Urine TREM-1 as a marker of urinary tract infection in children

The Diagnostic Value of Soluble Triggering Receptor Expressed on Myeloid Cells for Patients with Acute Stone Pyelonephritis

Soluble triggering receptor expressed on myeloid cells (sTREM-1) is a new biomarker that can be used for the diagnosis and monitoring of urinary system infections. This study aimed to evaluate the diagnostic performance of serum sTREM-1 in patients with a diagnosis of acute stone pyelonephritis (ASP). This prospective study included 46 patients with a diagnosis of ASP and a control group of 23 individuals without urinary system infection. Blood samples were taken from participants upon hospital admission, and basal serum sTREM-1 levels were analyzed using the ELISA method. Serum sTREM-1 concentrations were measured after treatment of ASP patients. Basal leukocyte counts, C-reactive protein (CRP) levels, procalcitonin (PCT), and sTREM-1 (98.6 vs. 68.4 pg/mL, p < 0.001) levels were higher in the ASP group compared to the control group. After treatment, the median leukocyte counts, PCT, and sTREM-1 levels decreased and were similar to those of the control group. The median CRP level also decreased after treatment, but it remained higher than that of the control group. In predicting patients with ASP, the baseline sTREM-1 exhibited a sensitivity of 74.6% and a specificity of 78.2%, while its diagnostic performance was lower than that of leukocyte counts, CRP, and PCT. Despite the findings that levels of sTREM-1 were higher upon hospital admission in patients with ASP and significantly decreased after treatment, the utility of sTREM-1 as a biomarker for predicting patients with ASP remains constrained when compared to established inflammatory markers.

Transcriptional alterations in bladder epithelial cells in response to infection with different morphological states of uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) may undergo a cyclic cascade of morphological alterations that are believed to enhance the potential of UPEC to evade host responses and re-infect host cell. However, knowledge on the pathogenic potential and host activation properties of UPEC during the morphological switch is limited. Microarray analysis was performed on mRNA isolated from human bladder epithelial cells (HBEP) after exposure to three different morphological states of UPEC (normal coliform, filamentous form and reverted form). Cells stimulated with filamentous bacteria showed the lowest number of significant gene alterations, although the number of enriched gene ontology classes was high suggesting diverse effects on many different classes of host genes. The normal coliform was in general superior in stimulating transcriptional activity in HBEP cells compared to the filamentous and reverted form. Top-scored gene entities activated by all three morphological states included IL17C, TNFAIP6, TNF, IL20, CXCL2, CXCL3, IL6 and CXCL8. The number of significantly changed canonical pathways was lower in HBEP cells stimulated with the reverted form (32 pathways), than in cells stimulated with the coliform (83 pathways) or filamentous bacteria (138 pathways). A host cell invasion assay showed that filamentous bacteria were unable to invade bladder cells, and that the number of intracellular bacteria was markedly lower in cells infected with the reverted form compared to the coliform. In conclusion, the morphological state of UPEC has major impact on the host bladder response both when evaluating the number and the identity of altered host genes and pathways.

Diagnostic Value of Plasma Soluble Triggering Receptor Expressed on Myeloid Cells-1 in Children with Urinary Tract Infections

Objective The aim of the present study was to evaluate the diagnostic value of soluble triggering receptor on myeloid cells-1 as a novel marker for diagnosis of childhood urinary tract infections (UTI).

Methods This study enrolled 30 pediatric patients diagnosed with acute febrile UTIs; 30 healthy children were included as the control group. The blood samples from the patients and healthy controls were collected for a soluble triggering receptor on myeloid cells-1 (sTREM-1) test.

Results The study group was composed of 9 males and 21 females, and the mean age of the study population was 6.6 ± 3.2 (range = 1–14) years. sTREM-1 levels were significantly higher in UTI patients than in the controls (592 ± 323 vs. 490 ± 299 pg/mL, p = 0.04). The receiver operating curve analysis revealed a cut-off value of soluble triggering receptor expressed on myeloid cells-1 of 514 ng/mL (area under the curve = 0.562). When the cut-off value was taken 514 pg/mL, soluble triggering receptor expressed on myeloid cells-1 had a sensitivity of 57% and a specificity of 50% for the diagnosis of UTI.

Conclusion The present study revealed that plasma sTREM-1 level may be elevated in UTI and may therefore serve as a useful predictive tool for the diagnosis of UTI.

Biomarkers in urinary tract infections - which ones are suitable for diagnostics and follow-up?

