Clinical improvements in proliferative vs membranous lupus nephritis following B-cell depletion: pooled data from two cohorts

Abstract

To compare the clinical results after treatment with B-cell depleting therapy in patients with membranous (WHO Class V) vs proliferative (WHO Class III or IV) lupus nephritis (LN). Data were compiled from two European centres on all patients with LN who were treated with i.v. rituximab (RTX) in a combination protocol with i.v. cyclophosphamide and steroids. Laboratory and serological evaluations were performed at 3, 6 and 12 months of follow-up. No immunosuppressive drugs were given before B-cell repopulation. Forty-three patients, 28 with proliferate and 15 with membranous LN by renal biopsy, were evaluated. Six months after treatment with RTX, both the membranous and the proliferative LN patients had a significant reduction in proteinuria and an increase in serum albumin. The main improvements were observed during the first 6 months and only minor non-significant changes in albumin and proteinuria were observed thereafter. As expected, the patients with membranous nephritis had lower anti-dsDNA titres and higher complement C3 levels at baseline, but in both groups a significant reduction in anti-dsDNA titre and improvements in complement C3 levels were seen during the first 6 months after treatment; the kinetics of improvement were similar in both groups. The clinical course following B-cell depleting therapy is strikingly similar between patients with membranous and those with proliferative LN. These observational data suggest that, if controlled studies confirm the efficacy of B-cell depleting therapy in proliferative nephritis, clinicians may reasonably consider such therapy in membranous LN.