Abstract
Introduction: Immunosuppressives can be effective in skin and lung involvement in systemic sclerosis(SSc). This study aims to analyse the efficacy of azathioprine in skin and lung parameters in SSc patients, comparing its efficacy with other immunosuppressives.
Method: A systematic literature review was performed. “Patient, intervention, comparison, outcome” method was used to screen studies. All studies that reported pretreatment and posttreatment modified Rodnan skin score (mRSS), forced vital capacity (FVC) and diffusşon capacity for carbon monoxide (DLCO) in SSc patients were included. Meta-analysis was performed where “mean difference” was used to assess the size of the change of pretreatment and posttreatment mean mRSS, FVC and DLCO values in azathioprine group and comparison group.
Results: Ten studies were included. One study demonstrated the role of azathioprine in maintaining the improvement in mRSS after induction treatment with cyclophosphamide. Five studies demonstrated the role of azathioprine as a maintenance agent in SSc interstitial lung disease after cyclophosphamide and three retrospective studies demonstrated the role of azathioprine alone in preserving FVC and DLCO. Two studies were included in meta-analysis of azathioprine and cyclophosphamide, which did not demonstrate significant differences between two drugs in terms of the change in mRSS, FVC and DLCO.
Conclusion: Azathioprine seems to have a role in stabilizing lung function tests after induction treatment with cyclophosphamide. Azathioprine alone can be effective in preserving lung functions a subset of SSc patients with interstitial lung disease. There is no evidence to use azathioprine alone in treatment of skin disease. The failure of meta-analysis to find significant difference between azathioprine and cyclophosphamide is probably due to the major differences in the characteristics of the study populations.
Key points: -There is no evidence that supports use of azathioprine as a monotherapy for skin involvement in systemic sclerosis. Although azathioprine alone may be beneficial in some systemic sclerosis patients with interstitial lung disease, most of the evidence supports its use as a maintenance agent after induction therapy with cyclophosphamide.
-Meta-analyses failed to demonstrate signficant difference between azathioprine and cyclophosphamide, but this is most likely due to the different characteristics of the patient populations in the included studies.
-This is the most extensive systematic literature review that was performed on the effects of azathioprine in skin and lung involvements of systemic sclerosis in the last two decades, which brings together all the recent available data on this drug.