Surface TREM-1 as a Prognostic Biomarker in Pediatric Sepsis

The role of the TREM receptor family in cardiovascular diseases: Functions, mechanisms, and therapeutic target

The Triggering Receptor Expressed in the Myeloid Cells (TREM) family represents an emerging subgroup within the immunoglobulin superfamily, which includes key members such as TREM-1, TREM-2, TREM-3, TREM-like transcript-1 (TLT-1), TLT-2, and TLT-4. TREM-1 serves as a potent amplifier of immune responses, exacerbating atherosclerosis and myocardial injury by enhancing inflammatory reactions. In contrast, TREM-2 exerts protective effects by regulating lipid metabolism, mitigating inflammation, and promoting phagocytic activity, thereby attenuating cardiovascular damage. Both soluble TLT-1 and TLT-4 have been identified as potential biomarkers for cardiovascular risk. In recent years, the roles of the TREM family in the pathogenesis of cardiovascular diseases (CVD) have garnered growing interest within the scientific community. This review aims to illuminate the functional roles, underlying mechanisms, and clinical relevance of TREM family members in the regulation of CVD, while exploring their potential applications in early diagnosis, disease monitoring, and the development of novel therapeutic targets for CVD, ultimately laying a foundation for their clinical translation and advancement in precision medicine.

Surface triggering receptor expressed on myeloid cells-1 (sTREM1) in critically ill children: a prospective observational controlled study

BACKGROUND

In children admitted to the pediatric intensive care unit (PICU), early detection of risk factors and alarming indicators improves the prognosis and may even save lives. Several prognostic markers and scores have been studied in children who are seriously ill. Recently, surface triggering receptor expressed on myeloid cells-1 (sTREM1) has been studied in many infectious and non-infectious settings; however, there is little information on critically ill children. Our aim is to evaluate the sTREM1 level in critically ill children and assess its prognostic role.

METHOD

A prospective observational study was conducted in a tertiary care hospital. 70 critically ill children and 50 healthy controls were enrolled in the study. Demographic, clinical, and laboratory data were obtained. sTREM1 level was assessed on admission to the PICU. Patients with conditions affecting immunity were excluded. The primary outcome was to assess the level of sTREM1 in both patients and controls. Secondary outcomes were mortality, morbidities as sepsis, need for mechanical ventilation, and PICU stay.

RESULTS

The level of sTREM1 was significantly higher in patients than in controls (850 pg/mL, interquartile range [IQR] 510.0- 1375.0 vs. 67.5 pg/mL, IQR 40.0- 85.0; p.

The role of TREM-1 in septic myocardial pyroptosis and septic cardiomyopathy in vitro and in vivo

Septic cardiomyopathy (SCM) is an acute cardiac dysfunction involving myocardial cell pyroptosis. TREM-1 is a known receptor on cell membrane that can amplify the inflammatory response. Our previous studies have shown that TREM-1 in cardiomyocytes is involved in the activation of NLRP3 through the SMC4/NEMO pathway. Here, we aimed to use Trem-1 and Nlrp3 knockout mice to verify the effect of TREM-1 through NLRP3 on cardiac function in septic mice. The results showed that TREM-1 knockout resulted in a decrease in the release of downstream cell signals, including SMC4 and NLRP3, resulting in a decrease in cytokine release and improvement of cardiac dysfunction. Knockout of NLRP3 also reduced cardiomyocyte pyroptosis and increased survival rate. The therapeutic targeting of TREM-1 activation of NLRP3 and its pathway may contribute to the treatment or prevention of SCM.

Diagnostic and Prognostic Value of Soluble Triggering Receptor Expressed on Myeloid Cells-1 (sTREM-1) for Septic Cardiomyopathy

Purpose

The early diagnosis of septic cardiomyopathy remains a challenge. The present work aims to evaluate the diagnostic and prognostic value of plasma soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) levels in septic cardiomyopathy when compared with traditional myocardial biomarkers.

