Evaluation of quantiferon microtube, using 0.9 ml blood, for diagnosing tuberculosis infection
European Respiratory Journal
Dept of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark; Dept for Infectious Diseases, University Hospital Odense, Odense, Denmark; Muhimbili Medical Research Centre, National Institute for Medical Research, Dar es Salaam, Tanzania; NIMR-Mbeya Medical Research Programme, Mbeya, Tanzania; Dept of Infectious Diseases and Tropical Medicine, Klinikum of the University of Munich, Munich, Germany; Dept of Infectious Diseases, University Hospital Hillerød, Dyrehavevej 29, DK-3400 HillerØd, Denmark
The performance of QuantiFERON microtube (QFT-MT), using 0.9 mL blood, and QuantiFERON-TB Gold in-tube test (QFT-IT) (3 mL blood), for diagnosing tuberculosis (TB) was compared in children and adults in an endemic setting. In 152 children with suspected TB and 87 adults with confirmed TB, QFT-IT was compared with two QFT-MT concentrations (QFT-MT A and B). Proportions of positive and indeterminate results, interferon (IFN)-γ responses, interassay agreement and sensitivity were assessed. We found similar proportions of indeterminate results, levels of IFN-γ and comparable sensitivity. The interassay agreement was moderate in all children (QFT-IT versus QFT-MT A: 85%, k50.44 and QFT-IT versus QFT-MT B: 88%, k=50.50) and adults (QFT-IT versus QFT-MT A: 88%, k50.50 and QFT-IT versus QFT-MT B: 89%, k=50.49). Sensitivity was low (QFT-IT 23%, QFTMT A 18% and B 19%) in children with confirmed or highly probable TB compared with adults (83%, 86% and 88%, respectively). The QFT-MT test can be reliably performed using less than one-third of the blood volume used in QFT-IT. The reduced volume may be useful for research and future diagnosis of paediatric TB. The poor sensitivity and high indeterminate rate of both IFN-c release assays in severely ill children, with immature or impaired immunity in an endemic setting, warrants further investigations. Copyright © ERS 2013.
gamma interferon; adolescent; adult; age distribution; article; blood sampling; blood volume; child; controlled study; diagnostic test; diagnostic test accuracy study; enzyme release; female; human; immunostimulation; lung tuberculosis; major clinical study; male; priority journal; QuantiFERON microtube; quantiferon tb gold in tube test; risk factor; sensitivity and specificity; tuberculin test; Adolescent; Adult; Child; Child, Preschool; Female; Humans; Infant; Interferon-gamma Release Tests; Male; Middle Aged; Reproducibility of Results; Risk Factors; Sensitivity and Specificity; Tuberculin Test; Tuberculosis; Young Adult