The diagnostic performance of TB-IGRA on HIV infected patients with active tuberculosis is associated with CD4+ T-cell counts

Abstract Objective: To investigate the factors associated with the diagnostic performance of interferon-gamma release assay (IGRA) in HIV infected patients with active tuberculosis (TB). Methods: We retrospectively analyzed the data of HIV infected patients with active tuberculosis patients from 2016-2019 who conformed with the inclusion criteria and the exclusion criteria. All patients included were performed with TB-IGRA. For evaluating the diagnostic performance of TB-IGRA, patients were divided into positive TB-IGRA and negative TB-IGRA groups. And all statistical analysis was performed using SPSS Results: Performed by logistic regression analysis, we found that CD4 cell counts is independent risk factor for false negative of TB-IGRA(P<0.001). Additionally, false negative of TB-IGRA were 68.75%, 24.29% and 14.63%, respectively, in the three groups whose CD4+ T cell counts were <20/μL, 20-100/μL and >100/μL, with the highest frequency in subjects with CD4+ T cell counts <20/μL(P<0.001). And false negative of TB-IGRA were 68.75%, 27.77%, 20.58% and 14.63%, respectively, in the four groups <20/μL (n = 32), 20-50/μL (n = 36) ,51-100/μL (n = 34) and >100/μL (n = 82). The group of CD4+ T cell counts <20/μL had the highest false negative (P<0.001). There was no significant difference in the groups of 20-50/μL, 51-100/μL and >100/μL (P=0.483, P=0.623, respectively). Conclusion: The low level of CD4+ T-cell counts increase false negative TB-IGRA in HIV infected patients with active tuberculosis. These data suggest IGRA assays may have unreliable diagnostic performance results among patients with advanced HIV especially CD4+ T cell counts were <20/μL.