Evidence for the participation of soluble triggering receptor expressed on myeloid cells-1 in the systemic inflammatory response syndrome after multiple trauma.

BACKGROUND: Based on the implication of soluble triggering receptor expressed on myeloid cells (sTREM-1) in the septic cascade, it was investigated whether it participates or not in posttraumatic systemic inflammatory response syndrome (SIRS). METHODS: Blood was sampled on days 1, 4, 7, and 15 from 69 patients with SIRS after multiple injuries and upon presentation of a septic complication. Concentrations of sTREM-1, tumor necrosis factor-alpha (TNFalpha), interleukin (IL)-6, IL-8, and interferon-gamma were determined by an enzyme immunoassay. Samples drawn on day 1 from 10 trauma patients without SIRS served as controls. RESULTS: In 26 patients with SIRS without septic complication, sTREM-1, TNFalpha, and IL-8 remained stable over follow-up; IL-6 decreased and interferon-gamma increased on days 4 and 7 compared with day 1. TNFalpha was the only variable being higher upon advent of septic shock compared with patients without SIRS and upon presentation of SIRS, sepsis, and severe sepsis (p of comparisons with all subgroups <0.0001). Mortality of patients with sTREM-1 greater than 180 pg/mL was 5.3% compared with 28.0% of those with sTREM-1 lower than 180 pg/mL (p 0.035). sTREM-1 higher than 40 pg/mL had sensitivity 56.5% and specificity 91.7% for the differential diagnosis between SIRS and sepsis after multiple injuries. CONCLUSIONS: This is the first study providing evidence about the participation of sTREM-1 in posttraumatic SIRS. Its levels are increased and remain constant over time in patients who did not develop any complications whereas it seems to behave as an anti-inflammatory mediator.

Evidence for the role of gastric mucosa at the secretion of soluble triggering receptor expressed on myeloid cells (strem-1) in peptic ulcer disease.

AIM: To investigate the role of gastric mucosa at the secretion of sTREM-1 in peptic ulcer. METHODS: Seventy two patients were enrolled; 35 with duodenal, 21 with gastric ulcer and 16 with chronic gastritis. Patients were endoscoped and gastric juice was aspirated. Patients with duodenal and gastric ulcer underwent a second endoscopy post-treatment. Biopsies were incubated in the absence/presence of endotoxins or gastric juice. Supernatants were collected and sTREM-1 and TNFalpha were measured by enzyme immunoabsorbent assays. Scoring of gastritis was performed before and after treatment according to updated Sydney score. RESULTS: Patients with duodenal and gastric ulcer and those with chronic gastritis had similar scores of gastritis. sTREM-1 was higher in supernatants of tissue samples of H pylori-positive than of H pylori-negative patients with gastric ulcer. Median (+/- SE) sTREM-1 was found increased in supernatants of patients with gastric ulcer before treatment (203.21 +/- 88.91 pg/1000 cells) compared to supernatants either from the same patients post-treatment (8.23 +/- 5.79 pg/1000 cells) or from patients with chronic gastritis (6.21 +/- 0.71 pg/1000 cells) (P < 0.001 and < 0.001, respectively). Similar differences for sTREM-1 were recorded among LPS-stimulated tissue samples of patients (P = 0.001). Similar differences were not found for TNFalpha. Positive correlations were found between sTREM-1 of supernatants from patients with both duodenal and gastric ulcer before treatment and the degree of infiltration of neutrophils and monocytes. CONCLUSION: sTREM-1 secreted by the gastric mucosa is an independent mechanism connected to the pathogenesis of peptic ulcer. sTREM-1 was released at the presence of H pylori from the inflamed gastric mucosa in the field of gastric ulcer.

Monocytes in systematic inflammatory response syndrome: differences between sepsis and acute pancreatitis.