Methods

In the 143 sepsis enrolled patients, 67 and 76 patients were classified as non-septic cardiomyopathy and septic cardiomyopathy, respectively. Their blood samples were harvested up to 14th day after hospital admission for measurements of sTREM-1 and other biomarkers, such as N-terminal pronatriuretic peptide (NT-proBNP), highly sensitive troponin (TNT-HS), myoglobin (MYO), creatine kinase isoenzyme (CK-MB), etc. All the data were collected at 8:00 a.m. The area under the receiver operating characteristic curve was obtained to assess the diagnostic accuracy of those biomarkers. The Log rank test was utilized to evaluate the prognostic value of sTREM-1 on septic cardiomyopathy.

Results

Circulating sTREM-1 showed a high specificity (88.1%) and moderate sensitivity (64.5%) to distinguish patients with septic cardiomyopathy in the 143 septic patients. The diagnostic efficiency of sTREM-1 was higher than inflammatory biomarkers and traditional myocardial markers. Logistic regression revealed that plasma sTREM-1 was an independent predictor of septic cardiomyopathy. Furthermore, in the whole septic cardiomyopathy cohorts, the sTREM-1 levels in the non-survivors were significantly higher than those of survivors during ICU stay. In addition, the left ventricular systolic dysfunction had a high odds ratio (3.968) to predict 90-day mortality in septic patients with cardiomyopathy.

Conclusion

High plasma sTREM-1 level may be a diagnostic marker in predicting ICU poor outcome of patients with septic cardiomyopathy.

Biomarkers for sepsis: more than just fever and leukocytosis-a narrative review

A biomarker describes a measurable indicator of a patient's clinical condition that can be measured accurately and reproducibly. Biomarkers offer utility for diagnosis, prognosis, early disease recognition, risk stratification, appropriate treatment (theranostics), and trial enrichment for patients with sepsis or suspected sepsis. In this narrative review, we aim to answer the question, "Do biomarkers in patients with sepsis or septic shock predict mortality, multiple organ dysfunction syndrome (MODS), or organ dysfunction?" We also discuss the role of pro- and anti-inflammatory biomarkers and biomarkers associated with intestinal permeability, endothelial injury, organ dysfunction, blood-brain barrier (BBB) breakdown, brain injury, and short and long-term mortality. For sepsis, a range of biomarkers is identified, including fluid phase pattern recognition molecules (PRMs), complement system, cytokines, chemokines, damage-associated molecular patterns (DAMPs), non-coding RNAs, miRNAs, cell membrane receptors, cell proteins, metabolites, and soluble receptors. We also provide an overview of immune response biomarkers that can help identify or differentiate between systemic inflammatory response syndrome (SIRS), sepsis, septic shock, and sepsis-associated encephalopathy. However, significant work is needed to identify the optimal combinations of biomarkers that can augment diagnosis, treatment, and good patient outcomes.

Evaluation of sTREM1 and suPAR Biomarkers as Diagnostic and Prognostic Predictors in Sepsis Patients

Background

The purpose of this study was to explore the diagnostic role of sTREM1 in the diagnosis of sepsis and in differentiating between sepsis and systemic inflammatory response syndrome (SIRS). We also aimed to assess the prognostic value of suPAR in comparison to sequential organ-failure assessment (SOFA), acute physiology and chronic health evaluation (APACHE) II scores, and 28-day mortality.

Methods

This was a cross-sectional study conducted in the Medical Microbiology and Immunology Department and Central Research Laboratory, Faculty of Medicine, Sohag University from June 2019 to January 2021. The study population was classified into two groups: SIRS (no evidence of infection) and sepsis (with SIRS and evidence of infection). Patients were rated on the SOFA and APACHE II scoring systems at admission and after 7 days. Serum levels of sTREM1 and suPAR were measured by ELISA at the same time points.

Results

CRP and sTREM1 values were significantly higher in the sepsis group than the SIRS group on both days (P<0.0001). The area under the curve (AUC) for CRP was 0.87 on the first day and 0.97 on the seventh, while the AUC for sTREM1 was 1.00 and 0.93 on the first and seventh days, respectively. The sensitivity of sTREM1 was 100% and specificity 84% at a cutoff of 49 pg/mL. There was a significantly positive correlation between CRP and sTREM1 values (P<0.0001). On the seventh day, nonsurvivors had significantly higher serum levels of suPAR (median 4.9 ng/mL) than survivors (median 2.9 ng/mL; P<0.0001). Nonsurvivors also had significantly higher SOFA and APACHE II scores than survivors (P<0.0001 and P<0.0001, respectively).

