CD4 and tuberculosis: In contrast, our data suggested that QFT-G had high sensitivity and specificity in HIV-infected populations with CD4+ T cell count greater than 50/μL. However, neither test performed well in HIV-positive patients with CD4+ T cell count less than 50/μL. Therefore, care should be taken when interpreting negative or indeterminate QFT-G results in HIV-infected patients with CD4+ T cell count less than 50/μL. Further studies in HIV-infected people are required to accumulate more QFT-G performance data in active TB patients in developed countries.