The goals of the present study were to evaluate serum levels of all of three isotype antibodies, IgG, IgM and IgA, specific to 38 F-64 F, in patients with active TB and in BCG-vaccinated healthy individuals, and to assess whether determination of 38 F-64 F specific antibody responses could be useful for monitoring the efficacy of chemotherapy. This evidence concerns the gene CD40LG and tuberculosis.