Conclusion

sTREM1 can be used as a good indicator for diagnosing sepsis in intensive care–unit patients. suPAR can also be used as a predictor of bad prognosis and poor survival at 7 days following admission.

Triggering receptor expressed on myeloid cells-1 as pediatric sepsis biomarker

OBJECTIVE

Triggering receptor expressed on myeloid cells-1 concentration can be used as a predictive, diagnostic, and prognostic marker in patients with sepsis. The objective of this study was to determine the validity of triggering receptor expressed on myeloid cells-1 levels as a biomarker of sepsis in pediatric patients.

METHODS

This was an integrative literature review. PubMed, ScienceDirect, LILACS, MEDLINE, and VHL databases were searched for papers published between 2015 and 2020, using the keywords triggering receptor expressed on myeloid cells-1, sepsis, and child.

RESULTS

The review included ten studies, of which four used triggering receptor expressed on myeloid cells-1 as a predictive biomarker; four, as a diagnostic biomarker; and two, as a prognostic biomarker. A total of 1,409 and 1,628 patients were included in primary and review studies, respectively. There was a predominance of significant results for the validity of triggering receptor expressed on myeloid cells-1 levels in the prediction, diagnosis, and prognosis of sepsis in pediatric patients.

CONCLUSIONS

Triggering receptor expressed on myeloid cells-1 is a valid predictive, diagnostic, and prognostic biomarker of sepsis with good sensitivity and specificity in the pediatric population.

Role of soluble triggering receptor expressed in myeloid cells-1 in distinguishing SIRS, sepsis, and septic shock in the pediatric intensive care unit

BACKGROUND

Research into new markers has been intensified for early diagnosis, prognosis, and differentiation of SIRS, sepsis, and septic shock in recent years. This study aimed to investigate the role of soluble triggering receptor expressed in myeloid cells-1 (sTREM-1) and interleukin (IL)-6 in distinguishing between systemic inflammatory response syndrome (SIRS), sepsis, and septic shock in pediatric intensive care unit (PICU) patients.

METHODS

Between June 2014 and July 2015, 90 consecutive patients who were treated in the PICU were included in this prospective observational study. Patients were divided into four groups: control (n = 23), SIRS (n = 22), sepsis (n = 23), and septic shock (n = 22). All patients were evaluated for white blood cell (WBC), serum C-reactive protein (CRP), procalcitonin (PCT), IL-6, and sTREM-1 levels at 0, 24, and 72 h of admission. The prognostic evaluations were made using the Pediatric Risk of Mortality III (PRISM III) and Pediatric Logistic Organ Dysfunction (PELOD) scores. Patients were evaluated in terms of age, gender, prognosis, pathogen growth in culture, PRISM III and PELOD score, WBC, CRP, PCT, IL-6, and sTREM-1 levels and a comparison was made between groups.

RESULTS

There was no significant difference between all groups in terms of the 0-, 24-, and 72-h sTREM-1 values (p = 0.761, p = 0.360, and p = 0.822, respectively). CRP and PCT values did not differ between the septic shock, sepsis, and SIRS groups at 0, 24, and 72 h. In the septic shock group, the 0-h IL-6 value was significantly higher than that of the SIRS group (p = 0.025). The 24-h IL-6 value in the septic shock group was significantly higher than the values of the sepsis and SIRS groups (p = 0.048 and p = 0.043, respectively). No significant difference was detected between the septic shock, sepsis, and SIRS groups in terms of IL-6 values at 72 h.

CONCLUSION

sTREM-1 is not useful for the diagnosis of infection and for distinguishing between sepsis, septic shock, and SIRS since it does not offer a clear diagnostic value for PICU patients, unlike other reliable markers such as WBC, CRP, and PCT. Elevated IL-6 levels may indicate septic shock in PICU patients. More research on sTREM-1 is needed in this setting.