Biomarkers and infection in the emergency unit

Predicting sepsis at emergency department triage: Implementing clinical and laboratory markers within the first nursing assessment to enhance diagnostic accuracy

BACKGROUND

Early identification of sepsis in the emergency department (ED) triage is both valuable and challenging. Numerous studies have endeavored to pinpoint clinical and biochemical criteria to assist clinicians in the prompt diagnosis of sepsis, but few studies have assessed the efficacy of these criteria in the ED triage setting. The aim of the study was to explore the accuracy of clinical and laboratory markers evaluated at the triage level in identifying patients with sepsis.

METHODS

A prospective study was conducted in a large academic urban hospital, implementing a triage protocol aimed at early identification of septic patients based on clinical and laboratory markers. A multidisciplinary panel of experts reviewed cases to ensure accurate identification of septic patients. Variables analyzed included: Charlson comorbidity index, mean arterial pressure (MAP), partial pressure of carbon dioxide (PetCO2), white cell count, eosinophil count, C-reactive protein to albumin ratio, procalcitonin, and lactate.

RESULTS

A total of 235 patients were included. Multivariable analysis identified procalcitonin ≥1 ng/mL (OR 5.2; p < 0.001); CRP-to-albumin ratio ≥32 (OR 6.6; p < 0.001); PetCO2 ≤ 28 mmHg (OR 2.7; p = 0.031), and MAP <85 mmHg (OR 7.5; p < 0.001) as independent predictors for sepsis. MAP ≥85 mmHg, CRP/albumin ratio <32, and procalcitonin <1 ng/mL demonstrated negative predictive values for sepsis of 90%, 89%, and 88%, respectively.

CONCLUSIONS

Our study underscores the significance of procalcitonin and mean arterial pressure, while introducing CRP/albumin ratio and PetCO2 as important variables to consider in the very initial assessment of patients with suspected sepsis in the ED.

CLINICAL RELEVANCE

Early identification of sepsis since the emergency department (ED) triage is challenging Implementing the ED triage protocol with simple clinical and laboratory markers allows to recognize patients with sepsis with a very good discriminatory power (AUC 0.88).

Severe Acute Bronchial Asthma with Sepsis: Determining the Status of Biomarkers in the Diagnosis of the Disease

Bronchial asthma is a widely prevalent illness that substantially impacts an individual's health standard worldwide and has a significant financial impact on society. Global guidelines for managing asthma do not recommend the routine use of antimicrobial agents because most episodes of the condition are linked to viral respiratory tract infections (RTI), and bacterial infection appears to have an insignificant impact. However, antibiotics are recommended when there is a high-grade fever, a consolidation on the chest radiograph, and purulent sputum that contains polymorphs rather than eosinophils. Managing acute bronchial asthma with sepsis, specifically the choice of whether or not to initiate antimicrobial treatment, remains difficult since there are currently no practical clinical or radiological markers that allow for a simple distinction between viral and bacterial infections. Researchers found that serum procalcitonin (PCT) values can efficiently and safely minimize antibiotic usage in individuals with severe acute asthma. Again, the clinical manifestations of acute asthma and bacterial RTI are similar, as are frequently used test values, like C-reactive protein (CRP) and white blood cell (WBC) count, making it harder for doctors to differentiate between viral and bacterial infections in asthma patients. The role and scope of each biomarker have not been precisely defined yet, although they have all been established to aid healthcare professionals in their diagnostics and treatment strategies.

Discrepancy of C-Reactive Protein, Procalcitonin and Interleukin-6 at Hospitalization: Infection in Patients with Normal C-Reactive Protein, Procalcitonin and High Interleukin-6 Values

C-reactive protein (CRP) or procalcitonin (PCT) alone has limitations in the early detection of infection or inflammation due to shortcomings in specificity and varied cut-off values. Recently, interleukin (IL)-6 has been assessed, but it is not known to what extent the three values are homogeneous in reality. This retrospective study was conducted with two large datasets (discrepancy set with results within 24 h of admission [7149 patients] and follow-up set until 2 weeks of hospital stay [5261 tests]) consisting of simultaneous examinations of CRP, PCT, and IL-6 between January 2015 and August 2021. The specific discrepant group (n = 102, 1.4%) with normal CRP (<10 mg/L) and PCT (<0.1 ng/mL) and high IL-6 (≥100 pg/mL) values was extracted from the discrepancy set. Dimensionality reduction and visualization were performed using Python. The three markers were not clearly clustered after t-distributed stochastic neighbor embedding. Pearson’s correlation coefficients between two markers were substantially low (0.23−0.55). Among the high normalized IL-6 levels (≥0.5) (n = 349), 17.8% and 38.7% of CRP and PCT levels were very low (≤0.01). 9.2% and 13.4% of normal CRP (n = 1522) had high PCT (≥0.5 ng/mL) and IL-6 (≥100 pg/mL) values, respectively. Infection and bacteremia among 102 patients occurred in 36 (35.3%) and 9 (8.8%) patients, respectively. In patients with bacteremia, IL-6 was the first to increase, followed by PCT and CRP. Our study revealed that CRP, PCT, and IL-6 levels were considerably discrepant, which could be misinterpreted if only CRP tests are performed.

