Characteristics of serum anti-phospholipase A2 receptor-IgG and its related factors in patients with hepatitis B virus-associated membranous nephropathy

Abstract

Objective To study the positive rate of serum anti-phospholipase A2 receptor (PLA2R)-IgG in patients with hepatitis B virus-associated membranous nephropathy (HBV-MN), and to analyze the factors related to anti-PLA2R-IgG titer. Methods In this study, 108 patients with HBV-MN diagnosed by renal biopsy were enrolled. The titers of serum PLA2R-IgG, serum creatinine, and serum albumin, as well as 24 h urine protein were measured. The glomerular filtration rate was calculated. The positive rates of PLA2R expression and the immunofluorescence of IgG, C3, and C1q besides IgG subtypes in the renal biopsy tissues were counted. And the relationships between age, gender, or proteinuria and anti-PLA2R-IgG detection results from serum and renal biopsies were analyzed. Results Among the 108 patients with HBV-MN, the positive rate of serum anti-PLA2R-IgG was 37%, and the positive rate of PLA2R in the renal tissues was 54.6%. The positive rate and titer of serum anti-PLA2R-IgG were not statistically correlated with age and gender (P>0.05), but were correlated with the urinary protein levels (χ2=9.159, P=0.010; χ2=11.327, P=0.004). patients with urinary protein>3.5 g/d have significantly higher positive rate than patients with urinary protein <1 g/d and 1-3.5 g/d group (Z=2.863, P=0.012 and Z=2.356, P=0.049). Conclusion The positive rate of anti-PLA2R-IgG was high in the HBV-MN patients, and its positive rate and titer were associated with the proteinuria level. The higher proteinuria level, the higher positive rate and titer of anti-PLA2R-IgG. Key words: Hepatitis B-associated membranous nephropathy; Phospholipase A2 receptor; Diagnosis