Response to immunosuppressive therapy in PLA2R- associated and non-PLA2R- associated idiopathic membranous nephropathy: a retrospective, multicenter cohort study

Background According to renal M type phospholipase A.sub.2 receptor (PLA.sub.2R) immunohistochemistry, idiopathic membranous nephropathy (IMN) could be categorized into PLA.sub.2R-associated and non-PLA.sub.2R-associated IMN. We conducted a retrospective, multicenter cohort study with 91 patients to compare the effect of immunosuppressive therapy between PLA.sub.2R-associated and non-PLA.sub.2R-associated IMN patients. Methods A total of 91 biopsy-proven IMN patients from Huashan hospital and People's Hospital of Wuxi in past 5 years were collected into this study. IMN with positive PLA.sub.2R immunohistochemistry in kidney biopsies were designated as PLA.sub.2R-associated IMN. Seventy-eight of the 91 IMN patients was PLA.sub.2R-associated IMN and 13 were non-PLA.sub.2R-associated IMN. Forty-five patients were treated with prednisone plus cyclophosphamide (CTX), and 46 with prednisone plus calcineurin inhibitors (CNIs). The follow-up duration was 15 months. Results The total remission rate (76.9% versus 44.9%, p = 0.032) and complete remission rate (30.8% versus 2.6%, p = 0.003) were both significantly higher in the non-PLA.sub.2R-associated group than in the PLA.sub.2R-associated group at the 3rd month visit point, and at the 6th month time point, the complete remission rate was still significantly higher in the non-PLA.sub.2R-associated group (46.2% versus 11.5%,p = 0.007). But similar remission rates were found after the 9th month. Relapses were observed in 8 patients in PLA.sub.2R-associated group and none in non-PLA.sub.2R-associated group, although there was no significant difference between these two groups. Conclusion Compared with the PLA.sub.2R-associated IMN, the non-PLA.sub.2R-associated IMN responded quicker to the immunosuppressive therapy. Keywords: Calcineurin inhibitors, Cyclophosphamide, Idiopathic membranous nephropathy, M type phospholipase A.sub.2 receptor, Immunosuppressive therapy, Remission