https://doi.org/10.1351/goldbook.13497
Part of the naturally occurring repertoire of polyreactive antibodies that bind to autoantigens with low affinity. They are mainly of immunoglobulin M (IgM) isotype and produced by CD5+ B lymphocytes.
Notes:
- Natural antibodies and their producing cells may have a physiological role in the following processes: (i) first line of protection against external invaders, (ii) elimination of degraded autoantigens and senescent cells, and (iii) tolerization (see tolerance) of T cells by presenting autoantigens, thereby in protecting from development of pathological autoimmunity.
- In contrast, natural autoantibodies may become pathogenic in clonal B cell disorders, e.g., monoclonal anti-I antibodies in cold agglutinin disease cause autoimmune hemolytic anemia.