Predictors of response and relapse in patients with idiopathic membranous nephropathy treated with tacrolimus

Background Although tacrolimus is recommended by KDIGO Clinical Practice Guideline for Glomerulonephritis for the treatment of idiopathic membranous nephropathy (MN), little is known about factors that influence response and relapse of the disease after tacrolimus therapy. Methods Multicentre study that collected 122 MN patients with nephrotic syndrome and stable renal function treated with tacrolimus. Duration of treatment was 17.6 ± 7.2 months, including a full-dose and a tapering period. Results The percentage of remission was 60, 78 and 84% after 6, 12 and 18 months of treatment, respectively. The amount of proteinuria at baseline significantly predicted remission, the lower the baseline proteinuria the higher the probability of remission. Only 10 patients (8%) received concomitantly corticosteroids, and their rate of remission was similar (80% at 18 months). Among responders, 42% achieved complete remission (CR) and 58% partial remission (PR). Almost half (44%) of the responder patients relapsed. The amount of proteinuria at the onset of tacrolimus tapering was significantly higher in relapsing patients. By multivariable analysis, the presence of a PR versus CR at the onset of tacrolimus tapering and a shorter duration of the tapering period significantly predicted relapses. Tolerance was good and the number of adverse events low. Conclusions Tacrolimus monotherapy is an effective and safe option for the treatment of MN with stable renal function. Relapses are frequent in patients with PR and can be partially prevented by a longer tapering period.