ABSTRACT
Introduction: Control of TB depends on early detection and treatment of active cases
Aim of the work: Investigating the utility, sensitivity and specificity of interferon gamma inducible protein IP-10 in both blood and bronchoalveolar lavage [BAL] in the diagnosis of TB infection in clinically suspected patients
Methods: Thirty patients with clinical and/or radiological suspicion of pulmonary tuberculosis and negative sputum smear for AFB with Z-N stain were included in the study. BAL and blood samples were sent for the estimation of the level of interferon gamma inducible protein IP-10
Results: IP-10 levels in both blood and BAL were significantly higher in TB patients [P = 0.005 and 0.007 respectively]. Sensitivity of IP-10 in blood was 100% and specificity was 60%. Positive predictive value was 56%, negative predictive value was 100% and accuracy was 73%. Sensitivity of IP-10 in BAL was 100% and specificity was 35%. Positive predictive value was 44%, negative predictive value was 100% and accuracy was 57%. Sensitivity of IP-10 in blood and BAL were similar [100%] and both were more sensitive than tuberculin skin test [TST] [sensitivity 67%]. Detection of IP-10 in blood [specificity = 60%] was more specific than its detection in BAL [specificity = 35%]. On the other hand, specificity of detection of IP-10 in blood [60%] was comparable to the tuberculin test [specificity = 62%]
Conclusion: Interferon gamma inducible protein IP-10 may help in detecting M. tuberculosis infection and monitoring disease activity and efficacy of therapy