Immunoglobulin M autoantibody (IgM autoantibody)

Immunoglobulin M (IgM) autoantibodies are large, pentameric proteins produced by the immune system that mistakenly target the body's own tissues or circulating molecules. While natural IgM autoantibodies play a crucial role in clearing cellular debris and maintaining immune homeostasis, pathogenic IgM autoantibodies are central to the pathogenesis of several rare and severe conditions. In Cold Agglutinin Disease, these antibodies bind to red blood cells at low temperatures, triggering the classical complement pathway and leading to chronic hemolysis. In neurological contexts, such as anti-MAG neuropathy, IgM autoantibodies target myelin-associated glycoproteins, resulting in progressive nerve damage and sensory loss. Therapeutic interventions focus on reducing their production through B-cell or plasma cell depletion, physically removing them from circulation via plasmapheresis, or blocking the downstream inflammatory cascades they trigger. Monitoring the titers of these specific autoantibodies is essential for the diagnosis and clinical management of IgM-mediated autoimmune syndromes.

Other names

Auto-IgMNatural IgM autoantibodiesPathogenic IgM autoantibodiesIgM-type autoantibodyMonoclonal IgM with antibody activity

Therapeutic strategies involve the depletion of B-cells or plasma cells to reduce antibody production, physical removal from the blood via plasmapheresis, or inhibition of the classical complement pathway to prevent IgM-mediated tissue destruction.