DIAGNOSTIC ACCURACY AND ADDED VALUE OF INFECTION BIOMARKERS IN PATIENTS WITH POSSIBLE SEPSIS IN THE EMERGENCY DEPARTMENT

ABSTRACT

Background: Biomarkers for early recognition of infection are warranted. The hypothesis of this study was that calprotectin, C-reactive protein (CRP), IL-6 and procalcitonin (PCT), alone or in combination, provide clinically useful information to the clinicians for early identification of infection in patients with possible sepsis in the emergency department (ED). Biomarker dynamics in the first week of hospitalization were explored. Methods: Adult patients in rapid response teams in the ED were included in a prospective observational study (n = 391). Patients who received antibiotics after biomarker availability were excluded. The ED clinician (EDC) decision whether to start antibiotics was registered. Calprotectin, CRP, IL-6, and PCT were analyzed in blood samples drawn within 15 min after ED arrival and in a subgroup for 1 week. Infection likelihood was evaluated post hoc . Results: In identifying patients with infection, CRP (area under the receiver operating characteristic curve [AUC], 0.913) and IL-6 (AUC, 0.895) were superior to calprotectin (AUC, 0.777) and PCT (AUC, 0.838). The best regression model predicting infections included EDC, CRP, and IL-6. Using optimal cutoff values, CRP and IL-6 in combination reached 95% positive and 90% negative predictive values for infection. The EDC undertreated or overtreated 65 of 391 patients (17%), and CRP and IL-6 optimal cutoff values could correct this in 32 of 65 patients (49%). Longitudinal samples revealed that IL-6 peaked in the ED, whereas CRP and PCT peaked later. Conclusion: C-reactive protein and IL-6 were superior to calprotectin and PCT for recognizing infection in patients with possible sepsis in the ED. Combining these two biomarkers with different dynamics improved recognition of infection and could aid clinical management in rapid response teams in the ED.

Sphingosine-1-phosphate and CRP as potential combination biomarkers in discrimination of COPD with community-acquired pneumonia and acute exacerbation of COPD

Background

 Chronic obstructive pulmonary disease (COPD) is a significant public health concern. The patients with acute exacerbations of COPD (AECOPD) and pneumonia have similar clinical presentations. The use of conventional diagnostic markers, such as complete blood count with differential and C-reactive protein (CRP), is the current mainstream method for differentiating clinically relevant pneumonia from other mimics. However, those conventional methods have suboptimal sensitivity and specificity for patients with a clinical suspicion of infection. The limitations often cause the ambiguity of the initiation of antibiotic treatment. Recently, our pilot study suggested that the patients with pneumonia have significantly higher plasma Sphingosine-1-phosphate (S1P) levels than controls. The initial findings suggest that plasma S1P is a potential biomarker for predicting prognosis in pneumonia. The aim of this study was to evaluate the value of S1P and CRP for discriminating COPD with pneumonia and AECOPD in an Emergency Department (ED) setting.

Methods

 Patients diagnosed with AECOPD or COPD with pneumonia were recruited from the Emergency Department of Wan Fang Hospital. The clinical data, demographics, and blood samples were collected upon ED admission. The concentration of plasma S1P was measured by ELISA.

Results

 Thirty-nine patients with AECOPD and 78 with COPD plus pneumonia were enrolled in this observational study. The levels of blood S1P and CRP were significantly higher in patients with COPD plus CAP compared to those in AE COPD patients. The area under the receiver operator characteristic (ROC) curve for the S1P and CRP for distinguishing between patients with COPD plus CAP and AECOPD is 0.939 (95% CI: 0.894–0.984) and 0.886 (95% CI: 0.826–0.945), whereas the combination of S1P and CRP yielded a value of 0.994 (95% CI: 0.897–1.000). By comparing with CRP or S1P, combining CRP and S1P had significantly higher AUC value for differentiating between the COPD with pneumonia group and the AECOPD group.

