Predictive values of serum amyloid A, toll-like receptor 4, and sTREM-1 for ventilator-associated pneumonia in elderly patients undergoing abdominal surgery with tracheal intubation and general anesthesia.

OBJECTIVES: This study aimed to conduct a retrospective study to identify inflammatory biomarkers for predicting ventilator-associated pneumonia in elderly patients. METHODS: Our retrospective study included 265 elderly patients (age ≥60 years) undergoing abdominal surgery with tracheal intubation and general anesthesia, with 93 experiencing varying degrees of ventilator-associated pneumonia during hospitalization, and 172 without. Serum concentrations of serum amyloid A (SAA), toll-like receptor 4 (TLR4), and soluble myeloid triggering receptor 1 (sTREM-1) were measured at 24 h post-operation using enzyme-linked immunosorbent assay. Comparisons of SAA, TLR4, and sTREM-1 and other risk factors at 24 h post-operation between elderly patients with and without ventilator-associated pneumonia were performed. RESULTS: The study revealed a 35.1% incidence of postoperative ventilator-associated pneumonia among elderly patients. Upregulations of SAA, TLR4, and sTREM-1 were observed in patients with ventilator-associated pneumonia. Chronic obstructive pulmonary disease, smoking, and tracheal intubation were identified as independent risk factors. The joint prediction model was demonstrated with superior predictive accuracy (area under the curve = 0.89) compared to individual biomarkers. Correlations with procalcitonin further supported the predictive potential of SAA, TLR4, and sTREM-1 in an inflammatory response. CONCLUSIONS: SAA, TLR4, and sTREM-1, particularly when combined, serve as valuable prognostic indicators for postoperative ventilator-associated pneumonia in elderly patients undergoing abdominal surgery with tracheal intubation and general anesthesia. The joint prediction model offered a promising tool for early risk assessment.

Soluble Triggering Receptors Expressed on Myeloid Cells (sTREM) in Acute Ischemic Stroke: A Potential Pathway of sTREM-1 and sTREM-2 Associated with Disease Severity.

In 2022, stroke emerged as the most significant cerebrovascular disorder globally, causing 6.55 million deaths. Microglia, crucial for CNS preservation, can exacerbate brain damage in ischemic stroke by triggering neuroinflammation. This process is mediated by receptors on microglia, triggering receptors expressed on myeloid cells (TREM-1 and TREM-2), which have contrasting roles in neuroinflammation. In this study, we recruited 38 patients within 4.5 h from the onset of ischemic stroke. The degree of severity was evaluated by means of the National Institutes of Health Stroke Scale (NIHSS) at admission (T0) and after one week of ischemic events (TW) and the Modified Rankin Scale (mRS) at three months. The plasma concentration of TREMs (sTREM) was analyzed by next-generation ELISA at T0 and TW. The sTREM-1 concentrations at T0 were associated with mRS, while the sTREM-2 concentrations at T0 were associated with both the NIHSS at T0 and the mRS. A strong correlation between sTREM-1 and sTREM-2 was observed, suggesting a dependent modulation of the levels. This study provides insights into the potential pathway of TREM-1 and TREM-2 as a future biomarker for stratifying high-risk patients with ischemic stroke.

The Effect of Soluble TREM-1 in Idiopathic Granulomatous Mastitis.

BACKGROUND AND OBJECTIVES: The aim of this study is to investigate the effect of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in idiopathic granulomatous mastitis (IGM). METHODS: This case-control study was conducted in Saglik Bilimleri and Necmettin Erbakan Universities. Sixty patients with IGM diagnosis (Group P) and 25 healthy females as control group (Group C) were included. Group P was divided into two subgroups according to the activity of disease: patients with active lesion (Group PA), and patients without any symptoms, in remission (Group PR). The ELISA method was used to measure sTREM-1 level. RESULTS: Group P's sTREM-1 were higher than Group C (p < .0001). The difference between sTREM-1 levels of Groups PA, PR and C was significant statistically (p < .0001). Group PA's sTREM-1 levels were higher than Group C (p < .0001). Also, sTREM-1 levels of Group PR were higher than Group C (p = .006). When sTREM-1 levels of patients receiving steroid therapy and did not in Group PR were analyzed, the sTREM-1 levels of the patients not receiving steroid treatment were found to be statistically higher than Group C (p = .002). Although the sTREM-1 levels of the patients who did not receive steroid therapy were higher than those who received steroid therapy, the difference was not statistically significant (p > .05). CONCLUSION: We concluded that the detected high sTREM-1 levels contributed to inflammation in IGM. In particular, blockade of TREM may be a promising treatment option in resistant or multiple recurrent patients.

