[Common variable immunodeficiency and its association with memory B-cell defects].

Common variable immunodeficiency (CVID) is the most common symptomatic immunodeficiency in adulthood. CVID diagnosis is by exclusion and should be considered in patients of any age who have hypogammaglobulinemia of unknown origin. Numerous patients with CVID show alterations in the development of B lymphocytes, both in plasma cells and memory cells. The absence of memory B cells suggests an insufficient germinal reaction, which can be associated with a blockade of the transition of T1 cells into T2 in patients with IDCV, owing to B-cell activating factor (BAFF) receptor deficiency. In patients with IDCV, memory B cell alterations with isotype change favor the development of concomitant comorbidities such as lymphadenopathy, splenomegaly, autoimmunity and granulomatous disease, and multiple classifications that use memory B cells in common have therefore been made trying to generate a classification of patients with IDCV, as well as to establish prognostic factors.