Conclusions

Our findings suggest that S1P is a potential diagnostic biomarker in distinguishing COPD with CAP from AECOPD. Additionally, the diagnostic ability of S1P can be improved when used in combination with CRP.

A Clinical Diagnostic Study: Fibulin-2 is a Novel Promising Biomarker for Predicting Infection

Introduction

Infection remains a major cause of morbidity and mortality in hospital. As uncontrolled early infection may develop into systemic infection and eventually progress to sepsis, it is important to address infection at an early stage. Furthermore, early detection and prompt diagnosis of infection are the basis of clinical intervention. However, as a result of the interference of complex aetiologies, including fever and trauma, problems regarding the sensitivity and specificity of current diagnostic indices remain, such as for C-reactive protein (CRP), procalcitonin (PCT), white blood cells (WBC), neutrophil ratio (NEU%), interleukin-6 (IL-6) and D-dimer. As a result, there is an urgent need to develop new biomarkers to diagnose infection.

Methods

From January to October 2021, consecutive patients in the emergency department (ED) were recruited to investigate the feasibility of fibulin-2 as a diagnostic indicator of early infection. Fibulin-2 concentrations in plasma were determined with enzyme-linked immunosorbent assay (ELISA). The performance of fibulin-2 for predicting infection was analysed by receiver operating characteristic (ROC) curves.

Results

We found that the plasma fibulin-2 level was elevated in patients with infection compared with those without infection. ROC curve analysis showed that the area under the curve (AUC) for fibulin-2 was 0.712. For all patients included, the diagnostic ability of fibulin-2 (AUC 0.712) performed as well as CRP (AUC 0.667) and PCT (AUC 0.632), and better than WBC (AUC 0.620), NEU% (AUC 0.619), IL-6 (AUC 0.561) and D-dimer (AUC 0.630). In patients with fever, fibulin-2 performed as well as PCT and better than the other biomarkers in infection diagnosis. In particular, fibulin-2 performed better than all these biomarkers in patients with trauma.

Conclusion

Fibulin-2 is a novel promising diagnostic biomarker for predicting infection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-022-00622-y.

Use of infection biomarkers in the emergency department

The use of infection biomarkers in the emergency department is discussed in terms of their possible contributions to diagnostic-prognostic uncertainties, appropriate antibiotic treatments, and triage and follow-up planning. Procalcitonin (PCT), C-reactive protein (CRP), proadrenomedullin (proADM), and presepsin are among the most discussed infection biomarkers for use in the emergency department. Due to the variable sensitivity results and cutoff values, there are insufficient data to recommend the widespread use of CRP and procalcitonin (PCT) for the diagnosis and prognosis of infection in the emergency department. However, these biomarkers can be used for appropriate antibiotic use in selected infection groups, such as community-acquired pneumonia, especially to reduce unnecessary antibiotic prescribing. With its prognostic superiority over other biomarkers and its contribution to prognostic score systems in community-acquired pneumonia (CAP), proADM can be used to predict hospitalization, preferably within the scope of clinical studies. Although presepsin has been shown to have some advantages over other biomarkers to rule out sepsis, there are insufficient data for its clinical use in the emergency department.

Prognostic Role of Serum Procalcitonin Measurement in Adult Patients Admitted to the Emergency Department with Fever

Background and Objectives. Fever is one of the most common presenting complaints in the Emergency Department (ED). This study aimed at evaluating the prognostic role of serum Procalcitonin (PCT) measurement among adult patients admitted to the ED with fever. Materials and Methods. This is a retrospective cross-sectional study including all consecutive patients admitted to ED with fever and subsequently hospitalized in a period of six-year (January 2014 to December 2019). Inclusion criteria were age > 18 years, fever (T ≥ 38 °C) or chills within 24 h from presentation to the ED as the main symptom, and availability of a PCT determination obtained <24 h since ED access. The primary endpoint was overall in-hospital mortality. Results. Overall, 6595 patients were included in the study cohort (3734 males, 55.6%), with a median age of 71 [58-81] years. Among these, based on clinical findings and quick sequential organ failure assessment (qSOFA), 422 were considered septic (36.2% deceased), and 6173 patients non-septic (16.2% deceased). After correction for baseline covariates, a PCT > 0.5 ng/mL was an independent risk factor for all-cause in-hospital death in both groups (HR 1.77 [1.27-2.48], and 1.80 [1.59-2.59], respectively). Conclusions. Among adult patients admitted with fever, the PCT assessment in ED could have reduced prognostic power for patients with a high suspicion of sepsis. On the other hand, it could be useful for sepsis rule-out for patients at low risk. In these latter patients, the prognostic role of PCT is higher for those with a final diagnosis of bloodstream infection.

