Abstract: A 53-year-old male presented with nephrotic syndrome was diagnosed as phospholipase A2 receptor (PLA2R) associated membranous nephropathy (MN) by renal biopsy. Initial immunosuppressive regimen was steroid plus tacrolimus but no remission was achieved. Then the patient received standard dose Rituximab (1g×2) treatment. But B cell reconstituted at the third months following RTX administration, accompanied with anti-PLA2R antibody (aPLA2Rab) rebounded, proteinuria aggravation and serum creatinine increase. Repeated renal biopsy revealed focal segmental glomerulosclerosis, tubulointerstitial injury aggravation and immune complex deposition increase. The diagnosis of PLA2R associated MN, acute renal tubulointerstitial injury was established. Obinutuzumab 1g×2 was used for induction and the third dose was given at month 6 for maintain. At last visit (14.5 months following Obinutuzumab treatment), serum creatine declined from 185.6 μmol/L to 103.4 μmol/L, proteinuria declined from 14.12 g/24h to 0.68 g/24h, aPLA2Rab remained negative and B cell remained depletion.

Key words: membranous nephropathy, Rituximab, Obinutuzumab