoriasis.
Keywords:
Psoriatic arthritis, genetics, genomics, genome-wide association studies, epigenetics, pharmacogenetics
Article Details
How to Cite
O'RIELLY, Darren D.; RAHMAN, Proton.
Genetics of Psoriatic Arthritis – an update.
Medical Research Archives, [S.l.], v. 6, n. 3, mar. 2018.
ISSN 2375-1924.
Available at: <https://esmed.org/MRA/mra/article/view/1690>. Date accessed: 15 dec. 2024.
doi: https://doi.org/10.18103/mra.v6i3.1690.
Section
Review Articles
The Medical Research Archives grants authors the right to publish and reproduce the unrevised contribution in whole or in part at any time and in any form for any scholarly non-commercial purpose with the condition that all publications of the contribution include a full citation to the journal as published by the Medical Research Archives.
References
References:
1. Gladman DD, Antoni C, Mease P, Clegg DO and Nash P. Psoriatic arthritis: epidemiology, clinical features, course, and outcome. Ann Rheum Dis. 2005; 64 Suppl 2: ii14-7.
2. Moll JM and Wright V. Psoriatic arthritis. Semin Arthritis Rheum. 1973; 3: 55-78.
3. Mallbris L, Ritchlin CT and Stahle M. Metabolic disorders in patients with psoriasis and psoriatic arthritis. Curr Rheumatol Rep. 2006; 8: 355-63.
4. Taylor W, Gladman D, Helliwell P, et al. Classification criteria for psoriatic arthritis: development of new criteria from a large international study. Arthritis Rheum. 2006; 54: 2665-73.
5. Sutherland A, Power RJ, Rahman P and O'Rielly DD. Pharmacogenetics and pharmacogenomics in psoriasis treatment: current challenges and future prospects. Expert Opin Drug Metab Toxicol. 2016; 12: 923-35.
6. Ritchlin CT, Colbert RA and Gladman DD. Psoriatic Arthritis. N Engl J Med. 2017; 376: 957-70.
7. McGonagle D, Lories RJ, Tan AL and Benjamin M. The concept of a "synovio-entheseal complex" and its implications for understanding joint inflammation and damage in psoriatic arthritis and beyond. Arthritis Rheum. 2007; 56: 2482-91.
8. Lories R. The balance of tissue repair and remodeling in chronic arthritis. Nat Rev Rheumatol. 2011; 7: 700-7.
9. Lande R, Giacomini E, Serafini B, et al. Characterization and recruitment of plasmacytoid dendritic cells in synovial fluid and tissue of patients with chronic inflammatory arthritis. J Immunol. 2004; 173: 2815-24.
10. Wenink MH, Santegoets KC, Butcher J, et al. Impaired dendritic cell proinflammatory cytokine production in psoriatic arthritis. Arthritis Rheum. 2011; 63: 3313-22.
11. Canete JD, Martinez SE, Farres J, et al. Differential Th1/Th2 cytokine patterns in chronic arthritis: interferon gamma is highly expressed in synovium of rheumatoid arthritis compared with seronegative spondyloarthropathies. Ann Rheum Dis. 2000; 59: 263-8.
12. Leipe J, Grunke M, Dechant C, et al. Role of Th17 cells in human autoimmune arthritis. Arthritis Rheum. 2010; 62: 2876-85.
13. Jandus C, Bioley G, Rivals JP, Dudler J, Speiser D and Romero P. Increased numbers of circulating polyfunctional Th17 memory cells in patients with seronegative spondylarthritides. Arthritis Rheum. 2008; 58: 2307-17.
14. Noordenbos T, Yeremenko N, Gofita I, et al. Interleukin-17-positive mast cells contribute to synovial inflammation in spondylarthritis. Arthritis Rheum. 2012; 64: 99-109.
15. Gottlieb A, Menter A, Mendelsohn A, et al. Ustekinumab, a human interleukin 12/23 monoclonal antibody, for psoriatic arthritis: randomised, double-blind, placebo-controlled, crossover trial. Lancet. 2009; 373: 633-40.
16. Gottlieb AB, Langley RG, Philipp S, et al. Secukinumab Improves Physical Function in Subjects With Plaque Psoriasis and Psoriatic Arthritis: Results from Two Randomized, Phase 3 Trials. J Drugs Dermatol. 2015; 14: 821-33.
17. Mease PJ. Inhibition of interleukin-17, interleukin-23 and the TH17 cell pathway in the treatment of psoriatic arthritis and psoriasis. Current opinion in rheumatology. 2015; 27: 127-33.
18. Mease PJ, Gladman DD, Ritchlin CT, et al. Adalimumab for the treatment of patients with moderately to severely active psoriatic arthritis: results of a double-blind, randomized, placebo-controlled trial. Arthritis Rheum. 2005; 52: 3279-89.
19. Nash P, Kirkham B, Okada M, et al. Ixekizumab for the treatment of patients with active psoriatic arthritis and an inadequate response to tumour necrosis factor inhibitors: results from the 24-week randomised, double-blind, placebo-controlled period of the SPIRIT-P2 phase 3 trial. Lancet. 2017; 389: 2317-27.
20. Ritchlin CT, Kavanaugh A, Gladman DD, et al. Treatment recommendations for psoriatic arthritis. Ann Rheum Dis. 2009; 68: 1387-94.
21. Siannis F, Farewell VT, Cook RJ, Schentag CT and Gladman DD. Clinical and radiological damage in psoriatic arthritis. Ann Rheum Dis. 2006; 65: 478-81.
22. Schett G and David JP. The multiple faces of autoimmune-mediated bone loss. Nat Rev Endocrinol. 2010; 6: 698-706.
23. Ritchlin CT, Haas-Smith SA, Li P, Hicks DG and Schwarz EM. Mechanisms of TNF-alpha- and RANKL-mediated osteoclastogenesis and bone resorption in psoriatic arthritis. J Clin Invest. 2003; 111: 821-31.
24. Colucci S, Brunetti G, Cantatore FP, et al. Lymphocytes and synovial fluid fibroblasts support osteoclastogenesis through RANKL, TNFalpha, and IL-7 in an in vitro model derived from human psoriatic arthritis. J Pathol. 2007; 212: 47-55.
25. Okamoto K and Takayanagi H. Osteoclasts in arthritis and Th17 cell development. Int Immunopharmacol. 2011; 11: 543-8.
26. Lories RJ, Derese I, Ceuppens JL and Luyten FP. Bone morphogenetic proteins 2 and 6, expressed in arthritic synovium, are regulated by proinflammatory cytokines and differentially modulate fibroblast-like synoviocyte apoptosis. Arthritis Rheum. 2003; 48: 2807-18.
27. Lories RJ, Luyten FP and de Vlam K. Progress in spondylarthritis. Mechanisms of new bone formation in spondyloarthritis. Arthritis research & therapy. 2009; 11: 221.
28. Diarra D, Stolina M, Polzer K, et al. Dickkopf-1 is a master regulator of joint remodeling. Nat Med. 2007; 13: 156-63.
29. Elder JT, Nair RP, Henseler T, et al. The genetics of psoriasis 2001: the odyssey continues. Arch Dermatol. 2001; 137: 1447-54.
30. Moll JM and Wright V. Familial occurrence of psoriatic arthritis. Ann Rheum Dis. 1973; 32: 181-201.
31. Myers A, Kay LJ, Lynch SA and Walker DJ. Recurrence risk for psoriasis and psoriatic arthritis within sibships. Rheumatology (Oxford). 2005; 44: 773-6.
32. Chandran V, Schentag CT, Brockbank JE, et al. Familial aggregation of psoriatic arthritis. Ann Rheum Dis. 2009; 68: 664-7.
33. Karason A, Love TJ and Gudbjornsson B. A strong heritability of psoriatic arthritis over four generations--the Reykjavik Psoriatic Arthritis Study. Rheumatology (Oxford). 2009; 48: 1424-8.
34. Bowes J, Budu-Aggrey A, Huffmeier U, et al. Dense genotyping of immune-related susceptibility loci reveals new insights into the genetics of psoriatic arthritis. Nat Commun. 2015; 6: 6046.
35. Liu Y, Helms C, Liao W, et al. A genome-wide association study of psoriasis and psoriatic arthritis identifies new disease loci. PLoS Genet. 2008; 4: e1000041.
36. Nair RP, Duffin KC, Helms C, et al. Genome-wide scan reveals association of psoriasis with IL-23 and NF-kappaB pathways. Nat Genet. 2009; 41: 199-204.
37. Huffmeier U, Uebe S, Ekici AB, et al. Common variants at TRAF3IP2 are associated with susceptibility to psoriatic arthritis and psoriasis. Nat Genet. 2010; 42: 996-9.
38. Ellinghaus E, Ellinghaus D, Stuart PE, et al. Genome-wide association study identifies a psoriasis susceptibility locus at TRAF3IP2. Nat Genet. 2010; 42: 991-5.
39. Stuart PE, Nair RP, Ellinghaus E, et al. Genome-wide association analysis identifies three psoriasis susceptibility loci. Nat Genet. 2010; 42: 1000-4.
40. Ellinghaus E, Stuart PE, Ellinghaus D, et al. Genome-wide meta-analysis of psoriatic arthritis identifies susceptibility locus at REL. J Invest Dermatol. 2012; 132: 1133-40.
41. Bowes J, Loehr S, Budu-Aggrey A, et al. PTPN22 is associated with susceptibility to psoriatic arthritis but not psoriasis: evidence for a further PsA-specific risk locus. Ann Rheum Dis. 2015.
42. Stuart PE, Nair RP, Tsoi LC, et al. Genome-wide Association Analysis of Psoriatic Arthritis and Cutaneous Psoriasis Reveals Differences in Their Genetic Architecture. Am J Hum Genet. 2015; 97: 816-36.
43. Lories RJ and de Vlam K. Is psoriatic arthritis a result of abnormalities in acquired or innate immunity? Curr Rheumatol Rep. 2012; 14: 375-82.
44. Ganguly D, Chamilos G, Lande R, et al. Self-RNA-antimicrobial peptide complexes activate human dendritic cells through TLR7 and TLR8. J Exp Med. 2009; 206: 1983-94.
45. Gallagher J, Howlin J, McCarthy C, et al. Identification of Naf1/ABIN-1 among TNF-alpha-induced expressed genes in human synoviocytes using oligonucleotide microarrays. FEBS Lett. 2003; 551: 8-12.
