Common Variable Immunodeficiency (CVID)

Common Variable Immunodeficiency (CVID) is a disorder that affects the body's immune system, which normally helps fight infections. People with this condition have low levels of antibodies, important proteins that protect against germs. Because of this, they often experience frequent and severe infections, especially in the lungs, sinuses, and ears. CVID can also cause problems with the digestive system and increase the risk of certain autoimmune diseases and cancers. It usually appears in adolescence or adulthood and requires ongoing medical care to manage symptoms and prevent complications.

Common Variable Immunodeficiency (CVID) is a primary immunodeficiency characterized by markedly reduced serum levels of immunoglobulins IgG, IgA, and/or IgM and impaired antibody responses to vaccines or infections. The core pathology involves defective B cell differentiation and impaired plasma cell function, often with normal or low B cell counts. The etiology is heterogeneous, with some cases linked to mutations in genes regulating immune function, but most are idiopathic. Clinically, CVID presents with recurrent bacterial infections, particularly of the respiratory and gastrointestinal tracts, along with increased risk of autoimmune disorders, lymphoproliferative disease, and granulomatous inflammation. Diagnosis is important to prevent chronic organ damage and guide immunoglobulin replacement therapy.