Comparison of sPLA2IIA performance with high-sensitive CRP neutrophil percentage PCT and lactate to identify bacterial infection

Early bacterial infection (BI) identification in resource-limiting Emergency Departments (ED) is challenging, especially in low- and middle-income counties (LMIC). Misdiagnosis predisposes to antibiotic overuse and propagates antimicrobial resistance. This study evaluates new emerging biomarkers, secretory phospholipase A2 group IIA (sPLA2-IIA) and compares with other biomarkers on their performance characteristic of BI detection in Malaysia, an LMIC. A prospective cohort study was conducted involving 151 consecutive patients admitted to the ED. A single measurement was taken upon patient arrival in ED and was analysed for serum levels of sPLA2-IIA, high-sensitive C-reactive protein (CRP), procalcitonin (PCT), neutrophil percentage (N%), and lactate. All biomarkers' performance was compared for the outcomes using area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity. The performance of sPLA2-IIA (AUROC 0.93 [95% CI: 0.89-0.97]; Sn 80% [95% CI: 72-87]; Sp 94% [95% CI: 81-89]) was the highest among all. It was comparable with high-sensitive CRP (AUROC 0.93 [95% CI: 0.88-0.97]; Sn 75% [95% CI: 66-83]; Sp 91 [95% CI: 77-98]) but had a higher Sn and Sp. The sPLA2-IIA was also found superior to N%, PCT, and lactate. This finding suggested sPLA2-IIA was recommended biomarkers for BI detection in LMIC.

Neuropeptide signalling systems - An underexplored target for venom drug discovery

Neuropeptides are signalling molecules mainly secreted from neurons that act as neurotransmitters or peptide hormones to affect physiological processes and modulate behaviours. In humans, neuropeptides are implicated in numerous diseases and understanding their role in physiological processes and pathologies is important for therapeutic development. Teasing apart the (patho)physiology of neuropeptides remains difficult due to ligand and receptor promiscuity and the complexity of the signalling pathways. The current approach relies on a pharmacological toolbox of agonists and antagonists displaying high selectivity for independent receptor subtypes, with the caveat that only few selective ligands have been discovered or developed. Animal venoms represent an underexplored source for novel receptor subtype-selective ligands that could aid in dissecting human neuropeptide signalling systems. Multiple endogenous-like neuropeptides as well as peptides acting on neuropeptide receptors are present in venoms. In this review, we summarise current knowledge on neuropeptides and discuss venoms as a source for ligands targeting neuropeptide signalling systems.

[Association of non-thyroidal illness syndrome with interleukin-6 and interleukin-10 in critically ill children with sepsis]

OBJECTIVE

To study the incidence rate of non-thyroidal illness syndrome (NTIS) in critically ill children with or without sepsis and the association of NTIS with interleukin-6 (IL-6) and interleukin-10 (IL-10).

METHODS

A retrospective analysis was performed on the medical data of 97 children with sepsis (sepsis group) and 80 non-sepsis children with bacterial infection (non-sepsis group). The correlations of IL-6 and IL-10 with the thyroid function parameters triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) were analyzed.

RESULTS

There were no significant differences in age and sex between the sepsis and non-sepsis groups (P>0.05). Compared with the non-sepsis group, the sepsis group had a significantly higher Sequential Organ Failure Assessment score, a significantly longer length of hospital stay, and a significantly higher rate of use of ventilator (P<0.05). As for inflammation markers, the sepsis group had significantly higher levels of C-reactive protein, procalcitonin, and IL-6 than the non-sepsis group (P<0.05). As for thyroid function parameters, the sepsis group had significantly lower levels of T3, T4, free T3, free T4, and TSH than the non-sepsis group (P<0.05). Compared with the non-sepsis group, the sepsis group had significantly higher incidence rates of NTIS, low T3 and T4, and low TSH (P<0.001). The correlation analysis revealed that IL-6 level was not correlated with T3, T4, and TSH levels in children with or without sepsis (P>0.05), but the pooled analysis of the two groups showed that IL-6 level was negatively correlated with T3 and T4 levels (P<0.001).

