RT Journal Article SR Electronic T1 Immune profiling to differentiate progressive from non-progressive non-tuberculous mycobacteria lung disease: A pilot study JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA3088 DO 10.1183/13993003.congress-2021.PA3088 VO 58 IS suppl 65 A1 Marty, Paige A1 Escalante, Patricio A1 Van Keulen, Virginia A1 Erskine, Courtney A1 Shah, Maleeha A1 Pennington, Kelly A1 Peikert, Tobias YR 2021 UL http://erj.ersjournals.com/content/58/suppl_65/PA3088.abstract AB 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.FootnotesCite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA3088.This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.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).