Triggering receptor expressed on myeloid cells (TREM)-1 is a recently described molecule that plays an important role in myeloid cell-activated inflammatory responses. The aim of this study was to investigate the evolutional change of soluble TREM-1 (sTREM-1) in bronchoalveolar lavage (BAL) fluid of clinically diagnosed ventilator-associated pneumonia (VAP) and its correlation with response to treatment and outcome.

A prospective, interventional study conducted between August 2006 and August 2007 in MICU in Mackay Memorial Hospital, 35 patients with clinically diagnosed VAP were investigated. sTREM-1 was measured in BAL samples using ELISA at the onset, 4th - 5th and 7th - 9th day of clinical diagnosis of VAP.Of these 35 patients, 27 had positive BAL culture. The sTREM-1 levels in BAL fluid were measured and compared between patients with positive BAL culture and negative BAL culture. Serial changes in sTREM-1 levels were evaluated in relation to patient outcome.

Inclusion Criteria:

• adult patients (older than 18 years)with clinically suspected VAP

Exclusion Criteria:

• mechanically ventilated patients post cardiopulmonary resuscitation
• patients with end stage diseases with life expectancy less than 3 months
• patients with solid or hematology transplantation
• patients on immunosuppressive agents

Patients who were clinically suspected to have VAP were enrolled in the study. VAP was clinically diagnosed with a new infiltrate on a chest radiograph in a patient receiving mechanical ventilation for more than 48 hr with at least one of the following: purulent tracheal secretions, a body temperature >38°C or <36°C, and leukocytosis (WBC > 10,000/mm³) or leukopenia (WBC < 4000/mm³)