Abstract: Objective  To explore  clinical significance of serum antiPLA2R antibody test and IgG subclass test in elderly patients with idiopathic membranous nephropathy(IMN).Methods  Clinical manifestations of nephrotic syndrome were collected and confirmed as IMN (46 cases), secondary membranous nephropathy (46 cases) and atypical membranous nephropathy (46 cases).Serum biochemical indicators and urine protein quantification were detected.  Serum PLA2RAB and IgG subclasss were detected by indirect immunofluorescence, and the expression distribution of PLA2R and IgG subclasss in renal pathology was detected by immunofluorescence method. The serum antiPLA2R antibody test and IgG subclass level were analyzed in elderly patients with IMN and secondary membranous nephropathy, and the differences in the distribution of glomeruli and IgG subclasss.Results  The sensitivity and specificity of serum antiPLA2R antibody for IMN diagnosis were 77.4% and 89.9%, respectively.The sensitivity and specificity of the glomerular PLA2R diagnostic IMN were 66.5% and 94.8%, respectively,  those of the glomerular igg14 diagnostic IMN were 80.6%,  60.2%, 42.0%, 93.8% and 78.5%, 83.6%,84.6% and 89.7%.Conclusion  Combined detection of antiPLA2R antibody and IgG subclass expression  in elderly patients is helpful to improve the differentiation of  IMN and secondary membranous  nephropathy,  and to guide clinical treatment and prognosis evaluation.

Key words: membranous , nephropathy, phospholipase A2 receptor, IgG subclass