Coombs'-positive hemolytic anemia and ibuprofen

Area of Science:

• Hematology
• Immunology
• Pharmacology

Background:

• Autoimmune hemolytic anemia (AIHA) is a condition where the immune system attacks red blood cells.
• Drug-induced AIHA can occur, necessitating identification of the causative agent.
• Ibuprofen is a common nonsteroidal anti-inflammatory drug (NSAID) with potential adverse effects.

Observation:

• A patient developed AIHA while undergoing treatment with ibuprofen (Motrin).
• Testing revealed a positive indirect Coombs' reaction in the presence of ibuprofen, indicating drug-related immune hemolysis.
• A positive direct Coombs' test with anti-C3 antiserum suggested complement-mediated hemolysis.

Findings:

• Laboratory analysis indicated that the orange dye coating of the Motrin tablet, not ibuprofen, was the likely cause of the immune hemolysis.
• While complement appeared to be the primary mediator, the possibility of undetected IgG antibodies could not be entirely ruled out.

Implications:

• This case highlights the importance of considering excipients, such as dyes, as potential triggers for drug-induced immune reactions.
• Further investigation into the immunogenic potential of pharmaceutical dyes is warranted.
• Clinicians should consider all components of a medication when diagnosing drug-induced hemolytic anemia.