Biomarkers Improve Diagnostics of Sepsis in Adult Patients With Suspected Organ Dysfunction Based on the Quick Sepsis-Related Organ Failure Assessment (qSOFA) Score in the Emergency Department.

OBJECTIVES: Consensus regarding biomarkers for detection of infection-related organ dysfunction in the emergency department is lacking. We aimed to identify and validate biomarkers that could improve risk prediction for overt or incipient organ dysfunction when added to quick Sepsis-related Organ Failure Assessment (qSOFA) as a screening tool. DESIGN: In a large prospective multicenter cohort of adult patients presenting to the emergency department with a qSOFA score greater than or equal to 1, admission plasma levels of C-reactive protein, procalcitonin, adrenomedullin (either bioavailable adrenomedullin or midregional fragment of proadrenomedullin), proenkephalin, and dipeptidyl peptidase 3 were assessed. Least absolute shrinkage and selection operator regression was applied to assess the impact of these biomarkers alone or in combination to detect the primary endpoint of prediction of sepsis within 96 hours of admission. SETTING: Three tertiary emergency departments at German University Hospitals (Jena University Hospital and two sites of the Charité University Hospital, Berlin). PATIENTS: One thousand four hundred seventy-seven adult patients presenting with suspected organ dysfunction based on qSOFA score greater than or equal to 1. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The cohort was of moderate severity with 81% presenting with qSOFA = 1; 29.2% of these patients developed sepsis. Procalcitonin outperformed all other biomarkers regarding the primary endpoint (area under the curve for receiver operating characteristic [AUC-ROC], 0.86 [0.79-0.93]). Adding other biomarkers failed to further improve the AUC-ROC for the primary endpoint; however, they improved the model regarding several secondary endpoints, such as mortality, need for vasopressors, or dialysis. Addition of procalcitonin with a cutoff level of 0.25 ng/mL improved net (re)classification by 35.2% compared with qSOFA alone, with positive and negative predictive values of 60.7% and 88.7%, respectively. CONCLUSIONS: Biomarkers of infection and organ dysfunction, most notably procalcitonin, substantially improve early prediction of sepsis with added value to qSOFA alone as a simple screening tool on emergency department admission.

Non-patient-related SARS-CoV-2 exposure from colleagues and household members poses the highest infection risk for hospital employees in a German university hospital: follow-up of the prospective Co-HCW seroprevalence study.

PURPOSE: The Co-HCW study is a prospective, longitudinal, single-center observational study that aims to assess the SARS-CoV-2 seroprevalence and infection status in staff members of Jena University Hospital (JUH) in Jena, Germany. METHODS: This follow-up study covers the observation period from 19th May 2020 to 22nd June 2021. At each of the three voluntary study visits, participants filled out a questionnaire regarding their SARS-CoV-2 exposure and provided serum samples to detect specific SARS-CoV-2 antibodies. Participants who were tested positive for antibodies against nucleocapsid and/or spike protein without previous vaccination and/or reported a positive SARS-CoV-2 PCR test were regarded to have been infected with SARS-CoV-2. Multivariable logistic regression modeling was applied to identify potential risk factors for infected compared to non-infected participants. RESULTS: Out of 660 participants that were included during the first study visit, 406 participants (61.5%) were eligible for the final analysis as their COVID-19 risk area (high-risk n = 76; intermediate-risk n = 198; low-risk n = 132) did not change during the study. Forty-four participants [10.8%, 95% confidence interval (95%CI) 8.0-14.3%] had evidence of a current or past SARS-CoV-2 infection detected by serology (n = 40) and/or PCR (n = 28). No association between SARS-CoV-2 infection and the COVID-19 risk group according to working place was detected. However, exposure to a SARS-CoV-2 positive household member [adjusted OR (AOR) 4.46, 95% CI 2.06-9.65] or colleague (AOR 2.30, 95%CI 1.10-4.79) was found to significantly increase the risk of a SARS-CoV-2 infection. CONCLUSION: Our results demonstrate that non-patient-related SARS-CoV-2 exposure posed the highest infection risk for hospital staff members of JUH.

Immunosuppressive effects of circulating bile acids in human endotoxemia and septic shock: patients with liver failure are at risk.