46. De Molfetta GA, Luciola Zanette D, Alexandre Panepucci R, Dos Santos AR, da Silva WA, Jr. and Antonio Zago M. Role of NFKB2 on the early myeloid differentiation of CD34+ hematopoietic stem/progenitor cells. Differentiation. 2010; 80: 195-203.
47. Vereecke L, Beyaert R and van Loo G. Genetic relationships between A20/TNFAIP3, chronic inflammation and autoimmune disease. Biochem Soc Trans. 2011; 39: 1086-91.
48. Lowenstein CJ and Padalko E. iNOS (NOS2) at a glance. J Cell Sci. 2004; 117: 2865-7.
49. Koch AE. Chemokines and their receptors in rheumatoid arthritis: future targets? Arthritis Rheum. 2005; 52: 710-21.
50. Zhu J, Qu H, Chen X, Wang H and Li J. Single nucleotide polymorphisms in the tumor necrosis factor-alpha gene promoter region alter the risk of psoriasis vulgaris and psoriatic arthritis: a meta-analysis. PLoS One. 2013; 8: e64376.
51. Rahman P, Siannis F, Butt C, et al. TNFalpha polymorphisms and risk of psoriatic arthritis. Ann Rheum Dis. 2006; 65: 919-23.
52. Hohler T, Kruger A, Schneider PM, et al. A TNF-alpha promoter polymorphism is associated with juvenile onset psoriasis and psoriatic arthritis. J Invest Dermatol. 1997; 109: 562-5.
53. Mossner R, Kingo K, Kleensang A, et al. Association of TNF -238 and -308 promoter polymorphisms with psoriasis vulgaris and psoriatic arthritis but not with pustulosis palmoplantaris. J Invest Dermatol. 2005; 124: 282-4.
54. Murdaca G, Gulli R, Spano F, et al. TNF-alpha gene polymorphisms: association with disease susceptibility and response to anti-TNF-alpha treatment in psoriatic arthritis. J Invest Dermatol. 2014; 134: 2503-9.
55. Feng BJ, Sun LD, Soltani-Arabshahi R, et al. Multiple Loci within the major histocompatibility complex confer risk of psoriasis. PLoS Genet. 2009; 5: e1000606.
56. Croft M and Siegel RM. Beyond TNF: TNF superfamily cytokines as targets for the treatment of rheumatic diseases. Nat Rev Rheumatol. 2017; 13: 217-33.
57. Azuma Y, Kaji K, Katogi R, Takeshita S and Kudo A. Tumor necrosis factor-alpha induces differentiation of and bone resorption by osteoclasts. J Biol Chem. 2000; 275: 4858-64.
58. Ritchlin C, Haas-Smith SA, Hicks D, Cappuccio J, Osterland CK and Looney RJ. Patterns of cytokine production in psoriatic synovium. J Rheumatol. 1998; 25: 1544-52.
59. Danning CL, Illei GG, Hitchon C, Greer MR, Boumpas DT and McInnes IB. Macrophage-derived cytokine and nuclear factor kappaB p65 expression in synovial membrane and skin of patients with psoriatic arthritis. Arthritis Rheum. 2000; 43: 1244-56.
60. Gladman DD. Traditional and newer therapeutic options for psoriatic arthritis: an evidence-based review. Drugs. 2005; 65: 1223-38.
61. Olivieri I, D'Angelo S, Palazzi C and Padula A. Advances in the management of psoriatic arthritis. Nat Rev Rheumatol. 2014; 10: 531-42.
62. Hertzog P, Forster S and Samarajiwa S. Systems biology of interferon responses. J Interferon Cytokine Res. 2011; 31: 5-11.
63. Budu-Aggrey A, Bowes J, Stuart PE, et al. A rare coding allele in IFIH1 is protective for psoriatic arthritis. Ann Rheum Dis. 2017; 76: 1321-4.
64. Piganis RA, De Weerd NA, Gould JA, et al. Suppressor of cytokine signaling (SOCS) 1 inhibits type I interferon (IFN) signaling via the interferon alpha receptor (IFNAR1)-associated tyrosine kinase Tyk2. J Biol Chem. 2011; 286: 33811-8.
65. Blazek K, Eames HL, Weiss M, et al. IFN-lambda resolves inflammation via suppression of neutrophil infiltration and IL-1beta production. J Exp Med. 2015; 212: 845-53.
66. Nejentsev S, Walker N, Riches D, Egholm M and Todd JA. Rare variants of IFIH1, a gene implicated in antiviral responses, protect against type 1 diabetes. Science. 2009; 324: 387-9.
67. Stanford SM and Bottini N. PTPN22: the archetypal non-HLA autoimmunity gene. Nat Rev Rheumatol. 2014; 10: 602-11.
68. Vandooren B, Noordenbos T, Ambarus C, et al. Absence of a classically activated macrophage cytokine signature in peripheral spondylarthritis, including psoriatic arthritis. Arthritis Rheum. 2009; 60: 966-75.
69. Morales-Zambrano R, Bautista-Herrera LA, De la Cruz-Mosso U, et al. Macrophage migration inhibitory factor (MIF) promoter polymorphisms (-794 CATT5-8 and -173 G>C): association with MIF and TNFalpha in psoriatic arthritis. Int J Clin Exp Med. 2014; 7: 2605-14.
70. Fousteri G, Liossis SN and Battaglia M. Roles of the protein tyrosine phosphatase PTPN22 in immunity and autoimmunity. Clin Immunol. 2013; 149: 556-65.
71. Denkinger CM, Metz C, Fingerle-Rowson G, Denkinger MD and Forsthuber T. Macrophage migration inhibitory factor and its role in autoimmune diseases. Arch Immunol Ther Exp (Warsz). 2004; 52: 389-400.
72. Bacher M, Metz CN, Calandra T, et al. An essential regulatory role for macrophage migration inhibitory factor in T-cell activation. Proc Natl Acad Sci U S A. 1996; 93: 7849-54.
73. Julia A, Pinto JA, Gratacos J, et al. A deletion at ADAMTS9-MAGI1 locus is associated with psoriatic arthritis risk. Ann Rheum Dis. 2015; 74: 1875-81.
74. Davidson RK, Waters JG, Kevorkian L, et al. Expression profiling of metalloproteinases and their inhibitors in synovium and cartilage. Arthritis research & therapy. 2006; 8: R124.
75. Lohmander LS, Neame PJ and Sandy JD. The structure of aggrecan fragments in human synovial fluid. Evidence that aggrecanase mediates cartilage degradation in inflammatory joint disease, joint injury, and osteoarthritis. Arthritis Rheum. 1993; 36: 1214-22.
76. Laura RP, Ross S, Koeppen H and Lasky LA. MAGI-1: a widely expressed, alternatively spliced tight junction protein. Exp Cell Res. 2002; 275: 155-70.
77. Veale DJ, Barnes L, Rogers S and FitzGerald O. Immunohistochemical markers for arthritis in psoriasis. Ann Rheum Dis. 1994; 53: 450-4.
78. Miossec P. IL-17 and Th17 cells in human inflammatory diseases. Microbes Infect. 2009; 11: 625-30.
79. O'Rielly DD and Rahman P. Advances in the genetics of spondyloarthritis and clinical implications. Curr Rheumatol Rep. 2013; 15: 347.
80. Bowes J, Ashcroft J, Dand N, et al. Cross-phenotype association mapping of the MHC identifies genetic variants that differentiate psoriatic arthritis from psoriasis. Ann Rheum Dis. 2017.
81. Lopez-Larrea C, Torre Alonso JC, Rodriguez Perez A and Coto E. HLA antigens in psoriatic arthritis subtypes of a Spanish population. Ann Rheum Dis. 1990; 49: 318-9.
82. McHugh NJ, Laurent MR, Treadwell BL, Tweed JM and Dagger J. Psoriatic arthritis: clinical subgroups and histocompatibility antigens. Ann Rheum Dis. 1987; 46: 184-8.
83. Chandran V, Bull SB, Pellett FJ, Ayearst R, Rahman P and Gladman DD. Human leukocyte antigen alleles and susceptibility to psoriatic arthritis. Hum Immunol. 2013; 74: 1333-8.
84. Eder L, Chandran V, Pellet F, et al. Human leucocyte antigen risk alleles for psoriatic arthritis among patients with psoriasis. Annals of the rheumatic diseases. 2012; 71: 50-5.
85. Winchester R, Minevich G, Steshenko V, et al. HLA associations reveal genetic heterogeneity in psoriatic arthritis and in the psoriasis phenotype. Arthritis Rheum. 2012; 64: 1134-44.
86. Okada Y, Han B, Tsoi LC, et al. Fine mapping major histocompatibility complex associations in psoriasis and its clinical subtypes. Am J Hum Genet. 2014; 95: 162-72.
87. Chandran V and Rahman P. Update on the genetics of spondyloarthritis--ankylosing spondylitis and psoriatic arthritis. Best Pract Res Clin Rheumatol. 2010; 24: 579-88.
88. Gladman D, Anhorn K, Schachter R and Mervart H. HLA antigens in psoriatic arthritis. Journal of Rheumatology. 1986; 13: 586.
89. Haroon M, Winchester R, Giles JT, Heffernan E and FitzGerald O. Clinical and genetic associations of radiographic sacroiliitis and its different patterns in psoriatic arthritis. Clin Exp Rheumatol. 2017; 35: 270-6.
90. Gladman DD, Ziouzina O, Thavaneswaran A and Chandran V. Dactylitis in psoriatic arthritis: prevalence and response to therapy in the biologic era. J Rheumatol. 2013; 40: 1357-9.
91. Haroon M, Winchester R, Giles JT, Heffernan E and FitzGerald O. Certain class I HLA alleles and haplotypes implicated in susceptibility play a role in determining specific features of the psoriatic arthritis phenotype. Ann Rheum Dis. 2016; 75: 155-62.
92. Queiro R, Morante I, Cabezas I and Acasuso B. HLA-B27 and psoriatic disease: a modern view of an old relationship. Rheumatology (Oxford). 2016; 55: 221-9.
93. Winchester R, Giles J, Jadon D, Haroon M, McHugh N and FitzGerald O. Implications of the diversity of class I HLA associations in psoriatic arthritis. Clin Immunol. 2016; 172: 29-33.
94. Groh V, Steinle A, Bauer S and Spies T. Recognition of stress-induced MHC molecules by intestinal epithelial gammadelta T cells. Science. 1998; 279: 1737-40.
95. Gonzalez S, Martinez-Borra J, Torre-Alonso JC, et al. The MICA-A9 triplet repeat polymorphism in the transmembrane region confers additional susceptibility to the development of psoriatic arthritis and is independent of the association of Cw*0602 in psoriasis. Arthritis Rheum. 1999; 42: 1010-6.
