Abstract
Rationale: Assessment of reactivation risk for latent tuberculosis infection (LTBI) remains challenging. We previously reported a non-cytokine immunoprofiling strategy based on a flow cytometric (FC) detection of co-expression of CD25 (IL-2α receptor) and CD134 (OX40 TNFa receptor superfamily) that differentiates unexposed subjects, treated LTBI, and untreated LTBI subjects. We aim to test if an immunoprofiling based on co-expression of CD25 and PD-L1 would also be able to accurately differentiate treatment status in LTBI in a validation cohort.
Methods: FC detection of CD25+CD134+ and CD25+PD-L1+ co-expression on antigen-stimulated T-cells was performed using PBMCs samples, which were stimulated with TB-specific peptides, or control antigens. Cells were stained with fluorescent dye-conjugated antibodies and 2x105 cells were analyzed per condition. The proportions of CD3+CD4+ (and CD8+) T-cells co-expressing CD25/CD134 and CD25/PD-L1 were compared between study groups. We applied non-parametric statistics.
Results: Seventy-six subjects were studied in 2015-17, including 14 untreated LTBI and 11 treated LTBI subjects, and 26 unexposed controls. Significant differences in CD25+CD134+ and CD25+PD-L1+ co-expression was seen between TB peptides-stimulated CD4+ and CD8+ T-cells of unexposed subjects and untreated LTBI subjects (p<0.001). There was also a significant reduction in TB peptides-stimulated CD25+CD134+ and CD25+PD-L1+ T-cells in treated compared to untreated LTBI subjects (P< 0.05), but not under control conditions.
Conclusion: The strategy of non-cytokine activation immunoprofiling is capable to differentiate treatment status in LTBI, and may stratify TB reactivation risk.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 2808.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020