Diagnostic value of the soluble triggering receptor expressed on myeloid cells-1 in lower respiratory tract infections: a meta-analysis

TREM-1 as a Marker of Multiple Organ Failure in Cardiac Surgery

Systemic inflammatory response syndrome (SIRS) frequently accompanies early postoperative period after cardiac surgery and in some cases is complicated by multiple organ failure (MOF). Inherited variation in the innate immune response genes (e.g., TREM1) is among the major factors determining the development of SIRS and the risk of MOF. This research was aimed to study whether the polymorphisms within the TREM1 gene are associated with MOF after the coronary artery bypass graft (CABG) surgery. Here we enrolled 592 patients who underwent CABG surgery in the Research Institute for Complex Issues of Cardiovascular Diseases (Kemerovo, Russia) and documented 28 cases of MOF. Genotyping was performed by allele-specific PCR using TaqMan probes. In addition, we measured serum soluble triggering receptor expressed on myeloid cells 1 (sTREM-1) using enzyme-linked immunosorbent assay. Five polymorphisms (rs1817537, rs2234246, rs3804277, rs7768162 andrs4711668) within the TREM1 gene were significantly associated with MOF. Patients with MOF had higher serum sTREM-1 as compared with those without MOF at both pre- and post-intervention stages. Serum sTREM-1 was associated with the rs1817537,rs2234246 and rs3804277 polymorphisms within the TREM1 gene. Minor alleles within the TREM1 gene define the level of serum sTREM-1 and are associated with MOF after CABG surgery.

Comparison of CRP, Procalcitonin, Neutrophil Counts, Eosinophil Counts, sTREM-1, and OPN between Pneumonic and Nonpneumonic Exacerbations in COPD Patients

Introduction

The patients with community-acquired pneumonia (CAP) and acute exacerbations of COPD (AECOPD) could have a higher risk of acute and severe respiratory illness than those without CAP in AECOPD. Consequently, early identification of pneumonia in AECOPD is quite important. Methods. 52 subjects with AECOPD + CAP and 93 subjects with AECOPD from two clinical centers were enrolled in this prospective observational study. The values of osteopontin (OPN), soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), C-reactive protein (CRP), procalcitonin (PCT), eosinophil (EOS) counts, and neutrophil (Neu) counts in blood on the first day of admission and clinical symptoms were compared in AECOPD and AECOPD + CAP. In addition, subgroup analyses of biomarker difference were conducted based on the current use of inhaled glucocorticoids (ICS) or systemic corticosteroids (SCS).

Results

Patients with AECOPD + CAP had increased sputum volume, sputum purulence, diabetes mellitus, and longer hospital stays than AECOPD patients (p < 0.05). A clinical logistic regression model showed among the common clinical symptoms, purulent sputum can independently predict pneumonia in AECOPD patients after adjusting for a history of diabetes. At day 1, AECOPD + CAP patients had higher values of Neu, CRP, PCT, and OPN, while serum sTREM-1 levels and EOS counts were similar in the two groups. CRP fared best at predicting AECOPD with CAP (p < 0.05 for the test of difference), while OPN had similar accuracy with Neu, PCT, and purulent sputum (p > 0.05 for the test of difference). Multivariate analysis, including clinical symptoms and biomarkers, suggested that CRP ≥15.8 mg/dL at day 1 was a only promising predictor of pneumonia in AECOPD. CRP and OPN were not affected by ICS or SCS.

Conclusions

CRP ≥15.8 mg/dL is an ideal promising predictor of pneumonia in AECOPD, and its plasma level is not affected by ICS or SCS. The diagnostic performance of CRP is not significantly improved when combined with clinical symptoms or other markers (OPN, PCT, and Neu).

Role of triggering receptor expressed on myeloid cells-1 (TREM-1) in COVID-19 and other viral pneumonias: a systematic review and meta-analysis of clinical studies

Background

Triggering receptor expressed on myeloid cells-1 (TREM-1) has emerged as an important inflammatory marker of immune response associated with severity and mortality outcomes in infection diseases, including viral pneumonias.

Aim

(1) To evaluate the expression of TREM-1 in patients with COVID-19 and other viral pneumonias compared to healthy individuals; and (2) to analyze the levels of these biomarkers according to disease severity.

Materials and methods

This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Searches were performed in PubMed, Scopus, Embase, and Google Scholar. Studies were considered eligible if they were observational studies that provided data on the levels of TREM-1 in humans with viral pneumonia compared to healthy controls. The results of the meta-analysis were expressed as standardized mean difference (SMD) and an effect size of 0.8 was considered a large effect. A subgroup analysis was performed according to the disease severity.

