Time-dependent IFN-γ and CXCL-10 production in tuberculosis patients after the establishment of clinical cure (164.5)

Abstract

Abstract Introduction: The immune response involved in the establishment of the clinical cure is not fully elucidated in human tuberculosis. The understanding of Th1 cytokines and chemokines role may drive the development of new therapeutic and diagnostic approaches. Objectives: The objective was to evaluate the IFN-γ and CXCL-10 production by BCG soluble antigen-stimulated PBMCs from patients with pulmonary tuberculosis. Methods: Blood samples were collected from 26 TB patients being 12 with active disease, 7 clinically cured patients with less than 12 months of treatment end and 7 with more than 12 months. PBMCs were cultured in RPMI medium alone or stimulated with 2ug/ml PHA or 10ug/ml BCG antigen. The IFN-γ and CXCL-10 production was determined in culture supernatants by ELISA. Results: The TB-treated patients showed significantly higher production of IFN-γ and CXCL-10 in all culture conditions than active disease patients. The augmented production of IFN-γ was mainly observed in clinically cured patients with more than 12 months of treatment. However, the CXCL-10 elevation was observed mainly on clinically cured patients with less than 12 months treatment. Conclusion: These results indicate that the potentiation of IFN-γ and CXCL-10 production occurs at different times after the establishment of clinical cure. This may suggest that the turn toward a Th1 immune response occur later, after clinical cure.