High Proportion of Indeterminate Qua.jpegERON-TB Gold In-Tube Results in an Inpatient Population Is Related to Host Factors and Preanalytical Steps. (19th September 2014)

• Record Type: Journal Article
• Authors: Fabre, Valeria; Shoham, Shmuel; Page, Kathleen R.; Shah, Maunank
• Is Part Of: Open forum infectious diseases. Volume 1:Number 2(2014)
• Publication Date: 2014-09-19
• Subjects: IGRA -- TB screening -- TB diagnostics; Communicable diseases -- Periodicals; Medical microbiology -- Periodicals; Infection -- Periodicals; 616.9
• DOI: 10.1093/ofid/ofu088
• Languages: English
• ISSNs: 2328-8957

Abstract

Abstract : Background. Qua.jpegERON-TB Gold In-Tube test (QFT-GIT) can be used as an alternative to tuberculin skin testing (TST) for the targeted testing of latent tuberculosis. Due to many shortcomings with TST, QFT-GIT usage is increasing. QFT-GIT implementation in the inpatient setting remains unclear. Methods. We retrospectively ide.jpegied patients admitted to a tertiary care academic center who received either a TST or a QFT-GIT in the 18 months prior to and after QFT-GIT implementation in March 2012. Risk factors associated with indeterminate results were evaluated. Results. The proportion of inpatients receiving a test for tuberculosis infection doubled following QFT-GIT implementation (1.4% vs 2.9%). After QFT-GIT became available, 75% of tested people received a QFT-GIT and 25% received a TST. We found indeterminate test results in 19.8%. Independent predictors of indeterminate results were female sex (adjusted odds ratio [AOR], 1.64), lymphopenia (AOR, 2.21), hypoalbuminemia (AOR, 6.81) and sample collection by nonphlebotomists (AOR, 3.0, vs phlebotomists). Of patients who had indeterminate results, 42% had a subsequent indeterminate result on repeat testing. All indeterminate results were due to a low mitogen response. Conclusions. QFT-GIT testing in the inpatient setting is associated with a high proportion of indeterminate results that is associated with host factors and preanalytical errors. Careful selection of patients to be tested and training on sample processing for QFT-GIT testing should be considered to decrease indeterminate results.