Results

Seven studies were included in this systematic review. Four studies included patients with COVID-19 and three analyzed patients with different viruses. The meta-analysis was performed only with patients with COVID-19, which showed increased levels of soluble form of TREM-1 (sTREM-1) among patients with COVID-19 compared to healthy controls (SMD 1.53; 95% CI 0.53–2.52; p < 0.01). No differences were found between patients with mild-to-moderate COVID-19 and healthy controls, but higher levels of sTREM-1 were shown among patients with severe COVID-19 (SMD 1.83; 95% CI 0.77–2.88; p < 0.01). All three studies including patients with other viral pneumonias showed that TREM-1 levels were significantly elevated in infected patients compared with controls.

Conclusion

These findings may provide evidence on the pro-inflammatory role of TREM-1 in these infections, contributing to the inflammatory profile and disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10787-022-00972-6.

Evaluation of "soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), interleukin-1β, and matrix metalloproteinase-8" as a short panel of salivary biomarkers in patients with and without stage III/IV periodontitis and type 2 diabetes mellitus

Background and aim

Periodontitis involves a dynamic disease process, demanding the identification of biomarkers to diagnose the current state of disease activity. Therefore this study assessed the potential of "sTREM-1, IL-1β, and MMP-8" as a short panel of biomarkers of host biological process indicating the inflammatory burden in periodontium and thereby serving as a panel of diagnostic markers in periodontal disease.

Methods

Sixty eight patients were recruited and allotted into four groups comprising of subjects with clinically healthy gingiva and Stage III/IV Periodontitis with and without type 2 diabetes with HbA1c levels in the range of 6.5-7.9%. Periodontal parameters were measured and full mouth radiographic assessment was done. Whole saliva (unstimulated) samples were collected from all patients and estimation of the levels of markers was done employing ELISA.

Results

All the three biomarkers were noted to be the lowest in group I (sTREM-1: 75.63 ± 13.77; IL-1β: 15.67 ± 3.39; MMP-8: 85.83 ± 22.32) and highest in group IV (sTREM-1: 138.83 ± 14.89; IL-1β: 39.19 ± 7.20; MMP-8: 201.15 ± 50.32) with statistically significant difference. The difference observed between groups II and III for all the biomarkers assessed were statistically insignificant. The clinical parameters and HbA1c levels had positive correlation with the levels of biomarkers which was statistically significant.

Conclusion

This study unveils the potential of the short panel of biomarkers ("sTREM-1, IL-1β, and MMP-8") to be used as diagnostic and possible prognostic markers for Periodontitis. It further corroborates the role of type 2 diabetes mellitus in amplifying the diverse processes that result in periodontal destruction.

Utility of presepsin, soluble triggering receptor expressed on myeloid cells-1, and neutrophil CD64 for early detection of neonatal sepsis

Background

Neonatal sepsis (NS) is an important cause of morbidity and mortality among newborns. Its diagnosis depends mainly on blood culture that takes at least 48 hours to give results. Therefore, searching for biomarkers for early diagnosis is of value. We aimed to assess presepsin, soluble triggering receptor expressed on myeloid cells (sTREM-1), and neutrophil CD64 (nCD64) as early diagnostic biomarkers in NS, and to compare them individually and in combination.

Methods

This hospital-based case–control study has been conducted on 60 full-term neonates recruited from the neonatal intensive care unit, Al-Zahraa Hospital, Al-Azhar University, Cairo, Egypt. Thirty infants with sepsis were compared to 30 postnatal age- and sex-matched healthy controls. Studied neonates were evaluated using clinical and laboratory indicators for sepsis. nCD64 was measured by flow cytometry and, serum presepsin and sTREM-1 were measured by ELISA.

Results

Presepsin, sTREM-1, and nCD64 levels were significantly elevated in septic neonates vs control group (P<0.05). The sensitivities of presepsin, sTREM, and nCD64 were 100%, 96.7%, and 86.7%, respectively. Presepsin had the best diagnostic performance in early diagnosis of NS followed by sTREM-1 and nCD64.

Conclusion

Presepsin and sTREM-1 are promising biomarkers in screening for NS in comparison with nCD64. However, nCD64 is better used in combination with other biomarkers as CRP.

