What antibody deficiency is seen in patients with transfusion-related anaphylaxis?

Transfusion-related anaphylaxis is primarily associated with a deficiency of Immunoglobulin A (IgA). This type of reaction typically occurs in individuals who have anti-IgA antibodies and are exposed to IgA present in blood products. When these individuals receive transfusions containing IgA, their immune system mounts an anaphylactic response due to the recognition of IgA as a foreign substance.

Those with IgA deficiency can produce normal levels of other immunoglobulin classes, such as IgG and IgM, but they lack the ability to produce IgA. The presence of anti-IgA antibodies in these patients makes them susceptible to severe allergic reactions upon exposure to IgA-containing blood components.

Recognizing this, it's clear that IgA deficiency is specifically relevant in the context of transfusion-related anaphylaxis, providing a key connection between the antibody and the reaction observed in these patients.