1684Diagnostic usefulness of IFN-gamma releasing assays in patients with disseminated tuberculosis compared with conventional tests

Background. Rapid diagnosis and treatment for disseminated tuberculosis (TB) are important prognostic factors for patients with disseminated TB. Recently, IFNgamma releasing assay (IGRA) shows promising results for diagnosis of TB. However, little is known about the usefulness of these assays for diagnosing disseminated TB. We therefore evaluated their usefulness compared with traditional tests in patients with disseminated TB. Methods. All adult patients with suspected disseminated TB were prospectively enrolled at a tertiary hospital in an intermediate TB-burden country during a 6-year period. Disseminated TB was defined as the involvement of bone marrow, ≥ 2 noncontiguous organs, or the presence of miliary lung lesions. Results. A total of 101 patients with confirmed and probable disseminated TB were finally analyzed. Of these 101 patients, 52 (52%) were miliary TB and the remaining 49 (48%) were non-miliary disseminated TB. The 29 (29%) patients including 6 HIV patients had immunosuppressive conditions. T-SPOT.TB assay was positive in 90% (91/101). The sensitivity of T-SPOT.TB assay in patients with miliary TB (90%) was similar to that in those with non-miliary TB (90%)(p > 0.99). In the subgroup analysis including the 58 patients in whom both QFT-GIT and T-SPOT.TB were available, the sensitivity of QFT-GIT (67%) showed a trend of being lower than that of T-SPOT.TB (90%). Result of diagnostic test for disseminated TB