Isolated IgA Deficiency

Overview
  • Isolated IgA Deficiency is caused by an unknown molecular defect that leads to inability of IgA-subtype B-cells to mature into IgA-secreting Plasma Cells. Thus, although the levels of peripheral IgA-subtype B-cells are normal, they simply cannot differentiate into antibody-secreting Plasma Cells, thus resulting in a selective IgA hypogammaglobulinemia. Isolated IgA Deficiency may represent a subtype of Common Variable Immunodeficiency.
Clinical Consequences
  • Most patients with this disease are thought to be completely asymptomatic. When symptoms do arise, they manifest as an infection susceptibility to sinopulmonary infections as well as gastrointestinal infections consistent with reduced mucosal immunity. Consequently, these patients suffer from recurrent URIs, pneumonia, bronchitis leading to bronchiectasis, and infectious diarrhea. When giving blood transfusions to these patients one must be careful of inducing anaphylaxis as they may possess preformed anti-IgA antibodies.
Incidence
  • Isolated IgA Deficiency is the most common primary immundeficiency and occurs in roughly 1 of 700 individuals.