Anti-IgA-mediated transfusion reactions in Canada

Area of Science:

• Immunology
• Transfusion Medicine
• Clinical Pathology

Background:

• Severe nonhemolytic transfusion reactions pose a diagnostic challenge.
• Immunoglobulin A (IgA) deficiency is a known risk factor for transfusion reactions.

Purpose of the Study:

• To investigate the cause of severe nonhemolytic transfusion reactions in Canadian patients.
• To determine the incidence of anti-IgA antibody-mediated transfusion reactions.

Main Methods:

• Analysis of blood samples from 152 Canadian patients referred over a 6-year period (1977-1982).
• Identification of IgA deficiency and class-specific anti-IgA antibodies.
• Documentation of clinical symptoms in affected patients.

Main Results:

• Twenty-one of 152 patients (13.8%) were found to be IgA deficient.
• Twelve of the IgA-deficient patients had strong anti-IgA antibodies, presumed to cause the reactions.
• The incidence of anti-IgA-mediated reactions was estimated at a minimum of 1.3 per million transfused units.

Conclusions:

• IgA deficiency with anti-IgA antibodies is a significant cause of severe nonhemolytic transfusion reactions.
• Routine screening for IgA deficiency and anti-IgA antibodies may be warranted in patients experiencing such reactions.
• The findings highlight the importance of identifying specific antibody-mediated transfusion reactions for patient safety.