Introduction: Urinary tract infections (UTIs) are one of the most common infections worldwide. Under special circumstances, clinicians must rely on laboratory findings, which might have a weak predicting value, misguiding the practitioners and leading to incorrect diagnosis and overuse of antibiotics. Therefore, there is an urgent need for reliable biomarkers in UTIs. Methods: We performed a literature search for biomarkers used in UTIs from January 1999 until May 2020. We used "urinary tract infection" and "biomarker" as the main key words in the PubMed, Medline and Cochrane databases. After peer review, we excluded the duplicates and identified the suitable articles, from which we collected the data and divided the available biomarkers into 5 groups: i) conventional markers; ii) promising, thoroughly studied biomarkers; iii) promising biomarkers that need further studies; iv) biomarkers of unknown significance; v) controversial, not useful markers. Results: We found 131 articles, mostly from the paediatric population. Neutrophil gelatinase-associated lipocalin (NGAL) and interleukins (IL) have a leading role in diagnosing and differentiating UTIs based on a lot of observational, comparative trials. Heparin Binding Protein (HBP), Lactoferrin (LF), Heat-Shock Protein-70 (HSP-70), Human Defensin-5 (HD-5), Lipopolysaccharide Binding Protein (LBP) and mass spectrometry studies are promising, but confirming data are lacking. The measurable components of the innate immune system and local host cell response could be appropriate biomarkers, but their significance is currently unknown. Conclusions: Conventional biomarkers for UTIs have low specificity. The use of urinary NGAL and interleukins could improve the sensitivity and specificity of laboratory diagnosis of UTIs.

Human Islet Response to Selected Type 1 Diabetes-Associated Bacteria: A Transcriptome-Based Study

Type 1 diabetes (T1D) is a chronic autoimmune disease that results from destruction of pancreatic β-cells. T1D subjects were recently shown to harbor distinct intestinal microbiome profiles. Based on these findings, the role of gut bacteria in T1D is being intensively investigated. The mechanism connecting intestinal microbial homeostasis with the development of T1D is unknown. Specific gut bacteria such as Bacteroides dorei (BD) and Ruminococcus gnavus (RG) show markedly increased abundance prior to the development of autoimmunity. One hypothesis is that these bacteria might traverse the damaged gut barrier, and their constituents elicit a response from human islets that causes metabolic abnormalities and inflammation. We have tested this hypothesis by exposing human islets to BD and RG in vitro, after which RNA-Seq analysis was performed. The bacteria altered expression of many islet genes. The commonly upregulated genes by these bacteria were cytokines, chemokines and enzymes, suggesting a significant effect of gut bacteria on islet antimicrobial and biosynthetic pathways. Additionally, each bacteria displayed a unique set of differentially expressed genes (DEGs). Ingenuity pathway analysis of DEGs revealed that top activated pathways and diseases included TREM1 signaling and inflammatory response, illustrating the ability of bacteria to induce islet inflammation. The increased levels of selected factors were confirmed using immunoblotting and ELISA methods. Our data demonstrate that islets produce a complex anti-bacterial response. The response includes both symbiotic and pathogenic aspects. Both oxidative damage and leukocyte recruitment factors were prominent, which could induce beta cell damage and subsequent autoimmunity.

Diagnostic value of urine soluble triggering receptor expressed on myeloid cells (sTREM-1) for late-onset neonatal sepsis in infected preterm neonates

Objective

Sepsis is a complex clinical condition caused by a dysregulated immune response to an infection resulting in a fatal outcome. This study aimed to investigate the value of urine soluble triggering receptor expressed on myeloid cells (sTREM-1) for diagnosing culture-proven sepsis in preterm infants.

Methods

Preterm neonates were evaluated for late-onset sepsis (LOS). Laboratory investigations were performed. Urine sTREM-1 samples and blood cultures were synchronously collected. Using blood culture results, preterm neonates were divided into the culture-proven group and suspected sepsis group.

Results

A total of preterm 62 infants were included in the study; 31 had culture-proven sepsis and 31 were suspected as having sepsis. There were no significant differences in gestational age, sex, birth weight, and delivery mode between the groups. Neonates in the culture-proven group had significantly higher urine sTREM-1 levels than did those in the suspected sepsis group. Using a cut-off point for a urine sTREM-1 level of 78.5 pg/mL, the sensitivity was 0.90, specificity was 0.78, positive predictive value was 0.68, and negative predictive value was 0.94.

Conclusions

The present study highlights the role of urine sTREM-1 levels in LOS. Urine sTREM-1 may be a reliable and sensitive marker in detecting sepsis in preterm infants.