Background: CyTOF (cytometry by time-of-flight) enabled more comprehensive view of the cellular landscape through the simultaneous analysis of multiple markers. We performed CyTOF analysis using peripheral blood mononuclear cells (PBMCs) to compare differential immune cellular profile between active tuberculosis (TB) and latent TB infection (LTBI).

Methods: Subjects with active pulmonary TB and LTBI were prospectively included. Cryopreserved PBMCs of them were analyzed using CyTOF and flow cytometry.

Results: A total of 51 patients (active TB [n=34] and LTBI [n=17]) were included. Initial analysis by CyTOF of 16 subjects with LTBI (n=8) and active TB (n=8) identified a significantly higher CD3+CD4+CD196+Th17 like cell population in those with active TB than in those with LTBI. This finding was verified by flow cytometry analysis performed in additional 35 individuals revealing a higher percentage of CD3+CD4+CD196+CD183-CD194+ Th17 cell population in active TB (p=0.032). Th1/Th17 ratio represented good ability to discriminate between active TB and LTBI (AUC=0.812). Additionally, Th17 cell percentage positively correlated with the level of IL-6 and neutrophil-lymphocyte ratio, respectively.

Conclusions: CyTOF analysis showed a higher Th17 cell percentage in active TB than in LTBI. Further research is needed to verify this finding in a larger population.