Cover Story：Objective Serum anti-phospholipase A2 receptor antibody IgG (PLA2R-IgG) is an important basis for the diagnosis and treatment of idiopathic membranous nephropathy. By now, its conventional detection method is ELISA. To improve the reaction convenience, and obtain the assay sensitivity and wide detecting range, a novel immunoassay was established for PLA2R-IgG detection.Methods Here, based on europium fluorescent microspheres an indirect immunochromatographic assay (ICA) for PLA2R-IgG was developed and evaluated. The reaction process was firstly chosen, and the method parameters were assessed like pH of activating buffer for microspheres, the ratio of europium microspheres to antibodies, and reaction time.Results The performance metrics of the newly proposed assay were analyzed that the sensitivity was 0.7 RU/ml of PLA2R-IgG, the standard curve equation was y=0.771x－1.437 with 0.995 of R, the linear working range was 0.7-1 500 RU/ml, the recoveries were 86.27%-98.98%, the average variable coefficient of intra assay was 8.13%, the cross reaction ratio were above 0.1% and PLA2R-IgG-ICA reagents were stable for 10 d at 37℃. The correlation was 0.953 between developed method and commercial ELISA kits, the consistency was also high. The positive detection rate was 76.9%.Conclusion The established PLA2R-IgG-ICA using two-step dosing was rapid, sensitive, quantitative and accurate with potential clinical application.
