Immunohistology of tuberculous adenitis in symptomatic HIV infection

Monoclonal antibodies and immunoperoxidase staining were used to characterize the cellular subpopulations in lymph nodes from 10 patients with tuberculous lymphadenitis, seven of whom had symptomatic human immunodeficiency virus (HIV) infection. CD4+ cells were significantly fewer in nodes of patients with HIV infection than in those of immunocompetent patients. CD8+ cells were distributed throughout the granuloma in patients with HIV infection, but confined to the periphery in normal hosts. Blastoid Ta1+ cells, putatively antigen-reactive T lymphocytes, were seen in immunocompetent patients but not in those with HIV infection, suggesting that these cells fail to mature appropriately in the latter group. The immunopathological features noted above provide preliminary evidence that the cell-mediated immune response to tuberculosis is abnormal in patients with HIV infection, and may in part explain both the severe and the unusual manifestations of tuberculosis in these individuals.