Effects of the expression of serum PLA2R antibody on the diagnosis and immunological therapy of idiopathic membranous nephropathy

Objective: To explore the correlation between the expression of serum phospholipase A2 receptor (PLA2R) antibody and the diagnosis and immunological therapy of idiopathic membranous nephropathy (IMN). Methods: A total of 329 patients undergoing renal biopsy were enrolled and analyzed prospectively, including 142 patients with IMN and 187 patients with non-IMN, and 40 healthy individuals during the same period were also enrolled for control. The expression of serum PLA2R in all enrolled patients was determined, and the efficacy of immunological therapy on IMN patients with different expression of serum PLA2R antibody was evaluated. Results: Among the three groups, the highest serum PLA2R antibody titer was found in the IMN group, which was significantly different from that in the non-IMN group and the healthy group (both P<0.001). The area under the receiver operating characteristic curve of serum PLA2R antibody in diagnosing IMN was 0.961, and when the cut-off value of serum PLA2R antibody was 29.09 RU/mL, its Youden index, specificity, and sensitivity were 0.908, 1 and 0.908, respectively. In addition, comparison of the efficacy between the two patient groups revealed that there were significant differences between the two groups in complete remission, partial remission, and non-remission (all P<0.05). The effective rate of the negative group was significantly higher than that of the positive group (87.50% vs. 66.36%, P<0.05), and the negative group showed higher serum albumin level and less 24 h-proteinuria than the positive group after treatment (both P<0.001). Conclusion: Serum PLA2R antibody is highly expressed in IMN patients and enjoys a high diagnostic value. In addition, the effective treatment rate of the positive serum PLA2R antibody expression group was lower than that of the negative group, implying that the positive expression of serum PLA2R antibody suggested poor prognosis.