96. Korendowych E RJ, Owen PA. Disease-specific alleles of the MHC Class I related gene, MICA, are associated with type I psoriasis and psoriatic arthritis. Br J Dermatol. 2006; 154: 4.
97. Song GG, Kim JH and Lee YH. Associations between the major histocompatibility complex class I chain-related gene A transmembrane (MICA-TM) polymorphism and susceptibility to psoriasis and psoriatic arthritis: a meta-analysis. Rheumatol Int. 2014; 34: 117-23.
98. Mameli A, Cauli A, Taccari E, et al. Association of MICA alleles with psoriatic arthritis and its clinical forms. A multicenter Italian study. Clin Exp Rheumatol. 2008; 26: 649-52.
99. Pollock R, Chandran V, Barrett J, et al. Differential major histocompatibility complex class I chain-related A allele associations with skin and joint manifestations of psoriatic disease. Tissue Antigens. 2011; 77: 554-61.
100. Pollock RA, Chandran V, Pellett FJ, et al. The functional MICA-129 polymorphism is associated with skin but not joint manifestations of psoriatic disease independently of HLA-B and HLA-C. Tissue Antigens. 2013; 82: 43-7.
101. Lanier LL. NK cell recognition. Annu Rev Immunol. 2005; 23: 225-74.
102. Chen L, Ridley A, Hammitzsch A, et al. Silencing or inhibition of endoplasmic reticulum aminopeptidase 1 (ERAP1) suppresses free heavy chain expression and Th17 responses in ankylosing spondylitis. Ann Rheum Dis. 2016; 75: 916-23.
103. Payeli SK, Kollnberger S, Marroquin Belaunzaran O, et al. Inhibiting HLA-B27 homodimer-driven immune cell inflammation in spondylarthritis. Arthritis Rheum. 2012; 64: 3139-49.
104. Bowness P, Ridley A, Shaw J, et al. Th17 cells expressing KIR3DL2+ and responsive to HLA-B27 homodimers are increased in ankylosing spondylitis. J Immunol. 2011; 186: 2672-80.
105. Chandran V, Bull SB, Pellett FJ, Ayearst R, Pollock RA and Gladman DD. Killer-cell immunoglobulin-like receptor gene polymorphisms and susceptibility to psoriatic arthritis. Rheumatology (Oxford). 2014; 53: 233-9.
106. Mpakali A, Giastas P, Mathioudakis N, Mavridis IM, Saridakis E and Stratikos E. Structural Basis for Antigenic Peptide Recognition and Processing by Endoplasmic Reticulum (ER) Aminopeptidase 2. J Biol Chem. 2015; 290: 26021-32.
107. Cifaldi L, Romania P, Lorenzi S, Locatelli F and Fruci D. Role of endoplasmic reticulum aminopeptidases in health and disease: from infection to cancer. Int J Mol Sci. 2012; 13: 8338-52.
108. Yang Q, Liu H, Qu L, et al. Investigation of 20 non-HLA (human leucocyte antigen) psoriasis susceptibility loci in Chinese patients with psoriatic arthritis and psoriasis vulgaris. Br J Dermatol. 2013; 168: 1060-5.
109. Popa OM, Cherciu M, Cherciu LI, et al. ERAP1 and ERAP2 Gene Variations Influence the Risk of Psoriatic Arthritis in Romanian Population. Arch Immunol Ther Exp (Warsz). 2016; 64: 123-9.
110. Andres AM, Dennis MY, Kretzschmar WW, et al. Balancing selection maintains a form of ERAP2 that undergoes nonsense-mediated decay and affects antigen presentation. PLoS Genet. 2010; 6: e1001157.
111. Robinson PC, Costello ME, Leo P, et al. ERAP2 is associated with ankylosing spondylitis in HLA-B27-positive and HLA-B27-negative patients. Ann Rheum Dis. 2015; 74: 1627-9.
112. International Genetics of Ankylosing Spondylitis C, Cortes A, Hadler J, et al. Identification of multiple risk variants for ankylosing spondylitis through high-density genotyping of immune-related loci. Nat Genet. 2013; 45: 730-8.
113. Apel M, Uebe S, Bowes J, et al. Variants in RUNX3 contribute to susceptibility to psoriatic arthritis, exhibiting further common ground with ankylosing spondylitis. Arthritis Rheum. 2013; 65: 1224-31.
114. Smith RL, Hebert HL, Massey J, et al. Association of Toll-like receptor 4 (TLR4) with chronic plaque type psoriasis and psoriatic arthritis. Arch Dermatol Res. 2016; 308: 201-5.
115. Akbal A, Oguz S, Gokmen F, et al. C-reactive protein gene and Toll-like receptor 4 gene polymorphisms can relate to the development of psoriatic arthritis. Clin Rheumatol. 2015; 34: 301-6.
116. O'Donnell H, Pham OH, Li LX, et al. Toll-like receptor and inflammasome signals converge to amplify the innate bactericidal capacity of T helper 1 cells. Immunity. 2014; 40: 213-24.
117. Cheung PF, Wong CK and Lam CW. Molecular mechanisms of cytokine and chemokine release from eosinophils activated by IL-17A, IL-17F, and IL-23: implication for Th17 lymphocytes-mediated allergic inflammation. J Immunol. 2008; 180: 5625-35.
118. Sonder SU, Saret S, Tang W, Sturdevant DE, Porcella SF and Siebenlist U. IL-17-induced NF-kappaB activation via CIKS/Act1: physiologic significance and signaling mechanisms. J Biol Chem. 2011; 286: 12881-90.
119. Raychaudhuri SP, Raychaudhuri SK and Genovese MC. IL-17 receptor and its functional significance in psoriatic arthritis. Mol Cell Biochem. 2012; 359: 419-29.
120. Wilson NJ, Boniface K, Chan JR, et al. Development, cytokine profile and function of human interleukin 17-producing helper T cells. Nat Immunol. 2007; 8: 950-7.
121. Mitra A, Raychaudhuri SK and Raychaudhuri SP. Functional role of IL-22 in psoriatic arthritis. Arthritis research & therapy. 2012; 14: R65.
122. Dolcino M, Ottria A, Barbieri A, et al. Gene Expression Profiling in Peripheral Blood Cells and Synovial Membranes of Patients with Psoriatic Arthritis. PLoS One. 2015; 10: e0128262.
123. Pollock RA, Abji F, Liang K, et al. Gene expression differences between psoriasis patients with and without inflammatory arthritis. J Invest Dermatol. 2015; 135: 620-3.
124. Abji F, Pollock RA, Liang K, Chandran V and Gladman DD. Th17 gene expression in psoriatic arthritis synovial fluid and peripheral blood compared to osteoarthritis and cutaneous psoriasis. Clin Exp Rheumatol. 2017.
125. Al-Mossawi MH, Chen L, Fang H, et al. Unique transcriptome signatures and GM-CSF expression in lymphocytes from patients with spondyloarthritis. Nat Commun. 2017; 8: 1510.
126. Celis R, Planell N, Fernandez-Sueiro JL, et al. Synovial cytokine expression in psoriatic arthritis and associations with lymphoid neogenesis and clinical features. Arthritis research & therapy. 2012; 14: R93.
127. Sato K, Suematsu A, Okamoto K, et al. Th17 functions as an osteoclastogenic helper T cell subset that links T cell activation and bone destruction. J Exp Med. 2006; 203: 2673-82.
128. Adamopoulos IE, Chao CC, Geissler R, et al. Interleukin-17A upregulates receptor activator of NF-kappaB on osteoclast precursors. Arthritis research & therapy. 2010; 12: R29.
129. Adamopoulos IE, Suzuki E, Chao CC, et al. IL-17A gene transfer induces bone loss and epidermal hyperplasia associated with psoriatic arthritis. Ann Rheum Dis. 2015; 74: 1284-92.
130. Sherlock JP, Joyce-Shaikh B, Turner SP, et al. IL-23 induces spondyloarthropathy by acting on ROR-gammat+ CD3+CD4-CD8- entheseal resident T cells. Nat Med. 2012; 18: 1069-76.
131. Adamopoulos IE, Tessmer M, Chao CC, et al. IL-23 is critical for induction of arthritis, osteoclast formation, and maintenance of bone mass. J Immunol. 2011; 187: 951-9.
132. Torres T and Faria R. Ustekinumab: The "New Kid on the Block" in the Treatment of Psoriatic Arthritis. Drug Dev Res. 2015; 76: 428-31.
133. McInnes IB, Mease PJ, Kirkham B, et al. Secukinumab, a human anti-interleukin-17A monoclonal antibody, in patients with psoriatic arthritis (FUTURE 2): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2015.
134. Ghoreschi K, Laurence A, Yang XP, et al. Generation of pathogenic T(H)17 cells in the absence of TGF-beta signalling. Nature. 2010; 467: 967-71.
135. Alenius GM, Eriksson C and Rantapaa Dahlqvist S. Interleukin-6 and soluble interleukin-2 receptor alpha-markers of inflammation in patients with psoriatic arthritis? Clin Exp Rheumatol. 2009; 27: 120-3.
136. Choy EH and Panayi GS. Cytokine pathways and joint inflammation in rheumatoid arthritis. N Engl J Med. 2001; 344: 907-16.
137. Rahman P, Sun S, Peddle L, et al. Association between the interleukin-1 family gene cluster and psoriatic arthritis. Arthritis Rheum. 2006; 54: 2321-5.
138. Ravindran JS, Owen P, Lagan A, et al. Interleukin 1alpha, interleukin 1beta and interleukin 1 receptor gene polymorphisms in psoriatic arthritis. Rheumatology (Oxford). 2004; 43: 22-6.
139. Bowes J, Ho P, Flynn E, et al. Investigation of IL1, VEGF, PPARG and MEFV genes in psoriatic arthritis susceptibility. Ann Rheum Dis. 2012; 71: 313-4.
140. Cubino N, Montilla C, Usategui-Martin R, et al. Association of IL1Beta (-511 A/C) and IL6 (-174 G > C) polymorphisms with higher disease activity and clinical pattern of psoriatic arthritis. Clin Rheumatol. 2016; 35: 1789-94.
141. Langrish CL, Chen Y, Blumenschein WM, et al. IL-23 drives a pathogenic T cell population that induces autoimmune inflammation. J Exp Med. 2005; 201: 233-40.
