Common Variable Immunodeficiency (CVID)

Common variable immunodeficiency disorder (CVID) is diverse, both in its clinical presentation and in the types of deficiency. It is a primary humoral immunodeficiency disorder characterized by reduced serum levels of immunoglobulin G (IgG) and immunoglobulin A (IgA) or immunoglobulin M (IgM), recurrent sinopulmonary infections, autoimmune disorders, granulomatous diseases, enhanced risk of malignancy, and impaired antibody response despite the adequate number of B cells.It is the most frequent symptomatic primary immunodeficiency disorder worldwide. Rather than a disease, it is a collection of hypogammaglobulinemia syndromes resulting from various genetic defects (almost all of them are specific molecular defects with as yet an unknown cause), named “variable” because of its heterogeneous clinical manifestations.