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

Common variable immunodeficiency (CVID) is a major antibody-deficiency synd rome, associated with increased risk of bacterial infection, as well as aut oimmune and granulomatous disease. The clinical and immunological features are heterogeneous. This heterogeneity is expressed by the case reports of t hree selected patients. These observations will be discussed, with referenc e 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 immunolog ical features of X-linked hyper-IgM syndrome; iii) CVID associated with sys temic granulomatous disease; and iiii) CVID associated with autoimmune mani festations.