85–90% of IgA-deficient individuals are asymptomatic, although the reason for lack of symptoms is relatively unknown and continues to be a topic of interest and controversy. Some patients with IgA deficiency have a tendency to develop recurrent sinopulmonary infections, gastrointestinal infections and disorders, allergies, autoimmune conditions, and malignancies. These infections are generally mild and would not usually lead to an in-depth workup except when unusually frequent. They rarely present with severe reactions, including anaphylaxis, to blood transfusions or intravenous immunoglobulin due to the presence of IgA in these blood products. Patients have an increased susceptibility to pneumonia and recurrent episodes of other respiratory infections and a higher risk of developing autoimmune diseases in middle age. IgA deficiency and common variable immunodeficiency (CVID) feature similar B cell differentiation arrests, but it does not present the same lymphocyte subpopulation abnormalities. IgA-deficient patients may progress to panhypogammaglobulinemia characteristic of CVID.<unk>  IgA and CVID are found in the same family.
Selective immunoglobulin A deficiency
Isolated primary immunoglobulin M deficiency
Primary immunodeficiency
IgG deficiency
X-linked agammaglobulinemia
Transient hypogammaglobulinemia of infancy
Chronic granulomatous disease
Combined immunodeficiencies