The Diagnostic Accuracy of the Qualitative Polyclonal Antibody Assay for Detecting an Active Pulmonary Tuberculosis, Case Control Study

Background: The accuracy of diagnostic methods in clinical trials that focus on controlling Mycobacterium tuberculosis is essential. Objective: This study aims to determine the accuracy of the polyclonal antigen cocktail in the diagnosis and follow up the pulmonary tuberculosis. Methodology: The study included 77 patients who had pulmonary tuberculosis (PTB) and 83 individuals who had never contracted tuberculosis. All PTB patients submitted sputum specimens on days 0 and 30 for diagnostic and follow-up assessments, whereas each normal participant provided a single sputum specimen. We performed microscopy with smears, Xpert MTB/RIF, solid culture, and TB antigen cocktail determination with the sputum specimens. We used the sandwich ELISA to detect the tuberculosis antigen. The receiver operating characteristic analysis determined the optimal threshold measurement for antigen absorption. Results: The accuracy of antigen cocktail for diagnosing PTB ranged between 84.0% and 100%. The zone below the ROC curve was 0.987 (98.6% CI 97.2–100). The follow-up process of PTB patients before and after treatment indicated that the antigen cocktails significantly decreased following anti-TB therapy. Conclusion: The current investigation demonstrated that the TB antigen cocktail was faster, inexpensive and a useful way to identify active pulmonary tuberculosis and predict successful therapy during a follow-up.