COVID-19 risk stratification algorithms based on sTREM-1 and IL-6 in emergency department.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has led to surges of patients presenting to emergency departments (EDs) and potentially overwhelming health systems. OBJECTIVE: We sought to assess the predictive accuracy of host biomarkers at clinical presentation to the ED for adverse outcome. METHODS: Prospective observational study of PCR-confirmed COVID-19 patients in the ED of a Swiss hospital. Concentrations of inflammatory and endothelial dysfunction biomarkers were determined at clinical presentation. We evaluated the accuracy of clinical signs and these biomarkers in predicting 30-day intubation/mortality, and oxygen requirement by calculating the area under the receiver-operating characteristic curve and by classification and regression tree analysis. RESULTS: Of 76 included patients with COVID-19, 24 were outpatients or hospitalized without oxygen requirement, 35 hospitalized with oxygen requirement, and 17 intubated/died. We found that soluble triggering receptor expressed on myeloid cells had the best prognostic accuracy for 30-day intubation/mortality (area under the receiver-operating characteristic curve, 0.86; 95% CI, 0.77-0.95) and IL-6 measured at presentation to the ED had the best accuracy for 30-day oxygen requirement (area under the receiver-operating characteristic curve, 0.84; 95% CI, 0.74-0.94). An algorithm based on respiratory rate and sTREM-1 predicted 30-day intubation/mortality with 94% sensitivity and 0.1 negative likelihood ratio. An IL-6-based algorithm had 98% sensitivity and 0.04 negative likelihood ratio for 30-day oxygen requirement. CONCLUSIONS: sTREM-1 and IL-6 concentrations in COVID-19 in the ED have good predictive accuracy for intubation/mortality and oxygen requirement. sTREM-1- and IL-6-based algorithms are highly sensitive to identify patients with adverse outcome and could serve as early triage tools.

Soluble TREM-1, as a new ligand for the membrane receptor Robo2, promotes hepatic stellate cells activation and liver fibrosis.

Triggering receptor expressed on myeloid cells-1 (TREM-1) exists in two forms: a transmembrane form and a soluble form (sTREM-1). The levels of sTREM-1 are elevated in supernatants of activated HSCs. However, the role of sTREM-1 in HSC activation and liver fibrosis remains undefined. Previous studies have primarily focused on the transmembrane form of TREM-1; we innovatively observed the function of sTREM-1 as a ligand in liver fibrosis and screened its receptor. Here, recombinant sTREM-1 was used as a stimulator which induced HSC activation and further aggravated liver fibrosis. Then, screening for sTREM-1 interacting membrane receptors was performed using pull-down assay followed by mass spectrometry, and the membrane receptor roundabout guidance receptor 2 (Robo2) was identified as a candidate receptor for sTREM-1. The interaction between sTREM-1 and Robo2 was verified by pull-down and immunofluorescence. The role of Robo2 on sTREM-1-induced HSC activation and its downstream signal pathways was assessed by knockdown of Robo2 in LX-2 cells. Furthermore, HSC-specific knockdown of Robo2 was achieved in a mouse model of liver fibrosis by using a recombinant adeno-associated virus (AAV) vector to confirm the role of the receptor, and we proved that Robo2 knockdown inhibited the activation of HSC and liver fibrosis, which also led to the inactivation of Smad2/3 and PI3K/Akt pathways in sTREM-1-induced HSC activation and liver fibrosis. In conclusion, sTREM-1 acts as a new ligand of Robo2; the binding of sTREM-1 to Robo2 initiates the activation of the downstream Smad2/3 and PI3K/Akt signalling pathways, thereby promoting HSC activation and liver fibrosis.

Soluble TREM-1 Levels in Familial Mediterranean Fever Related AA-Amyloidosis.

