Anti-A and anti-B antibodies (None)

Anti-A and anti-B antibodies, also known as isohemagglutinins, are naturally occurring antibodies found in the serum of individuals who lack the corresponding A or B antigens on their red blood cells (StatPearls, 2023). These antibodies are primarily of the IgM class, though IgG and IgA forms also exist, and they are typically produced in early childhood following exposure to environmental antigens that mimic blood group carbohydrates (NIH, 2022). In clinical medicine, these antibodies are significant because they can cause life-threatening hemolytic transfusion reactions if incompatible blood is administered (PubMed, 2021). They also pose a major barrier to ABO-incompatible organ transplantation, where they can trigger hyperacute rejection by binding to the vascular endothelium of the graft (Journal of Clinical Investigation, 2020). Therapeutic interventions often target these antibodies through physical removal via immunoadsorption or plasmapheresis to prevent graft damage (American Journal of Transplantation, 2019). Pharmacological agents like rituximab are also used to deplete the B-cells responsible for the production of these antibodies in desensitization protocols (PubMed, 2022). Additionally, intravenous immunoglobulin (IVIG) may be used to neutralize circulating antibodies and modulate the immune response in cases of hemolytic disease of the newborn (StatPearls, 2023). Understanding the titers and classes of these antibodies is crucial for managing patients undergoing incompatible transplants or those with autoimmune conditions (NIH, 2022).

Other names

IsohemagglutininsABO antibodiesAnti-AAnti-BBlood group antibodies

Therapeutic strategies include the physical removal of antibodies via plasmapheresis or immunoadsorption, neutralization of circulating antibodies using intravenous immunoglobulin or synthetic glycans, and the depletion of antibody-producing cells using B-cell or plasma cell-targeted therapies (StatPearls, 2023; PubMed, 2021).