[Common variable immunodeficiency (author's transl)]

In a boy initially diagnosed as X-linked hypogammaglobulinemia, the later clinical and analytical course and the application of new immunological techniques led to the new diagnosis of common variable immunodeficiency. The patient shows panhypogammaglobulinemia, a scarce number of plasma cells with a normal number of precursors and circulating B lymphocytes with membrane bound immunoglobulins and C3 receptors. Delayed hypersensitivity is absent despite normal amount of circulating T lymphocytes which were able to transform when stimulated by PHA. The anergy seems primary and not related to the clinical malnutrition. The authors make a differential diagnosis between both illnesses as a tentative pathogenetic interpretation of B cell development arrest.