Membranous glomerulopathy associated with rheumatoid arthritis may respond to rituximab.

Membranous glomerulonephritis is an uncommon extra-articular manifestation of rheumatoid arthritis, which need not be associated with prior DMARD (disease-modifying antirheumatic drug) therapies (Clin Rheum 1996, 15, 385). We observed a patient with an 8-year history of seropositive erosive rheumatoid arthritis complicated by the development of refractory nephrotic syndrome secondary to biopsy-proven membranous glomerulonephritis. Signs and symptoms of his disabling kidney disease included renal insufficiency, massive proteinuria (25 grams), edema and a hypercoaguable state (deep venous thrombosis and pulmonary emboli). Alkylating agents, antimetabolites and glucocorticoids were ineffective in reducing his proteinuria over a 2 year period. The patient subsequently received 2 courses (1 gram twice over a 2 week period) of rituximab (a monoclonal antibody to CD20 that specifically depletes B cells), 6 months apart. Serum albumin at initial treatment was 2.0 gm/dl and normalized (3.7 gm/dl) one month after the second course of therapy. This was accompanied by a corresponding decrease of urinary protein (22 grams to 7.4 grams/24 hours) and a reduction in diuretic requirements. B cell directed therapy may prove useful in treating membranous glomerulopathies. Abstract