BACKGROUND: Sepsis-induced immunosuppression is a frequent cause of opportunistic infections and death in critically ill patients. A better understanding of the underlying mechanisms is needed to develop targeted therapies. Circulating bile acids with immunosuppressive effects were recently identified in critically ill patients. These bile acids activate the monocyte G-protein coupled receptor TGR5, thereby inducing profound innate immune dysfunction. Whether these mechanisms contribute to immunosuppression and disease severity in sepsis is unknown. The aim of this study was to determine if immunosuppressive bile acids are present in endotoxemia and septic shock and, if so, which patients are particularly at risk. METHODS: To induce experimental endotoxemia in humans, ten healthy volunteers received 2 ng/kg E. coli lipopolysaccharide (LPS). Circulating bile acids were profiled before and after LPS administration. Furthermore, 48 patients with early (shock onset within < 24 h) and severe septic shock (norepinephrine dose > 0.4 µg/kg/min) and 48 healthy age- and sex-matched controls were analyzed for circulating bile acids. To screen for immunosuppressive effects of circulating bile acids, the capability to induce TGR5 activation was computed for each individual bile acid profile by a recently published formula. RESULTS: Although experimental endotoxemia as well as septic shock led to significant increases in total bile acids compared to controls, this increase was mild in most cases. By contrast, there was a marked and significant increase in circulating bile acids in septic shock patients with severe liver failure compared to healthy controls (61.8 µmol/L vs. 2.8 µmol/L, p = 0.0016). Circulating bile acids in these patients were capable to induce immunosuppression, as indicated by a significant increase in TGR5 activation by circulating bile acids (20.4% in severe liver failure vs. 2.8% in healthy controls, p = 0.0139). CONCLUSIONS: Circulating bile acids capable of inducing immunosuppression are present in septic shock patients with severe liver failure. Future studies should examine whether modulation of bile acid metabolism can improve the clinical course and outcome of sepsis in these patients.

Association between preoperative serum C-reactive protein level and leukocyte count and postoperative pain after otolaryngological surgery.

PURPOSE: To determine whether the preoperative inflammatory serum C-reactive protein (CRP) and leukocyte count (LEUK) are associated with postoperative pain and complaints after otolaryngological surgery. METHODS: Retrospective evaluation of 680 patients (33% female, median age 50 years) receiving otolaryngological surgery between November 2008 and March 2017 in a tertiary university hospital. Postoperative pain on the first postoperative day was assessed using the validated questionnaire of the German-wide project Quality Improvement in Postoperative Pain Treatment (QUIPS) including a numeric rating scale for assessment of postoperative pain (NRS, 0-10). The influence of preoperative parameters including CRP and LEUK on patients' postoperative pain was estimated. RESULTS: Mean CRP value was 15.6 ± 34.6 mg/l and mean LEUK value 7.8 ± 3.2 Gpt/l. Patients with pharyngeal surgery had the highest CRP values (34.6 ± 52.9 mg/l), highest LEUK values (9.2 ± 4.2 Gpt/l) and the highest pain levels (3.1 ± 2.4 NRS) compared to all other surgical procedures (all p < 0.05). Higher postoperative pain was associated with LEUK values > 11.3 Gpt/l (r = 0.093, p = 0.016) and higher preoperative chronic pain (r = 0.127, p = 0.001). Multivariate analysis confirmed younger age, female gender, duration of surgery, preoperative chronic pain, type of surgery, and higher LEUK values > 11.3 as independent factors for postoperative pain. Perioperative antibiotics had no effect on the postoperative pain. CONCLUSION: Beyond known factors, preoperative LEUK as inflammation marker is an independent predictor for pain on the first postoperative day.

Determination of individual bile acids in acute respiratory distress syndrome reveals a specific pattern of primary and secondary bile acids and a shift to the acidic pathway as an adaptive response to the critical condition.

