Atypical presentation of iga-related immediate reaction with back pain and relative hypotension – Anaphylaxis or not?

Abstract

Anaphylactic transfusion reactions are rare, occurring in approximately 1 in 50,000 red cell transfusions.1 One aetiology includes the development of antibodies against transfused IgA in patients with severe IgA deficiency. Diagnosis of IgA-related anaphylaxis involves the measurement of IgA levels and anti-IgA antibodies.2 Recently, the evidence underlying this entity and the causal relationship between laboratory tests and clinical manifestation has been questioned.3 We describe a case of a 50-year-old man with chronic anaemia with an infected enterocutaneous fistula. He received six red cell transfusions where he developed severe back pain and relative hypotension within 15–30 minutes of transfusion, settling after transfusion was ceased. He was afebrile with no respiratory, dermatological or gastrointestinal manifestations typical of anaphylaxis. Direct antiglobulin test was negative, and blood cultures were sterile. Tryptase taken 2.6 hours after symptom onset was raised 16 μg/L (0.0–11.4 μg/L). IgA level was <0.10 g/L (0.80–4.40g/L). Anti-IgA titre was 400 U/mL (0–7 U/mL). IgA deficient components were prepared pre-operatively. He subsequently received three washed red cells uneventfully, one during a laparotomy for the enterocutaneous fistula. This case describes an atypical presentation of a rare but important complication of blood transfusion, as well as the diagnostic process and subsequent management.