CONCLUSIONS

Children with sepsis have a higher incidence rate of NTIS than those without sepsis. The high level of IL-6 may be associated with the development of NTIS.

Calprotectin, a new biomarker for diagnosis of acute respiratory infections

Respiratory tract infections require early diagnosis and adequate treatment. With the antibiotic overuse and increment in antibiotic resistance there is an increased need to accurately distinguish between bacterial and viral infections. We investigated the diagnostic performance of calprotectin in respiratory tract infections and compared it with the performance of heparin binding protein (HBP) and procalcitonin (PCT). Biomarkers were analyzed in patients with viral respiratory infections and patients with bacterial pneumonia, mycoplasma pneumonia and streptococcal tonsillitis (n = 135). Results were compared with values obtained from 144 healthy controls. All biomarkers were elevated in bacterial and viral infections compared to healthy controls. Calprotectin was significantly increased in patients with bacterial infections; bacterial pneumonia, mycoplasma pneumonia and streptococcal tonsillitis compared with viral infections. PCT was significantly elevated in patients with bacterial pneumonia compared to viral infections but not in streptococcal tonsillitis or mycoplasma caused infections. HBP was not able to distinguish between bacterial and viral causes of infections. The overall clinical performance of calprotectin in the distinction between bacterial and viral respiratory infections, including mycoplasma was greater than performance of PCT and HBP. Rapid determination of calprotectin may improve the management of respiratory tract infections and allow more precise diagnosis and selective use of antibiotics.

Accuracy of neutrophil lymphocyte ratio for diagnosis of acute appendicitis in children: A diagnostic study

Background

Many biomarkers for diagnosis of acute appendicitis in children have been reported, however, the results are still controversial. We assessed the accuracy of neutrophil-lymphocyte ratio (NLR) for diagnosis of acute appendicitis and discriminating simple and complicated appendicitis in children.

Methods

We included 121 patients with acute appendicitis and 49 children with intussusception as controls who were admitted at our hospital from 2013 to 2017. White blood count (WBC), neutrophil, and NLR were compared between groups.

Results

Neutrophil and NLR were significantly higher in the acute appendicitis group than control (76.17 ± 14.41 vs. 62.43 ± 15.9%, p=<0.0001; and 8.44 ± 6.63 vs. 3.38 ± 2.84, p=<0.0001, respectively), while WBC, neutrophil, and NLR were significantly greater in complicated than simple appendicitis (15.86 ± 6.48 vs. 12.64 ± 6.27 × 10³/μL, p = 0,008; 82.64 ± 8.41 vs. 68.99 ± 16.23%, p=<0.0001; and 11.32 ± 6.87 vs. 5.25 ± 4.65, p=<0.0001, respectively). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), area under the receiver operating characteristic (ROC) curve, and cutoff point of NLR for diagnosis of acute appendicitis were 83.5%, 57.7%, 81.4%, 61.2%, 0.764, and 2.87, respectively; whereas the sensitivity, specificity, PPV, NPV, area under the ROC curve, and cutoff point of NLR for differentiating complicated and simple appendicitis were 84.6%, 56.5%, 35.5%, 92.9%, 0.790, and 6.59, respectively.

Conclusion

NLR shows a high accuracy for diagnosis of acute appendicitis and distinguishing a complicated appendicitis from the simple one.

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Many biomarkers for diagnosis of acute appendicitis in children are still controversial.

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Neutrophil lymphocyte ratio (NLR) shows a high accuracy for diagnosis of acute appendicitis.

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NLR reveals a high accuracy for distinguishing a complicated appendicitis from the simple one.

Inflammation and remission in older patients with depression treated with electroconvulsive therapy; findings from the MODECT study✰

BACKGROUND

Compelling evidence links elevated levels of C-reactive protein (CRP) and other inflammatory markers to poor treatment outcome of antidepressant medication. Little is known about the contribution of low-grade inflammation to treatment response to electroconvulsive therapy (ECT) in severely depressed patients.

METHOD

Associations between serum levels of CRP, interleukin-6, interleukin-10, and tumour necrosis factor-α as well as remission of depression, time to remission, and speed of decline of depressive symptoms were examined in 95 older (mean age: 73.1 years) depressed patients treated with ECT.

RESULTS

Moderately elevated levels of CRP at baseline (3 to 10 mg/L), but no other inflammatory markers, were associated with higher remission rates. In patients with moderately elevated CRP levels, the odds ratio for remission was 3.62 (95% confidence interval [CI], 1.09-11.97; p = 0.04). Time to remission was shorter in those with moderately elevated CRP levels (p = 0.05). Speed of decline was higher in patients with moderately elevated CRP levels as compared with those with low CRP levels (decline of 3.2 Montgomery Åsberg Depression Rating Scale points per administration vs. 2.3 points per administration, p = 0.03).

