A 24-year-old woman who had previously been uneventfully transfused,receives a blood transfusion during surgery and sholy thereafter develops itching, generalized uicaria, laryngeal edema, and dyspnea with wheezing respiration. She has a past history of recurrent upper respiratory tract infections and frequent episodes of diarrhea. Laboratory studies are most likely to reveal decreased concentrations of which of the following immunoglobulins?

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.