Interferon Gamma Release Assays and Tubercolin Skin Test Performance in Different Settings of HIV Immunodeficiency

摘要

Background/Aim: HIV infection is a risk factor for re-activation of latent tubercolosis infection (LTBI). In recent years new blood tests for the detection of TB infection have been developed: Quantiferon TB Gold in Tube and TSPOT TB, which are interferon-gamma releasing assays (IGRAs), have improved the identification of LTBI. In our study we have compared IGRAs and TST in HIV-positive patients with different settings of immunodeficiency. Patients and Methods: 98 consecutive HIV patients were recruited. They underwent a blood draw, a chest radiography and a tuberculin skin test. The HIV infection setting was detected and IGRAs were carried-out. Five patients showed a complete correspondence of TST, TSPOT-TB and QFT-IT. Discordant results were observed in patients testing positive to IGRAs but negative to TST. Only 2 patients showed positive TST and negative IGRAs. Conclusion: Our study showed a poor concordance between tuberculin skin test and IGRAs, mainly in patients with a low CD4 cell count.