SERUM ANTI-THROMBOSPONDIN TYPE-1-DOMAIN CONTAINING 7A PROTEIN ANTIBODIES - DIAGNOSTIC RELIABILITY
Keywords:
membranous nephropathy, primary membranous nephropathy, phospholipase receptor antibodiesAbstract
Various researchers have defined membranous nephropathy (MN) as a disease of autoimmune origin (Ronco et al., 2021; Dantas et al., 2023). The probable mechanism by which it occurs is the binding of circulating autoantibodies to podocyte antigens expressed by renal glomeruli. This leads to the formation of electron-dense immune complexes with subsequent activation of the complement system. Clinically disease presents with proteinuria in the nephrotic range and edema (Hoxha et al., 2022). The disease can evolve into severe thrombotic complications or the development of end-stage renal failure. Over the past twenty years, great progress has been made in discovery of probable antigens, being the protein “M-type phospholipase-A2 receptor”. According to Radhakrishnan et al. (2024), it is a transmembrane receptor that is expressed on the surface of podocytes. Due to loss of immune tolerance by mechanisms that, according to the author, are not yet fully understood, antibodies are formed against this autoantigen, mainly of the immunoglobulin G4 class. This likely mechanism of injury is responsible for 70% to 80% of primary MH cases. The study of the amount of allows us to assess the disease and its activity and prognosis. In 2014, Tomas et al. reported their discovery of a novel antigen, called thrombospondin type-1 domain containing 7A protein (THSD7A), which they believe is a novel target antigen responsible for the pathogenesis of primary membranous nephropathy (PMN). Autoantibodies directed against THS7DA are predominantly of the IgG4 class, which have been observed using immunofluorescence microscopy of kidney biopsy preparations. Various groups of authors (Hoxha et al., 2017; Hanset et al., 2020) report that THSD7A-associated MN has a higher incidence (20% to 50%). Currently, testing for antibodies against THSD7A (anti-THSD7A) is poorly used in clinical laboratory practice. Data on in scientific literature are quite scarce. According to Tomas et al. (2016) primary membranous nephropathy is still not fully understood. We studied a total group of 134 individuals, which was composed of patients with kidney diseases n = 84 and the control group of healthy individuals n = 50. The renal disease group included three subgroups of patients: 23 PMN patients who were negative for anti-PLA2R antibodies, 12 with secondary membranous nephropathy (SMN) and 49 with other nephropathies (ON). EUROIMMUN indirect immunofluorescence assay (IIFT) was used serum titer. The obtained data were statistically processed. The summary results for the anti-THSD7A antibody marker showed very good diagnostic reliability. This allows us to determine the titer of these circulating antibodies in patients with PMN. In conclusion, we can say method for determining has good diagnostic reliability.
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