Cellular responses to MPT-51, GlcB and ESAT-6 among MDR-TB and active tuberculosis patients in Brazil

Multi-drug resistant pulmonary tuberculosis (MDR-TB) may result from either insufficiency of the host cellular immune response or mycobacterial. mechanisms of resistance. Mycobacterium tuberculosis-specific CD8(+) and CD4(+) T lymphocytes from MDR-TB patients are poorly studied. The aim of this study was to evaluate CD4(+)-IFN-gamma(+), CD4(+)-IL-10(+), CD8(+)IFN-gamma(+) and CD8(+)IL-10(+) cell populations by flow cytometry in non-resistant TB and multi-drug resistant tuberculosis (MDR-TB) patients from mid-central Brazil after stimulation with MPT-51, GlcB and ESAT-6 recombinant antigens from M. tuberculosis in comparison to tuberculin skin test negative (TST) healthy individuals. Non-resistant TB patients present specific cellular responses (CD4 and CD8, both IFN-gamma and IL-10) to GLcB, MPT-51 and ESAT-6; while MDR-TB patients present only CD8(+)IFN-gamma(+) responses to ESAT-6 and CD8(+)IL-10(+) responses to GlcB and ESAT-6. The results show that MDR-TB patients present impaired specific CD4 IFN-gamma and IL-10 responses and increased/normal specific CD8 IFN-gamma and IL-10 responses. This suggests an important role for CD8 function in these patients. (c) 2008 El.sevier Ltd. All rights reserved.