Antibody response in common variable immunodeficiency.

BACKGROUND: Common variable immunodeficiency (CVID) describes a heterogeneous group of immunologic disorders of unknown etiology. It is characterized by low levels of serum immunoglobulin (Ig) and impaired antibody response. OBJECTIVE: To describe antibody response and the kinetics of IgG decline in patients identified with CVID. METHODS: Clinical and immunologic observations of four patients identified with CVID were obtained by chart review. RESULTS: Antibody response to polysaccharide antigens in patients identified with CVID is lost earlier than the antibody response to protein antigens, which may be preserved even in the face of profound hypogammaglobulinemia. In three patients who were followed prospectively, the Ig loss was progressive. CONCLUSIONS: Absence of antibody response to polysaccharide antigens may be a universal finding in patients with CVID, whereas preservation of T cell-dependent protein antibody response may be seen.