TREM-1 expression on monocytes is not a parameter specific for infectious etiology of systemic inflammatory response syndrome.

UNLABELLED Determination of mTREM-1 expression on monocytes has been investigated as a perspective diagnostic method to distinguish infectious from non-infectious etiology of the inflammation. THE AIMS OF OUR STUDY WERE i) to investigate the expression of TREM-1 on monocytes in septic patients and in those after elective spinal surgery without infection; ii) to assess the dynamics of mTREM-1 expression on monocytes and its association with the outcome in patients with severe sepsis. Fifty two patients with severe sepsis, 20 healthy volunteers, and 20 patients after elective spinal surgery were involved in our study. TREM-1 expression on monocytes was evaluated by flow cytometry. Compared with the group of healthy adults (median 42.0, interquartile range (IQR) 30.3-76 MFI), mTREM-1 expression was increased in the group of septic patients both at entry (median 138.4, IQR 78.4-187.5 MFI) and the last examination (median 136.5, IQR 69.0-170.0 MFI) as well as in patients 24 hours after spinal surgery (median 138.5, IQR 45.3-165.5 MFI). The increase was statistically significant. mTREM-1 expression in patients undergoing spinal surgery and those with severe sepsis did not differ. TREM-1 expression on the monocytes in survivors was higher than in non-survivors (p=0.007). TREM-1 levels in septic non-surviving patients correlated weakly with TNF-α levels (r=0.38; p=0.003) and with HLA-DR/CD14 levels (r=0.38; p=0.003). Increased TREM-1 expression on monocytes is not associated exclusively with the presence of systemic infection.