Evaluation on clinical application of PLA2R and THSD7A in idiopathic membranous nephropathy

ObjectiveTo evaluate the clinical application of glomerular M-type phospholipase A2 receptor(PLA2R), thrombospondin type 1 domain-containing 7A(THSD7A) and their serum antibody levels in membranous nephropathy.

MethodsA total of 172 cases of idiopathic membranous nephropathy(IMN) patients diagnosed by renal biopsy were selected as IMN group, and 7 cases of secondary membranous nephropathy(SMN) diagnosed in the same period were selected as SMN group.The expressions of PLA2R and THSD7A antigens in renal tissues were detected by immumofluorescence method, and the level of their serum PLA2R and THSD7A antibodies was measured by ELISA.

ResultsA total of 167 cases in the IMN group showed positive for PLA2R alone(97.1%), and 3 cases in the SMN group were positive for PLA2R(42.9%), which showed statistically significant difference(P < 0.01).In the IMN group, 5 cases were positive for THSD7A(2.9%), and 5 cases showed positive for both PLA2R and THSD7A(2.9%); no THSD7A-positive case was detected in the SMN group, and the difference had no statistical significance(P>0.05).In the test of serum PLA2R, 143 cases in the IMN group showed positive result(83.1%), 2 cases in the SMN group were positive(28.6%), and the differences were statistically significant(P < 0.01).No THSD7A antibody was detected in the serum of the two groups.There were no statistically significant differences in sex, age, Alb, 24hUpro, SCr, and eGFR between the two groups(P>0.05).PLA2R-Ab had no correlation with SCr and eGFR(P>0.05), but had a significant negative correlation with Alb(P < 0.01), and a positive correlation with 24hUpro(P < 0.05).The Alb level in the PLA2R antibody-positive group was significantly lower than that in the negative group(P < 0.01), the 24hUpro level in the PLA2R-positive group was significantly higher than that in the negative group(P < 0.05), and the differences were statistically significant.

ConclusionsThe detection of PLA2R, THSD7A and their antibodies can contribute to the diagnosis and classification of membranous nephropathy.The level of PLA2R antibody can reflect the disease activity and can be used to evaluate treatment effect.The incidence rate of THSD7A-related MN in membranous nephropathy patients is relatively low.