142. Di Cesare A, Di Meglio P and Nestle FO. The IL-23/Th17 axis in the immunopathogenesis of psoriasis. J Invest Dermatol. 2009; 129: 1339-50.
143. Eiris N, Gonzalez-Lara L, Santos-Juanes J, Queiro R, Coto E and Coto-Segura P. Genetic variation at IL12B, IL23R and IL23A is associated with psoriasis severity, psoriatic arthritis and type 2 diabetes mellitus. J Dermatol Sci. 2014; 75: 167-72.
144. Budu-Aggrey A, Bowes J, Loehr S, et al. Replication of a distinct psoriatic arthritis risk variant at the IL23R locus. Ann Rheum Dis. 2016; 75: 1417-8.
145. Cenit MC, Ortego-Centeno N, Raya E, et al. Influence of the STAT3 genetic variants in the susceptibility to psoriatic arthritis and Behcet's disease. Hum Immunol. 2013; 74: 230-3.
146. Myrthianou E, Zervou MI, Budu-Aggrey A, et al. Investigation of the genetic overlap between rheumatoid arthritis and psoriatic arthritis in a Greek population. Scand J Rheumatol. 2017; 46: 180-6.
147. Yang XP, Ghoreschi K, Steward-Tharp SM, et al. Opposing regulation of the locus encoding IL-17 through direct, reciprocal actions of STAT3 and STAT5. Nat Immunol. 2011; 12: 247-54.
148. Korn T, Bettelli E, Oukka M and Kuchroo VK. IL-17 and Th17 Cells. Annu Rev Immunol. 2009; 27: 485-517.
149. Chandran V. The genetics of psoriasis and psoriatic arthritis. Clin Rev Allergy Immunol. 2013; 44: 149-56.
150. Harris TJ, Grosso JF, Yen HR, et al. Cutting Edge: An In Vivo Requirement for STAT3 Signaling in TH17 Development and TH17-Dependent Autoimmunity. The Journal of Immunology. 2007; 179: 4313-7.
151. Mrabet D, Laadhar L, Sahli H, et al. Synovial fluid and serum levels of IL-17, IL-23, and CCL-20 in rheumatoid arthritis and psoriatic arthritis: a Tunisian cross-sectional study. Rheumatol Int. 2013; 33: 265-6.
152. Muntyanu A, Abji F, Liang K, Pollock RA, Chandran V and Gladman DD. Differential gene and protein expression of chemokines and cytokines in synovial fluid of patients with arthritis. Arthritis research & therapy. 2016; 18: 296.
153. Belasco J, Louie JS, Gulati N, et al. Comparative genomic profiling of synovium versus skin lesions in psoriatic arthritis. Arthritis Rheumatol. 2015; 67: 934-44.
154. de Cid R, Riveira-Munoz E, Zeeuwen PL, et al. Deletion of the late cornified envelope LCE3B and LCE3C genes as a susceptibility factor for psoriasis. Nat Genet. 2009; 41: 211-5.
155. Bowes J, Flynn E, Ho P, et al. Variants in linkage disequilibrium with the late cornified envelope gene cluster deletion are associated with susceptibility to psoriatic arthritis. Ann Rheum Dis. 2010; 69: 2199-203.
156. Docampo E, Giardina E, Riveira-Munoz E, et al. Deletion of LCE3C and LCE3B is a susceptibility factor for psoriatic arthritis: a study in Spanish and Italian populations and meta-analysis. Arthritis Rheum. 2011; 63: 1860-5.
157. Chiraz BS, Myriam A, Ines Z, et al. Deletion of late cornified envelope genes, LCE3C_LCE3B-del, is not associated with psoriatic arthritis in Tunisian patients. Mol Biol Rep. 2014; 41: 4141-6.
158. Huffmeier U, Estivill X, Riveira-Munoz E, et al. Deletion of LCE3C and LCE3B genes at PSORS4 does not contribute to susceptibility to psoriatic arthritis in German patients. Ann Rheum Dis. 2010; 69: 876-8.
159. Hunter JA, Skelly RH, Aylwin SJ, et al. The relationship between pituitary tumour transforming gene (PTTG) expression and in vitro hormone and vascular endothelial growth factor (VEGF) secretion from human pituitary adenomas. Eur J Endocrinol. 2003; 148: 203-11.
160. Veale D, Yanni G, Rogers S, Barnes L, Bresnihan B and Fitzgerald O. Reduced synovial membrane macrophage numbers, ELAM-1 expression, and lining layer hyperplasia in psoriatic arthritis as compared with rheumatoid arthritis. Arthritis Rheum. 1993; 36: 893-900.
161. Ciccia F, Guggino G, Ferrante A, et al. Interleukin-9 Overexpression and Th9 Polarization Characterize the Inflamed Gut, the Synovial Tissue, and the Peripheral Blood of Patients With Psoriatic Arthritis. Arthritis Rheumatol. 2016; 68: 1922-31.
162. Guggino G, Ciccia F, Di Liberto D, et al. Interleukin (IL)-9/IL-9R axis drives gammadelta T cells activation in psoriatic arthritis patients. Clin Exp Immunol. 2016; 186: 277-83.
163. Pedersen OB, Svendsen AJ, Ejstrup L, Skytthe A and Junker P. On the heritability of psoriatic arthritis. Disease concordance among monozygotic and dizygotic twins. Ann Rheum Dis. 2008; 67: 1417-21.
164. Rahman P, Gladman DD, Schentag CT and Petronis A. Excessive paternal transmission in psoriatic arthritis. Arthritis Rheum. 1999; 42: 1228-31.
165. Pollock RA, Thavaneswaran A, Pellett F, et al. Further evidence supporting a parent-of-origin effect in psoriatic disease. Arthritis Care Res (Hoboken). 2015.
166. Theeuwes M and Morhenn V. Allelic instability in the mitosis model and the inheritance of psoriasis. J Am Acad Dermatol. 1995; 32: 44-52.
167. Pollock RA, Abji F and Gladman DD. Epigenetics of psoriatic disease: A systematic review and critical appraisal. J Autoimmun. 2017; 78: 29-38.
168. Karason A, Gudjonsson JE, Upmanyu R, et al. A susceptibility gene for psoriatic arthritis maps to chromosome 16q: evidence for imprinting. Am J Hum Genet. 2003; 72: 125-31.
169. Martinez C, Blanco G, Ladero JM, et al. Genetic predisposition to acute gastrointestinal bleeding after NSAIDs use. Br J Pharmacol. 2004; 141: 205-8.
170. Chandran V, Siannis F, Rahman P, Pellett FJ, Farewell VT and Gladman DD. Folate pathway enzyme gene polymorphisms and the efficacy and toxicity of methotrexate in psoriatic arthritis. J Rheumatol. 2010; 37: 1508-12.
171. Cuchacovich R, Perez-Alamino R, Zea AH and Espinoza LR. Distinct genetic profile in peripheral blood mononuclear cells of psoriatic arthritis patients treated with methotrexate and TNF-inhibitors. Clin Rheumatol. 2014; 33: 1815-21.
172. Menter A, Gottlieb A, Feldman SR, et al. Guidelines of care for the management of psoriasis and psoriatic arthritis: Section 1. Overview of psoriasis and guidelines of care for the treatment of psoriasis with biologics. J Am Acad Dermatol. 2008; 58: 826-50.
173. Kavanaugh A, Antoni CE, Gladman D, et al. The Infliximab Multinational Psoriatic Arthritis Controlled Trial (IMPACT): results of radiographic analyses after 1 year. Ann Rheum Dis. 2006; 65: 1038-43.
174. Mease PJ, Goffe BS, Metz J, VanderStoep A, Finck B and Burge DJ. Etanercept in the treatment of psoriatic arthritis and psoriasis: a randomised trial. Lancet. 2000; 356: 385-90.
175. Tong Q, Zhao L, Qian XD, et al. Association of TNF-alpha polymorphism with prediction of response to TNF blockers in spondyloarthritis and inflammatory bowel disease: a meta-analysis. Pharmacogenomics. 2013; 14: 1691-700.
176. Julia A, Rodriguez J, Fernandez-Sueiro JL, et al. PDE3A-SLCO1C1 locus is associated with response to anti-tumor necrosis factor therapy in psoriatic arthritis. Pharmacogenomics. 2014; 15: 1763-9.
177. Ramirez J, Fernandez-Sueiro JL, Lopez-Mejias R, et al. FCGR2A/CD32A and FCGR3A/CD16A variants and EULAR response to tumor necrosis factor-alpha blockers in psoriatic arthritis: a longitudinal study with 6 months of followup. J Rheumatol. 2012; 39: 1035-41.
178. Morales-Lara MJ, Canete JD, Torres-Moreno D, et al. Effects of polymorphisms in TRAILR1 and TNFR1A on the response to anti-TNF therapies in patients with rheumatoid and psoriatic arthritis. Joint Bone Spine. 2012; 79: 591-6.
179. Rosenberg A, Fan H, Chiu YG, et al. Divergent gene activation in peripheral blood and tissues of patients with rheumatoid arthritis, psoriatic arthritis and psoriasis following infliximab therapy. PLoS One. 2014; 9: e110657.
180. McInnes IB, Kavanaugh A, Gottlieb AB, et al. Efficacy and safety of ustekinumab in patients with active psoriatic arthritis: 1 year results of the phase 3, multicentre, double-blind, placebo-controlled PSUMMIT 1 trial. Lancet. 2013; 382: 780-9.
181. Kavanaugh A, Puig L, Gottlieb AB, et al. Efficacy and safety of ustekinumab in psoriatic arthritis patients with peripheral arthritis and physician-reported spondylitis: post-hoc analyses from two phase III, multicentre, double-blind, placebo-controlled studies (PSUMMIT-1/PSUMMIT-2). Ann Rheum Dis. 2016; 75: 1984-8.
182. Ritchlin C, Rahman P, Kavanaugh A, et al. Efficacy and safety of the anti-IL-12/23 p40 monoclonal antibody, ustekinumab, in patients with active psoriatic arthritis despite conventional non-biological and biological anti-tumour necrosis factor therapy: 6-month and 1-year results of the phase 3, multicentre, double-blind, placebo-controlled, randomised PSUMMIT 2 trial. Ann Rheum Dis. 2014; 73: 990-9.
183. Prieto-Perez R, Cabaleiro T, Dauden E and Abad-Santos F. Gene polymorphisms that can predict response to anti-TNF therapy in patients with psoriasis and related autoimmune diseases. Pharmacogenomics J. 2013; 13: 297-305.
