Introduction: Mycobacterium tuberculosis, the prime etiological factor of Tuberculosis (TB), latently infects almost 33% of the global population. It is further buoyed by the emerging multidrug resistance and human immunodeficiency virus type I (HIV-1) pandemic, necessitating the development of novel control measures and stratagems for its specific diagnosis and prognosis. Although tuberculin skin test (TST) is the first choice for detecting latent Mycobacterium tuberculosis infection (LTBI), it cannot be regarded as the gold standard as it randomly gives false implication of the test and there is eccentric variation in its interpretation.
Objective: The current study was designed to assess the degree of sensitivity and specificity of IFN-c as QuantiFERON-TB Gold In-Tube (QFT-Gold IT) assay in the diagnosis of TB as compared to the TST.
Subjects and methods: The students from medical and paramedical students at Umm Al-Qura University were selected in the study and all selected students entered into the study before the commencement of their internship program. Pre-internship: A total of 47 blood samples were collected from medical and paramedical students at Umm Al-Qura University. Post-internship: On follow up after the internship program we managed to get back only 36 subjects of the 47, due to the unavailability of the subjects due to unanticipated reasons.
Results: Out of the 47 samples tested by ELISA test using QFT-Gold IT and TST, none of pre-internship subjects were positive in either of the test, however, of the 36 post-internship students only 1 (2.8%) tested positive in both tests.
Conclusion: In this study, the two tests, QFT-Gold IT and TST were found to be 100% correlated and it was found that QFT-Gold IT with remarkable sensitivity and specificity which is equivalent to that of the TST. Moreover, QFT-Gold IT is impervious to BCG vaccination and other similar variables but not TST. Since, the current study was only a pilot study and the sample size were very small, hence, further studies need to be done to determine the true sensitivity and specificity of the QFT-Gold IT.