Use of soluble triggering receptor expressed on myeloid cells-1 in non-tuberculous mycobacterial lung disease

BACKGROUND: Serum biomarkers are rarely studied in patients with non-tuberculous mycobacterial lung disease (NTM-LD). OBJECTIVE: To investigate the role of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) and other inflammatory markers in NTM-LD. DESIGN: From April 2009 to March 2010, patients with NTM culture-positive respiratory specimens who were clinically and radiographically suspected of NTM-LD were evaluated for serum levels of sTREM-1, C-reactive protein, procalcitonin and interferon-gamma. RESULTS: Of the 86 patients enrolled, 60 fulfilled the diagnosis of NTM-LD. Using the receiver-operating characteristics curve analysis, serum sTREM-1 had the highest discriminative power for NTM-LD and colonisation (area under the curve = 0.714). Using a cut-off value of 180 pg/ml, the sensitivity and specificity of sTREM-1 were respectively 58% and 89%. Logistic regression analysis revealed that Mycobacterium avium complex, M. kansasii, positive sputum acid-fast smear and higher serum sTREM-1 level were independent risk factors for NTM-LD. Age ≥65 years and higher serum sTREM-1 level were associated with worse 6-month survival. CONCLUSION: In patients with respiratory specimens that are culture-positive for NTM with clinical suspicion of NTM-LD, serum sTREM-1 level measurements may be helpful in diagnosing and predicting outcome for NTM-LD.