LIMITATIONS

Because of the observational design, residual confounding through other lifestyle or demographic factors cannot be ruled out.

CONCLUSIONS

Although earlier studies showed that low-grade inflammation contributes to poor treatment response in those treated with antidepressants, our study provides clues that low-grade inflammation does not have such a detrimental effect on the treatment response to ECT. This is underscored by our finding that moderately elevated CRP levels were associated with increased remission rates in depressed patients treated with ECT. Replication studies are warranted.

Bedside-measurement of serum cholinesterase activity predicts patient morbidity and length of the intensive care unit stay following major traumatic injury

Major traumatic injury (MTI), a life-threatening condition requiring prompt medical intervention, is associated with an extensive inflammatory response often resulting in multiple organ dysfunction. Early stratification of trauma severity and the corresponding inflammation may help optimize resources at the intensive care unit (ICU). The cholinergic system counters inflammation by quickly modulating the immune response. Serum cholinesterase (butyrylcholinesterase, BChE) is an enzyme that hydrolyses acetylcholine. We tested whether a change in the BChE activity correlates with the morbidity and the length of ICU stay. Blood samples from 10 healthy volunteers and 44 patients with MTI were gathered at hospital admission, followed by measurements 12, 24 and 48 hours later. Point-of-care approach was used to determine the BChE activity. Disease severity was assessed by clinical scoring performed within 24 hours following hospital admission. BChE activity, measured at hospital admission, showed a significant and sustained reduction and correlated with disease severity scores obtained 24 hours following admission. BChE activity, obtained at hospital admission, correlated with the length of ICU stay. Bedside measurement of BChE activity, as a complementary addition to established procedures, might prove useful in the primary assessment of the disease severity and might therefore optimize therapy in the ICU.

Laryngoscope-assisted and cotton ball wiping methods in prevention of oral and pulmonary infection in patients receiving mechanical ventilation and the influence on hypersensitive C-reactive protein and procalcitonin

Effects of laryngoscope-assisted and cotton ball wiping methods on the prevention of oral and pulmonary infection in patients receiving mechanical ventilation were compared to explore the influence of the two methods on high-sensitivity C-reactive protein (hs-CRP) and procalcitonin (PCT). In total, 152 patients who underwent mechanical ventilation in the ICU of Beijing Jishuitan Hospital from May 2005 to January 2018 were assigned and equally divided into two groups: 76 patients who had their oropharynxes scrubbed and rinsed by an electric toothbrush under direct vision by the use of a laryngoscope were selected as the laryngoscope group, and 76 patients who received the conventional cotton ball wiping method and the flushing method for oropharyngeal cleaning were assigned in the cotton ball group. Detection of serum hs-CRP and PCT levels in a 2-ml sample of fasting venous blood was performed on both groups of patients before hospitalization, and on the 5th and 10th day of hospitalization. The incidence rate of oral infection and ventilator-associated pneumonia, as well as the length of the cleaning time were recorded. The incidence rate of oral infection and ventilator-associated pneumonia in the laryngoscope group was statistically much lower than that in the cotton ball group (P<0.05). Before the experiment, there was no significant difference in the hs-CRP and PCT levels between the two groups (P>0.050), whereas the laryngoscope group had significantly lower hs-CRP and PCT levels at the 5th and 10th day of hospitalization than those in the cotton ball group (P<0.05). The hs-CRP and PCT levels at the three time-points in the same group were statistically different (P<0.05). In conclusion, oropharyngeal scrub and rinse by an electric toothbrush assisted by a laryngoscope, can not only better prevent oral infection and reduce the incidence of ventilator-associated pneumonia, but it also has shorter cleaning time and results in lower levels of inflammatory factors, which make this method beneficial in the clinic.