OBJECTIVES: Cholestasis and elevated serum bile1 acid levels are common in critically ill patients. This study aims to define the specific pattern of bile acids associated with acute respiratory distress syndrome (ARDS) and the changes in pattern over time. METHODS: Prospective observational study. Serum samples of 70 ARDS patients were analyzed for primary bile acids (cholic acid, chenodeoxycholic acid) and secondary bile acids (deoxycholic acid, litocholic acid, and ursodeoxycholic acid) as well as their glycine and taurine glycation products. RESULTS: Primary bile acid levels increased from day zero to day five by almost 50% (p<0.05). This change bases on a statistically significant increase in all primary bile acids between day 0 and day 5 (cholic acid [CA] p=0.001, taurocholic acid [TCA] p=0.004, glycocholic acid [GCA] p<0.001, chenodeoxycholic acid [CDCA] p=0.036, taurochenodeoxycholic acid [TCDCA] p<0.001, glycochenodeoxycholic acid [GCDCA] p<0.001). Secondary bile acids showed predominantly decreased levels on day 0 compared to the control group and remained stable throughout the study period; the differences between day zero and day five were not statistically significant. Non-survivors exhibited significantly higher levels of TCDCA on day 5 (p<0.05) than survivors. This value was also independently associated with survival in a logistic regression model with an odds ratio of 2.24 (95% CI 0.53-9.46). CONCLUSIONS: The individual bile acid profile of this ARDS patient cohort is unique compared to other disease states. The combination of changes in individual bile acids reflects a shift toward the acidic pathway of bile acid synthesis. Our results support the concept of ARDS-specific plasma levels of bile acids in a specific pattern as an adaptive response mechanism.

Introduction of BD Vacutainer® Barricor™ tubes in clinical biobanking and application of amino acid and cytokine quality indicators to Barricor plasma.

OBJECTIVES: The use of BD Vacutainer® Barricor™ tubes (BAR) can reduce turnaround time (TAT) and improve separation of plasma from cellular components using a specific mechanical separator. Concentrations of amino acids (AAs) and cytokines, known to be labile during pre-analytical time delays, were compared in heparin (BAR, BD Heparin standard tube [PST]), EDTA and serum gel tubes (SER) to validate previously identified quality indicators (QIs) in BAR. METHODS: Samples of healthy individuals (n=10) were collected in heparin, EDTA and SER tubes and exposed to varying pre- and post-centrifugation delays at room temperature (RT). Cytokines (interleukin [IL]-8, IL-16 and sCD40L) were analyzed by enzyme-linked immunosorbent assay (ELISA) and AAs were characterized by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). RESULTS: All QIs, AAs/AA ratio and cytokines increased during prolonged blood storage in heparin plasma (PST, BAR) and SER tubes. Comparison of 53 h/1 h pre-centrifugation delay resulted in an increase in taurine (Tau) and glutamic acid (Glu) concentrations by more than three times, soluble CD40L increased by 13.6, 9.2 and 4.3 fold in PST, BAR-CTRL and BAR-FAST, and IL-8 increased even more by 112.8 (PST), 266.1 (BAR-CTRL), 268.1 (BAR-FAST) and 70.0 (SER) fold, respectively. Overall, compared to prolonged blood storage, effects of post-centrifugation delays were less pronounced in all tested materials. CONCLUSIONS: BAR tubes are compatible with the use of several established QIs and can therefore be used in clinical biobanking to reduce pre-analytical TAT without compromising QIs and thus pre-analytical sample quality analysis.

UVB-exposed wheat germ oil increases serum 25-hydroxyvitamin D2 without improving overall vitamin D status: a randomized controlled trial.

PURPOSE: This study investigated whether UVB-exposed wheat germ oil (WGO) is capable to improving the vitamin D status in healthy volunteers. METHODS: A randomized controlled human-intervention trial in parallel design was conducted in Jena (Germany) between February and April. Ultimately, 46 healthy males and females with low mean 25-hydroxyvitamin D (25(OH)D) levels (34.9 ± 10.6 nmol/L) were randomized into three groups receiving either no WGO oil (control, n = 14), 10 g non-exposed WGO per day (- UVB WGO, n = 16) or 10 g WGO, which was exposed for 10 min to ultraviolet B-light (UVB, intensity 500-630 µW/cm2) and provided 23.7 µg vitamin D (22.9 µg vitamin D2 and 0.89 µg vitamin D3) (+ UVB WGO, n = 16) for 6 weeks. Blood was obtained at baseline, after 3 and 6 weeks and analyzed for serum vitamin D-metabolite concentrations via LC-MS/MS. RESULTS: Participants who received the UVB-exposed WGO were characterized by an increase of circulating 25(OH)D2 after 3 and 6 weeks of intervention. However, the 25(OH)D3 concentrations decreased in the + UVB WGO group, while they increased in the control groups. Finally, the total 25(OH)D concentration (25(OH)D2 + 25(OH)D3) in the + UVB WGO group was lower than that of the non-WGO receiving control group after 6 weeks of treatment. In contrast, circulating vitamin D (vitamin D2 + vitamin D3) was higher in the + UVB WGO group than in the control group receiving no WGO. CONCLUSION: UVB-exposed WGO containing 23.7 µg vitamin D can increase 25(OH)D2 levels but do no improve total serum levels of 25(OH)D of vitamin D-insufficient subjects. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03499327 (registered, April 13, 2018).