184. Talamonti M, Botti E, Galluzzo M, et al. Pharmacogenetics of psoriasis: HLA-Cw6 but not LCE3B/3C deletion nor TNFAIP3 polymorphism predisposes to clinical response to interleukin 12/23 blocker ustekinumab. Br J Dermatol. 2013; 169: 458-63.
185. Galluzzo M, Boca AN, Botti E, et al. IL12B (p40) Gene Polymorphisms Contribute to Ustekinumab Response Prediction in Psoriasis. Dermatology. 2015.
1. Gladman DD, Antoni C, Mease P, Clegg DO and Nash P. Psoriatic arthritis: epidemiology, clinical features, course, and outcome. Ann Rheum Dis. 2005; 64 Suppl 2: ii14-7.
2. Moll JM and Wright V. Psoriatic arthritis. Semin Arthritis Rheum. 1973; 3: 55-78.
3. Mallbris L, Ritchlin CT and Stahle M. Metabolic disorders in patients with psoriasis and psoriatic arthritis. Curr Rheumatol Rep. 2006; 8: 355-63.
4. Taylor W, Gladman D, Helliwell P, et al. Classification criteria for psoriatic arthritis: development of new criteria from a large international study. Arthritis Rheum. 2006; 54: 2665-73.
5. Sutherland A, Power RJ, Rahman P and O'Rielly DD. Pharmacogenetics and pharmacogenomics in psoriasis treatment: current challenges and future prospects. Expert Opin Drug Metab Toxicol. 2016; 12: 923-35.
6. Ritchlin CT, Colbert RA and Gladman DD. Psoriatic Arthritis. N Engl J Med. 2017; 376: 957-70.
7. McGonagle D, Lories RJ, Tan AL and Benjamin M. The concept of a "synovio-entheseal complex" and its implications for understanding joint inflammation and damage in psoriatic arthritis and beyond. Arthritis Rheum. 2007; 56: 2482-91.
8. Lories R. The balance of tissue repair and remodeling in chronic arthritis. Nat Rev Rheumatol. 2011; 7: 700-7.
9. Lande R, Giacomini E, Serafini B, et al. Characterization and recruitment of plasmacytoid dendritic cells in synovial fluid and tissue of patients with chronic inflammatory arthritis. J Immunol. 2004; 173: 2815-24.
10. Wenink MH, Santegoets KC, Butcher J, et al. Impaired dendritic cell proinflammatory cytokine production in psoriatic arthritis. Arthritis Rheum. 2011; 63: 3313-22.
11. Canete JD, Martinez SE, Farres J, et al. Differential Th1/Th2 cytokine patterns in chronic arthritis: interferon gamma is highly expressed in synovium of rheumatoid arthritis compared with seronegative spondyloarthropathies. Ann Rheum Dis. 2000; 59: 263-8.
12. Leipe J, Grunke M, Dechant C, et al. Role of Th17 cells in human autoimmune arthritis. Arthritis Rheum. 2010; 62: 2876-85.
13. Jandus C, Bioley G, Rivals JP, Dudler J, Speiser D and Romero P. Increased numbers of circulating polyfunctional Th17 memory cells in patients with seronegative spondylarthritides. Arthritis Rheum. 2008; 58: 2307-17.
14. Noordenbos T, Yeremenko N, Gofita I, et al. Interleukin-17-positive mast cells contribute to synovial inflammation in spondylarthritis. Arthritis Rheum. 2012; 64: 99-109.
15. Gottlieb A, Menter A, Mendelsohn A, et al. Ustekinumab, a human interleukin 12/23 monoclonal antibody, for psoriatic arthritis: randomised, double-blind, placebo-controlled, crossover trial. Lancet. 2009; 373: 633-40.
16. Gottlieb AB, Langley RG, Philipp S, et al. Secukinumab Improves Physical Function in Subjects With Plaque Psoriasis and Psoriatic Arthritis: Results from Two Randomized, Phase 3 Trials. J Drugs Dermatol. 2015; 14: 821-33.
17. Mease PJ. Inhibition of interleukin-17, interleukin-23 and the TH17 cell pathway in the treatment of psoriatic arthritis and psoriasis. Current opinion in rheumatology. 2015; 27: 127-33.
18. Mease PJ, Gladman DD, Ritchlin CT, et al. Adalimumab for the treatment of patients with moderately to severely active psoriatic arthritis: results of a double-blind, randomized, placebo-controlled trial. Arthritis Rheum. 2005; 52: 3279-89.
19. Nash P, Kirkham B, Okada M, et al. Ixekizumab for the treatment of patients with active psoriatic arthritis and an inadequate response to tumour necrosis factor inhibitors: results from the 24-week randomised, double-blind, placebo-controlled period of the SPIRIT-P2 phase 3 trial. Lancet. 2017; 389: 2317-27.
20. Ritchlin CT, Kavanaugh A, Gladman DD, et al. Treatment recommendations for psoriatic arthritis. Ann Rheum Dis. 2009; 68: 1387-94.
21. Siannis F, Farewell VT, Cook RJ, Schentag CT and Gladman DD. Clinical and radiological damage in psoriatic arthritis. Ann Rheum Dis. 2006; 65: 478-81.
22. Schett G and David JP. The multiple faces of autoimmune-mediated bone loss. Nat Rev Endocrinol. 2010; 6: 698-706.
23. Ritchlin CT, Haas-Smith SA, Li P, Hicks DG and Schwarz EM. Mechanisms of TNF-alpha- and RANKL-mediated osteoclastogenesis and bone resorption in psoriatic arthritis. J Clin Invest. 2003; 111: 821-31.
24. Colucci S, Brunetti G, Cantatore FP, et al. Lymphocytes and synovial fluid fibroblasts support osteoclastogenesis through RANKL, TNFalpha, and IL-7 in an in vitro model derived from human psoriatic arthritis. J Pathol. 2007; 212: 47-55.
25. Okamoto K and Takayanagi H. Osteoclasts in arthritis and Th17 cell development. Int Immunopharmacol. 2011; 11: 543-8.
26. Lories RJ, Derese I, Ceuppens JL and Luyten FP. Bone morphogenetic proteins 2 and 6, expressed in arthritic synovium, are regulated by proinflammatory cytokines and differentially modulate fibroblast-like synoviocyte apoptosis. Arthritis Rheum. 2003; 48: 2807-18.
27. Lories RJ, Luyten FP and de Vlam K. Progress in spondylarthritis. Mechanisms of new bone formation in spondyloarthritis. Arthritis research & therapy. 2009; 11: 221.
28. Diarra D, Stolina M, Polzer K, et al. Dickkopf-1 is a master regulator of joint remodeling. Nat Med. 2007; 13: 156-63.
29. Elder JT, Nair RP, Henseler T, et al. The genetics of psoriasis 2001: the odyssey continues. Arch Dermatol. 2001; 137: 1447-54.
30. Moll JM and Wright V. Familial occurrence of psoriatic arthritis. Ann Rheum Dis. 1973; 32: 181-201.
31. Myers A, Kay LJ, Lynch SA and Walker DJ. Recurrence risk for psoriasis and psoriatic arthritis within sibships. Rheumatology (Oxford). 2005; 44: 773-6.
32. Chandran V, Schentag CT, Brockbank JE, et al. Familial aggregation of psoriatic arthritis. Ann Rheum Dis. 2009; 68: 664-7.
33. Karason A, Love TJ and Gudbjornsson B. A strong heritability of psoriatic arthritis over four generations--the Reykjavik Psoriatic Arthritis Study. Rheumatology (Oxford). 2009; 48: 1424-8.
34. Bowes J, Budu-Aggrey A, Huffmeier U, et al. Dense genotyping of immune-related susceptibility loci reveals new insights into the genetics of psoriatic arthritis. Nat Commun. 2015; 6: 6046.
35. Liu Y, Helms C, Liao W, et al. A genome-wide association study of psoriasis and psoriatic arthritis identifies new disease loci. PLoS Genet. 2008; 4: e1000041.
36. Nair RP, Duffin KC, Helms C, et al. Genome-wide scan reveals association of psoriasis with IL-23 and NF-kappaB pathways. Nat Genet. 2009; 41: 199-204.
37. Huffmeier U, Uebe S, Ekici AB, et al. Common variants at TRAF3IP2 are associated with susceptibility to psoriatic arthritis and psoriasis. Nat Genet. 2010; 42: 996-9.
38. Ellinghaus E, Ellinghaus D, Stuart PE, et al. Genome-wide association study identifies a psoriasis susceptibility locus at TRAF3IP2. Nat Genet. 2010; 42: 991-5.
39. Stuart PE, Nair RP, Ellinghaus E, et al. Genome-wide association analysis identifies three psoriasis susceptibility loci. Nat Genet. 2010; 42: 1000-4.
40. Ellinghaus E, Stuart PE, Ellinghaus D, et al. Genome-wide meta-analysis of psoriatic arthritis identifies susceptibility locus at REL. J Invest Dermatol. 2012; 132: 1133-40.
41. Bowes J, Loehr S, Budu-Aggrey A, et al. PTPN22 is associated with susceptibility to psoriatic arthritis but not psoriasis: evidence for a further PsA-specific risk locus. Ann Rheum Dis. 2015.
42. Stuart PE, Nair RP, Tsoi LC, et al. Genome-wide Association Analysis of Psoriatic Arthritis and Cutaneous Psoriasis Reveals Differences in Their Genetic Architecture. Am J Hum Genet. 2015; 97: 816-36.
43. Lories RJ and de Vlam K. Is psoriatic arthritis a result of abnormalities in acquired or innate immunity? Curr Rheumatol Rep. 2012; 14: 375-82.
44. Ganguly D, Chamilos G, Lande R, et al. Self-RNA-antimicrobial peptide complexes activate human dendritic cells through TLR7 and TLR8. J Exp Med. 2009; 206: 1983-94.
45. Gallagher J, Howlin J, McCarthy C, et al. Identification of Naf1/ABIN-1 among TNF-alpha-induced expressed genes in human synoviocytes using oligonucleotide microarrays. FEBS Lett. 2003; 551: 8-12.
46. De Molfetta GA, Luciola Zanette D, Alexandre Panepucci R, Dos Santos AR, da Silva WA, Jr. and Antonio Zago M. Role of NFKB2 on the early myeloid differentiation of CD34+ hematopoietic stem/progenitor cells. Differentiation. 2010; 80: 195-203.
47. Vereecke L, Beyaert R and van Loo G. Genetic relationships between A20/TNFAIP3, chronic inflammation and autoimmune disease. Biochem Soc Trans. 2011; 39: 1086-91.
