Calcineurin inhibitors in treatment of membranous nephropathy – kidney function long term outcomes

Abstract

SUMMARY. Aim Calcineurin inhibitors (CNI) are the mainstay treatment of membranous nephropathy (MN). Nephrotoxicity of CNI remains a concern and limits their use. We aimed to evaluate long-term outcomes of patients with MN treated with CNI alone or in combination with rituximab (RTX) compared to other regimens. Methods We retrospectively reviewed patients with MN treated with CNI for at least two months and who had at least one year of follow-up. We compared them to patients treated with cyclophosphamide (CYC) or RTX alone without CNI. Results There were in total 27 patients, 78,8% male, median age 54 years (IQR 43,5 – 59.5). At presentation 75.8% had nephrotic syndrome. Median follow-up time was 75 months (IQR 20.5 – 121.5). There were 19 patients in the CNI group, median age 48 years (IQR 39 – 55.5), 71.4% male, and eight patients who didn’t receive CNIs, median age 60 years (IQR 57 – 66), 75% male. There was no significant difference in aPLA2R positivity, 76.5% vs 50% respectively, p=0.359. No significant difference in change of eGFR at one year was detected, p=0.186. There was no significant difference in proteinuria at one year, p=0.275. At one year 89.5% patients were in full remission in the CNI group, vs 87.5% in the other group (p=0.663). Mean eGFR at last follow-up was 74.1±22.8mL/min/1.73m 2 in the CNI group, and 72.3±18.1mL/min/1.73m 2 in the group who hadn’t received CNIs (p=0.840). None of the patients in both groups had ESKD at last follow-up. Conclusion CNIs present a safe and effective treatment of MN, both alone and as a part of combination regimens. Larger studies on long-term outcomes are needed to further evaluate our findings.