Evaluation of CD27 Expression on Mycobacterial Antigen-Specific CD4+ T Cells as an Immunological Marker for Diagnosis of Active Pulmonary Tuberculosis

Abstract

Background: Until now, there is a need for novel tools helping the prompt diagnosis tuberculosis (TB). Objective: This study aims to explore the extent of CD27 expression on ESAT-6 & CFP-10 antigen-specific CD4+ T cells as a recent biomarker for rapid diagnosis of active pulmonary TB in Egypt. Methodology: Based on IFN-γ+ expression, ESAT-6 & CFP-10 antigen-specific CD4+ T cells were identified and the CD27 expression was analyzed for 60 M. tuberculosis-infected patients and 20 healthy controls. Results: The present data, in fact, displayed that patients with pulmonary TB had significantly lowered CD27 expression than healthy controls (P <0.001). The persistent active TB patients had much lesser percentages of CD27+ T cells than culture-positive recently infected TB patients (P =0.014) and healthy controls (P< 0.001). On evaluating the diagnostic performance of CD27 expression, it has been declared that at a cutoff value of 43.64%. CD27 had a sensitivity, specificity, positive predicted value (PPV), and negative predicted value (NPV) 86.7%, 100%, 100%, 71.4% respectively, for discrimination between patients with TB from healthy subjects. Conclusion: Thereby, proportion of CD27+ antigen-specific CD4 T cells could be used as an immunological marker for active TB.