AbstractAcetyl-L-carnitine (ALC), a drug for the treatment of ageing-related neuroendocrine dysfunctions, was orally administered -2 gm/day for 30 days -to 10 patients with active pulmonary tuberculosis (TBC). Lymphocyte-mediated antibacterial activity and serum levels of tumor necrosis factor (TNF)-U were evaluated before and after treatment, comparing the values with those of 10 TBC patients receiving placebo.Results show that by day 30, antibacterial activity remained unmodified or increased in ALC-treated subjects, while decreased in the placebo group. No influence of ALC on TNF-U levels was detectable.These data suggest that the host's immune responses toM. tuberculosisinfection can be selectively modulated by drugs acting on the neuroendocrine axis.