SARS-CoV-2 antibody testing-questions to be asked.

Severe acute respiratory syndrome coronavirus 2 infection and development of coronavirus disease 2019 presents a major health care challenge of global dimensions. Laboratory diagnostics of infected patients, and the assessment of immunity against severe acute respiratory syndrome coronavirus 2, presents a major cornerstone in handling the pandemic. Currently, there is an increase in demand for antibody testing and a large number of tests are already marketed or are in the late stage of development. However, the interpretation of test results depends on many variables and factors, including sensitivity, specificity, potential cross-reactivity and cross-protectivity, the diagnostic value of antibodies of different isotypes, and the use of antibody testing in identification of acutely ill patients or in epidemiological settings. In this article, the recently established COVID-19 Task Force of the German Society for Clinical Chemistry and Laboratory Medicine (DGKL) addresses these issues on the basis of currently available data sets in this rapidly moving field.

Dynamics of cytokines, immune cell counts and disease severity in patients with community-acquired pneumonia - Unravelling potential causal relationships.

BACKGROUND: Community acquired pneumonia (CAP) is a severe and often rapidly deteriorating disease. To better understand its dynamics and potential causal relationships, we analyzed time series data of cytokines, blood and clinical parameters in hospitalized CAP patients. METHODS: Time series data of 10 circulating cytokines, blood counts and clinical parameters were related to baseline characteristics of 403 CAP patients using univariate mixed models. Bivariate mixed models were applied to analyze correlations between the time series. To identify potential causal relationships, we inferred cross-lagged relationships between pairs of parameters using latent curve models with structured residuals. RESULTS: IL-6 levels decreased faster over time in younger patients (Padj = 0.06). IL-8, VCAM-1, and IL-6 correlated strongly with disease severity as assessed by the sequential organ failure assessment (SOFA) score (r = 0.49, 0.48, 0.46, respectively; all Padj < 0.001). IL-6 and bilirubin correlated with respect to their mean levels and slopes over time (r = 0.36 and r = 0.46, respectively; Padj < 0.001). A number of potential causal relationships were identified, e.g., a negative effect of ICAM-1 on MCP-1, or a positive effect of the level of creatinine on the subsequent VCAM-1 concentration (P < 0.001). CONCLUSIONS: These results suggest that IL-6 trajectories of CAP patients are associated with age and run parallel to bilirubin levels. The time series analysis also unraveled directed, potentially causal relationships between cytokines, blood parameters and clinical outcomes. This will facilitate the development of mechanistic models of CAP, and with it, improvements in treatment or surveillance strategies for this disease. TRIAL REGISTRATION: clinicaltrials.gov NCT02782013, May 25, 2016, retrospectively registered.

Vibrational spectroscopy as a powerful tool for follow-up immunoadsorption therapy treatment of dilated cardiomyopathy - a case report.

