Time-course of sTREM (soluble triggering receptor expressed on myeloid cells)-1, procalcitonin, and C-reactive protein plasma concentrations during sepsis

Gibot S, et al. Crit Care Med 2005;33:792-796

Introduction

The triggering receptor on myeloid cells (TREM-1) a member of the immunoglobulin superfamily, the expression of which is up-regulated on phagocytic cells in the presence of bacteria or fungi. The aim of the current study was to investigate the time course of plasma levels of (soluble) sTREM-1, C-reactive protein (CRP) and procalcitonin (PCT) in patients with sepsis and to compare their predictive value on outcome.

Study

The population studied consisted of a cohort of 40 patients enrolled in a previously published study and included an additional 23 patients. All patients presented with a clinical suspicion of infection and at least two SIRS criteria. Immune compromised patients or those older than 80 were excluded. Plasma concentrations of sTREM-1, CRP and PCT were taken within 12 hours after admission and on days 0, 2, 5, 7 and 14.

Baseline plasma CRP was comparable in the survivors and the non-survivors whereas PCT levels were higher and sTREM-1 levels were lower in the non-survivors [94 [30-258] versus 154 [52-435] pg/ml). Both survivors and non-survivors showed a progressive decrease of CRP and PCT during the course of sepsis. sTREM-1 levels however increased in the non-survivors while showing a decrease in the survivors resulting in a significant difference between these groups from day 5. Logistic regression analysis showed that at admission the SOFA score and sTREM-1 levels were the only parameters independently associated with death. Using a sTREM-1 threshold of 180 pg/mL the sensitivity was 0.86 (95% CI 0.83 - 090) the specificity 0.70 (95% CI 0.67 - 0.74), the AUC 0.74 (95% CI 0.68 - 0.80) and the positive likelihood ratio of 2.9.

Discussion

In this study sTREM-1 is presented as an important marker for infection and predictor of outcome in patients with sepsis. The design of the study is weak however and as a proper power calculation is missing it is unclear why inclusion stopped after 63 patients. sTREM-1 levels at admission appear to be an important predictor of outcome although the positive likelihood ratio of 2.9 is rather low. A likelihood ratio of 5 - 10 is usually necessary to have a clinically relevant meaning. More intriguing is the fact that non-survivors show an increase in sTREM-1 levels. As the authors speculate increasing sTREM-1 levels may point to inappropriate sepsis therapy and should result in reevaluation. If confirmed in a properly designed study this may be very useful for the clinician

W. Dijkman, fellow Intensive Care
J.G. van der Hoeven, Internist-intensivist