Regional enteritis-like enteropathy in a patient with agammaglobulinemia: histologic and immunocytologic studies.

A 24-year-old man with agammaglobulinemia developed a form of chronic inflammatory bowel disease over the past 18 years characterized by recurrent diarrhea, malabsorption, and protein-losing enteropathy. In the most recent admission he presented with abdominal cramps and active intestinal bleeding. Radiologic studies showed distal ileal irregularities and strictures that led to two distal intestinal and ileocecal resections. The gross pathologic appearance of these specimens was consistent with regional enteritis. Microscopically, healing ulcers, mucosal irregularities, and a prominent lymphocytic infiltrate without plasma cells or granulomas were observed. Immunocytochemical studies revealed a prominent T-helper cell and a modest T-suppressor/cytotoxic lymphocyte population in the lamina propria. Early and late B-cell differentiation markers were not detected in any of the cells. The immunocytologic findings suggest that T-helper lymphocytes proliferated without inhibition to stimulate non-existent B cells. The study confirms the occurrence of a regional enteropathy-like lesion in the total absence of B-cell function.