Dilated cardiomyopathy (DCM) is a leading cardiomyopathy condition and is the leading reason for heart transplantation. Due to high etiologic and genetic heterogeneity of the pathologies, different therapeutic treatment strategies are available and have been successful for different treatments. Immunoadsorption (IA) therapy removes the circulating anticardiac antibodies and improves the left ventricular function in substantial proportion of DCM patients. Powerful, non-invasive analytical tools are highly desired to investigate the efficiency and success of IA therapy. In this contribution, we followed the changes of a female DCM patient undergoing IA therapy at different treatment time points in a label-free, non-invasive manner from blood samples (plasma and serum) on the basis of vibrational spectroscopy (Raman scattering and IR absorption). Chemometric methods, including dimension reduction and statistical modeling, were used to interpret spectral data. The impact of different time points of the IA treatment can be identified in both the plasma and serum, using both techniques, with high accuracy. The removal of antibodies of immunoglobulin G (IgG) group during IA therapy and their restoration was reflected in both Raman and FTIR spectra. Relative changes in the spectral bands assigned to IgG agreed well with the immunoturbidimetry measurement of total IgG. Successful clinical treatment was accompanied by spectral differences between vibrational spectra obtained at initial disease state and 11 months after the IA treatment. The long-term follow-up of the patient reveals the stabilization of the health state after therapy. It is noteworthy that the treatment time points were distinguished with a better accuracy using spectra from plasma compared to those from serum samples, which might indicate the involvement of corresponding proteins in the coagulation. Vibrational spectroscopy is a powerful tool for personalized medicine to follow-up the treatment success of IA therapy for the DCM disorder.

Simultaneous Quantification of Nine Antimicrobials by LC-MS/MS for Therapeutic Drug Monitoring in Critically Ill Patients.

BACKGROUND: Adequate antibiotic treatment is a prerequisite for the successful treatment of systemic infections. Based on accumulating scientific evidence, a fixed dosage regimen can lead to insufficient and ineffective antibiotic therapy. Thus, the aim of this study was to develop and validate a simplified, but sensitive method for the simultaneous quantification of antimicrobials by using liquid chromatography with tandem mass spectrometry (LC-MS/MS) for the development of personalized therapy regimens using therapeutic drug monitoring. METHODS: A method was developed for the simultaneous quantification of 9 antimicrobials (aciclovir, ampicillin, cefuroxime, ciprofloxacin, meropenem, metronidazole, piperacillin, rifampicin, and tazobactam) in lithium-heparin plasma. A simple sample preparation method and a chromatographic run time of 10 minutes enabled the quick processing of the samples. The method was validated according to the guidelines for bioanalytical method validation of the European Medicines Agency and addressed sensitivity, specificity, linearity, accuracy, precision, dilution integrity, carry-over, recovery, matrix effects, and stability. RESULTS: The chromatographic run time was 10 minutes and antimicrobials eluted at retention times ranging from 1.1 to 2.2 minutes. Calibration curve for all antimicrobials was linear over a range of 1-100 mg/L, and a 2-fold or 5-fold dilution of the samples was possible. The method accuracy ranged from 85.1% to 114.9% for all measured antimicrobials, and the within- and between-run precision values were <11.9% and <16.5% for the lower limit of quantification. No interferences and carry-over were observed. The samples were stable for at least 5 hours at room temperature or in the autosampler (10°C). CONCLUSIONS: The LC-MS/MS method developed in this study is appropriate and practical for the therapeutic drug monitoring of antimicrobials in the daily clinical laboratory practice because of its short analysis time, the need for a small amount of plasma, high specificity, and accuracy.

Sequential organ failure assessment score is an excellent operationalization of disease severity of adult patients with hospitalized community acquired pneumonia - results from the prospective observational PROGRESS study.

BACKGROUND: CAP (Community acquired pneumonia) is frequent, with a high mortality rate and a high burden on health care systems. Development of predictive biomarkers, new therapeutic concepts, and epidemiologic research require a valid, reproducible, and quantitative measure describing CAP severity. METHODS: Using time series data of 1532 patients enrolled in the PROGRESS study, we compared putative measures of CAP severity for their utility as an operationalization. Comparison was based on ability to correctly identify patients with an objectively severe state of disease (death or need for intensive care with at least one of the following: substantial respiratory support, treatment with catecholamines, or dialysis). We considered IDSA/ATS minor criteria, CRB-65, CURB-65, Halm criteria, qSOFA, PSI, SCAP, SIRS-Score, SMART-COP, and SOFA. RESULTS: SOFA significantly outperformed other scores in correctly identifying a severe state of disease at the day of enrollment (AUC = 0.948), mainly caused by higher discriminative power at higher score values. Runners-up were the sum of IDSA/ATS minor criteria (AUC = 0.916) and SCAP (AUC = 0.868). SOFA performed similarly well on subsequent study days (all AUC > 0.9) and across age groups. In univariate and multivariate analysis, age, sex, and pack-years significantly contributed to higher SOFA values whereas antibiosis before hospitalization predicted lower SOFA. CONCLUSIONS: SOFA score can serve as an excellent operationalization of CAP severity and is proposed as endpoint for biomarker and therapeutic studies. TRIAL REGISTRATION: clinicaltrials.gov NCT02782013 , May 25, 2016, retrospectively registered.