Serum and Synovial Fluid Interleukin-6 for the Diagnosis of Periprosthetic Joint Infection

A gold standard for diagnosis of periprosthetic joint infection (PJI) has not yet been established. The objective of this study was to evaluate the diagnostic value of serum and synovial fluid interleukin (IL)-6 levels for PJI. The MEDLINE and EMBASE databases were searched for studies describing PJI diagnosis using serum and synovial fluid IL-6 and published between January 1990 and October 2016. Seventeen studies were included in the analysis. The pooled sensitivities of serum and synovial fluid IL-6 were 0.72 (95% confidence interval [CI]: 0.63–0.80) and 0.91 (95% CI: 0.82–0.96), respectively. The pooled specificities of serum and synovial fluid IL-6 were 0.89 (95% CI: 0.77–0.95) and 0.90 (95% CI: 0.84–0.95), respectively. The pooled diagnostic odds ratios (DORs) of serum and synovial fluid IL-6 were 20 (95% CI: 7–58) and 101 (95% CI: 28–358), respectively, and the pooled areas under the curve (AUCs) were 0.83 (95% CI: 0.79–0.86) and 0.96 (95% CI: 0.94–0.98), respectively. Synovial fluid IL-6 had high diagnostic value for PJI. Although serum IL-6 test was less sensitive than synovial fluid IL-6 test, it may be regularly prescribed for patients with prosthetic failure owing to its high specificity.

Presepsin is an early monitoring biomarker for predicting clinical outcome in patients with sepsis

Despite their undoubted helpfulness in diagnosing sepsis, increased blood C-reactive protein (CRP) and procalcitonin (PCT) levels have been described in many noninfectious conditions. Presepsin is a soluble fragment of the cluster of differentiation 14 involved in pathogen recognition by innate immunity. We aimed to investigate the diagnostic and prognostic performance of presepsin in comparison to PCT and CRP in patients presenting with systemic inflammatory response syndrome (SIRS) and suspected sepsis. Seventy-six subjects were enrolled in this study, including 51 patients with SIRS as well as 25 healthy subjects. Plasma presepsin, PCT and CRP levels were serially measured on admission and at days 1, 3, 7 and 15. Presepsin and PCT yielded similar diagnostic accuracy, whereas presepsin performed significantly better than CRP. Presepsin and PCT showed comparable performance for predicting 28-day mortality, and both biomarkers performed significantly better than CRP. In septic patients, presepsin revealed earlier concentration changes over time when compared to PCT and CRP. Presepsin and PCT could differentiate between septic and non-septic patients with comparable accuracy and both biomarkers showed similar performance for predicting 28-day mortality. Early changes in presepsin concentrations might reflect the appropriateness of the therapeutic modality and could be useful for making effective treatment decisions.

Elevated miR-155 expression induces immunosuppression via CD39(+) regulatory T-cells in sepsis patient

BACKGROUND

An altered microRNA profile exists in many infectious diseases, including sepsis. CD39(+) regulatory T-cells (Tregs) have a remarkable immunosuppressive effect and play an important role in the regulation of immune balance in sepsis. However, the correlation between microRNA changes and the ratio of CD39(+) Tregs in sepsis patients has not yet been reported. The altered microRNA expression profile in sepsis patients was analyzed in this study. Moreover, the correlation between microRNAs and disease severity and prognosis was investigated. Furthermore, the correlation between microRNAs and the percentage of peripheral blood CD39(+) Tregs was investigated and further verified in an animal model.

METHODS

Sixty sepsis patients and 30 healthy controls were included. The difference in microRNA expression was investigated by microRNA microarray and was further confirmed by real-time quantitative PCR. The correlations between microRNA changes and the Sepsis-related Organ Failure Assessment (SOFA) score, severity of sepsis, and survival were analyzed. The percentage CD39(+) Tregs in the peripheral blood of sepsis patients was measured by flow cytometry. The correlation between microRNAs and the percentage CD39(+) Tregs was analyzed and further confirmed in a mouse sepsis model.

RESULTS

Compared to healthy controls, sepsis patients exhibited a significantly elevated microRNA-155 (miR-155) level (p < 0.05), which was positively related to a higher SOFA score (r = 0.641, p < 0.05) and a greater severity of sepsis. The area under the receiver operating characteristic curve of miR-155 used for the prediction of 28-day survival was 0.763, with a cut-off point of 2.47. Patients with a miR-155 level >2.47 had a lower 28-day survival (p < 0.05). The miR-155 level of patients was proportional to the percentage of CD39(+) Tregs (r = 0.637, p < 0.05). After transfection with miR-155 inhibitor, the ratio of CD39(+) Tregs in mice with sepsis was significantly reduced (p < 0.05).

CONCLUSIONS

A higher level of miR-155 indicated a more severe condition and poorer prognosis in sepsis patients. The possible underlying mechanism could be that miR-155 induces an increased percentage of CD39(+) Tregs and thus immunosuppression.

