Sestre Milosrdnice University hospital and Institute of Clinical Medical Research
Abstract
Human soluble triggering receptor expressed on myeloid cells (sTREM -1) is a glycoprotein of the immunoglobulin superfamily. In normal lung tissue, sTREM -1 is selectively expressed in lung alveolar macrophages specialized for pathogen clearance and is up-regulated in the presence of bacteria and fungi. The aim of this study was to assess sTREM -1 levels in serum and lungs of patients with ventilator associated pneumonia (VAP) and to evaluate its potential diagnostic role. The study cohort included 31 patients meeting the criteria for VAP, including clinical, microbiological, radiological and laboratory findings in patients on mechanical ventilation for more than 48 hours and with Clinical Pulmonary Infection Score (CPIS) >6. Serum and lung levels of sTREM -1 were obtained and tested for differences. The samples were analyzed using ELI SA technique and the values were expressed in pg/mL. The samples for lung sTREM -1 were obtained from direct bronchial lavage fluid and serum samples from peripheral blood. Differences were tested by Mann Whitney U test with p<0.05 considered significant. In patients with bacterial VAP, a statistically significant difference was found between serum and lung sTREM -1 levels (p<0.05), with very high levels of sTREM -1 recorded in lung samples (mean value 1565 pg/mL). There was no statistically significant difference in pulmonary sTREM -1 level between the polymicrobial and monomicrobial VAP groups. In conclusion, sTREM -1 is present in a high concentration in the lungs of patients with bacterial VAP. sTREM -1 levels can help in making the diagnosis of bacterial pneumonia as a standalone marker.Humani topljivi okidački receptor izražen na mijeloidnim stanicama (sTREM -1) je glikoprotein iz superporodice imunoglobulina. U normalnom plućnom tkivu sTREM -1 je selektivno izražen na makrofazima plućnih alveola, koji su specijalizirani za uklanjanje patogena, te podliježe regulaciji naviše u prisutnosti bakterija i gljiva. Cilj ove studije bio je procijeniti razine sTREM -1 u serumu i plućima bolesnika s upalom pluća povezanom s uređajem za umjetno disanje (VAP), kao i njegovu moguću dijagnostičku vrijednost. Ispitivanje je obuhvatilo 31 bolesnika koji su zadovoljavali kriterije za VAP, uključujući kliničke, mikrobiološke, radiološke i laboratorijske nalaze bolesnika priključenih na mehaničku ventilaciju kroz više od 48 sati i sa zbirom CPIS (Clinical Pulmonary Infection Score) većim od 6. Izmjerene su serumske i plućne razine sTREM -1 i izračunate razlike među njima. Uzorci su analizirani pomoću tehnike ELI SA, a vrijednosti su izražene u pg/mL. Uzorci za procjenu sTREM -1 u plućima dobiveni su direktnom bronhijalnom lavažom, a uzorci seruma iz periferne krvi. Razlike su testirane Mann Whitneyevim U testom uz razinu značajnosti P<0,05. Kod bolesnika s bakterijskom VAP utvrđena je statistički značajna razlika između serumske i plućne razine sTREM -1 (P<0,05), uz vrlo visoke razine sTREM -1 zabilježene u plućnim uzorcima (srednja vrijednost 1565 pg/mL). Nije bilo statistički značajne razlike u plućnoj razini sTREM -1 između skupina s polimikrobnom i monomikrobnom VAP. U zaključku, sTREM -1 je prisutan u visokoj koncentraciji u plućima bolesnika s bakterijskom VAP, pa bi stoga razine sTREM -1 mogle biti korisne u postavljanju dijagnoze bakterijske upale pluća kao jedan jedinstveni biljeg