Deficiency in mTORC1-controlled C/EBPß-mRNA translation improves metabolic health in mice.

The mammalian target of rapamycin complex 1 (mTORC1) is a central regulator of physiological adaptations in response to changes in nutrient supply. Major downstream targets of mTORC1 signalling are the mRNA translation regulators p70 ribosomal protein S6 kinase 1 (S6K1p70) and the 4E-binding proteins (4E-BPs). However, little is known about vertebrate mRNAs that are specifically controlled by mTORC1 signalling and are engaged in regulating mTORC1-associated physiology. Here, we show that translation of the CCAAT/enhancer binding protein beta (C/EBPß) mRNA into the C/EBPß-LIP isoform is suppressed in response to mTORC1 inhibition either through pharmacological treatment or through calorie restriction. Our data indicate that the function of 4E-BPs is required for suppression of LIP. Intriguingly, mice lacking the cis-regulatory upstream open reading frame (uORF) in the C/EBPß-mRNA, which is required for mTORC1-stimulated translation into C/EBPß-LIP, display an improved metabolic phenotype with features also found under calorie restriction. Thus, our data suggest that translational adjustment of C/EBPß-isoform expression is one of the key processes that direct metabolic adaptation in response to changes in mTORC1 activity.

Measurement of piperacillin plasma concentrations in cancer patients with suspected infection.

BACKGROUND: Piperacillin (PIP) in combination with tazobactam is commonly used for anti-infective treatment in cancer patients. PIP exerts a time-dependent killing. Thus, the maintenance of plasma concentrations above a pre-defined target concentration for a pre-defined time may be relevant for optimal efficacy. It is assumed that PIP-plasma concentrations above the clinical breakpoint of the target pathogen [Pseudomonas aeruginosa, clinical breakpoint at minimal inhibitory concentration (MIC) 16 mg/L] should be reached for 100% of the dosing interval or >4xMIC (64 mg/L) for 50% of the dosing interval. Whereas studies in the intensive-care setting have shown underdosing in patients with sepsis, little is known about PIP-plasma concentrations in cancer patients. METHODS: Data of 56 cancer patients who received piperacillin/tazobactam (PIP/TAZ, 4.5 g three times daily) as empiric therapy for suspected infection were analysed at baseline and 4 h after the infusion. RESULTS: Median trough concentrations in steady state [median 3 days (IQR 3-5) after start of PIP/TAZ] were 4.6 mg/L (95% CI 0.3-136.3) and median PIP-plasma concentrations 4 h after infusion were 46.2 mg/L (95% CI 10.1-285.6). A second evaluation 5 days (IQR 4-7) after start of PIP/TAZ confirmed these results: trough concentrations were 2.7 mg/L (95% CI 0.5-6.3), concentrations after 4 h 28.0 mg/L (95% CI 1.7-47.3). A good renal function was associated with lower plasma concentrations (r = -0.388, p < 0.003). Detailed pharmacokinetic measurements in six patients showed low maximum plasma concentration (median 165 mg/L) and a rapid decline of plasma concentrations (median plasma half time 1.38 h). CONCLUSION: In conclusion, piperacillin plasma concentrations in cancer patients are below target levels warranting prospective trials to investigate therapeutic drug monitoring.

Metabolite Profiles in Sepsis: Developing Prognostic Tools Based on the Type of Infection.

