Performance of whole-blood interferon-gamma release assay in patients admitted to the emergency department with pulmonary infiltrates.

Abstract

BACKGROUND:

This study was conducted to evaluate the performance of a whole-blood interferon-gamma release assay in inpatients who were admitted to the emergency department (ED) with pulmonary infiltrates who required a differential diagnosis with pulmonary tuberculosis (TB).

METHODS:

The patients with pulmonary infiltrates who received a QuantiFERON (QFT) test in the ED were included as an inpatient group and were divided into TB and non-TB group based on the final diagnosis. Patients with pulmonary TB who were tested in the outpatient department served as a control group.

RESULTS:

In total, 377 QFT tests were analyzed. Of the 284 inpatient QFT tests, 29.6% had an indeterminate result (35.2% in the 196 patients with non-TB and 17.0% in the 88 patients with TB). In contrast, only 1.1% of the 93 outpatients with TB returned an indeterminate result (p<0.001). The indeterminate QFT results in the inpatient group were independently associated with lymphocytopenia, hypoalbuminemia, and high C-reactive protein levels. Non-positive QFT results in inpatients with TB were associated with lymphocytopenia and hypoalbuminemia, while non-positive QFT results in outpatients with TB were associated with high erythrocyte sedimentation rates and radiographically more severe diseases.

CONCLUSIONS:

QFT tests in ED-based inpatients with pulmonary infiltrate return indeterminate results relatively frequently. In addition, inpatients and outpatients with pulmonary TB may differ in terms of the risk factors on non-positive QFT results.

• Authors: Yoon Jee Lee, Jaehee Lee, Yi Young Kim, Dong Il Won, Seung Ick Cha, Jae Yong Park, Tae Hoon Jung, Chang Ho Kim
• Journal: BMC infectious diseases (BMC Infect Dis) Vol. 11 Pg. 107 (Apr 24 2011) ISSN: 1471-2334 [Electronic] England
• PMID: 21513568 (Publication Type: Evaluation Study, Journal Article)

Chemical References

• Reagent Kits, Diagnostic
• Interferon-gamma

Topics

• Adult
• Aged
• Aged, 80 and over
• Diagnostic Techniques and Procedures (instrumentation)
• Emergency Service, Hospital
• Female
• Humans
• Interferon-gamma (blood)
• Interferon-gamma Release Tests
• Male
• Middle Aged
• Mycobacterium tuberculosis (immunology)
• Outpatients
• Prospective Studies
• Reagent Kits, Diagnostic
• Tuberculosis, Pulmonary (blood, diagnosis, immunology)