PURPOSE:To investigate the potential role of serum and alveolar soluble triggering receptor expressed on myeloid cells (sTREM-1) as a biological marker of pulmonary aspiration syndromes.
METHODS:Blood and bronchoalveolar lavage (BAL) fluid samples were collected on enrollment of seventy-five patients with pulmonary aspiration and 13 controls receiving mechanical ventilation in a prospective cohort study.Soluble TREM-1 levels were measured by an enzyme-linked immunosorbent assay.
RESULTS:Thirty-eight of 75 participants had documented BAL culture-positive pulmonary aspiration. While circulating levels of sTREM-1 were comparable between those with aspiration syndromes(19.81± 12.09 pg/ml) and controls (15.96± 11.16 pg/ml)(p = 0.27), the alveolar levels of sTREM-1 were higher in patients with culture-positive pulmonary aspiration (344.41± 152.82 pg/ml) compared with those culture-negative pulmonaryaspiration (142.76± 89.88 pg/ml; p < 0.001). A cut-off value of250 pg/ml for alveolar sTREM-1 achieved a sensitivity of 65.8%(95% CI 48.6–80.4) and a specificity of 91.9% (95% CI 78.1–98.2) with an area under the curve of 0.87 (95% CI 0.78–0.94).
CONCLUSION:Alveolar sTREM-1 levels can be a potential biomarker for distinguishing BAL culture-positive from BAL culture negativepulmonary aspiration.
CLINICAL IMPLICATIONS:In the absence of an accurate and valid marker to distinguish“aspiration pneumonia” with resultant bacterial pneumonia from non-bacterial “aspiration pneumonitis,” the majority of patients with the diagnosis of pulmonary aspiration receive antimicrobial therapy when treatment is indicated only for those with infectious pneumonitis.Alveolar sTREM-1 may be useful in separating infectious from noninfectious pulmonary aspiration and reduce injudicious antibiotic use.
DISCLOSURE:Ahmad Alhajhusain, No Financial Disclosure Information; No Product/Research Disclosure Information