Treatment with rituximab in idiopathic membranous nephropathy.

Background: Rituximab represents a valid therapeutic option to induce remission in patients with primary glomerulonephritis. Despite several studies proving its efficacy in improving outcomes in patients with membranous nephropathy (MN), its role in therapeutic protocols is not yet defined.

Methods: We studied 38 patients with idiopathic MN treated with rituximab (in 13 patients as first-line therapy, in the remaining 25 after conventional immunosuppressive therapy). The patients were analyzed for a 15-month median (interquartile range 7.7-30.2) follow-up, with serial monitoring of 24-h proteinuria, renal function and circulating CD19 B cells.

Results: The percentages of patients who achieved complete remission, partial remission and the composite endpoint (complete or partial remission) were 39.5% (15 patients), 36.8% (14 patients) and 76.3% (29 patients), respectively. The 24-h proteinuria was reduced significantly during the entire period of follow-up (from a baseline value of 6.1 to 0.9 g/day in the last visit; P < 0.01), while albuminemia increased constantly (from a baseline value of 2.6 to 3.5 g/dL in the last observation; P < 0.01). Renal function did not significantly change during the observation period. Circulating CD19 B cells were reduced significantly from the baseline value to the 24-month value (P < 0.01); data about anti-phospholipase A receptor antibodies were available in 14 patients, 10 of which experienced a decreasing trend after treatment. No significant adverse events were described during and after infusions.

Conclusions: The present study confirmed that treatment with rituximab was remarkably safe and allowed for a large percentage of complete or partial remissions in patients with MN.