Résumé
Objective To detect the expression levels of renal tissue M-type phospholipase A2 receptor 1(PLA2R1) antigen and its antibody in the patients with membranous nephropathy(MN).Methods Fifty-eight cases of biopsy-proved idiopathic membranous nephropathy(IMN),fifteen cases of hepatitis B-associated membranous nephropathy(HBV-MN) and seventeen cases of V type lupus nephritis(V-LN) were selected.Renal tissue PLA2R1 antigen was detected by indirect immunofluorescence and colocaliazed with IgG4.Serum anti-PLA2R1 antibody was simultaneously examined.The expression difference of PLA2R1 antigen and antiPLA2R1 antibody in MN was analyzed.And the differences of clinical data were analyzed between PLA2R1 positive and negative patients.Results The PLA2R1 antibody was not found in the renal tissue and serum of the patients with LN and HBV-MN;PLA2R1 antigen was found in 81.03％ of IMN patients,and its antibody was found in serum of 70.69％ of IMN patients.PLA2R1 antigen and IgG4 co-localization all deposited along glomerular capillary loop presenting as fine granules.The 24 h urine protein level in the patients with PLA2R1 antigen deposition in renal tissues was higher than that in the patients without PLA2R1 deposition (P＜0.05),moreover serum albumin level was lower than that in the patients without PLA2R1 deposition(P＜0.05).Conclusion The sensitivity and specificity of renal tissue PLA2R1 antigen in the diagnosis of IMN are higher.The expression of PLA2R1 antigen in renal tissue by biopsy is significantly correlated with the clinical severity.
Résumé
After the research of PLA2R1 and its antibodies, Thrombospondin type-1 domain-containing 7A and its antibodies to membranous nephropathy (MN) has made a new understanding.Some researches have reported that the antibodies of PLA2R1 and THSD7A were mutually exclusive in MN, because THSD7A was found in PLA2R1-negative MN patients.But the latest researcher showed that these antibodies can be both positive in MN patients.Similar to the function of PLA2R1, THSD7A can assist clinical diagnosis, treatment, and monitor of MN.In contrast to PLA2R1, THSD7A was also highly expressed on both human and murine podocytes.We can use the mice model to study the pathogenesis of THSD7A-associated MN in the future.In this review, we describe the structure and function of Thrombospondin type-1 domain-containing 7A and its autoantibodies, highlight its role in MN and suggest possible aspects of its future clinical application.