Isolated IgA deficiency It is most often asymptomatic but can be characterized by anaphylactic reactions to transfused blood. It is critical to notify the transfusion service about a patient with possible IgA deficiency prior to giving blood products so that products can be washed to remove any immunoglobulins prior to administration. Associated with:- Frequent episodes of diarrhea and recurrent infections. This inherited B-cell defect is due to inability of B cells to mature into IgA-producing plasma cells Patients lacking IgA can develop IgE antibodies against the IgA antibodies present in transfused blood. As the body don't recognise it as a self antigen. This sensitization can result in susceptibility to anaphylaxis on subsequent transfusion.