Common variable immunodeficiency:: more than one disease?: Three case reports.

Common variable immunodeficiency (CVID) is a major antibody-deficiency syndrome, associated with increased risk of bacterial infection, as well as autoimmune and granulomatous disease. The clinical and immunological features are heterogeneous. This heterogeneity is expressed by the case reports of three selected patients. These observations will be discussed, with reference to a recent classification of CVID distinguishing four different clinical entities: i) CVID presenting with clinical and immunological features of X-linked agammaglobulinemia; ii) CVID presenting with clinical and immunological features of X-linked hyper-IgM syndrome; iii) CVID associated with systemic granulomatous disease; and iiii) CVID associated with autoimmune manifestations.