Clinical significance of Mtype phospholipase A2 receptor and thrombospondin Type 1 domaincontaining 7A in primary membranous nephropathy / 中南大学学报(医学版)

ABSTRACT

OBJECTIVES@#To evaluate the value of thrombospond in Type I domain-containing 7A (THSD7A) and M-type phospholipase A2 receptor (PLA2R) in primary membranous nephropathy (PMN) and to explore the relationship between their antibody levels and prognosis.@*METHODS@#Renal tissues in 128 patients with membranous nephropathy in the Second Xiangya Hospital of Central South University were collected from February 2015 to August 2017, including 108 patients with primary membranous nephropathy (PMN group) and 20 patients with secondary membranous nephropathy (SMN) (SMN group). Indirect immunofluorescence method was used to detect the expression of PLA2R antigen in kidney tissues,and the glomerular expression of THSD7A antigen was examined by immunohistochemistry and indirect immunofluorescence. The serum levels of anti-PLA2R antibodies and THSD7A antibodies were also detected by ELISA. According to the results of PMN examination,the patients were also divided into a PLA2R-related membranous nephropathy group and a THSD7A-related membranous nephropathy group.@*RESULTS@#The positive rate of PLA2R in the renal tissues in the PMN group was higher than that in the SMN group (78% in the PMN group, 35% in the SMN group, <0.01),while the positive rate of anti-PLA2R antibody in the PMN group was also higher than that in the SMN group (50% in the PMN group, 25% in the SMN group, <0.05).The serum level of anti-PLA2R antibody was positively correlated with 24 h urine protein (=0.254, <0.05) and negatively correlated with serum albumin (=-0.236, <0.05). The expression of THSD7A was positive in glomeruli in 7 cases of the PMN group (6%) by immuno-histochemistry, and which was positive in 1case of the SMN group (5%).The serum levels of anti-THSD7A antibody in the PMN group were higher than those in the SMN group [(0.49±0.26) pg/mL in the PMN group,(0.34±0.27) pg/mL in the SMN group, <0.05]. There was no difference in the clinical characteristics between the PLA2R-related membranous nephropathy group and the THSD7A-related membranous nephropathy group.@*CONCLUSIONS@#PLA2R and THSD7A are the target antigen of PMN, and the associated autoantibodies are helpful for the differential diagnosis of PMN. The anti-PLA2R antibody levels can reflect the severity of the disease and evaluate the effect of treatment. The incidence of THSD7A membranous nephropathy is low, and monitoring the serum anti-THSD7A antibody levels can assess patients' condition and predict disease outcome.