Changes In Host Cytokine Patterns Of Tb Patients With Different Bacterial Loads Detected Using S-16 Rrna Analysis

BackgroundTuberculosis (TB) has overtaken HIV as the biggest infectious disease killer, with the majority of deaths occurring in sub-Saharan Africa. However it is unknown how differences in bacterial load alter host immune profiles in the sputum and blood of TB patients.MethodsS-16 ribosomal RNA analysis was used to determine bacterial load in sputum samples obtained from 173 patients with active TB (57 pre-treatment and 116 post-treatment). Host analyte concentrations in sputum and Mycobacterium tuberculosis (Mtb) antigen stimulated whole blood assay supernatants were analysed using multiplex cytokine arrays.ResultsMultiple logistic regression adjusting for age, sex and HIV status showed highly significant correlation of bacterial load with IL1 beta, IL2, IL1RA, IL4, IL6, IL8, IL9, IL15, IL17, EOTAX, FGF, IFN-gamma, GCSF, MCP1, M1P1 alpha, M1P1 beta, PDGF, TNF alpha, VEGF in sputum. With increasing time on treatment, FGF levels in sputum displayed the most significant inverse correlation with reduction in bacterial load.ConclusionsWe show that differences in bacterial load correlates with changes in several host biomarkers. These findings have implications for development of tests for TB diagnosis and treatment response.