Human Neutrophil Lipocalin as a Superior Diagnostic Means To Distinguish between Acute Bacterial and Viral Infections

The distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) concentrations in serum or whole blood activated by formyl-methionine-leucine-phenylalanine (fMLP) were shown to distinguish acute infections of bacterial or viral cause with high accuracy. The aim was therefore to compare the clinical performance of HNL with currently used biomarkers. Seven hundred twenty-five subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the study. C-reactive protein (CRP), the expression of CD64 on neutrophils, procalcitonin (PCT), and blood neutrophil counts were measured by established techniques, and HNL concentrations were measured in whole-blood samples after activation with fMLP. All tested biomarkers were elevated in bacterial as opposed to viral infections (P < 0.001). CRP, PCT, and CD64 expression in neutrophils was elevated in viral infections compared to healthy controls (P < 0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the receiver operating characteristic (ROC) curves were >0.85 for all biomarkers, whereas for the distinction between bacterial and viral infections, only HNL concentration in fMLP-activated whole blood showed an area under the ROC curve (AUROC) of >0.90 and superior clinical performance. The clinical performance of HNL in fMLP-activated whole blood was superior to current biomarkers and similar to previous results of HNL in serum. The procedure can be adopted for point-of-care testing with response times of <15 min.

Human neutrophil lipocalin in fMLP-activated whole blood as a diagnostic means to distinguish between acute bacterial and viral infections

The distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) in serum distinguishes acute infections with high accuracy, but in the emergency setting the assay time should be <15-20min, which excludes the use of serum samples. The aim was therefore to develop a novel rapid assay principle and test its clinical performance.

METHODS

Serum and neutrophils obtained from 84 infected and 20 healthy subjects were used in the experimental study. 725 subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the clinical study. HNL was measured in EDTA-plasma by ELISA or in heparinized whole blood after fMLP activation by a prototype point-of-care assay.

RESULTS

Increased release of HNL from neutrophils after activation with fMLP was seen already after 5 min incubation. The release of HNL from purified neutrophils after 15 min incubation with fMLP was significantly correlated to the HNL concentrations in serum obtained from the same patient (r = 0.74, p < 0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the ROC-curves were 0.95 (95% CI 0.91-0.97) and 0.88 (95% CI 0.84-0.91) for HNL in fMLP-activated whole blood and EDTA-plasma, respectively, (p < 0.001) and in the distinction between bacterial and viral infections 0.91 (95% CI 0.86-0.95) and 0.76 (95% CI 0.70-0.81), respectively (p < 0.001).

CONCLUSION

The clinical performance of HNL in fMLP-activated whole blood was superior to HNL in EDTA-plasma and similar to HNL in serum. The procedure can be adopted for point-of-care testing with response times of <15 min.

Low T3 syndrome in canine babesiosis associated with increased serum IL-6 concentration and azotaemia

Low triiodothyronine (T3) syndrome, also named euthyroid sick syndrome or non-thyroidal illness syndrome, has been recognized in canine babesiosis caused by Babesia rossi, where it manifested by lowering of the serum thyrotropin (TSH), total thyroxin (TT4) and free thyroxin (FT4) concentrations. This syndrome has also been observed in critical diseases in humans and animals, and the severity of the disease is considered an important factor in lowering of thyroid hormone concentrations. Interleukin-6 (IL-6) plays a role in the development of low T3 syndrome by causing a decrease in deiodinases 1 and 2 activity and increased activity of deiodinase 3, enzymes involved in the conversion of thyroxin (T4) to T3. The purpose of this study was to compare the concentrations of serum thyroid hormones and TSH between healthy dogs and dogs with babesiosis, and to determine correlations between serum IL-6 concentration and serum total T3 (TT3), TT4, FT4, and TSH concentrations, and the level of azotaemia in dogs with babesiosis. The concentrations of IL-6, TT3, TT4, FT4, TSH, urea and creatinine were determined in 13 dogs with canine babesiosis caused by Babesia canis and in 10 healthy dogs. The results of this study showed decreases in TT3, TT4, FT4, and TSH and increases in IL-6, urea and creatinine concentrations in affected dogs in comparison to healthy dogs. The concentration of IL-6 was negatively correlated with TT3 and TSH concentrations and the TT3 concentration was negatively correlated with serum urea and creatinine concentrations. This study showed low T3 syndrome in canine babesiosis, which was confirmed by the determination of the T3 concentration, and demonstrates that in canine babesiosis the T3 concentration is associated with IL-6 concentration.