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Updated: Apr 16, 2026

Synthesis, Characterization, and Application of Superparamagnetic Iron Oxide Nanoprobes for Extrapulmonary Tuberculosis Detection
Published on: February 16, 2020
Diagnostic utility of interferon-gamma release assay in extrapulmonary tuberculosis
Jung Ar Shin1, Yoon Soo Chang2, Hyung Jung Kim2
1Division of Pulmonology, Department of Internal Medicine, G Sam Hospital, 591 Gunpo-ro, Gunpo-si, Gyeonggi-do, 435-010, Republic of Korea.
Abstract:
Early diagnosis of extrapulmonary tuberculosis (EP-TB) is essential. However, diagnosis of EP-TB is difficult. We evaluated the diagnostic utility of an interferon-gamma release assay (IGRA) in diagnosing active EP-TB among suspected patients in Korea. We retrospectively reviewed the clinical records of all patients with suspected EP-TB at Gangnam Severance Hospital in Seoul, Korea. Of the 418 patients with suspected EP-TB, 324 had active EP-TB. The tuberculosis (TB) group had a higher percentage of positive IGRAs (70.2%, 33/47) than the non-TB group (33.3%, 3/9) (P=0.034). The IGRA sensitivity and specificity were 70.2% (63.7-74.8%) and 66.7% (32.9-90.6%), respectively. The sensitivity and specificity of IGRAs in patients with TB lymphadenitis were 81.8% (61.4-90.4%) and 80.0% (35.1-98.9%), but 38.5% (31.2-45.7%) and 50.0% (2.7-97.3%) in patients with TB pleurisy. The diagnostic performance of IGRAs may vary depending on the site of EP-TB involvement. IGRA was potentially valuable for diagnosis of active EP-TB in TB lymphadenopathy.
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