Combined application of enzyme-linked immunospot assay, positron emission tomography, and gene chip assay in the diagnosis of a case of chronic disseminated tuberculosis / 中国医学科学院学报

ABSTRACT

<p><b>OBJECTIVE</b>To highlight the clinical features and diagnosis of chronic disseminated tuberculosis, with emphasizing the usefulness of several recently available diagnostic technologies in this setting.</p><p><b>METHOD</b>We presented a case of chronic disseminated tuberculosis diagnosed with the combined application of interferon-gamma release assay T-SPOT. TB, 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET), and gene chip assay.</p><p><b>RESULTS</b>A 53-year-old gentleman who had chronic cough for 7 years and fever for 2 weeks was referred to our hospital for further evaluation. 18F-FDG-PET/CT scan showed increased FDG uptake in multiple lesions involving bilateral lungs, supraclavicular, mediastinal and intro-abdominal lymph nodes and bones, mimicking metastatic malignancy. T-SPOT. TB assay revealed significant responses [ early secreting antigen target 6 (ESAT-6): 3 908 spot forming cells (SFCs)/10(6) peripheral blood mononuclear cells (PBMCs), culture filtrate protein (CFP-10): 3 400 SFCs/10(6) PBMCs]. Subsequent biopsy of supraclavicular lymph node, lung, and ilium revealed granulomas, while culture of the obtained tissue yeilded mycobacteria. Gene chip testing identified M. tuberculosis sensitive to isoniazid and rifampin. After 10 weeks of treatment for tuberculosis, the patient's condition was improved and a second T-SPOT. TB assay showed significantly reduced responses (ESAT-6: 1528 SFCs/10(6) PBMCs; CFP-10: 1460 SFCs/10(6) PBMCs).</p><p><b>CONCLUSIONS</b>Timely diagnosis of chronic disseminated tuberculosis requires high index of suspicion. T-SPOT. TB assay, PET/CT, and gene chip assay may provide valuable information that facilitates further diagnostic procedures and treatment decision.</p>