Enhancing Tuberculosis Diagnosis and Treatment Monitoring: Evaluating Ki67 and HLA-DR Biomarkers Via Point-of-Care Testing and Comparative Analysis of Flow Cytometry Versus ELISA in Whole Blood Samples

Introduction: Timely diagnosis and monitoring of tuberculosis (TB) remain critical challenges, especially in resource-limited settings. This study aimed to evaluate the diagnostic and treatment-monitoring utility of Ki67 and HLA-DR biomarkers in TB and to compare their quantification using flow cytometry and ELISA in whole blood samples. Methods: A total of 60 participants were enrolled, including 40 newly diagnosed TB patients and 20 healthy controls. Whole blood samples were analyzed at baseline, 2 months, and 6 months. Ki67 and HLA-DR expression were measured using both flow cytometry and ELISA. Statistical comparisons and agreement between methods were assessed using Pearson correlation and Bland-Altman analysis. Results: Both Ki67 and HLA-DR levels were significantly higher in TB patients compared with controls ( P < 0.001). Biomarker levels declined progressively with treatment. ELISA values showed strong correlation with flow cytometry ( r > 0.85), and Bland-Altman analysis demonstrated acceptable agreement with minimal bias. Conclusion: Ki67 and HLA-DR are promising biomarkers for TB diagnosis and treatment monitoring. ELISA provides a reliable, cost-effective alternative to flow cytometry, supporting its use in decentralized, point-of-care settings.