Acute Hemolytic Transfusion Reaction Due to Pooled Platelets: A Rare but Serious Adverse Event

A female patient aged 65 years with blood group A with relapsed lymphoma had thrombocytopenia; leukocyte-reduced group O prestorage pooled platelet concentrates (PPLTs) were transfused without adverse events. She was discharged home, but 1.5 hours later she returned with fever and dark urine. Hypotension and tachycardia developed; she was admitted to the intensive care unit. Post-transfusion blood and urine samples were obtained. Serial dilutions from 5 donor testing tubes and a simulated PLT pool were performed and read at immediate spin and IgG. Testing confirmed an acute hemolytic transfusion reaction (AHTR): elevated lactate dehydrogenase (996 U/L; normal range 135 U/L-225 U/L) and undetectable haptoglobin (<10 mg/dL; normal range 30 mg/dL-200 mg/dL) levels. Urinalysis showed dark amber urine but no significant quantity of red blood cells. At 37ºC the simulated pool and donor number 5 had high-titer anti-A. As a precaution, the donor was permanently deferred. Research has shown that PLT-associated AHTR has occurred with apheresis platelets but is very rare with whole blood-derived PLTs.