Rituximab treatment for fibrillary glomerulonephritis

Background: Approximately 50% of patients with fibrillary glomerulonephritis (GN) progress to end-stage renal disease (ESRD) within 2 years of diagnosis, and no standard therapy exists. The data on rituximab therapy for fibrillary GN are limited and have inconsistent outcomes. Here, we report the largest case series to date using rituximab for fibrillary GN.

Methods: Retrospective chart reviews were conducted on 12 patients with fibrillary GN who were treated with rituximab (1 g i.v. × 2 doses or 375 mg/m(2) × 4 doses) at the Center for Glomerular Diseases at Columbia University Medical Center. Non-progression of disease was defined as stable/improved serum creatinine (SCr) with a minimum of 1 year of follow-up.

Results: The median SCr was 2.1 (range 0.7-2.7) mg/dL, median estimated glomerular filtration rate (eGFR) 39 (range 21-98) mL/min/1.73 m(2) and median proteinuria 4497 (range 210-7542) mg/day at the time of rituximab initiation. Four patients had received immunosuppression before rituximab, and nine received immunosuppression after rituximab, with four receiving a second rituximab course. Four of 12 patients were non-progressors, 3 of 12 had progressive renal dysfunction without reaching ESRD, and 5 patients reached ESRD. The median follow-up for patients who did not reach ESRD was 38 (range 14-76) months after rituximab treatment. Non-progressors had lower SCr values, higher eGFRs and shorter median duration from diagnosis to treatment than progressors. No serious adverse events were noted.

Conclusions: Rituximab therapy was associated with non-progression of renal disease in 4 of 12 patients. At the time of treatment, these non-progressors had better renal function and shorter time from diagnosis to treatment than progressors.