Soluble Siglec-14 glycan-recognition protein is generated by alternative splicing and suppresses myeloid inflammatory responses

Human sialic acid-binding immunoglobulin-like lectin 14 (Siglec-14) is a glycan-recognition protein that is expressed on myeloid cells, recognizes bacterial pathogens, and elicits pro-inflammatory responses. Although Siglec-14 is a transmembrane protein, a soluble form of Siglec-14 is also present in human blood. However, the mechanism that generates soluble Siglec-14 and what role this protein form may play remain unknown. Here, investigating the generation and function of soluble Siglec-14, we found that soluble Siglec-14 is derived from an alternatively spliced mRNA that retains intron 5, containing a termination codon and thus preventing the translation of exon 6, which encodes Siglec-14's transmembrane domain. We also note that the translated segment in intron 5 encodes a unique C-terminal 7-amino acid extension, which allowed the specific antibody-mediated detection of this isoform in human blood. Moreover, soluble Siglec-14 dose-dependently suppressed pro-inflammatory responses of myeloid cells that expressed membrane-bound Siglec-14, likely by interfering with the interaction between membrane-bound Siglec-14 and Toll-like receptor 2 on the cell surface. We also found that intron 5 contains a G-rich segment that assumes an RNA tertiary structure called a G-quadruplex, which may regulate the efficiency of intron 5 splicing. Taken together, we propose that soluble Siglec-14 suppresses pro-inflammatory responses triggered by membrane-bound Siglec-14.

Soluble TREM-1 as a predictive factor of neonatal sepsis: a meta-analysis

BACKGROUND

The efficacy of soluble triggering receptor expressed on myeloid cell-1 (TREM-1) in detecting sepsis in adults has already been proven. To date, however, consensus in the field of neonatal sepsis is lacking. The purpose of the present systematic review is to accumulate current evidence in this field.

SEARCH STRATEGY

We systematically searched Medline (1966-2017), Scopus (2004-2017), Clinicaltrials.gov (2008-2017), EMBASE (1980-2017), Cochrane Central Register of Controlled Trials CENTRAL (1999-2017) and Google Scholar (2004-2017) along with reference lists from included studies.

MAIN RESULTS

Eight studies were finally included in the present analysis, with a total number of 667 neonates. The estimated sensitivity for the summary point was 0.95 [95% CI (0.81-0.99)] and the specificity was 0.87 [95% CI (0.56-0.97)]. The diagnostic odds ratio was calculated at 132.49 [95% CI (6.85-2560.70)]. Fagan's nomogram demonstrated that the post-test probability increased to 71% and decreased to 2%, when the pre-test probability was set at 25%. However, significant discrepancy was observed in terms of the used cut-offs; therefore, the sensitivity and specificity presented in our meta-analysis should be reviewed with caution, as they may present an overestimation of the actual predictive efficacy of this protein.

CONCLUSION

Current evidence suggests that sTREM-1 may become a useful biomarker for the prediction of neonatal sepsis. However, the small number of studies and the variation of the threshold values limit its implementation in clinical practice. Future large-scale studies are needed to determine the optimal cut-off value that may discriminate normal levels from those suggestive of the presence of neonatal sepsis.

Soluble triggering receptor expressed on myeloid cell-1 (sTREM-1): a potential biomarker for the diagnosis of infectious diseases

Sensitive and useful biomarkers for the diagnosis and prognosis of infectious diseases have been widely developed. An example of these biomarkers is triggering receptor expressed on myeloid cell-1 (TREM-1), which is a cell surface receptor expressed on monocytes/macrophages and neutrophils. TREM-1 amplifies inflammation by activating the TREM-1/DAP12 pathway. This pathway is triggered by the interaction of TREM-1 with ligands or stimulation by bacterial lipopolysaccharide. Consequently, pro-inflammatory cytokines and chemokines are secreted. Soluble TREM-1 (sTREM-1) is a special form of TREM-1 that can be directly tested in human body fluids and well-known biomarker for infectious diseases. sTREM-1 level can be potentially used for the early diagnosis and prognosis prediction of some infectious diseases, including infectious pleural effusion, lung infections, sepsis, bacterial meningitis, viral infections (e.g., Crimean Congo hemorrhagic fever and dengue fever), fungal infections (e.g., Aspergillus infection), and burn-related infections. sTREM-1 is a more sensitive and specific biomarker than traditional indices, such as C-reactive protein and procalcitonin levels, for these infectious diseases. Therefore, sTREM-1 is a feasible biomarker for the targeted therapy and rapid and early diagnosis of infectious diseases.

Role of sTREM-1 in predicting mortality of infection: a systematic review and meta-analysis

OBJECTIVES

Several studies have investigated the prognostic value of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in patients with infection. However, the result was controversial. Thus, the purpose of the present meta-analysis was to determine the prognostic value of the sTREM-1 level in predicting mortality at the initial stage of infection.

