Anti-Jka-mediated delayed hemolytic transfusion reaction mimicking warm autoimmune hemolytic anemia in a multiparous woman: a case report.

BACKGROUND

Autoimmune hemolytic anemia (AIHA) and delayed hemolytic transfusion reaction (DHTR) are distinct but occasionally overlapping immune-mediated hemolytic disorders. Kidd (Jka) alloantibodies are a frequent cause of DHTR, yet their transient nature often makes them difficult to detect with routine pretransfusion testing.

CASE PRESENTATION: A 46-year-old multiparous Black woman with chronic abnormal uterine bleeding and prior transfusions presented with dark urine and abdominal pain. Laboratory evaluation revealed anemia with hemolysis (elevated lactate dehydrogenase, indirect hyperbilirubinemia, low haptoglobin, and schistocytes). Direct antiglobulin testing was positive for IgG, and antibody screening identified anti-Jka alloantibodies, confirming DHTR with overlapping features of warm AIHA. The patient was managed with high-dose oral prednisone, folic acid, and supportive measures, resulting in marked clinical and biochemical improvement.

CLINICAL DISCUSSION: This case illustrates the diagnostic complexity of DHTR mimicking AIHA, particularly in multiparous, multi-transfused patients predisposed to alloimmunization. It highlights the limitations of conventional antibody screening, the role of advanced immunohematology testing and genotyping in high-risk individuals, and the importance of immunosuppressive therapy when AIHA overlap occurs.

CONCLUSION

Early recognition of DHTR and prompt initiation of appropriate therapy are essential to prevent misdiagnosis, avoid unnecessary transfusions, and reduce morbidity in at-risk patients.