Mixed-type AIHA is present when the individual has both cold and warm autoantibodies. The cold autoantibody in mixed-type AIHA has broad thermal amplitude with reactivity at 30°C or above with either a high titer or low titer. The cold autoantibody is an IgM and the warm autoantibody is an IgG.
Both IgG and C3 are detectable on the patient's red cells. This usually results in reactivity in all phases of testing with all cells tested. Both cold and warm autoadsorptions may be required to determine the presence of alloantibodies. The cold antibody usually demonstrates anti-I or anti-i specificity. The warm antibody is serologically indistinguishable from the autoantibodies in a typical warm autoimmune hemolytic anemia (WAIHA). Considerations for blood selection, if transfusion is needed, is similar to that for CHD and WAIHA.