Serum BAFF levels are associated with the prognosis of idiopathic membranous nephropathy

Objective High serum levels of BAFF (B-cell activation factor) and APRIL (a proliferation-inducing ligand) have been observed in patients with idiopathic membranous nephropathy (iMN); however, their relationships with disease severity and progression remain unclear. Methods Patients with iMN diagnosed via renal biopsy were enrolled in this study. The concentrations of BAFF and APRIL were determined using ELISA kits. Proteinuria remission, including complete remission (CR) and partial remission (PR), was defined as a clinical event. The Cox proportional hazards method was used to analyze the relationship between survival and disease progression. Results Seventy iMN patients were enrolled in this study, with a median follow-up time of 24 months (range 6–72 months).The serum levels of BAFF and APRIL were higher in iMN patients than in healthy controls but lower than those in minimal change disease (MCD) patients. The serum BAFF level was positively correlated with the serum APRIL level, serum anti-PLA2R antibody level and 24-h proteinuria and negatively correlated with the serum albumin (Alb) level. However, there was no significant correlation between the serum APRIL level and clinical parameters. According to the multivariate Cox proportional hazards regression model adjusted for sex, age, systolic blood pressure, eGFR, immunosuppressive agent use, 24-h proteinuria, APRIL level, and anti-PLA2R antibody, the serum BAFF level was identified as an independent predictor of PR(HR, 0.613; 95% CI, 0.405–0.927; p = 0.021) and CR of proteinuria (HR, 0.362; 95% CI, 0.202–0.648; p < 0.001). Conclusions A high serum BAFF level is associated with severe clinical manifestations and poor disease progression in patients with iMN.