Immune profiling to differentiate progressive from non-progressive non-tuberculous mycobacteria lung disease: A pilot study

Abstract

Rationale: Prediction of disease progression in non-tuberculous mycobacteria lung disease (NTM-LD) remains challenging. Flow cytometric (FC) detection of activation induced markers (AIM) in T-cells after ex vivo antigen challenge in peripheral blood mononuclear cells (PBMC) can diferentiate the state of infection in tuberculosis. We aim to test if AIM immunoprofiling would also be able to accurately diagnose and differentiate progressive vs. non-progressive NTM-LD.

Methods: FC detection of AIM on antigen-stimulated T-cells was performed in PBMC, which were stimulated with mycobacteria-specific peptide pools (MTB300), PPD 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 AIM were compared between groups. We applied non-parametric statistics and ROC analysis.

Results: We studied 14 patients with NTM-LD, including 6 patients with progressive disease, and 12 TB-unexposed subjects. There were not statistical differences in age, sex, and smoking history. Significant differences in CD25+CD134+ co-expression was observed in PPD-stimulated CD4+ T-cells in NTM-LD patients vs. unexposed subjects (P<0.005; AUC-ROC = 0.84; Sens.= 78.6%; Spec.= 100%), and in MTB300-specific CD8+ CD25+CD134+ T-cells in patients with progressive vs. non-progressive NTM-LD (P<0.01; AUC-ROC = 0.92; Sens.= 100%; Spec.= 87.5%).

Conclusion: In this pilot study, AIM based immunoprofiling is able to accurately diagnose NTM-LD and differentiate progressive from non-progressive NTM-LD. We propose a longitudinal study to evaluate this novel immunoprofiling approach.