rates of latent tuberculosis infection using different diagnostica test

Background.The interferon 12g 12release assays (IGRA) are emerging as an attractive alternative to the tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection (LTBI).The absence of a gold standard for LTBI hampers the assessment of any diagnostic test. Methods.In a prospective study,229 patients (mean age 35.5\ub124.6 y) from different ward of the Hospital (Respiratory Diseases,Dermatology, Rheumatology, Pediatrics, Infectious Diseases, Hematology and Transplant Unit) were simultaneously tested for a suspect of either LTBI or active tuberculosis using all commercially available diagnostics: TST,QuantiFERON 12TB Gold (QFT 122G), QuantiFERON 12TB Gold In 12Tube(QFT 123G) and T 12SPOT.TB(TS.TB). Results. 42(18.3%),37(16.2%),59(25.8%) and 79(34.5%) patients were positive with TST,QFT 122G,QFT 123G and TS.TB, respectively.TS.TB(p<0.001) and QFT 123G(p=0.016) provided more positive results than TST, while no difference was found for TST and QFT 122G(p=0.53).All IGRA showed a good overall agreement (TS.TB vs QFT 122G,k=0.55; TS.TB vs QFT 123G,k=0.72;QFT 122G vs QFT 123G, k=0.62). In 22 subjects (9.6%) QFT 123G was positive and QFT 122G negative. Indeterminate results were more frequent with QFT 122G(18.3%) and QFT 123G (12.7%) than with TS.TB(1.3%,p