Study on mycophenolate mofetil combined with prednisone in the treatment of idiopathic membranous nephropathy with positive serum anti-phospholipase A2 receptor antibody

Abstract

Objective To assess the efficacy of mycophenolate mofetil (MMF) combined with prednisone in the treatment of idiopathic membranous nephropathy (IMN) patients with positive serum phospholipase A2 receptor (PLA2R) antibody. Methods An open prospective study was performed on twenty-four biopsy-proven IMN patients with positive serum PLA2R antibody in Guangzhou First People′s Hospital from June 2012 to June 2016.The 24 patients were divided into two groups: MMF group in which MMF combined with prednisone was given for 12 months and CTX group in which intravenous cyclophosphamide (CTX) was monthly given combined with oral prednisone. Results After 6 months of immunosuppressive therapy, complete remission and partial remission rates were 25.0% vs.16.7% and 25.0% vs.25.0% in the MMF group and CTX group, respectively (P>0.05). In the MMF group and CTX group, serum PLA2R antibody in the same amount (8/12, 66.7%) of patients turned negative.At the end of twelve-month treatment, all patients with negative PLA2R antibodies achieved complete or partial remission.Clinical remission (including complete and partial remission) rates in the MMF group and CTX group were both 66.7%.After immunosuppressive therapy, the levels of proteinuria and serum albumin in the two groups were significantly improved, but no significant difference were found between the two groups (proteinuria: F within-grouP=98.688, P<0.01; F between-grouP=0.133, P=0.719; F cross-grouP=1.223, P=0.304; serum albumin: F within-grouP=30.629, P<0.01; F between-grouP=0.137, P=0.715; F cros-grouP=0.455, P=0.565). At the end of six and twelve months of treatment, the proteinuria (after six months, MMF group: (2 893±2 515) mg/g vs.(6 236±2 117) mg/g, t=-3.522, P=0.002; CTX group: (2 690±2 254) mg/g vs.(5 386±2 447) mg/g, t=-2.808, P=0.010; after twelve months, MMF group: 1 025(99-4 635) mg/g vs.(6 236±2 117) mg/g, Z=-3.291, P<0.0005; CTX group: (775(41-3 517) mg/g vs.(5 386±2 447) mg/g, Z=-3.118, P=0.001) and serum albumin levels (after six months, MMF group: (28.5±9.7) g/L vs.(19.8±4.4) g/L, t=2.841, P=0.012; CTX group: (29.0±7.6) g/L vs.(22.3±4.1) g/L, t=2.690, P=0.016; at the end of twelve months of treatment, , MMF group: (32.4±8.5) g/L vs.(19.8±4.4) g/L, t=4.570, P<0.0005; TX group: (32.2±7.9) g/L vs.(22.3±4.1) g/L, t=3.862, P=0.001) of the two groups were better than those prior to treatment. Conclusion For the IMN patients with positive serum PLA2R antibody, MMF combined with prednisone was as effective as conventional CTX combined with prednisone in the negative conversion of PLA2R antibody and the remission.The negative conversion of PLA2R antibody after 6 months of immunosuppressive treatment was an important indicator of predicting the remission. Key words: Phospholipase A2 receptor; Membranous nephropathy; Mycophenolate mofetil