Delayed hemolytic transfusion reaction caused by a primary immune response

Area of Science:

• Immunology
• Hematology
• Transfusion Medicine

Background:

• Delayed hemolytic transfusion reactions (DHTRs) are typically linked to secondary immune responses, peaking around seven days post-transfusion.
• Understanding the kinetics of immune responses is crucial for diagnosing and managing transfusion complications.

Observation:

• A patient presented with hemoglobinuria, anemia, and reticulocytosis four weeks after a blood transfusion.
• The specific antibody, anti-C, was identified eight weeks post-transfusion using enzyme-treated red blood cells.

Findings:

• The observed four-week delay in symptom onset and antibody detection suggests a primary immune response, deviating from the typical secondary response pattern of DHTRs.
• Hemolysis occurred significantly later than the usual seven-day peak.

Implications:

• This case underscores the importance of considering primary immune responses in delayed hemolytic transfusion reactions, even with later symptom onset.
• Sequential antibody screening and testing are vital for accurate diagnosis of transfusion reactions, especially in atypical presentations.
• The findings emphasize the need for extended monitoring and diagnostic workups in suspected transfusion reactions.