Objectives: Triggering Receptor Expressed on Myeloid cells-1 (TREM-1) is a monocyte and neutrophil receptor functioning in innate immunity. TREM-1 activity has been studied in various autoimmune diseases such as RA and SLE but there is no data in autoinflammatory pathologies. We studied soluble TREM-1 (sTREM-1) activity in Familial Mediterranean Fever (FMF) cases to evaluate the clinical role of TREM-1 in amyloidosis. Methods: The study includes 62 patients with FMF (42 with amyloidosis) who are regular attendees of a tertiary center for autoinflammatory diseases. For control purposes, 5 patients with AA amyloidosis secondary to other inflammatory diseases, and 20 healthy individuals were also included. Soluble TREM-1 levels were measured using enzyme-linked immunosorbent assay (ELISA). All FMF patients were in an attack-free period during the collection of the blood samples.Results: Soluble TREM-1 levels were found to be significantly higher in the FMF amyloidosis group compared to FMF without amyloidosis group and healthy controls (p = .001 and 0.002). Nevertheless, this difference between sTREM-1 levels was not found among FMF amyloidosis and other AA amyloidosis groups (p = .447) as well as between only FMF patients and healthy controls (p = .532). Soluble TREM-1 levels were found in correlation with creatinine and CRP in the FMF patient group regardless of their amyloidosis diagnosis (r = 0.314, p = .013; r = 0.846, p < .001).Conclusion: TREM-1 seems to be related to renal function rather than disease activity in FMF. Its role as an early diagnostic marker of amyloidosis in FMF complicated with AA amyloidosis should be tested in larger patient groups.

Protective effect of quercetin against the metabolic dysfunction of glucose and lipids and its associated learning and memory impairments in NAFLD rats.

BACKGROUND: Quercetin (QUE) is a flavonol reported with anti-inflammatory and antioxidant activities, and previous results from the group of this study have demonstrated its neuroprotective effect against lipopolysaccharide-induced neuropsychiatric injuries. However, little is known about its potential effect on neuropsychiatric injuries induced or accompanied by metabolic dysfunction of glucose and lipids. METHODS: A nonalcoholic fatty liver disease (NAFLD) rat model was induced via a high-fat diet (HFD), and glucolipid parameters and liver function were measured. Behavioral performance was observed via the open field test (OFT) and the Morris water maze (MWM). The plasma levels of triggering receptor expressed on myeloid cells-1 (TREM1) and TREM2 were measured via enzyme-linked immunosorbent assay (ELISA). The protein expression levels of Synapsin-1 (Syn-1), Synaptatogmin-1 (Syt-1), TREM1 and TREM2 in the hippocampus were detected using western blotting. Morphological changes in the liver and hippocampus were detected by HE and Oil red or silver staining. RESULTS: Compared with the control rats, HFD-induced NAFLD model rats presented significant metabolic dysfunction, hepatocyte steatosis, and impaired learning and memory ability, as indicated by the increased plasma concentrations of total cholesterol (TC) and triglyceride (TG), the impaired glucose tolerance, the accumulated fat droplets and balloon-like changes in the liver, and the increased escaping latency but decreased duration in the target quadrant in the Morris water maze. All these changes were reversed in QUE-treated rats. Moreover, apart from improving the morphological injuries in the hippocampus, treatment with QUE could increase the decreased plasma concentration and hippocampal protein expression of TREM1 in NAFLD rats and increase the decreased expression of Syn-1 and Syt-1 in the hippocampus. CONCLUSIONS: These results suggested the therapeutic potential of QUE against NAFLD-associated impairment of learning and memory, and the mechanism might involve regulating the metabolic dysfunction of glucose and lipids and balancing the protein expression of synaptic plasticity markers and TREM1/2 in the hippocampus.

Elevated Plasma Soluble Triggering Receptor Expressed on Myeloid Cells-1 Level in Patients with Acute Coronary Syndrome (ACS): A Biomarker of Disease Severity and Outcome.

