Autoantibodies against Phospholipase A2 Receptor in Korean Patients with Membranous Nephropathy

Abstract

The data were presented in abstract form at the 45th meeting of the American Society of Nephrology, October 30-November 04 2012, San Diego, CA, USA. Circulating autoantibodies against M-type phospholipase A2 receptor (PLA2R) are important pathogenic antibodies of idiopathic membranous nephropathy (MN) in adults. However, previous studies on the clinical impact of anti-PLA2R antibodies demonstrated several limitations, including insufficient numbers of study subjects and different time points and methods for anti-PLA2R antibody measurement. To verify the clinical significance of anti-PLA2R antibodies in Korean patients with MN, we measured autoantibodies in serum samples obtained at the time of biopsy from a total of 100 patients with idiopathic MN who had not yet received immunosuppressive treatment. We detected anti-PLA2R antibody in 69 patients, and we observed that autoantibody reactivity reflected the severity of disease activity. Proteinuria and hypoalbuminemia were more severe in patients with anti-PLA2R than in those without the autoantibodies (2.95 g/g vs. 6.85 g/g, P = 0.003; 3.1 g/dL vs. 2.5 g/dL, P = 0.004, respectively). Additionally, the clinical severities worsened proportionally as the levels of anti-PLA2R antibodies increased (P = 0.015 and P for trend <0.001 for proteinuria and hypoalbuminemia, respectively). However, neither the levels nor the presence or absence of anti-PLA2R antibody showed a significant correlation with clinical outcomes, such as remission rate and time to remission. In conclusion, we observed that anti-PLA2R antibodies are highly prevalent in Korean patients with idiopathic MN and that they reflect the clinical disease activity before the administration of immunosuppressive treatment. However, the levels of anti-PLA2R antibody at the time of kidney biopsy may not predict the clinical outcomes in current clinical practice.

Membranous nephropathy: from models to man

“…The detection of circulating anti-PLA 2 R in a proteinuric subject is highly specific for the presence of primary MN on biopsy (24,39,40), and approximately 80% of patients with primary MN will be seropositive for anti-PLA 2 R when the disease first becomes clinically apparent (41)(42)(43)(44)(45). Small observational and retrospective studies have suggested a temporal relationship between anti-PLA 2 R and clinical disease activity.…”

Epitope Spreading of Autoantibody Response to PLA2R Associates with Poor Prognosis in Membranous Nephropathy

“…2 The presence of anti-PLA2R1 autoantibodies has been widely confirmed in subsequent studies in 53%-80% of patients with iMN. [3][4][5][6] The pathogenic role of these autoantibodies is not yet proven, but anti-PLA2R1 antibody titers appear to correlate with disease activity in most study populations. However, the individual outcome prediction from anti-PLA2R1 titers is unclear.…”

Anti-phospholipase A2 receptor antibody in membranous nephropathy; an Indian experience

“…shown that, the antibody titres disappear with remission and reappear with disease relapses (8,13,14,17,18,(27)(28)(29)(30)(31)(32). Moreover, anti-PLA 2 R levels were in direct proportion to proteinuria and serum albumin levels.…”