Generation of reactive oxygen intermediates in relation to short course chemotherapy in children suffering from pulmonary tuberculosis.

Functional status of phagocytes in relation to 6 months' short course chemotherapy of tuberculosis was studied with special reference to antigen-5 (Ag-5) of Mycobacterium tuberculosis. Phagocytic capacity and overall generation of reactive oxygen intermediates (ROI) measured as chemiluminescence (CL) response was studied in peripheral blood monocytes obtained from 20 children with pulmonary tuberculosis (PTb) and was compared with 20, age and sex matched, controls. In untreated children the CL response (mean+/-SD) with latex (0.90+/-0.08) and Ag-5 (0.99+/-0.11) was found to be severely depressed compared with controls (Latex, 19.2+/-5.10; Ag-5, 48.12+/-7.10). A significant improvement was seen in response to both the stimulants (Latex, 15.20+/-1.50; Ag-5, 28.15+/-7.32) after 3 months of therapy and became equal to, or slightly higher than, the values obtained with controls by the end of therapy. This study suggests that newly diagnosed untreated PTb is associated with an in vitro antigen specific compromise of phagocytic capacity and oxidative metabolic burst activity that is gradually and progressively corrected during the course of effective short course chemotherapy. In addition, Ag-5 is a potent stimulator of monocytes/macrophages; its potency being far greater than latex.