Evolution of antibody titre against the M-type phospholipase A2 receptor and clinical response in idiopathic membranous nephropathy patients treated with tacrolimus.

The level of circulating antibodies against M-type phospolipase A2 receptor has been reported as having a significant correlation with clinical activity in idiopathic membranous nephropathy. However, the usefulness of monitoring antibody titre as a predictor of clinical response following the onset of treatment has not been formally analysed. The predictive value of the evolution of anti-PLA2R antibody titre on the clinical response of idiopathic membranous nephropathy patients treated with tacrolimus is analysed in the following study.36 patients with nephrotic syndrome secondary to idiopathic membranous nephropathy with immunosuppressive treatment indication criteria were treated with tacrolimus in monotherapy. The level of anti-PLA2R antibodies was determined before treatment and at 3, 6, 9 and 12 months after the onset of treatment. The study analysed the predictive value of the reduction in antibody titre and the relative and absolute reduction in antibody titre at 3 and 6 months over the period until remission and on the probability of remission at 6, 9 and 12 months.The relative reduction in the anti-PLA2R antibody titre was significantly greater in those patients with remission and it preceded the clinical response. No association was observed between the antibody titre prior to treatment and the mean response time or the response at 12 months. Reduction in antibody titre is significantly associated with the time until signs of remission. Relative reduction in anti-PLA2R antibody titre at 3 months had a high sensitivity and specificity to predict the response at 6 and 9 months, but not at 12 months; however the relative reduction in the antibody titre at 6 months had a high sensitivity and specificity for predicting the response at 12 months.In patients with IMN associated with anti-PLA2R antibodies, the monitoring of antibody titre following the onset of treatment is useful for estimating the time period until remission and predicting the probability of remission at 12 months.