Common Variable Immunodeficiency
- Common Variable Immunodeficiency (CVID) is probably a heterogeneous group of disorders due to distinct molecular defects. The common etiological theme is some type of block in late stage B-cell Development leading to an absence of Plasma Cells and thus hypogammaglobulinemia which may affect all or specific antibody isotypes. Thus, although although diverse classes of isotype-switched B-cells exist in the periphery, they cannot properly differentiate into antibody-secreting Plasma Cells. Given the similar etiologies and frequent familial clustering, Isolated IgA Deficiency may be a subtype of CVID.