Immunosuppressive treatment for pure membranous lupus nephropathy in a Hispanic population

Abstract

Optimal treatment for pure membranous lupus nephritis (MLN) remains unknown. The aim of this study was to evaluate the response to immunosuppressive treatment of Hispanics with pure MLN. This was a retrospective cohort analysis from a tertiary care center. Pure MLN patients were segregated into three groups according to the received induction treatment. All patients received adjunctive steroids. Outcomes included complete remission (CR), partial remission (PR), flare incidence, adverse events, and renal and patient survival. All outcomes were analyzed by Cox regression analysis. A total of 60 patients diagnosed with pure MLN between 2004 and 2014 were segregated into mycophenolate mofetil (MMF) (n = 18), intravenous cyclophosphamide (IVC) (n = 16), or azathioprine (AZA) (n = 26) groups. Complete remission rates at 6, 12, and 24 months were 33.3, 52.9, and 76.4 %, respectively, for MMF; 26.9, 42.3, and 54.6 %, respectively, for AZA; and 6.2, 14.8, and 26.9 %, respectively, for IVC. Based on Cox-adjusted analysis, treatment with MMF was associated with higher CR rates (hazard ratio (HR) 4.43, 1.19-16.4, p = 0.026) compared to IVC. There were no differences in CR rates between MMF and AZA groups. Patients treated with adjunctive antimalarial drugs were more likely to achieve CR (HR 2.46, 1.08-5.64, p = 0.032) and had a non-significant trend to lower incidence of thrombotic events (odds ratio (OR) 0.10, 0.010-1.14, p = 0.064). There were no differences in adverse events, renal flares, and renal or patient survival between groups. MMF might be superior to IVC as induction treatment for pure MLN in Hispanics, while AZA might remain as a valid alternative for treatment. Adjunctive treatment with an antimalarial drug may enhance renal response to therapy.

Keywords: Hispanics; Immunosuppression; Lupus nephritis; Membranous nephropathy; Mycophenolate mofetil.