Peripheral T lymphocytes and their subsets in cutaneous tuberculosis.

Fifty-four patients with cutaneous tuberculosis, consisting of 23 with lupus vulgaris, 22 with scrofuloderma, and nine with verrucosa cutis, were investigated for cell-mediated immunity, through estimation of peripheral total T lymphocytes (CD3+), CD4+ (helper/inducer), and CD8+ (cytotoxic/suppressor) lymphocytes, by immunohistochemical staining of peripheral blood smears, using specific monoclonal antibodies and the alkaline phosphatase-antialkaline phosphatase (APAAP) method. Absolute values of total T lymphocytes (CD3+), and CD4+ and CD8+ subsets, were found to be significantly raised in scrofuloderma, but the percentage values and the CD4+/CD8+ ratio remained unaltered. In tuberculosis verrucosa cutis, only the percentage of the CD8+ subset of T lymphocytes was found to be significantly lowered, and this altered the CD4+/CD8+ ratio. No significant change was observed in the peripheral blood T cells and their subpopulations in patients suffering from lupus vulgaris.