Surface triggering receptor expressed on myeloid cells 1 expression patterns in septic shock

Objective: To analyze the pattern of cell-surface expression of the triggering receptor expressed on myeloid cells (TREM) 1 during septic shock. Design and setting: Prospective clinical study in an adult 16-bed medical ICU. Patients and methods: 25 septic shock patients, 15 patients with shock of noninfectious origin and 7 healthy volunteers. Arterial blood was drawn within 12 h of admission and subjected to flow cytometry analysis after staining with anti-TREM-1 and anti-CD14 antibodies. Repeated sampling was performed on days 2, 3, 5, 7, and 14 in septic shock patients. Results: Monocytic TREM-1 expression was significantly higher in septic shock patients (mean fluorescence intensity 2.3 +/- 0.2) than in nonseptic patients (1.0 +/- 0.1), and healthy volunteers (1.0 +/- 0.1). There was no difference in monocytic TREM-1 expression between nonseptic patients and healthy volunteers or between any of the three groups with respect to TREM-1 expression on neutrophils. The time course of TREM-1 expression on monocytes diverged significantly by day 3 between survivors and ns. Conclusions: The specificity of TREM-1 regulation by infection is highlighted. Moreover, surface TREM-1 expression on monocytes may prove useful in allowing the follow-up of septic patients during the course of the disease.