OBJECTIVES: Currently used biomarkers insufficiently discriminate between patients with systemic inflammatory response syndrome of non-infectious origin and sepsis. The aim of this study was to identify surrogate markers that distinguish between systemic inflammatory response syndrome and sepsis as well as the underlying type of infection by targeted metabolomics. DESIGN: Retrospective analysis. SETTINGS: Six sites of the Hellenic Sepsis Study Group and at Jena University Hospital. PATIENTS: A total of 406 patients were analyzed: 66 fulfilling criteria for diagnosis of systemic inflammatory response syndrome, 100 for community-acquired pneumonia, 112 for urinary tract infection, 83 for intra-abdominal infection and 45 for bloodstream infection. Patients were divided into test cohort (n = 268) and confirmation cohort (n = 138). INTERVENTIONS: A total of 186 metabolites were determined by liquid chromatography tandem mass spectrometry. MEASUREMENTS AND MAIN RESULTS: Serum concentrations of most acylcarnitines, glycerophospholipids and sphingolipids were altered in sepsis compared to systemic inflammatory response syndrome. A regression model combining the sphingolipid SM C22:3 and the glycerophospholipid lysoPCaC24:0 was discovered for sepsis diagnosis with a sensitivity of 84.1% and specificity of 85.7%. Furthermore, specific metabolites could be used for the discrimination of different types of infection. The glycerophospholipid lysoPCaC26:1 identified patients with community-acquired pneumonia in sepsis or severe sepsis/septic shock. Within severe sepsis/septic shock, patients with bloodstream infection could be discriminated by a decrease of acetylornithine. Changes of metabolites between sepsis and severe sepsis/septic shock also varied according to the underlying type of infection, showing that putrescine, lysoPCaC18:0 and SM C16:1 are associated with unfavorable outcome in community-acquired pneumonia, intra-abdominal infections and bloodstream infections, respectively. CONCLUSIONS: Using a metabolomics approach, single metabolites are identified that allow a good, albeit at about 14% false positive rate of sepsis diagnosis. Additionally, metabolites might be also useful for differentiation and prognosis according to the type of underlying infection. However, confirmation of the findings in ongoing studies is mandatory before they can be applied in the development of novel diagnostic tools for the management of sepsis.

Decrease in circulating plasmacytoid dendritic cells during short-term systemic normobaric hypoxia.

BACKGROUND: During exposure to high altitude, the immune system is altered. During hypoxia, an increase in interleukin (IL)-6 and high sensitivity C-reactive protein (hs-CRP), and an increase in natural killer cells and decrease in T cells in blood was shown. However, the impact of hypoxia on dendritic cells has not been investigated yet. MATERIAL AND METHODS: Twelve healthy volunteers were subjected to a transient normobaric hypoxia for 6·5 h simulating an oxygen concentration at 5500 m. During exposure to hypoxia, blood samples were collected and analysed by flow cytometrical cell sorting (FACS) for circulating myeloid (mDCs) and plasmacytoid (pDCs) DCs. Serum levels of IL-6 and tumour necrosis factor (TNF)-α were analysed. In a cell culture hypoxia chamber, blood samples were subjected to the same hypoxia and analysed regarding DCs. RESULTS: Exposure to normobaric hypoxia induced a significant decrease in circulating pDCs about 45% (P = 0·001) but not of mDC compared to baseline normoxia. Furthermore, we observed a significant increase of TNF-α about 340% (P = 0·03) and of IL-6 about 286% (P = 0·002). In cell culture experiments exposure of blood to hypoxia led to no significant changes in DCs, so that a direct cytotoxic effect was excluded. During hypoxia, we observed a transient increase in stromal-derived factor 1 (SDF-1) which is important for pDC tissue recruitment. CONCLUSIONS: We show a significant decrease in circulating pDCs during hypoxia in parallel to a pro-inflammatory response. Further studies are necessary to evaluate whether the decrease in circulating pDCs might be the result of an enhanced tissue recruitment.

Stress-induced decrease of uterine blood flow in sheep is mediated by alpha 1-adrenergic receptors.

