Clinical utility of interferon-? releases assay (IGRAs) in new and retreated cases of Pott�s disease at a tertiary care hospital

Abstract

Event Abstract Back to Event Clinical utility of interferon-γ releases assay (IGRAs) in new and retreated cases of Pott’s disease at a tertiary care hospital MANOJ KUMAR1, Raj Kumar1*, Arun Srivastava1, V. L. Nag2, ANAND K. MAURYA2, Nrendra Krishnani3 and Sunil G. Babu4 1 Sanjay Gandhi Post Graduate Institute of Medical Sciences, Neurosurgery, India 2 Sanjay Gandhi Post Graduate Institute of Medical Sciences, Microbiology, India 3 Sanjay Gandhi Post Graduate Institute of Medical Sciences, Pathology, India 4 Babasaheb Bhimrao Ambedkar University, Lucknow,India, Biotechnology, India Objective: Interferon-γ release assay (IGRAs) promised a sensitive and specific diagnosis of latent and active infection of Mycobacterium tuberculosis(M.tb). Therefore, the intent of this study was to appraise the clinical usefulness of Quantiferon-Gold in Tube (QFT-GIT) for diagnosis of M.tb infection of Pott’s disease. Method: We prospectively observed 55 clinical-radiological suspected cases of Pott’s disease. They were undergone to the detection of tubercular infection and Acid fast bacilli, on QFT-GIT followed by microscopy, culture and histopathological methods. The significance was observed between new and retreated cases. The sensitivity and specificity of QFT-GIT was calculated against the combined results of all performed tests were carried out. Results: Patients were classified into 2 groups. Group A: 24 (43.6%) were new cases and Group B: 31 (56.4%) were retreated cases. The diagnostic efficiency among group A and B were; 21(87.5%) and 19(61.3%) on QFT-GIT, 10(42%) and 10(32.2%) on microscopy, 14(58.3%) and 13(54%) on culture, 21(87.5%) and 18(58%) on histopathology were analyzed. The significant differences (pvalue <0.05) among group A and B were found by QFT-G IT and histopathology results. Moreover, we found 45 cases as a definite TB and 10 cases were negative by performed tests; on microscopy, culture and histopathology observations. Thus, the overall sensitivity was 84% and 80% specificity calculated for QFT-GIT respectively. Conclusion:QFT-GIT revealed higher sensitivity in new cases with significant differences of retreated cases. Despite, QFT-GIT showed notable sensitivity and specificity against combined results of laboratory proven methods. Hence, we can use in routine clinical diagnosis of Pott’s disease. Acknowledgements The present study was financially supported by an Intramural project from Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India (PGI/DIR/RC/200/2008). Manoj Kumar gratefully acknowledges the University Grants Commission, Government of India (UGC), New Delhi, for RGNF grant no. F-142 (SC) 2008 (SA III).Author also thankful to Miss Shruti Bajpai for her technical assistance.