BACKGROUND AND AIMS: Plasma levels of soluble triggering receptor expressed on myeloid cells (sTREM-1) reflect innate immune cell activation. We sought to evaluate sTREM-1 levels in patients with acute coronary syndrome (ACS) and their predictive value for disease severity and outcome. METHODS: Plasma sTREM-1 levels were prospectively measured by ELISA in 121 consecutive patients with new-onset (≤24 h) chest pain at arrival to the emergency department (ED) and 73 healthy controls. Secondary endpoints were the association of plasma levels of sTREM-1 with day 30 and month 6 major adverse cardiovascular events (MACE) defined as death, ACS, stroke, and need for coronary revascularization, as well as with CAD severity. The primary endpoint of the study was the association of plasma sTREM-1 level at the time of admission to the ED with a diagnosis of ACS at day 30. RESULTS: Fifty-nine patients (48.7%) were diagnosed with ACS and 62 (51.3%) with nonspecific chest pain (NSCP). Median plasma sTREM-1 level at admission was significantly higher in the ACS group than the NSCP group and the control group (539.4 ± 330.3 pg/ml vs. 432.5 ± 196.4 pg/ml vs. 230.1 ± 85.5 pg/ml, respectively; P < 0.001) and positively correlated with the number of stenosed/occluded coronary arteries on angiography (P < 0.001). On logistic regression analysis, higher sTREM-1 levels predicted definite ACS vs. NSCP determined on day 30 (OR 1.29, 95% CI 1.07-1.54, P = 0.01) as well as with recurrent ACS (P = 0.04) and stroke (P = 0.02) at 6 months. CONCLUSIONS: Plasma sTREM-1 levels are significantly elevated in patients with ACS and might serve as a biomarker differentiating ACS from NSCP in the ED as well as an inflammatory biomarker for coronary artery disease severity and outcome.

Diagnostic value of serum soluble triggering expressed receptor on myeloid cells 1 (sTREM-1) in suspected sepsis: a meta-analysis.

BACKGROUND: We aim to synthesize the up-to-date studies to investigate the diagnostic value of serum soluble triggering expressed receptor on myeloid cells 1 (sTREM-1) in suspected sepsis. RESULTS: A total of 19 studies with 2418 patients were finally enrolled in the meta-analysis. The pooled sensitivity was 0.82 (95% CI 0.73 to 0.89), specificity 0.81 (95% CI 0.75 to 0.86), positive likelihood ratio 4.3 (95% CI 3.02 to 6.12), negative likelihood ratio 0.22 (95% CI 0.24 to 0.35), diagnostic odds ratio 20 (95% CI 9 to 41) and AuROC 0.88 (95% CI 0.85 to 0.91). The meta-regression analysis revealed that the sample size, reference standard description, prevalence of sepsis in the trials and consecution of patient recruitment might be the source of heterogeneity. CONCLUSIONS: The serum sTREM-1 had a moderate ability in diagnosis in suspected sepsis based on the current studies. However, more large-scale studies were needed to further evaluate the diagnostic accuracy of sTREM-1.

Serum sTREM-1 in adult-onset Still's disease: a novel biomarker of disease activity and a potential predictor of the chronic course.

OBJECTIVES: Triggering receptor expressed on myeloid cells-1 (TREM-1) is an amplifier of inflammatory signals. Recently, a soluble form of TREM-1 (sTREM-1) was described. This study aimed to investigate the role of serum sTREM-1 in patients with adult-onset Still's disease (AOSD). METHODS: Serum sTREM-1 levels were detected in 108 AOSD patients, 88 RA patients and 112 healthy controls (HC). The correlations of sTREM-1 with disease activity, clinical characteristics and laboratory parameters in AOSD patients were analysed by the Spearman correlation test. Risk factors for the chronic course of AOSD were evaluated by multivariate logistic regression analysis. RESULTS: AOSD patients had significantly higher serum sTREM-1 levels than RA patients and HC, and serum sTREM-1 levels were correlated with the systemic score, ferritin, leucocyte count, CRP, IL-1ß and IL-6. The elevation in the initial sTREM-1 level by itself could discriminate patients developing the chronic course from patients developing the nonchronic course. Moreover, an elevated sTREM-1 level (> 526.4475 pg/ml) was an independent risk factor for the chronic course in active AOSD patients. Furthermore, interfering with TREM-1 engagement led to reductions in the secretion of pro-inflammatory cytokines, such as IL-1ß, IL-6 and TNF-α, in neutrophils and monocytes from active AOSD patients. CONCLUSION: Serum sTREM-1 levels are correlated with disease activity, and an elevation in the initial serum sTREM-1 level is a potential predictor of the chronic course in AOSD patients, which currently provides the best predictive model for identifying patients prone to developing the chronic course of AOSD.

Significance of sTREM-1 in early prediction of ventilator-associated pneumonia in neonates: a single-center, prospective, observational study.

