Role of the interferon-gamma assay in the diagnosis of active tuberculosis

Abstract number: P1837

Losi M., Fabio A., Meacci M., Luppi F., D'Amico R., Del Giovane C., Roversi P., Apice M., Meccugni B., Fabbri L.M., Richeldi L., Rumpianesi F.

Objectives: Diagnosis of pulmonary (pTB) and extra-pulmonary (eTB) active tuberculosis might be difficult when standard microbiological methods are negative, in particular in extra-pulmonary cases. Data are not completely consistent across different studies: the new interferon-gamma release assays (IGRA) might improve the diagnosis of active TB.

Methods: In a multicenter study, we retrospectively evaluated 87 patients with culture-confirmed active TB (77.0% pTB, 23.0% eTB) tested with QuantiFERON-TB Gold In-Tube (QFT-IT) (Cellestis Ltd, Carnegie, Australia). Most patients were male (62.1%), mean age was 40.7±19.0 years: 65 (74.7%) subjects were foreign-born. All QFT-IT assay were performed before initiation of anti-TB treatment.

Results: Indeterminate QFT-IT were 11.9% in pTB and 5.0% in eTB: the test was positive in 71.6% of pulmonary and 80.0% of extra-pulmonary patients (p=ns). IFN-g levels were similar in the two groups (4.6 pTB vs 7.0 eTB UI/ml, p=ns). Interestingly, 14 patients (16.1%) had determinate negative QFT-IT: 11 (78.5%) had pulmonary disease.

Conclusions: These preliminary data indicate that QFT-IT might be a reliable tool in diagnosing active TB, both in pulmonary and extra-pulmonary cases, in routine clinical practice.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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