Use of IFN-γ release assay in latent tuberculosis infection diagnosis in general and HTV-infected populations / 中华微生物学和免疫学杂志

ABSTRACT

Objective To assess the validity of a newly developed in-house ELISPOT IFN-γ release assay (IGRA) for the detection of latent tuberculosis infection among HIV infected individuals. Methods In-house ELISPOT assay were performed, together with a tuberculin skin test in 205 health controls and 110 HIV infected individuals , who had no signs of active tuberculosis at time of enrolment . Results Using the ELISPOT assay, positivity rates for the 205 health controls, 110 HIV infected individuals and 47 AIDS patients on highly active antiretrovial therapy (HAART) were 7. 3% , 24.5% , 29. 8% , respectively. These results indicated that the positive rates obtained from HIV infected individuals (include patient on HAART) was significantly higher than health controls( P ＜ 0.001). We found no significant correlation between the CD4 cell count and positivity of ELISPOT assay (P ＞0.05 ). The proportion of subjects with a positive response to ELISPOT assay were higher than the proportion of tuberculin skin test(TST) responders(P＜0.0001) in HIV infected individuals. Conclusion Our study indicates that IGRA using M. tuberculosis specific antigens are likely to retain their validity for the diagnosis of LTBI among HIV positive individuals.