AIM: To unravel the differences between systematic inflammatory response syndrome (SIRS) of acute pancreatitis compared to the same syndrome in sepsis. METHODS: Twenty-five patients were enrolled, 12 with sepsis and 13 acute pancreatitis. After diagnosis 20 mL blood was sampled. Half were assayed for isolation of monocytes and 10 mL was centrifuged for serum test of tumor necrosis factor alpha (TNFalpha and interleukin-6 (IL-6). Half of monocytes were incubated in the presence of patients' serum and supernatants were collected. The other half was treated for estimation of optical photometry under caspase-3 inhibition. TNFalpha and IL-6 were estimated by an enzyme immunoassay. RESULTS: median+/-SE of serum IL-6 in septic patients and acute pancreatitis patients was 192.30+/-35.40 ng/L and 21.00+/-16.05 ng/L, respectively (P<0.01). Respective values of caspase-3 were 0.94+/-0.17 pmol/min 10(4) cells and 0.34+/-0.09 pmol/min 10(4) cells (P<0.05). IL-6 of monocyte supernatants of patients with sepsis was significantly increased after addition of patients' serum, while that of patients with acute pancreatitis did not show significant difference. CONCLUSION: The data have shown that monocyte activity is different between acute pancreatitis and sepsis. This phenomenon might be explained as a different pathway to the pro-inflammatory cytokines release or could be a novel anti-inflammatory response in acute pancreatitis.

Early changes of CD4-positive lymphocytes and NK cells in patients with severe Gram-negative sepsis.

INTRODUCTION: Our aim was to define early changes of lymphocytes and of NK cells in severe sepsis and to correlate them with serum levels of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1). METHODS: Blood was sampled from 49 patients with proven highly suspected infection by Gram-negative pathogens, within 12 hours of the advent of severe sepsis, and was also sampled from six healthy volunteers. White blood cells were targeted with monoclonal antibodies and were analyzed by flow cytometry. The concentrations of sTREM-1 were estimated by ELISA. RESULTS: The presence of CD3/CD4 cells was significantly lower (P < 0.0001) and that of NK cells significantly higher among patients with sepsis compared with controls (P = 0.011). The proportions (median +/- standard error) of ANNEXIN-V/CD4/CD3-positive cells, of ANNEXIN-V/CD8/CD3-positive cells and of ANNEXIN-V/CD14-positive cells of the patient population were 7.41 +/- 2.26%, 7.69 +/- 3.42% and 1.96 +/- 4.22%, respectively. Patients with NK cells >20% survived longer compared with those patients with NK cells < or =20% (P = 0.041), and patients with sTREM-1 concentrations >180 pg/ml survived longer compared with those patients with sTREM-1 concentrations < or =180 pg/ml (P = 0.042). A negative correlation was found between the percentages of ANNEXIN-V/CD4/CD3-positive cells and of CD3/CD4 cells (rs = -0.305, P = 0.049), and a positive correlation was found between the serum sTREM-1 concentration and the percentage of NK cells (rs = +0.395, P = 0.014). NK cells isolated from two healthy volunteers released sTREM-1 upon triggering with endotoxins. CONCLUSION: Early severe sepsis is characterized by CD4-lymphopenia and increased NK cells, providing a survival benefit for the septic patient at percentages >20%. The survival benefit resulting from elevated NK cells might be connected to elevated serum levels of sTREM-1.

Monocytes as a site of production of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in the septic host.

The role of blood monocytes in the secretion of soluble triggering receptor expressed on myeloiod cells (sTREM-1) was studied in 90 patients with septic syndrome due to ventilator-associated pneumonia. Blood monocytes were isolated on 7 consecutive d after initiation of symptoms. Monocytes were incubated in the absence or presence of LPS and concentrations of sTREM-1 and TNFalpha in cell supernatants and serum were estimated by an enzyme-immunoassay. sTREM-1 and TNFalpha were consistently present at detectable levels in the cell supernatants. LPS induced increased levels of TNFalpha but not of sTREM-1. Supernatants recovered from monocytes on d 1 showed levels of sTREM-1 higher than those recovered on any of the following 6 d (p<0.05); these levels were higher in non-survivors than in survivors. Supernatants recovered from monocytes on d 1 of patients with severe sepsis had elevated concentrations of sTREM-1 compared to patients with septic shock and similar to patients with sepsis. A negative correlation was found between levels of sTREM-1 in the cell supernatants and the percentage of apoptotic monocytes. In essence, the above results suggest that monocytes contribute to the production of sTREM-1 in the event of septic syndrome.