48. Lowenstein CJ and Padalko E. iNOS (NOS2) at a glance. J Cell Sci. 2004; 117: 2865-7.
49. Koch AE. Chemokines and their receptors in rheumatoid arthritis: future targets? Arthritis Rheum. 2005; 52: 710-21.
50. Zhu J, Qu H, Chen X, Wang H and Li J. Single nucleotide polymorphisms in the tumor necrosis factor-alpha gene promoter region alter the risk of psoriasis vulgaris and psoriatic arthritis: a meta-analysis. PLoS One. 2013; 8: e64376.
51. Rahman P, Siannis F, Butt C, et al. TNFalpha polymorphisms and risk of psoriatic arthritis. Ann Rheum Dis. 2006; 65: 919-23.
52. Hohler T, Kruger A, Schneider PM, et al. A TNF-alpha promoter polymorphism is associated with juvenile onset psoriasis and psoriatic arthritis. J Invest Dermatol. 1997; 109: 562-5.
53. Mossner R, Kingo K, Kleensang A, et al. Association of TNF -238 and -308 promoter polymorphisms with psoriasis vulgaris and psoriatic arthritis but not with pustulosis palmoplantaris. J Invest Dermatol. 2005; 124: 282-4.
54. Murdaca G, Gulli R, Spano F, et al. TNF-alpha gene polymorphisms: association with disease susceptibility and response to anti-TNF-alpha treatment in psoriatic arthritis. J Invest Dermatol. 2014; 134: 2503-9.
55. Feng BJ, Sun LD, Soltani-Arabshahi R, et al. Multiple Loci within the major histocompatibility complex confer risk of psoriasis. PLoS Genet. 2009; 5: e1000606.
56. Croft M and Siegel RM. Beyond TNF: TNF superfamily cytokines as targets for the treatment of rheumatic diseases. Nat Rev Rheumatol. 2017; 13: 217-33.
57. Azuma Y, Kaji K, Katogi R, Takeshita S and Kudo A. Tumor necrosis factor-alpha induces differentiation of and bone resorption by osteoclasts. J Biol Chem. 2000; 275: 4858-64.
58. Ritchlin C, Haas-Smith SA, Hicks D, Cappuccio J, Osterland CK and Looney RJ. Patterns of cytokine production in psoriatic synovium. J Rheumatol. 1998; 25: 1544-52.
59. Danning CL, Illei GG, Hitchon C, Greer MR, Boumpas DT and McInnes IB. Macrophage-derived cytokine and nuclear factor kappaB p65 expression in synovial membrane and skin of patients with psoriatic arthritis. Arthritis Rheum. 2000; 43: 1244-56.
60. Gladman DD. Traditional and newer therapeutic options for psoriatic arthritis: an evidence-based review. Drugs. 2005; 65: 1223-38.
61. Olivieri I, D'Angelo S, Palazzi C and Padula A. Advances in the management of psoriatic arthritis. Nat Rev Rheumatol. 2014; 10: 531-42.
62. Hertzog P, Forster S and Samarajiwa S. Systems biology of interferon responses. J Interferon Cytokine Res. 2011; 31: 5-11.
63. Budu-Aggrey A, Bowes J, Stuart PE, et al. A rare coding allele in IFIH1 is protective for psoriatic arthritis. Ann Rheum Dis. 2017; 76: 1321-4.
64. Piganis RA, De Weerd NA, Gould JA, et al. Suppressor of cytokine signaling (SOCS) 1 inhibits type I interferon (IFN) signaling via the interferon alpha receptor (IFNAR1)-associated tyrosine kinase Tyk2. J Biol Chem. 2011; 286: 33811-8.
65. Blazek K, Eames HL, Weiss M, et al. IFN-lambda resolves inflammation via suppression of neutrophil infiltration and IL-1beta production. J Exp Med. 2015; 212: 845-53.
66. Nejentsev S, Walker N, Riches D, Egholm M and Todd JA. Rare variants of IFIH1, a gene implicated in antiviral responses, protect against type 1 diabetes. Science. 2009; 324: 387-9.
67. Stanford SM and Bottini N. PTPN22: the archetypal non-HLA autoimmunity gene. Nat Rev Rheumatol. 2014; 10: 602-11.
68. Vandooren B, Noordenbos T, Ambarus C, et al. Absence of a classically activated macrophage cytokine signature in peripheral spondylarthritis, including psoriatic arthritis. Arthritis Rheum. 2009; 60: 966-75.
69. Morales-Zambrano R, Bautista-Herrera LA, De la Cruz-Mosso U, et al. Macrophage migration inhibitory factor (MIF) promoter polymorphisms (-794 CATT5-8 and -173 G>C): association with MIF and TNFalpha in psoriatic arthritis. Int J Clin Exp Med. 2014; 7: 2605-14.
70. Fousteri G, Liossis SN and Battaglia M. Roles of the protein tyrosine phosphatase PTPN22 in immunity and autoimmunity. Clin Immunol. 2013; 149: 556-65.
71. Denkinger CM, Metz C, Fingerle-Rowson G, Denkinger MD and Forsthuber T. Macrophage migration inhibitory factor and its role in autoimmune diseases. Arch Immunol Ther Exp (Warsz). 2004; 52: 389-400.
72. Bacher M, Metz CN, Calandra T, et al. An essential regulatory role for macrophage migration inhibitory factor in T-cell activation. Proc Natl Acad Sci U S A. 1996; 93: 7849-54.
73. Julia A, Pinto JA, Gratacos J, et al. A deletion at ADAMTS9-MAGI1 locus is associated with psoriatic arthritis risk. Ann Rheum Dis. 2015; 74: 1875-81.
74. Davidson RK, Waters JG, Kevorkian L, et al. Expression profiling of metalloproteinases and their inhibitors in synovium and cartilage. Arthritis research & therapy. 2006; 8: R124.
75. Lohmander LS, Neame PJ and Sandy JD. The structure of aggrecan fragments in human synovial fluid. Evidence that aggrecanase mediates cartilage degradation in inflammatory joint disease, joint injury, and osteoarthritis. Arthritis Rheum. 1993; 36: 1214-22.
76. Laura RP, Ross S, Koeppen H and Lasky LA. MAGI-1: a widely expressed, alternatively spliced tight junction protein. Exp Cell Res. 2002; 275: 155-70.
77. Veale DJ, Barnes L, Rogers S and FitzGerald O. Immunohistochemical markers for arthritis in psoriasis. Ann Rheum Dis. 1994; 53: 450-4.
78. Miossec P. IL-17 and Th17 cells in human inflammatory diseases. Microbes Infect. 2009; 11: 625-30.
79. O'Rielly DD and Rahman P. Advances in the genetics of spondyloarthritis and clinical implications. Curr Rheumatol Rep. 2013; 15: 347.
80. Bowes J, Ashcroft J, Dand N, et al. Cross-phenotype association mapping of the MHC identifies genetic variants that differentiate psoriatic arthritis from psoriasis. Ann Rheum Dis. 2017.
81. Lopez-Larrea C, Torre Alonso JC, Rodriguez Perez A and Coto E. HLA antigens in psoriatic arthritis subtypes of a Spanish population. Ann Rheum Dis. 1990; 49: 318-9.
82. McHugh NJ, Laurent MR, Treadwell BL, Tweed JM and Dagger J. Psoriatic arthritis: clinical subgroups and histocompatibility antigens. Ann Rheum Dis. 1987; 46: 184-8.
83. Chandran V, Bull SB, Pellett FJ, Ayearst R, Rahman P and Gladman DD. Human leukocyte antigen alleles and susceptibility to psoriatic arthritis. Hum Immunol. 2013; 74: 1333-8.
84. Eder L, Chandran V, Pellet F, et al. Human leucocyte antigen risk alleles for psoriatic arthritis among patients with psoriasis. Annals of the rheumatic diseases. 2012; 71: 50-5.
85. Winchester R, Minevich G, Steshenko V, et al. HLA associations reveal genetic heterogeneity in psoriatic arthritis and in the psoriasis phenotype. Arthritis Rheum. 2012; 64: 1134-44.
86. Okada Y, Han B, Tsoi LC, et al. Fine mapping major histocompatibility complex associations in psoriasis and its clinical subtypes. Am J Hum Genet. 2014; 95: 162-72.
87. Chandran V and Rahman P. Update on the genetics of spondyloarthritis--ankylosing spondylitis and psoriatic arthritis. Best Pract Res Clin Rheumatol. 2010; 24: 579-88.
88. Gladman D, Anhorn K, Schachter R and Mervart H. HLA antigens in psoriatic arthritis. Journal of Rheumatology. 1986; 13: 586.
89. Haroon M, Winchester R, Giles JT, Heffernan E and FitzGerald O. Clinical and genetic associations of radiographic sacroiliitis and its different patterns in psoriatic arthritis. Clin Exp Rheumatol. 2017; 35: 270-6.
90. Gladman DD, Ziouzina O, Thavaneswaran A and Chandran V. Dactylitis in psoriatic arthritis: prevalence and response to therapy in the biologic era. J Rheumatol. 2013; 40: 1357-9.
91. Haroon M, Winchester R, Giles JT, Heffernan E and FitzGerald O. Certain class I HLA alleles and haplotypes implicated in susceptibility play a role in determining specific features of the psoriatic arthritis phenotype. Ann Rheum Dis. 2016; 75: 155-62.
92. Queiro R, Morante I, Cabezas I and Acasuso B. HLA-B27 and psoriatic disease: a modern view of an old relationship. Rheumatology (Oxford). 2016; 55: 221-9.
93. Winchester R, Giles J, Jadon D, Haroon M, McHugh N and FitzGerald O. Implications of the diversity of class I HLA associations in psoriatic arthritis. Clin Immunol. 2016; 172: 29-33.
94. Groh V, Steinle A, Bauer S and Spies T. Recognition of stress-induced MHC molecules by intestinal epithelial gammadelta T cells. Science. 1998; 279: 1737-40.
95. Gonzalez S, Martinez-Borra J, Torre-Alonso JC, et al. The MICA-A9 triplet repeat polymorphism in the transmembrane region confers additional susceptibility to the development of psoriatic arthritis and is independent of the association of Cw*0602 in psoriasis. Arthritis Rheum. 1999; 42: 1010-6.
96. Korendowych E RJ, Owen PA. Disease-specific alleles of the MHC Class I related gene, MICA, are associated with type I psoriasis and psoriatic arthritis. Br J Dermatol. 2006; 154: 4.
