Improved sensitivity of an interferon-gamma release assay (T-SPOT.TB) in combination with tuberculin skin test for the diagnosis of latent tuberculosis in the presence of HIV co-Infection

Publikation

Improved sensitivity of an interferon-gamma release assay (T-SPOT.TB) in combination with tuberculin skin test for the diagnosis of latent tuberculosis in the presence of HIV co-Infection

Wissenschaftlicher Artikel/Review - 15.11.2011

Elzi Luigia, Bassetti Stefano, Bernasconi Enos, Hoffmann Matthias, Hirschel Bernard, Cavassini Matthias, Fehr Jan, Furrer Hansjakob, Steffen Ingrid, Battegay Manuel

Zitation

Elzi L, Bassetti S, Bernasconi E, Hoffmann M, Hirschel B, Cavassini M, Fehr J, Furrer H, Steffen I, Battegay M. Improved sensitivity of an interferon-gamma release assay (T-SPOT.TB) in combination with tuberculin skin test for the diagnosis of latent tuberculosis in the presence of HIV co-Infection. BMC Infect Dis 2011; 11:319.

Art

Wissenschaftlicher Artikel/Review (Englisch)

Zeitschrift

BMC Infect Dis 2011; 11

Veröffentlichungsdatum

15.11.2011

eISSN (Online)

1471-2334

Seiten

319

Kurzbeschreibung/Zielsetzung

ABSTRACT: BACKGROUND: Interferon-gamma release assays (IGRA) are more specific than the tuberculin skin test (TST) for the diagnosis of Mycobacterium tuberculosis infection. Data on sensitivity are controversial in HIV infection. METHODS: IGRA (T-SPOT.TB) was performed using lymphocytes stored within 6 months before culture-confirmed tuberculosis was diagnosed in HIV-infected individuals in the Swiss HIV Cohort Study. RESULTS: 64 individuals (69% males, 45% of non-white ethnicity, median age 35 years (interquartile range [IQR] 31-42), 28% with prior AIDS) were analysed. Median CD4 cell count was 223 cells/ul (IQR 103-339), HIV-RNA was 4.7 log10 copies/mL (IQR 4.3-5.2). T-SPOT.TB resulted positive in 25 patients (39%), negative in 18 (28%) and indeterminate in 21 (33%), corresponding to a sensitivity of 39% (95% CI 27-51%) if all test results were considered, and 58% (95% CI 43-74%) if indeterminate results were excluded. Sensitivity of IGRA was independent of CD4 cell count (p=0.698). Among 44 individuals with available TST, 22 (50%) had a positive TST. Agreement between TST and IGRA was 57% (kappa=0.14, p=0.177), and in 34% (10/29) both tests were positive. Combining TST and IGRA (at least one test positive) resulted in an improved sensitivity of 67% (95% CI 52-81%). In multivariate analysis, older age was associated with negative results of TST and T-SPOT.TB (OR 3.07, 95% CI 1,22-7.74, p=0.017, per 10 years older). CONCLUSIONS: T-SPOT.TB and TST have similar sensitivity to detect latent TB in HIV-infected individuals. Combining TST and IGRA may help clinicians to better select HIV-infected individuals with latent tuberculosis who qualify for preventive treatment.