BACKGROUND: To evaluate whether soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) can be used as an early predictor of ventilator-associated pneumonia (VAP). METHODS: Ventilated neonatal patients admitted into the neonatology department between January 2017 and January 2018 were divided into VAP (n = 30) and non-VAP (n = 30) groups. Serum sTREM, procalcitonin (PCT), C-reactive protein and interleukin-6 levels were measured at 0, 24, 72, and 120 h after initiation of mechanical ventilation (MV). Correlations between blood biomarker concentrations and VAP occurrence were analyzed. Predictive factors for VAP were identified by logistic regression analysis and Hosmer-Lemeshow test, and the predictive value of sTREM-1 and biomarker combinations for VAP was determined by receiver operating characteristic curve analysis. RESULTS: The serum sTREM-1 concentration was significantly higher in the VAP group than in the non-VAP group after 72 and 120 h of MV (72 h: 289.5 (179.6-427.0) vs 202.9 (154.8-279.6) pg/ml, P < 0.001; 120 h: 183.9 (119.8-232.1) vs 141.3 (99.8-179.1) pg/ml, P = 0.042). The area under the curve (AUC) for sTREM-1 at 72 h was 0.902 with a sensitivity of 90% and specificity of 77% for the optimal cut-off value of 165.05 pg/ml. Addition of PCT to sTERM-1 at 72 h further improved the predictive value, with this combination having an AUC of 0.971 (95% confidence interval: 0.938-1.000), sensitivity of 0.96, specificity of 0.88, and Youden index of 0.84. CONCLUSION: sTREM-1 is a reliable predictor of VAP in neonates, and combined measurement of serum levels of sTREM-1 and PCT after 72 h of MV provided the most accurate prediction of VAP in neonatal patients.

Utility of sTREM-1 and Presepsin (sCD14-ST) as Diagnostic and Prognostic Markers of Sepsis.

BACKGROUND: Sepsis is a condition prevalent among hospitalized patients which carries a high risk of morbidity and mortality. Rapid recognition of sepsis as the cause of deterioration is desirable, and then effective treatment can be initiated rapidly. Traditionally, diagnosis was based on the presence of two or more positive SIRS criteria due to infection. However, recently published sepsis-3 criteria put more emphasis on organ dysfunction caused by infection in the definition of sepsis. Regardless of this, no gold standard for diagnosis exists, and clinicians still rely on a number of traditional and novel biomarkers to discriminate between patients with and without infection, as the cause of deterioration. The present study aims to observe the changes of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) and presepsin (sCD14-ST) 1evels in plasma of sepsis patients and explore the diagnosis and prognosis of sepsis. METHODS: Sixty patients with sepsis admitted to the Department of Critical Care medicine in Hainan General Hospital from October 2013 to March 2019 were selected as the experimental group. Also chosen in the same period were 60 cases of hospitalized non-sepsis patients as a control group. Plasma levels of sTREM-1 and presepsin were determined by enzyme-linked immunosorbent assay (ELISA) in the 60 patients with sepsis and the 60 non-sepsis patients. Changes of sTREM-1 and presepsin plasma 1evels were observed in the survival subgroup and non-survival subgroup of the patients with sepsis on days 1, 4, 7, and the day of discharge or death. RESULTS: Plasma levels of sTREM-1 and presepsin in the patients with sepsis were higher than those in the control group on the day of admission (p < 0.01). The levels of sTREM-1 and presepsin in the septic shock group were significantly higher than those in the sepsis group (p < 0.01). Plasma levels of sTREM-1 and presepsin showed a decreasing trend in the survival subgroup of the patients with sepsis, while maintaining high 1evels or increased in the subgroup of non-survivors. At different time points, the plasma levels of sTREM-1 and presepsin of the subgroup of non-survivors were all significantly higher than the subgroup of survivors. There was a significant positive correlation between plasma 1evels of sTREM-1 and presepsin (r = 0.596, p < 0.01). According to the plasma sTREM-1, presepsin, CRP, and PCT levels on the first day of enrollment in patients with sepsis, ROC curve analysis was performed and AUC was calculated. The results showed that the AUC values of sTREM-1 and presepsin were relatively high, which was 0.925 and 0.910, respectively. The AUC of PCT and CRP were slightly lower, which was 0.861 and 0.816, respectively (p < 0.01). CONCLUSIONS: ROC curve was used to study the value of sTREM-1 and presepsin in the diagnosis of sepsis, which suggested that sTREM-1 and presepsin should be significantly superior to CRP and PCT levels. The sTREM-1 combined with presepsin had the highest AUC. sTREM-1 has been shown to have an optimal threshold of 125.00 pg/mL for the diagnosis of sepsis, the specificity was 86.0% and the sensitivity was 87.0%. Presepsin has been shown to have an optimal threshold of 1,025.00 pg/mL for the diagnosis of sepsis, the specificity was 83.0% and the sensitivity was 85.0%. The sTREM-1 and presepsin plasma levels have great reference value for the diagnosis of sepsis, and the sTREM-1 and presepsin plasma levels are relative to the severity of sepsis. It is helpful to evaluate treatment effect and prognosis of sepsis by dynamically monitoring the plasma 1evels of sTREM-1 and presepsin.