97. Song GG, Kim JH and Lee YH. Associations between the major histocompatibility complex class I chain-related gene A transmembrane (MICA-TM) polymorphism and susceptibility to psoriasis and psoriatic arthritis: a meta-analysis. Rheumatol Int. 2014; 34: 117-23.
98. Mameli A, Cauli A, Taccari E, et al. Association of MICA alleles with psoriatic arthritis and its clinical forms. A multicenter Italian study. Clin Exp Rheumatol. 2008; 26: 649-52.
99. Pollock R, Chandran V, Barrett J, et al. Differential major histocompatibility complex class I chain-related A allele associations with skin and joint manifestations of psoriatic disease. Tissue Antigens. 2011; 77: 554-61.
100. Pollock RA, Chandran V, Pellett FJ, et al. The functional MICA-129 polymorphism is associated with skin but not joint manifestations of psoriatic disease independently of HLA-B and HLA-C. Tissue Antigens. 2013; 82: 43-7.
101. Lanier LL. NK cell recognition. Annu Rev Immunol. 2005; 23: 225-74.
102. Chen L, Ridley A, Hammitzsch A, et al. Silencing or inhibition of endoplasmic reticulum aminopeptidase 1 (ERAP1) suppresses free heavy chain expression and Th17 responses in ankylosing spondylitis. Ann Rheum Dis. 2016; 75: 916-23.
103. Payeli SK, Kollnberger S, Marroquin Belaunzaran O, et al. Inhibiting HLA-B27 homodimer-driven immune cell inflammation in spondylarthritis. Arthritis Rheum. 2012; 64: 3139-49.
104. Bowness P, Ridley A, Shaw J, et al. Th17 cells expressing KIR3DL2+ and responsive to HLA-B27 homodimers are increased in ankylosing spondylitis. J Immunol. 2011; 186: 2672-80.
105. Chandran V, Bull SB, Pellett FJ, Ayearst R, Pollock RA and Gladman DD. Killer-cell immunoglobulin-like receptor gene polymorphisms and susceptibility to psoriatic arthritis. Rheumatology (Oxford). 2014; 53: 233-9.
106. Mpakali A, Giastas P, Mathioudakis N, Mavridis IM, Saridakis E and Stratikos E. Structural Basis for Antigenic Peptide Recognition and Processing by Endoplasmic Reticulum (ER) Aminopeptidase 2. J Biol Chem. 2015; 290: 26021-32.
107. Cifaldi L, Romania P, Lorenzi S, Locatelli F and Fruci D. Role of endoplasmic reticulum aminopeptidases in health and disease: from infection to cancer. Int J Mol Sci. 2012; 13: 8338-52.
108. Yang Q, Liu H, Qu L, et al. Investigation of 20 non-HLA (human leucocyte antigen) psoriasis susceptibility loci in Chinese patients with psoriatic arthritis and psoriasis vulgaris. Br J Dermatol. 2013; 168: 1060-5.
109. Popa OM, Cherciu M, Cherciu LI, et al. ERAP1 and ERAP2 Gene Variations Influence the Risk of Psoriatic Arthritis in Romanian Population. Arch Immunol Ther Exp (Warsz). 2016; 64: 123-9.
110. Andres AM, Dennis MY, Kretzschmar WW, et al. Balancing selection maintains a form of ERAP2 that undergoes nonsense-mediated decay and affects antigen presentation. PLoS Genet. 2010; 6: e1001157.
111. Robinson PC, Costello ME, Leo P, et al. ERAP2 is associated with ankylosing spondylitis in HLA-B27-positive and HLA-B27-negative patients. Ann Rheum Dis. 2015; 74: 1627-9.
112. International Genetics of Ankylosing Spondylitis C, Cortes A, Hadler J, et al. Identification of multiple risk variants for ankylosing spondylitis through high-density genotyping of immune-related loci. Nat Genet. 2013; 45: 730-8.
113. Apel M, Uebe S, Bowes J, et al. Variants in RUNX3 contribute to susceptibility to psoriatic arthritis, exhibiting further common ground with ankylosing spondylitis. Arthritis Rheum. 2013; 65: 1224-31.
114. Smith RL, Hebert HL, Massey J, et al. Association of Toll-like receptor 4 (TLR4) with chronic plaque type psoriasis and psoriatic arthritis. Arch Dermatol Res. 2016; 308: 201-5.
115. Akbal A, Oguz S, Gokmen F, et al. C-reactive protein gene and Toll-like receptor 4 gene polymorphisms can relate to the development of psoriatic arthritis. Clin Rheumatol. 2015; 34: 301-6.
116. O'Donnell H, Pham OH, Li LX, et al. Toll-like receptor and inflammasome signals converge to amplify the innate bactericidal capacity of T helper 1 cells. Immunity. 2014; 40: 213-24.
117. Cheung PF, Wong CK and Lam CW. Molecular mechanisms of cytokine and chemokine release from eosinophils activated by IL-17A, IL-17F, and IL-23: implication for Th17 lymphocytes-mediated allergic inflammation. J Immunol. 2008; 180: 5625-35.
118. Sonder SU, Saret S, Tang W, Sturdevant DE, Porcella SF and Siebenlist U. IL-17-induced NF-kappaB activation via CIKS/Act1: physiologic significance and signaling mechanisms. J Biol Chem. 2011; 286: 12881-90.
119. Raychaudhuri SP, Raychaudhuri SK and Genovese MC. IL-17 receptor and its functional significance in psoriatic arthritis. Mol Cell Biochem. 2012; 359: 419-29.
120. Wilson NJ, Boniface K, Chan JR, et al. Development, cytokine profile and function of human interleukin 17-producing helper T cells. Nat Immunol. 2007; 8: 950-7.
121. Mitra A, Raychaudhuri SK and Raychaudhuri SP. Functional role of IL-22 in psoriatic arthritis. Arthritis research & therapy. 2012; 14: R65.
122. Dolcino M, Ottria A, Barbieri A, et al. Gene Expression Profiling in Peripheral Blood Cells and Synovial Membranes of Patients with Psoriatic Arthritis. PLoS One. 2015; 10: e0128262.
123. Pollock RA, Abji F, Liang K, et al. Gene expression differences between psoriasis patients with and without inflammatory arthritis. J Invest Dermatol. 2015; 135: 620-3.
124. Abji F, Pollock RA, Liang K, Chandran V and Gladman DD. Th17 gene expression in psoriatic arthritis synovial fluid and peripheral blood compared to osteoarthritis and cutaneous psoriasis. Clin Exp Rheumatol. 2017.
125. Al-Mossawi MH, Chen L, Fang H, et al. Unique transcriptome signatures and GM-CSF expression in lymphocytes from patients with spondyloarthritis. Nat Commun. 2017; 8: 1510.
126. Celis R, Planell N, Fernandez-Sueiro JL, et al. Synovial cytokine expression in psoriatic arthritis and associations with lymphoid neogenesis and clinical features. Arthritis research & therapy. 2012; 14: R93.
127. Sato K, Suematsu A, Okamoto K, et al. Th17 functions as an osteoclastogenic helper T cell subset that links T cell activation and bone destruction. J Exp Med. 2006; 203: 2673-82.
128. Adamopoulos IE, Chao CC, Geissler R, et al. Interleukin-17A upregulates receptor activator of NF-kappaB on osteoclast precursors. Arthritis research & therapy. 2010; 12: R29.
129. Adamopoulos IE, Suzuki E, Chao CC, et al. IL-17A gene transfer induces bone loss and epidermal hyperplasia associated with psoriatic arthritis. Ann Rheum Dis. 2015; 74: 1284-92.
130. Sherlock JP, Joyce-Shaikh B, Turner SP, et al. IL-23 induces spondyloarthropathy by acting on ROR-gammat+ CD3+CD4-CD8- entheseal resident T cells. Nat Med. 2012; 18: 1069-76.
131. Adamopoulos IE, Tessmer M, Chao CC, et al. IL-23 is critical for induction of arthritis, osteoclast formation, and maintenance of bone mass. J Immunol. 2011; 187: 951-9.
132. Torres T and Faria R. Ustekinumab: The "New Kid on the Block" in the Treatment of Psoriatic Arthritis. Drug Dev Res. 2015; 76: 428-31.
133. McInnes IB, Mease PJ, Kirkham B, et al. Secukinumab, a human anti-interleukin-17A monoclonal antibody, in patients with psoriatic arthritis (FUTURE 2): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2015.
134. Ghoreschi K, Laurence A, Yang XP, et al. Generation of pathogenic T(H)17 cells in the absence of TGF-beta signalling. Nature. 2010; 467: 967-71.
135. Alenius GM, Eriksson C and Rantapaa Dahlqvist S. Interleukin-6 and soluble interleukin-2 receptor alpha-markers of inflammation in patients with psoriatic arthritis? Clin Exp Rheumatol. 2009; 27: 120-3.
136. Choy EH and Panayi GS. Cytokine pathways and joint inflammation in rheumatoid arthritis. N Engl J Med. 2001; 344: 907-16.
137. Rahman P, Sun S, Peddle L, et al. Association between the interleukin-1 family gene cluster and psoriatic arthritis. Arthritis Rheum. 2006; 54: 2321-5.
138. Ravindran JS, Owen P, Lagan A, et al. Interleukin 1alpha, interleukin 1beta and interleukin 1 receptor gene polymorphisms in psoriatic arthritis. Rheumatology (Oxford). 2004; 43: 22-6.
139. Bowes J, Ho P, Flynn E, et al. Investigation of IL1, VEGF, PPARG and MEFV genes in psoriatic arthritis susceptibility. Ann Rheum Dis. 2012; 71: 313-4.
140. Cubino N, Montilla C, Usategui-Martin R, et al. Association of IL1Beta (-511 A/C) and IL6 (-174 G > C) polymorphisms with higher disease activity and clinical pattern of psoriatic arthritis. Clin Rheumatol. 2016; 35: 1789-94.
141. Langrish CL, Chen Y, Blumenschein WM, et al. IL-23 drives a pathogenic T cell population that induces autoimmune inflammation. J Exp Med. 2005; 201: 233-40.
142. Di Cesare A, Di Meglio P and Nestle FO. The IL-23/Th17 axis in the immunopathogenesis of psoriasis. J Invest Dermatol. 2009; 129: 1339-50.
143. Eiris N, Gonzalez-Lara L, Santos-Juanes J, Queiro R, Coto E and Coto-Segura P. Genetic variation at IL12B, IL23R and IL23A is associated with psoriasis severity, psoriatic arthritis and type 2 diabetes mellitus. J Dermatol Sci. 2014; 75: 167-72.
