Abnormalities of the intestinal immune system in AIDS.

Significant abnormalities in the distribution of lymphocyte subsets have been noted in the intestinal mucosa of ARC and AIDS patients. Abnormalities are most striking among the CD4 helper-inducer T-cell subset and likely reflects the direct effects of HIV infection of those cells. A deficiency in CD4-positive T cells in the intestinal mucosa potentially could result in significant abnormalities in mucosal immune function, including defects both in cell-mediated immunity and in the secretory IgA system. Such alterations in mucosal immunity and mucosal defense may render AIDS and ARC subjects susceptible to enteric infections and systemic infections in which the intestinal tract is the portal of entry.