Specific in vitro proliferative immune responses and lymphokine productionin Ethiopian children with and without tuberculosis

of cellular immune responses in non-HIV-infected Ethiopian children and you ng adults with and without tuberculosis (TB) as compared to healthy Ethiopi an and non-Ethiopian controls. The in vitro proliferative responses of peri pheral blood mononuclear cells (PBMC) to purified protein derivative (PPD) were determined in 15 Ethiopian children and young adults with TB, 12 healt hy Ethiopian children who were contacts of TB patients, to Ethiopian childr en without contact with TB and ten non-Ethiopian controls. All TB patients and contacts had a positive Mantoux skin test. The PBMC proliferative respo nse to PPD of the Ethiopian children with TB was significantly higher than that of the Ethiopian children without TB, while all Ethiopian children dem onstrated stronger proliferative response as compared to non-Ethiopian heal thy controls. Interleukin 2 (IL-2), interferon gamma (IFN-gamma), interleuk in 4 (IL-4) and interleukin 6 (IL-6) were measured by ELISA assays performe d on the supernatant of PPD-stimulated and non-stimulated PBMC cultures of seven Ethiopian children with TB, ten Ethiopian children without TB and eig ht non-Ethiopian controls. IFN-gamma and IL-4 were undetectable and IL-2 le vels in unstimulated supernatants were low in all groups. PPD stimulation i nduced a significant rise in IL-2 levels in Ethiopians with TB as compared to all other groups. There was no increase above baseline in IL-6 levels in any group studied. Conclusions: Ethiopian children with TB exhibit a stron g cellular immune response as expressed by Mantoux tests and lack of stimul ation of IL-4 and IL-6 production. This pattern suggests a Th1 type effecti ve cellular immune response to mycobacteria in a cohort of young Ethiopians with TB.