Diagnostic and Prognostic Value of IL-6 and sTREM-1 in SIRS and Sepsis in Children.

PURPOSE: The aim of this study was to evaluate the diagnostic and prognostic value of IL-6 and sTREM-1 in the course of SIRS and sepsis in children with reference to routinely used CRP and PCT. METHODS: A prospective study included 180 patients at the ages from 2 months to 18 years hospitalized due to fever from November 2015 to January 2017. Forty-nine children without fever hospitalized due to noninfectious causes formed the control group. IL-6 and sTREM-1 serum concentrations were assessed with the enzyme-linked immunosorbent assay method. RESULTS: The mean serum concentrations of all the analyzed biomarkers were statistically significantly higher in the study group compared to the control group. Mean IL-6, sTREM-1, and PCT serum concentrations were statistically significantly higher in the group of patients with SIRS/sepsis compared to the group of feverish patients without diagnosed SIRS (N-SIRS). Based on the ROC curve analysis, it was shown that of all the biomarkers tested, only two-IL-6 and procalcitonin-had potential usefulness in the diagnosis of SIRS/sepsis in children with fever. CONCLUSION: Elevated levels of IL-6 and PCT are important risk factors for the development of SIRS/sepsis in children with fever. It seems that elevated IL-6 baseline serum level may predict a more severe course of febrile illness in children, because based on the ROC curve analysis, it was found that IL-6 is a statistically significant prognostic marker of prolonged fever ≥ 3 days and prolonged hospitalization > 10 days. The assessment of the usefulness of sTREM-1 in the diagnosis of SIRS/sepsis in feverish children requires further research.

Dynamic Monitoring of sTREM-1 and Other Biomarkers in Acute Cholangitis.

BACKGROUND: Sepsis is a common complication of acute cholangitis (AC), which is associated with a high mortality rate. Our study is aimed at exploring the significance of white blood cell (WBC), C-reactive protein (CRP), procalcitonin (PCT), soluble triggering receptor expressed on myeloid cells 1 (sTREM-1), and temperature (T) alone or combined together in early identification and curative effect monitoring of AC with or without sepsis. METHODS: 65 consecutive cases with AC and 76 control cases were enrolled. They were divided into three groups: Group A (AC with sepsis), Group B (AC without sepsis), and Group C (inpatients without AC or other infections). The levels of WBC, CRP, PCT, sTREM-1, and temperature were measured dynamically. The study was carried out and reported according to STARD 2015 reporting guidelines. RESULTS: CRP had the highest AUC to identify AC from individuals without AC or other infections (AUC 1.000, sensitivity 100.0%, specificity 100.0%, positive predictive value 100.0%, and negative predictive value 100.0%). Among various single indexes, PCT performed best (AUC 0.785, sensitivity 75.8%, specificity 72.2%, positive predictive value 68.7%, and negative predictive value 78.8%) to distinguish sepsis with AC, while different combinations of indexes did not perform better. From day 1 to day 5 of hospitalization, the levels of sTREM-1 in Group A were the highest, followed by Groups B and C (P < 0.05); on day 8, sTREM-1 levels in Groups A and B declined back to normal. However, other index levels among three groups still had a significant difference on day 10. Both in Groups A and B, sTREM-1 levels declined fast between day 1 and day 2 (P < 0.05). CONCLUSIONS: CRP is the best biomarker to suggest infection here. PCT alone is sufficient enough to diagnose sepsis with AC. sTREM-1 is the best biomarker to monitor patients' response to antimicrobial therapy and biliary drainage.

A new inflammatory marker in overweight patients: triggering receptor expressed on myeloid cells-1.