144. Budu-Aggrey A, Bowes J, Loehr S, et al. Replication of a distinct psoriatic arthritis risk variant at the IL23R locus. Ann Rheum Dis. 2016; 75: 1417-8.
145. Cenit MC, Ortego-Centeno N, Raya E, et al. Influence of the STAT3 genetic variants in the susceptibility to psoriatic arthritis and Behcet's disease. Hum Immunol. 2013; 74: 230-3.
146. Myrthianou E, Zervou MI, Budu-Aggrey A, et al. Investigation of the genetic overlap between rheumatoid arthritis and psoriatic arthritis in a Greek population. Scand J Rheumatol. 2017; 46: 180-6.
147. Yang XP, Ghoreschi K, Steward-Tharp SM, et al. Opposing regulation of the locus encoding IL-17 through direct, reciprocal actions of STAT3 and STAT5. Nat Immunol. 2011; 12: 247-54.
148. Korn T, Bettelli E, Oukka M and Kuchroo VK. IL-17 and Th17 Cells. Annu Rev Immunol. 2009; 27: 485-517.
149. Chandran V. The genetics of psoriasis and psoriatic arthritis. Clin Rev Allergy Immunol. 2013; 44: 149-56.
150. Harris TJ, Grosso JF, Yen HR, et al. Cutting Edge: An In Vivo Requirement for STAT3 Signaling in TH17 Development and TH17-Dependent Autoimmunity. The Journal of Immunology. 2007; 179: 4313-7.
151. Mrabet D, Laadhar L, Sahli H, et al. Synovial fluid and serum levels of IL-17, IL-23, and CCL-20 in rheumatoid arthritis and psoriatic arthritis: a Tunisian cross-sectional study. Rheumatol Int. 2013; 33: 265-6.
152. Muntyanu A, Abji F, Liang K, Pollock RA, Chandran V and Gladman DD. Differential gene and protein expression of chemokines and cytokines in synovial fluid of patients with arthritis. Arthritis research & therapy. 2016; 18: 296.
153. Belasco J, Louie JS, Gulati N, et al. Comparative genomic profiling of synovium versus skin lesions in psoriatic arthritis. Arthritis Rheumatol. 2015; 67: 934-44.
154. de Cid R, Riveira-Munoz E, Zeeuwen PL, et al. Deletion of the late cornified envelope LCE3B and LCE3C genes as a susceptibility factor for psoriasis. Nat Genet. 2009; 41: 211-5.
155. Bowes J, Flynn E, Ho P, et al. Variants in linkage disequilibrium with the late cornified envelope gene cluster deletion are associated with susceptibility to psoriatic arthritis. Ann Rheum Dis. 2010; 69: 2199-203.
156. Docampo E, Giardina E, Riveira-Munoz E, et al. Deletion of LCE3C and LCE3B is a susceptibility factor for psoriatic arthritis: a study in Spanish and Italian populations and meta-analysis. Arthritis Rheum. 2011; 63: 1860-5.
157. Chiraz BS, Myriam A, Ines Z, et al. Deletion of late cornified envelope genes, LCE3C_LCE3B-del, is not associated with psoriatic arthritis in Tunisian patients. Mol Biol Rep. 2014; 41: 4141-6.
158. Huffmeier U, Estivill X, Riveira-Munoz E, et al. Deletion of LCE3C and LCE3B genes at PSORS4 does not contribute to susceptibility to psoriatic arthritis in German patients. Ann Rheum Dis. 2010; 69: 876-8.
159. Hunter JA, Skelly RH, Aylwin SJ, et al. The relationship between pituitary tumour transforming gene (PTTG) expression and in vitro hormone and vascular endothelial growth factor (VEGF) secretion from human pituitary adenomas. Eur J Endocrinol. 2003; 148: 203-11.
160. Veale D, Yanni G, Rogers S, Barnes L, Bresnihan B and Fitzgerald O. Reduced synovial membrane macrophage numbers, ELAM-1 expression, and lining layer hyperplasia in psoriatic arthritis as compared with rheumatoid arthritis. Arthritis Rheum. 1993; 36: 893-900.
161. Ciccia F, Guggino G, Ferrante A, et al. Interleukin-9 Overexpression and Th9 Polarization Characterize the Inflamed Gut, the Synovial Tissue, and the Peripheral Blood of Patients With Psoriatic Arthritis. Arthritis Rheumatol. 2016; 68: 1922-31.
162. Guggino G, Ciccia F, Di Liberto D, et al. Interleukin (IL)-9/IL-9R axis drives gammadelta T cells activation in psoriatic arthritis patients. Clin Exp Immunol. 2016; 186: 277-83.
163. Pedersen OB, Svendsen AJ, Ejstrup L, Skytthe A and Junker P. On the heritability of psoriatic arthritis. Disease concordance among monozygotic and dizygotic twins. Ann Rheum Dis. 2008; 67: 1417-21.
164. Rahman P, Gladman DD, Schentag CT and Petronis A. Excessive paternal transmission in psoriatic arthritis. Arthritis Rheum. 1999; 42: 1228-31.
165. Pollock RA, Thavaneswaran A, Pellett F, et al. Further evidence supporting a parent-of-origin effect in psoriatic disease. Arthritis Care Res (Hoboken). 2015.
166. Theeuwes M and Morhenn V. Allelic instability in the mitosis model and the inheritance of psoriasis. J Am Acad Dermatol. 1995; 32: 44-52.
167. Pollock RA, Abji F and Gladman DD. Epigenetics of psoriatic disease: A systematic review and critical appraisal. J Autoimmun. 2017; 78: 29-38.
168. Karason A, Gudjonsson JE, Upmanyu R, et al. A susceptibility gene for psoriatic arthritis maps to chromosome 16q: evidence for imprinting. Am J Hum Genet. 2003; 72: 125-31.
169. Martinez C, Blanco G, Ladero JM, et al. Genetic predisposition to acute gastrointestinal bleeding after NSAIDs use. Br J Pharmacol. 2004; 141: 205-8.
170. Chandran V, Siannis F, Rahman P, Pellett FJ, Farewell VT and Gladman DD. Folate pathway enzyme gene polymorphisms and the efficacy and toxicity of methotrexate in psoriatic arthritis. J Rheumatol. 2010; 37: 1508-12.
171. Cuchacovich R, Perez-Alamino R, Zea AH and Espinoza LR. Distinct genetic profile in peripheral blood mononuclear cells of psoriatic arthritis patients treated with methotrexate and TNF-inhibitors. Clin Rheumatol. 2014; 33: 1815-21.
172. Menter A, Gottlieb A, Feldman SR, et al. Guidelines of care for the management of psoriasis and psoriatic arthritis: Section 1. Overview of psoriasis and guidelines of care for the treatment of psoriasis with biologics. J Am Acad Dermatol. 2008; 58: 826-50.
173. Kavanaugh A, Antoni CE, Gladman D, et al. The Infliximab Multinational Psoriatic Arthritis Controlled Trial (IMPACT): results of radiographic analyses after 1 year. Ann Rheum Dis. 2006; 65: 1038-43.
174. Mease PJ, Goffe BS, Metz J, VanderStoep A, Finck B and Burge DJ. Etanercept in the treatment of psoriatic arthritis and psoriasis: a randomised trial. Lancet. 2000; 356: 385-90.
175. Tong Q, Zhao L, Qian XD, et al. Association of TNF-alpha polymorphism with prediction of response to TNF blockers in spondyloarthritis and inflammatory bowel disease: a meta-analysis. Pharmacogenomics. 2013; 14: 1691-700.
176. Julia A, Rodriguez J, Fernandez-Sueiro JL, et al. PDE3A-SLCO1C1 locus is associated with response to anti-tumor necrosis factor therapy in psoriatic arthritis. Pharmacogenomics. 2014; 15: 1763-9.
177. Ramirez J, Fernandez-Sueiro JL, Lopez-Mejias R, et al. FCGR2A/CD32A and FCGR3A/CD16A variants and EULAR response to tumor necrosis factor-alpha blockers in psoriatic arthritis: a longitudinal study with 6 months of followup. J Rheumatol. 2012; 39: 1035-41.
178. Morales-Lara MJ, Canete JD, Torres-Moreno D, et al. Effects of polymorphisms in TRAILR1 and TNFR1A on the response to anti-TNF therapies in patients with rheumatoid and psoriatic arthritis. Joint Bone Spine. 2012; 79: 591-6.
179. Rosenberg A, Fan H, Chiu YG, et al. Divergent gene activation in peripheral blood and tissues of patients with rheumatoid arthritis, psoriatic arthritis and psoriasis following infliximab therapy. PLoS One. 2014; 9: e110657.
180. McInnes IB, Kavanaugh A, Gottlieb AB, et al. Efficacy and safety of ustekinumab in patients with active psoriatic arthritis: 1 year results of the phase 3, multicentre, double-blind, placebo-controlled PSUMMIT 1 trial. Lancet. 2013; 382: 780-9.
181. Kavanaugh A, Puig L, Gottlieb AB, et al. Efficacy and safety of ustekinumab in psoriatic arthritis patients with peripheral arthritis and physician-reported spondylitis: post-hoc analyses from two phase III, multicentre, double-blind, placebo-controlled studies (PSUMMIT-1/PSUMMIT-2). Ann Rheum Dis. 2016; 75: 1984-8.
182. Ritchlin C, Rahman P, Kavanaugh A, et al. Efficacy and safety of the anti-IL-12/23 p40 monoclonal antibody, ustekinumab, in patients with active psoriatic arthritis despite conventional non-biological and biological anti-tumour necrosis factor therapy: 6-month and 1-year results of the phase 3, multicentre, double-blind, placebo-controlled, randomised PSUMMIT 2 trial. Ann Rheum Dis. 2014; 73: 990-9.
183. Prieto-Perez R, Cabaleiro T, Dauden E and Abad-Santos F. Gene polymorphisms that can predict response to anti-TNF therapy in patients with psoriasis and related autoimmune diseases. Pharmacogenomics J. 2013; 13: 297-305.
184. Talamonti M, Botti E, Galluzzo M, et al. Pharmacogenetics of psoriasis: HLA-Cw6 but not LCE3B/3C deletion nor TNFAIP3 polymorphism predisposes to clinical response to interleukin 12/23 blocker ustekinumab. Br J Dermatol. 2013; 169: 458-63.
185. Galluzzo M, Boca AN, Botti E, et al. IL12B (p40) Gene Polymorphisms Contribute to Ustekinumab Response Prediction in Psoriasis. Dermatology. 2015.