ABSTRACT
1. The purpose of the present study was to evaluate the intestinal secretory immunity of HIV-infected patients. Jejunal biopsies were obtained with a Watson capsule from 52 HIV-infected patients and compared to a control group consisting of 12 healthy subjects, matched for age and sex. IgA- and IgM-containing plasma cells were studied by immunofluorescence by two independent observers who had no knowledge of the history of the slides. 2. The IgA and IgM plasma cell density was significantly decreased in HIV-infected patients when compared to the controls (31/52 for IgA and 42/52 for IgM in the HIV group and normal density in all controls). The depletion of intestinal plasma cells was an early feature of HIV disease and did not correlate with diarrhea, enteropathogens or mucosal atrophy. Although IgA plasma cell depletion has been described in HIV infection, this is the first report of IgM cell density reduction. 3. A peripheral fluorescence pattern was observed in the intestinal cells of HIV-infected patients, contrasting with the normal cytoplasmic fluorescence pattern seen in controls. The cells presenting a rim of peripheral fluorescence in HIV disease might correspond to immature B lymphocytes. 4. The intestinal plasma cell depletion may result in hampered mucosal defense in HIV disease, and is likely to be a direct consequence of T lymphocyte function impairment. 5. The data indicate that the intestinal secretory immune system is altered in AIDS and also in the early stages of HIV disease.