Table 2.

Summary of studies and case reports identified by systemic literature search. We searched the Medline indexed literature after 1996 combining the words azathioprine, purpura, Schoenlein-Henoch and further searched the reference lists of identified articles for additional papers. We restricted results to English language published literature.

Author (year)	Number of patients	Reason for azathioprine use	Treatment used	Duration of study	Conclusions
Bergstein (1998) [16]	21	Crescentic HSP nephritis	Azathioprine and steroids	9–24 months and average follow up time of 32 months	Azathioprine is effective in reducing hematuria, proteinuria, serum creatinine and increasing creatine clearence in 19/21. Two patients progressed to ESKD
Foster (2000) [17]	17	Severe HSP nephritis	Azathioprine and prednisone	Azathioprine 1–4 mg/kg and prednisone for 46.7 +/− 19 weeks compared to historical controls treated in various ways	No progression of renal lesions after treatment initiation. Favorable outcome compared to historical control group.
Singh (2002) [18]	9	Severe HSP nephritis	Azathioprine and steroids	Azathioprine treatment of a mean of 14.7 months and steroids for 12.1 months, 4.7 years mean follow up	Mean resolution of proteinuria and hematuria 6.5 and 6.6 months respectively
Shin (2005) [19]	20	Severe HSP nephritis	Azathioprine and steroids versus steroids alone	Azathioprine for 8 months, steroids median of 1.7 years, median follow up 4.8 years	Azathioprine and steroids ameliorate histopathological features and improve the clinical course of severe HSP nephritis. No significant differences in hematuria and proteinuria between the groups.
Shenoy (2007) [20]	27	HSP nephritis grade IIIb or greater	Induction with steroids and CYC for 8–12 weeks followed by maintanance with azathioprine and steroids	Azathioprine for a mean of 12 months, 6.9 y mean follow up period,	37 % complete recovery, 40.7 % persistent proteinuria, 7.4 proteinuria and HTN, 14.8 % ESKD. Poor outcome on those being older at presentation and having crescents/heavy proteinuria 6 months post-diagnosis
Trapani (2010) [13]	1	Hemorrhagic bullous cutaneous involvement	Azathioprine 2.5 mg/kg with steroids	Follow up 5 months	Symptom resolution
Ninchoji (2011) [21]	32	Moderate or severe HSP nephritis	Azathioprine 2 mg/kg, steroids and anticoagulants for modarate severe and severe nephritis in comparison to ACE-I or ARB for moderate severe nephritis	Combination therapy including azathioprine for 6 months	90 % resolution of moderate HSP nephritis by 14.9 months and 90 % resolution of severe nephritis by 11.1 months

ACE-I angiotensin converting enzyme inhibitor, ARB angiotensin receptor blocker, CYC cyclophosphamide, ESKD end stage kidney disease, HSP Henoch-Schönlein purpura