BACKGROUND: Triggering receptor expressed on myeloid cells 1 (TREM-1) is secreted by phagocytes in adipose tissue and it also upregulates the expression of genes involved in the inflammatory response and atherosclerotic conditions. This study was aimed to investigate the serum TREM-1 levels in overweight patients. METHODS: Twenty-eight subjects in the overweight group (OG) and 20 age-matched healthy subjects in the control group (CG) (BMI 27.6±1.2 vs 23.1±2.17 kg/m2, respectively, p<0.001) were included in the study. The serum sTREM-1 level was measured by ELISA. The homeostasis model assessment score (HOMA-IR) was also calculated. RESULTS: The mean TREM-1 levels were significantly higher in OG than in CG (407.3±323.7 vs 150.3±152.7 pg/mL, respectively, p<0.001). The HOMA-IR score was also significantly higher in OG than in CG (3.42±3.63 vs 2.77±1.61, respectively). A positive correlation was detected between TREM-1 and BMI (r=0.318, p=0.028). CONCLUSIONS: This study mainly demonstrated that a high serum TREM-1 level might be an early inflammatory marker in overweight patients. We found that TREM-1 might be associated with BMI in overweight patients regardless of insulin resistance (Tab. 1, Ref. 21). Text in PDF www.elis.sk.

[Value of serum procalcitonin combined with soluble triggering receptor expressed on myeloid cells-1 in the differential diagnosis of bacterial and viral diarrhea in children].

OBJECTIVE: To study the value of serum procalcitonin (PCT) combined with soluble triggering receptor expressed on myeloid cells-1 (STREM-1) in the differential diagnosis of bacterial diarrhea and viral diarrhea in children. METHODS: A retrospective analysis was performed on the medical data of 73 children with bacterial infectious diarrhea (bacteria group) and 68 children with viral infectious diarrhea (virus group) who were treated from February 2018 to May 2019. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic efficacy of serum PCT and STREM-1 for bacterial infectious diarrhea and viral infectious diarrhea. RESULTS: Compared with the virus group, the bacteria group had significantly higher detection rates of fecal red blood cells (79% vs 43%, P<0.05) and pus (51% vs 19%, P<0.05), as well as significantly higher serum levels of PCT and STREM-1 (P<0.05). The ROC curve analysis showed that in the differential diagnosis of bacterial infectious diarrhea and viral infectious diarrhea, serum PCT had a cut-off value of 0.97 ng/mL and an area under the ROC curve (AUC) of 0.792, and STREM-1 had a cut-off value of 15.66 ng/mL and an AUC of 0.889. Serum PCT combined with STREM-1 had an AUC of 0.955, which was significantly higher than that of each index alone (P<0.05). CONCLUSIONS: Children with bacterial diarrhea have increased serum levels of PCT and STREM-1 than those with viral diarrhea. Both serum PCT and STREM-1 can be used as the indices for the differential diagnosis of bacterial diarrhea and viral diarrhea in children, and the combined measurement of PCT and STREM-1 can improve the efficiency of differential diagnosis.

Identification of early biomarkers in a rabbit model of primary Candida pneumonia.

BACKGROUND: Candida albicans is an opportunistic pathogen, but since it also belongs to the normal fungal flora, positive sputum culture as the solely basis for the diagnosis of invasive Candida albicans pneumonia can easily lead to excessive antifungal therapy. Therefore, identification of a pneumonia biomarker might improve diagnostic accuracy. METHODS: A rabbit model was established by inoculating 5 × 107 cfu/mL C. albicans into the trachea of 20 rabbits with 20 rabbits as control group. Infection was monitored by chest thin-layer computed tomography (CT). 2 mL blood samples were collected daily during each infection and serum levels of potential biomarkers were measured by enzyme-linked immunosorbent assay (ELISA). Seven-day post-inoculation the rabbits were sacrificed by CO2 asphyxiation and lung tissue was histopathologically examined and blood was brought to culture. Data were statistically analyzed. RESULTS: Infection became evident as early as day 3 post-inoculation. The levels of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), soluble hemoglobin-haptoglobin scavenger receptor (sCD163), procalcitonin (PCT) and tumor necrosis factor-α (TNF-α) were elevated in the experimental group compared to the control (P < 0.01), whereas the levels of C-reactive protein (CRP), interleukin-6 (IL-6), IL-8 and IL-10 showed no significant differences (P > 0.05). The dynamic curves of the levels of CRP, IL-6, IL-8, IL-10, SCD163 and TNF-α in both groups demonstrated a similar trend during infection but differences between the groups was observed only in the sTREM-1 levels. Receiver-operating characteristics (ROC) curve analysis showed that the sensitivity and specificity were 85 and 80% for sTREM-1 (cut-off value: 45.88 pg/mL) and 80 and 75% for SCD163 (cut-off value: 16.44 U/mL), respectively. The values of the area under the ROC curve (AUCROC) of sTREM-1 and SCD163 were 0.882 (95% CI: 0.922-0.976) and 0.814 (95% CI: 0.678-0.950), respectively. Other markers did not exhibit significant differences. CONCLUSION: sTREM-1 and SCD163 might be suitable biomarkers for pneumonia.