Prenatal maternal stress can be transferred to the fetus via a catecholamine-dependent decrease of uterine blood flow (UBF). However, it is unclear which group of adrenergic receptors mediates this mechanism of maternal-fetal stress transfer. We hypothesized that in sheep, alpha 1-adrenergic receptors may play a key role in catecholamine mediated UBF decrease, as these receptors are mainly involved in peripheral vasoconstriction and are present in significant number in the uterine vasculature. After chronic instrumentation at 125 ± 1 days of gestation (dGA; term 150 dGA), nine pregnant sheep were exposed at 130 ± 1 dGA to acute isolation stress for one hour without visual, tactile, or auditory contact with their flockmates. UBF, blood pressure (BP), heart rate (HR), stress hormones, and blood gases were determined before and during this isolation challenge. Twenty-four hours later, experiments were repeated during alpha 1-adrenergic receptor blockage induced by a continuous intravenous infusion of urapidil. In both experiments, ewes reacted to isolation with an increase in serum norepinephrine, cortisol, BP, and HR as typical signs of activation of sympatho-adrenal and the hypothalamic-pituitary-adrenal axis. Stress-induced UBF decrease was prevented by alpha 1-adrenergic receptor blockage. We conclude that UBF decrease induced by maternal stress in sheep is mediated by alpha 1-adrenergic receptors. Future studies investigating prevention strategies of impact of prenatal maternal stress on fetal health should consider selective blockage of alpha 1-receptors to interrupt maternal-fetal stress transfer mediated by utero-placental malperfusion.

Biomarker candidates for the detection of an infectious etiology of febrile neutropenia.

PURPOSE: Infections and subsequent septicemia are major complications in neutropenic patients with hematological malignancies. Here, we identify biomarker candidates for the early detection of an infectious origin, and monitoring of febrile neutropenia (FN). METHODS: Proteome, metabolome, and conventional biomarkers from 20 patients with febrile neutropenia without proven infection (FNPI) were compared to 28 patients with proven infection, including 17 patients with bacteremia. RESULTS: Three peptides (mass to charge ratio 1017.4-1057.3; p-values 0.011-0.024), six proteins (mass to charge ratio 6881-17,215; p-values 0.002-0.004), and six phosphatidylcholines (p-values 0.007-0.037) were identified that differed in FNPI patients compared to patients with infection or bacteremia. Seven of these marker candidates discriminated FNPI from infection at fever onset with higher sensitivity and specificity (ROC-AUC 0.688-0.824) than conventional biomarkers i.e., procalcitonin, C-reactive protein, or interleukin-6 (ROC-AUC 0.535-0.672). In a post hoc analysis, monitoring the time course of four lysophosphatidylcholines, threonine, and tryptophan allowed for discrimination of patients with or without resolution of FN (ROC-AUC 0.648-0.919) with higher accuracy compared to conventional markers (ROC-AUC 0.514-0.871). CONCLUSIONS: Twenty-one promising biomarker candidates for the early detection of an infectious origin or for monitoring the course of FN were found which might overcome known shortcomings of conventional markers.

Consequences of a high phosphorus intake on mineral metabolism and bone remodeling in dependence of calcium intake in healthy subjects - a randomized placebo-controlled human intervention study.

BACKGROUND: Epidemiological studies reported an association between plasma phosphate concentrations and a higher risk for death and cardiovascular events in subjects free of chronic kidney diseases. The main aims of the present study were to determine the influence of a high phosphorus intake in combination with different calcium supplies on phosphorus, calcium, magnesium and iron metabolism as well as fibroblast growth factor 23 (FGF23) concentrations within eight weeks of supplementation. METHODS: Sixty-two healthy subjects completed the double-blind, placebo-controlled parallel designed study. Supplements were monosodium phosphate and calcium carbonate. During the first two weeks, all groups consumed a placebo sherbet powder, and afterwards, for eight weeks, a sherbet powder according to the intervention group: P1000/Ca0 (1 g/d phosphorus), P1000/Ca500 (1 g/d phosphorus and 0.5 g/d calcium) and P1000/Ca1000 (1 g/d phosphorus and 1 g/d calcium). Dietary records, fasting blood samplings, urine and fecal collections took place. RESULTS: Fasting plasma phosphate concentrations did not change after any intervention. After all interventions, renal excretions and fecal concentrations of phosphorus increased significantly after eight weeks. Renal calcium and magnesium excretion decreased significantly after eight weeks of P1000/Ca0 intervention compared to placebo. Plasma FGF23 concentrations were significantly higher after four weeks compared to eight weeks of all interventions. CONCLUSIONS: The long-term study showed in healthy adults no influence of high phosphorus intakes on fasting plasma phosphate concentrations. A high phosphorus intake without adequate calcium intake seems to have negative impact on calcium metabolism. Plasma FGF23 concentrations increased four weeks after high phosphorus intake and normalized after eight weeks. TRIAL REGISTRATION: The trial is registered at ClinicalTrials.gov as NCT02095392 .