Snapshot A 26-year-old man with no significant past medical history presents with a prolonged period of cough and repeated sinus infections. He also reports persistent watery diarrhea. His physician orders immunoglobulin levels, which come back with decreased IgA and IgG, but normal IgM. Plasma cells are also decreased. There is no family history of immunodeficiencies. Introduction CVID is an immunodeficiency arising from B-cell dysfunction Pathogenesis unknown except that etiology is heterogeneous defect in B-cell differentiation no clear pattern of inheritance Can be acquired in young adulthood Associated conditions at increased risk for autoimmune diseases alopecia areata granulomatous diseases at increased risk for lymphoma Presentation Symptoms recurrent sinopulmonary infections permanent damage to lungs bronchiectasis persistent diarrhea Giardia lamblia Physical exam generalized lymphadenopathy splenomegaly Evaluation ↓ B-cells that produce antibodies (plasma cells) ↓ All immunoglobulin classes, especially IgA and IgG Lymph node biopsy – to exclude malignancy reactive follicular hyperplasia Differential Diagnosis X-linked agammaglobulinemia Sarcoidosis SCID Treatment IVIG replacement therapy Antibiotics Prognosis, Prevention, and Complications Complications common cause of death in patients with CVID lymphoma ~20% develop autoimmune diseases