Kinetics of Mycobacterium tuberculosis-specific IFN-γ responses and sputum bacillary clearance in HIV-infected adults during treatment of pulmonary tuberculosis. Issue 4 (July 2015)

• Record Type: Journal Article
• Authors: Mzinza, David T.; Sloan, Derek J.; Jambo, Kondwani C.; Shani, Doris; Kamdolozi, Mercy; Wilkinson, Katalin A.; Wilkinson, Robert J.; Davies, Geraint R.; Heyderman, Robert S.; Mwandumba, Henry C.
• Is Part Of: Tuberculosis. Volume 95:Issue 4(2015)
• Page Start: 463
• Page End: 469
• Publication Date: 2015-07
• Subjects: 616.995
• DOI: 10.1016/j.tube.2015.05.009
• Languages: English
• ISSNs: 1472-9792

Abstract

<abstract xml:lang="en" abstract-type="author" id="abs0010"> <title id="sectitle0010">Summary</title> <sec> <p id="abspara0010">In HIV-uninfected adults with pulmonary tuberculosis (TB), anti-TB treatment is associated with changes in <italic>Mycobacterium tuberculosis</italic> (Mtb)-specific immune responses, which correlate with sputum bacillary load. It is unclear if this occurs in HIV-infected TB patients. We investigated changes in Mtb-specific immune responses and sputum bacillary clearance during anti-TB treatment in HIV-infected and HIV-uninfected adults with pulmonary TB. Sputum bacillary load was assessed by smear microscopy and culture. Mtb-specific IFN-γ secreting peripheral blood mononuclear cells were enumerated using an ELISPOT assay following stimulation with PPD, ESAT-6 and CFP-10. The baseline frequency of Mtb-specific IFN-γ secreting cells was lower in HIV-infected than HIV-uninfected patients (median PPD 32 vs. 104 Spot Forming Units (SFU), p = 0.05; CFP-10 19 vs. 74 SFU, p = 0.01). ESAT-6-specific IFN-γ secreting cells and sputum bacillary load declined progressively during treatment in both HIV-infected and HIV-uninfected patients. HIV infection did not influence the 2-month sputum culture conversion rate (Odds Ratio 0.89, p = 0.95). These findings suggest that changes in ESAT-6-specific immune responses during anti-TB treatment correspond with changes in sputum bacillary load irrespective of host HIV infection status. The utility of Mtb-specific IFN-γ responses as a proxy measure of treatment response in HIV-infected TB patients warrants further evaluation in other settings.</p> </sec> </abstract>