Performance of a Whole-Blood Interferon-Gamma Release Assay with Mycobacterium RD1-Specific Antigens among HIV-Infected Persons

Abstract EN

To evaluate the usefulness of one of IGRAs, QuantiFERON-TB Gold (QFT-G), in human immunodeficiency virus- (HIV- ) infected patients with various CD4+ T cell counts.

Methods.

The QFT-G assay was performed using QFT-G kits among 107 HIV-infected patients including 9 cases with active tuberculosis (TB).

Results.

In HIV-infected patients with CD4+>50/μL, QFT-G positive rate for active TB patients was 5/6 (sensitivity =83%), and that for those without active disease was 1/69 (specificity =99%).

The frequency of indeterminate QFT-G test was significantly higher in those with CD4+ less than 50/μL (P<.0001).

At the same time there was a proportional relationship between CD4+ and interferon-gamma response to mitogen (positive control) in QFT-G test (P=.0001).

Conclusions.

Our data suggested that QFT-G had high sensitivity and specificity in HIV-infected populations with CD4+ greater than 50/μL.

However, QFT-G did not perform well in HIV-positive patients with CD4+ less than 50/μL.