CD4 and tuberculosis: As cell-mediated immunity (CD4 T-helper-response and interferon (INF)-gamma) play an essentialrole in M. tuberculosis infection [28, 29], anyimpairment in T cell proliferation due to reduced leptinconcentrations may contribute to the development of tuberculosis.In our patient group, both before and after treatment, leptinlevels were suppressed, supporting the concept that leptininduction represents a protective component of the immune responsein pulmonary tuberculosis.