Rare presentation of mixed autoimmune hemolytic anemia in children: Report of 2 cases

Immune hemolytic anemia is characterized by clinical and laboratory features of hemolytic anemia with direct antiglobulin test (DAT) positivity. It could be autoimmune hemolytic anemia (AIHA), alloimmune, or drug-induced hemolysis based on the antigenic stimulus. Furthermore, based on thermal amplitude of autoantibody, AIHA is classified as warm (65%), cold (30%), and mixed (5%) type. Mixed AIHA is extremely rare in children and must be differentiated from warm AIHA with clinically insignificant cold agglutinins and cold hemagglutinin disease as their treatment is different. It may present as blood group discrepancy or cross-match incompatibility leading to delay in arranging suitable blood unit for transfusion. Therefore, a thorough immunohematology workup including monospecific DAT, indirect antiglobulin test at 4°C and 37°C, determination of thermal amplitude and titer is essential. We hereby present two pediatric cases of mixed AIHA presenting as ABO forward and reverse blood group discrepancy and cross-match incompatibility.