T4 lymphopenia in patients with active pulmonary tuberculosis

The numbers of cells bearing the T3 (pan-T cell), the T4 (putative helper/inducer cells), the T8 (putative suppressor/cytotoxic cells) and B cell phenotypic markers were counted in venous blood samples from 26 newly diagnosed pulmonary tuberculosis patients and 29 healthy controls from East Java. The absolute T cell count was lower in the patients and T4 cells were fewer in patients (mean 748/mm3) than in controls (mean 1,043/mm3), but there were no significant differences in total T8 cell and B cell counts between patients and controls. The T4:T8 ratio was not disturbed in many patients, but it was less than 1.6 in 11 of 26 patients and in only three of 29 controls: this ratio was less than 1.2 (the lower limit of 'normal') in six patients but no controls. The intensity of the T4 lymphopenia was unrelated to the extent of the lesion seen radiologically or the size of the skin test reaction to PPD. Levels of interferon-alpha were not elevated in the serum of any of the patients or controls. It is suggested that the T4 lymphopenia was a reaction to the mycobacterial infection and not a manifestation of underlying secondary (acquired) immune deficiency.