Pathogenic Immunoglobulin G (IgG)

Pathogenic Immunoglobulin G (IgG) antibodies are a subset of antibodies that erroneously target self-antigens, serving as the primary mediators in numerous autoimmune and alloimmune diseases (Source: StatPearls, 2023). These antibodies exert their effects through mechanisms such as complement activation, opsonization, and direct functional interference with cellular receptors, as seen in Myasthenia Gravis where they block acetylcholine receptors (Source: NIH, 2024). A critical aspect of IgG biology is its long half-life, which is mediated by the neonatal Fc receptor (FcRn) that protects IgG from lysosomal degradation (Source: Nature Reviews Immunology, 2007). Therapeutic strategies have shifted toward reducing these pathogenic levels specifically, most notably through FcRn inhibitors like efgartigimod and rozanolixizumab, which accelerate the catabolism of IgG (Source: FDA, 2021). Other interventions include the use of IgG-degrading enzymes like imlifidase to rapidly neutralize antibodies in acute settings or transplant scenarios (Source: Hansa Biopharma, 2020).

Other names

AutoantibodiesSelf-reactive IgGPathogenic IgG antibodiesDisease-causing IgGAutoimmune IgG

Therapeutic strategies target pathogenic IgG through several mechanisms: 1) Neonatal Fc receptor (FcRn) antagonism, which blocks the recycling of IgG and promotes its lysosomal degradation (Source: Nature Reviews Drug Discovery, 2018); 2) Enzymatic cleavage using endopeptidases like Imlifidase, which neutralizes IgG effector functions (Source: NEJM, 2019); and 3) Physical removal from circulation via plasmapheresis or immunoadsorption (Source: Journal of Clinical Apheresis, 2019).