Significance of soluble triggering receptor expressed on myeloid cells-1 elevation in patients admitted to the intensive care unit with sepsis

BACKGROUND Among septic patients admitted to the intensive care unit (ICU), early recognition of those with the highest risk of death is of paramount importance. Since clinical judgment is sometimes uncertain biomarkers could provide additional information likely to guide critical illness management. We evaluated the prognostic value of soluble Triggering Receptor Expressed by Myeloid cells 1 (sTREM-1), procalcitonin (PCT) and leucocyte surface expression of CD64. METHODS This was a prospective cohort study, which included 190 septic patient admitted to the ICU in two hospitals. Blood samples for biomarker measurements were obtained upon admission and thereafter. The Simplified Acute Physiology Score (SAPS) II and the Sequential Organ Failure Assessment (SOFA) score were calculated. The primary outcome was all-cause death in the ICU. RESULTS The mortality rate reached 25.8 %. The best predictive value of the three biomarkers was obtained with baseline sTREM-1, although clinical scores outperformed this. Accuracy was greater in patients without prior exposure to antibiotics and in those with proven bacterial infection. Adding sTREM-1 levels to SAPS II increased its specificity to 98 %. The soluble TREM-1 level, core temperature and SAPS II value were the only independent predictors of death after adjustment for potential confounders. A decrease in sTREM-1 with time was also more pronounced in survivors than in non-survivors. CONCLUSIONS sTREM-1 was found to be the best prognostic biomarker among those tested. Both baseline values and variations with time seemed relevant. Although SAPS II outperformed sTREM-1 regarding the prediction of ICU survival, the biomarker could provide additional information.