Comparative Performance of Flow Cytometry and ELISA for Detecting Ki-67 and HLA-DR in Whole Blood: Implications for Tuberculosis Diagnosis and Treatment Monitoring

Background This study aimed to compare the performance of flow cytometry and enzyme-linked immunosorbent assay (ELISA) in detecting Ki-67 and HLA-DR in whole blood from individuals with active TB, latent TB infection (LTBI), and healthy controls. Methods A total of 60 participants were enrolled and categorized into three groups: active TB ( n = 20), LTBI ( n = 20), and healthy controls ( n = 20). Whole-blood samples were analyzed using flow cytometry for intracellular Ki-67 and surface HLA-DR expression in T cells, and ELISA for quantification of their soluble forms. Statistical comparisons were performed using ANOVA and Pearson correlation. Results Flow cytometry revealed significantly elevated Ki-67 (12.4 ± 2.1%) and HLA-DR (18.7 ± 3.6%) expression in active TB compared to LTBI (5.6 ± 1.4%, 9.5 ± 2.1%) and controls (1.9 ± 0.7%, 3.2 ± 1.2%), respectively ( P r > 0.75, P Conclusion Flow cytometry offers high sensitivity for TB immune markers, while ELISA is a practical alternative. Ki-67 and HLA-DR are promising biomarkers for TB diagnosis and monitoring.