METHODS

The literature was searched in the PubMed, EMBASE, Web of Knowledge and Cochrane databases. A 2×2 contingency table was constructed on the basis of mortality and sTREM-1 levels in patients with infection. 2 authors independently judged study eligibility and extracted data. The prognostic value of sTREM-1 in predicting mortality was determined using a bivariate meta-analysis model. Q-test and I(2) index were used to test heterogeneity.

RESULTS

9 studies were selected from 803 studies. An elevated sTREM-1 level was associated with a higher risk of death in infection, with pooled risk ratio (RR) was 2.54 (95% CI 1.77 to 3.65) using a random-effects model (I(2)=53.8%). With the bivariate random-effects regression model, the pooled sensitivity and specificity of sTREM-1 to predict mortality in infection were 0.75 (95% CI 0.61 to 0.86) and 0.66 (95% CI 0.54 to 0.75), respectively. The diagnostic OR was 6 (95% CI 3 to 10). The overall area under the summary receiver operator characteristic (SROC) curve was 0.76 (95% CI 0.72 to 0.79). When we calculated the sepsis subgroup, the pooled RR was 2.98 (95% CI 2.19 to 4.40). The pooled sensitivity and specificity were 0.74 (95% CI 0.58 to 0.85) and 0.72 (95% CI 0.62 to 0.80), respectively. The overall area under the SROC curve was 0.78 (95% CI 0.74 to 0.81).

CONCLUSIONS

Elevated sTREM-1 concentrations had a moderate prognostic significance in assessing the mortality of infection in adult patients. However, sTREM-1 alone is insufficient to predict mortality as a biomarker.

Toll-like receptors, triggering receptor expressed on myeloid cells family members and receptor for advanced glycation end-products in allergic airway inflammation

Asthma is a chronic disorder of the airways characterized by cellular infiltration, airway hyper-responsive and airway inflammation. Innate immune cells are the first line of defense against endogenous and exogenous signals in the airways and as such possess a diverse array of pattern recognition receptors. Toll-like receptors are crucial sentinels which when activated, can either promote or ameliorate the inflammatory response in predisposed individuals. The recently discovered triggering receptor expressed on myeloid cells family members are emerging mediators of inflammation. These receptors are believed to modulate inflammatory responses by collaborating with classic PRRs. Endogenous signals like HMGB-1, signaling through the receptor for advanced glycation end products, also promotes inflammation, however, its contribution to inflammation in the airways is not well known. Here, we discuss the role of each receptor in airway inflammation and highlight potential synergistic mechanisms, which contribute to disease pathogenesis in allergic asthma.

Improving diagnosis of pneumococcal disease by multiparameter testing and micro/nanotechnologies

The diagnosis and management of pneumococcal disease remains challenging, in particular in children who often are asymptomatic carriers, and in low-income countries with a high morbidity and mortality from febrile illnesses where the broad range of bacterial, viral and parasitic cases are in contrast to limited, diagnostic resources. Integration of multiple markers into a single, rapid test is desirable in such situations. Likewise, the development of multiparameter tests for relevant arrays of pathogens is important to avoid overtreatment of febrile syndromes with antibiotics. Miniaturization of tests through use of micro- and nanotechnologies combines several advantages: miniaturization reduces sample requirements, reduces the use of consumables and reagents leading to a reduction in costs, facilitates parallelization, enables point-of-care use of diagnostic equipment and even reduces the amount of potentially infectious disposables, characteristics that are highly desirable in most healthcare settings. This critical review emphasizes our vision on the importance of multiparametric testing for diagnosing pneumococcal infections in patients with fever and examines recent relevant developments in micro/nanotechnologies to achieve this goal.

Chronic inflammation and cancer: emerging roles of triggering receptors expressed on myeloid cells

Inflammation is tightly regulated by a vast system that is intricately interconnected with innate immunity. Aberrations in expression or signaling, such as in innate immune receptors, can create excessive inflammation and, when chronic, often promote oncogenesis. The triggering receptor expressed on myeloid cells receptor family has been characterized as a major player in the amplification and signaling of the inflammatory response. In a number of chronic inflammatory conditions and malignancies, the triggering receptor expressed on myeloid cells has been implicated in disease severity and progression. In this article, the current understanding of triggering receptor expressed on myeloid cells function in pre-malignant, malignant and chronic inflammatory conditions is critically reviewed. The potential for therapeutic application is also discussed.