A 26-year-old woman with no prior transfusions receives packed red cells during surgery and develops flushing, hypotension, and bronchospasm within minutes. Investigation reveals undetectable serum IgA with normal levels of other immunoglobulins. What is the most likely explanation?

• A Recipient IgE antibodies against donor leucocyte antigens
• B ABO-incompatible transfusion causing intravascular haemolysis
• C Contamination of the unit with endotoxin-producing Gram-negative bacteria
• D Preformed anti-IgA antibodies in the recipient reacting with IgA in donor plasma ✓

Explanation

Selective IgA deficiency is the commonest primary immunodeficiency, often asymptomatic but associated with sinopulmonary infections. Some affected individuals develop anti-IgA antibodies, so transfusion with IgA-containing blood products can trigger a life-threatening anaphylactoid reaction. Such patients should receive washed or IgA-deficient blood components. ABO incompatibility causes fever, flank pain, and haemoglobinuria rather than isolated anaphylaxis, and bacterial contamination presents with rigors and shock later in the transfusion.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.