IgA Antibodies Test – Role in Transfusion Reactions and IgA Deficiency
IgA Antibodies Test
Synonyms: Anti-immunoglobulin A
Abstract
This test identifies antibodies formed against IgA, typically in individuals with IgA deficiency. These antibodies may cause severe transfusion reactions when blood products containing IgA are introduced into their circulation.
Specimen Details
- Type: Serum
- Container: Red top tube
Reference Range
Antibody not present
Use
Evaluate patients with suspected anaphylactic reactions after receiving blood transfusions. Symptoms may include:
- Dyspnea
- Substernal chest pain
- Sweating and flushing
- Laryngeal edema
- Hypotension
- Shock or collapse after minor transfusions
Methodology
Immunodiffusion (ID)
Additional Information
IgA deficiency affects about 1 in 500–1000 individuals. These patients may produce antibodies (IgG or IgE) against IgA, perceiving it as foreign. Transfusion with IgA-containing products may cause severe, life-threatening reactions.
Testing for anti-IgA (IgG and IgE) is advised in patients with past transfusion-related anaphylaxis. While testing helps, a negative result does not rule out the risk of an IgE-mediated event.
Precautions: Such patients should ideally receive:
- Washed red cells or
- Autologous transfusion (self-donated blood)
IgA is also found in commercial immunoglobulin preparations, which can trigger reactions in IgA-deficient patients.
References
- Jacobs, Demott, Finley, Horvat, Kasten JR, Tilzer. Laboratory Test Handbook. Lexi-Comp Inc., 1994.
- Keren DF, Warren JS. “Immunodeficiency,” in Diagnostic Immunology. Williams & Wilkins, 1992:107–8.
