EL-Deeb, M., EL Malwany, H., Khalil, Y., Mourad, S. (2014). Interferon Gamma Release Assays (IGRA) in the Diagnosis of Active Pulmonary Tuberculosis. Journal of High Institute of Public Health, 44(1), 33-40. doi: 10.21608/jhiph.2014.20355
Mona EL-Deeb; Hatem EL Malwany; Yehia Khalil; Saher Mourad. "Interferon Gamma Release Assays (IGRA) in the Diagnosis of Active Pulmonary Tuberculosis". Journal of High Institute of Public Health, 44, 1, 2014, 33-40. doi: 10.21608/jhiph.2014.20355
EL-Deeb, M., EL Malwany, H., Khalil, Y., Mourad, S. (2014). 'Interferon Gamma Release Assays (IGRA) in the Diagnosis of Active Pulmonary Tuberculosis', Journal of High Institute of Public Health, 44(1), pp. 33-40. doi: 10.21608/jhiph.2014.20355
EL-Deeb, M., EL Malwany, H., Khalil, Y., Mourad, S. Interferon Gamma Release Assays (IGRA) in the Diagnosis of Active Pulmonary Tuberculosis. Journal of High Institute of Public Health, 2014; 44(1): 33-40. doi: 10.21608/jhiph.2014.20355
Interferon Gamma Release Assays (IGRA) in the Diagnosis of Active Pulmonary Tuberculosis
1Chemical Pathology Department, Medical Research Institute, Alexandria University, Egypt
2Chest Diseases Department, Faculty of Medicine, Alexandria University, Egypt
Abstract
Background: Tuberculosis is one of the deadliest diseases over the world. Diagnosis of pulmonary TB depends on combination various parameters. IGRA measure T cell release of IFN-γ in response to M.TB antigen. WHO policy statement as on IGRA use in low and middle income countries is not established yet. Objective: The present study aimed to compare between tuberculin skin test (TST) and interferon gamma release assay (IGRA) in the diagnosis of active tuberculosis infection and study the effect of 3 months of first line anti-TB therapy on the positivity of the IGRA test. Methods: 40 Egyptian patients were included in the study, and assigned as two groups; Group I comprised 20 patients with negative sputum for AFB by Ziehl-Neelsen stains with positive sputum culture for M.TB and Group II included 20 patients with positive sputum and Ziehl-Neelsen for AFB before and after 3 months of first line of anti-TB therapy. All patients were subjected to full history taking, clinical examination, X- ray chest, lab investigations, ESR measurements, microbiological tests and ELISA measurement of Quantiferon-TB Gold. Results: Lower significant values were found in group II after treatment than before treatment regarding clinical parameters and 1st and 2nd hours ESR. IGRA test and TST showed sensitivity (91.18%, 76.4%), specificity (83.33%, 66.67%), positive predictive value (96.88%, 92.86%), negative predictive value (62.5%, 33.3%) and accuracy of (90%, 75%) respectively. IGRA results had no statistical significant differences between the studied groups with poor agreement with TST ((κ) = 0.025). Conclusion: IGRAS test had high sensitivity and specificity in diagnosis of active TB. More studies are needed to evaluate the effect of anti-TB therapy on IGRA level.