Soluble TREM1 concentrations are increased and positively correlated with total tau levels in the plasma of patients with Alzheimer's disease.

BACKGROUND/AIMS: Recently, we showed that triggering receptor expressed on myeloid cells 1 (TREM1) was involved in the pathogenesis of Alzheimer's disease (AD) since it modulated microglial phagocytic functions and thus affected amyloid-ß clearance in the brain. Interestingly, a soluble form of TREM1 (sTREM1) can be detected in the plasma of human. To date, whether sTREM1 concentrations were altered in the plasma under AD context remained unclear. METHODS: In this study, we compared the plasma concentrations of sTREM1 between 110 AD patients and 128 age- and gender-matched controls. Meanwhile, the relationship of sTREM1 concentrations with total tau levels in the plasma of AD patients was also assessed. RESULTS: We revealed that the concentrations of sTREM1 were significantly increased in AD patients. Meanwhile, the sTREM1 concentrations were gradually increased during disease progression. More importantly, we showed that the sTREM1 concentrations were positively correlated with the levels of total tau in the plasma of AD patients (r = 0.61, P < 0.001). The subsequent subgroup analysis indicated that this correlation was more pronounced in patients with severe dementia (Mini-Mental State Exam score < 10, r = 0.81, P < 0.01). CONCLUSION: These findings indicate a potential association between sTREM1 and tau pathology, and further confirm an involvement of this immune receptor in AD pathogenesis.

Assessment of Serum sTREM-1 as a Marker of Subclinical Inflammation in Diarrhea-Predominant Patients with Irritable Bowel Syndrome.

BACKGROUND: Irritable bowel disease (IBS) is viewed upon as a functional disorder of subclinical inflammatory changes in recent years, and there is no reliable biomarker. Triggering receptor expressed on myeloid cells 1 (TREM-1), also produced in a soluble form (sTREM-1), is involved in the activation of inflammatory cascades of intracellular events and may play a role in pathogenesis of IBS. AIM: To investigate whether serum sTREM-1 level can be used as a marker of subclinical inflammation in D-IBS. METHODS: Abdominal pain was quantified by a validated questionnaire. Expression level of TREM-1 in colonic mucosa as well as sTREM-1 level in serum was also detected. Furthermore, we investigated the involvement of TREM-1-associated macrophage activation in IBS-like visceral hypersensitivity. RESULTS: No evidence for obvious inflammation was found in D-IBS patients. Serum sTREM-1 level in D-IBS patients was significantly higher than that in HCs, which was also significantly correlated with abdominal pain scores. We showed a marked increase in the proportion of TREM-1-expressing macrophages in D-IBS, which was significantly correlated with abdominal pain scores. Functionally, gadolinium chloride (GdCl3), a macrophage selective inhibitor, or LP17, the TREM-1-specific peptide, significantly suppressed the visceral hypersensitivity in trinitrobenzene sulfonic acid (TNBS)-treated mice with IBS-like visceral hypersensitivity. CONCLUSIONS: Serum sTREM-1 level is significantly higher in D-IBS patients and positively correlates with abdominal pain, which may be initiated by TREM-1-associated macrophage activation, indicating the existence of subclinical inflammation in D-IBS. Therefore, serum sTREM-1 is a potential marker of subclinical inflammation in D-IBS.

Triggering Receptor Expressed on Myeloid Cells-1 (TREM-1) and its soluble in the plasma form (sTREM-1) as a diagnostic biomarker in neonatal sepsis.

Neonatal sepsis, defined as sepsis occurring within the first 28 days of life, is associated with significant morbidity and mortality. It is undeniable that finding and appliance of biomarkers in clinical practice is of great importance, aiming at the early recognition of the impending clinical deterioration and the prompt and targeted therapeutic intervention. A er systematic and thorough research of the limited relevant literature, we attempt to present a documented point-of-view on the diagnostic value of TREM-1 and its soluble form both in early and late onset neonatal sepsis.