Negative anti-phospholipase A2 receptor antibody status at three months predicts remission in primary membranous nephropathy

Background The value of anti-phospholipase A2 receptor antibody (anti-PLA2R ab) monitoring at 3 months after diagnosis in membranous nephropathy (MN) remains uncertain. Methods We retrospectively examined the outcome on 1 August 2020 of 59 adult patients (age 54 (44, 68) years, 69% male, SCr 1.0 (0.9, 1.3) mg/dL) diagnosed with MN (kidney biopsy, positive serum anti-PLA2R ab). The outcomes were: kidney survival; partial and/or complete remission. Results Most of the studied patients (97%) received immunosuppression, cyclophosphamide regimens were the most frequent (87%), followed by cyclosporine (10%). The median time to remission was 12.0 months and the cumulative remission rates were 34% at 6, 54% at 12, and 73% at 24 months. Forty (69%) patients had negative anti-PLA2R ab at 3 months, they had similar age, serum creatinine, albumin, proteinuria, and treatment with the group with positive ab at 3 months. In the Cox proportional hazard model, three months anti-PLA2R ab negativization (HR 0.4 (95%CI 0.1, 0.9)) was an independent predictor for remission, while baseline hypoalbuminemia (HR 3.0 (95%CI 1.5, 5.7)) was associated with absence of remission. Six (10%) patients died, mostly due to cardiovascular disease and infections. A total of five (9%) patients started dialysis. Mean kidney survival time was 50.3 months and there was no survival difference in relation to baseline anti-PLA2R ab titer (p .09) or 3 months negativization (p .8). Conclusions Three months anti-PLA2R ab negativization seems to be a late predictor of remission, and lower serum albumin at diagnosis is an early marker for remission absence.