Clinical Study of THSD7A, SOD2 and AR Antigens in Idiopathic Membranous Nephropathy

Background To explore the expression of THSD7A, SOD2 and AR podocyte antigens in the renal tissue of patients with idiopathic membranous nephropathy (IMN) and its clinical diagnostic value in IMN. Method This study retrospectively collected 150 renal tissue specimens and clinical data of patients undergoing renal biopsy in the Department of Nephrology, Shandong Provincial Hospital, including 130 IMN and 20 non-IMN patients. We use immunohistochemical staining to detect the expression of THSD7A, SOD2, AR antigens in the kidney tissue of patients. We focus on analyzing the clinical and pathological characteristics of IMN patients with positive THSD7A antigen expression, and analyze the prognosis of THSD7A-IMN patients and tumor occurrence. Meanwhile, the sensitivity and specificity of those antigens for the diagnosis of IMN were discussed. Results There were only 6 patients with THSD7A positive expression among 150 patients with glomerular disease, of which 5 patients were all IMN patients, and the patients' serum anti-PLA2R antibodies(anti-PLA2R-ab) were all negative. The positive rate of THSD7A in IMN was 3.85%, and the positive rate in IMN patients with anti-PLA2R-ab negative was 5.50%. Meanwhile, the sensitivity and specificity of renal tissue THSD7A in diagnosing IMN is 4.0% and 95%. In addition, the IgG subtype of THSD7A-IMN was mainly IgG4; Among them, 2 patients with IMN had both THSD7A and PLA2R antigen staining. This study also suggests that there is no significant difference in clinical and pathological characteristics between THSD7A positive and negative group. The follow-up of THSD7A-IMN patients found no tumors. This study also showed that there were 11 cases of anti-PLA2R-ab negative IMN patients with SOD2 antigen expression (8.56%), 10 cases of anti-PLA2R-ab negative and 4 cases of anti-PLA2R-ab positive IMN patients with AR antigen expression (10.77%), but no obvious SOD2 and AR antigen expression in SMN and other glomerular diseases. Conclusions Glomerular THSD7A antigen has a certain expression rate and high specificity in IMN, but its expression rate is low, and it can be used as a specific diagnostic index for IMN supplement. Kidney tissue SOD2, AR podocyte target antigens have a low positive rate in IMN, and further research is needed to evaluate the condition of IMN.