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Acute kidney injury (AKI) recovery prediction remains challenging. The purpose of the present study is to develop and validate prediction models for AKI recovery at hospital discharge in critically ill patients with ICU-acquired AKI stage 3 (AKI-3).Models were developed and validated in a development cohort (n = 229) and a matched validation cohort (n = 244) from the multicenter EPaNIC database to create prediction models with the least absolute shrinkage and selection operator (Lasso) machine-learning algorithm. We evaluated the discrimination and calibration of the models and compared their performance with plasma neutrophil gelatinase-associated lipocalin (NGAL) measured on first AKI-3 day (NGAL_AKI3) and reference model that only based on age.Complete recovery and complete or partial recovery occurred in 33.20% and 51.23% of the validation cohort patients respectively. The prediction model for complete recovery based on age, need for renal replacement therapy (RRT), diagnostic group (cardiac/surgical/trauma/others), and sepsis on admission had an area under the receiver operating characteristics curve (AUROC) of 0.53. The prediction model for complete or partial recovery based on age, need for RRT, platelet count, urea, and white blood cell count had an AUROC of 0.61. NGAL_AKI3 showed AUROCs of 0.55 and 0.53 respectively. In cardiac patients, the models had higher AUROCs of 0.60 and 0.71 than NGAL_AKI3's AUROCs of 0.52 and 0.54. The developed models demonstrated a better performance over the reference models (only based on age) for cardiac surgery patients, but not for patients with sepsis and for a general ICU population.Models to predict AKI recovery upon hospital discharge in critically ill patients with AKI-3 showed poor performance in the general ICU population, similar to the biomarker NGAL. In cardiac surgery patients, discrimination was acceptable, and better than NGAL. These findings demonstrate the difficulty of predicting non-reversible AKI early.

CONTEXT: Muscle expresses and secretes several myokines that bring about benefits in distant organs. OBJECTIVE: We investigated the impact of critical illness on muscular expression of irisin, kynurenine aminotransferases, and amylase; association with clinical outcome; and impact of interventions that attenuate muscle wasting/weakness. METHODS: We studied critically ill patients who participated in 2 randomized controlled trials (EPaNIC/NESCI) and documented time profiles in critically ill mice. Included in the study were 174 intensive care unit (ICU) patients (day 8 ± 1) vs 19 matched controls, and 60 mice subjected to surgery/sepsis vs 60 pair-fed healthy mice. Interventions studied included 7-day neuromuscular electrical stimulation (NMES), and withholding parenteral nutrition (PN) in the first ICU week (late PN) vs early PN. The main outcome measures were FNDC5 (irisin- precursor), KYAT1, KYAT3, and amylase mRNA expression in skeletal muscle. RESULTS: Critically ill patients showed 34% to 80% lower mRNA expression of FNDC5, KYAT1, and amylases than controls (P < .0001). Critically ill mice showed time-dependent reductions in all mRNAs compared with healthy mice (P ≤ .04). The lower FNDC5 expression in patients was independently associated with a higher ICU mortality (P = .015) and ICU-acquired weakness (P = .012), whereas the lower amylase expression in ICU survivors was independently associated with a longer ICU stay (P = .0060). Lower amylase expression was independently associated with a lower risk of death (P = .048), and lower KYAT1 expression with a lower risk of weakness (P = .022). NMES increased FNDC5 expression compared with unstimulated muscle (P = .016), and late PN patients had a higher KYAT1 expression than early PN patients (P = .022). CONCLUSION: Expression of the studied myokines was affected by critical illness and associated with clinical outcomes, with limited effects of interventions that attenuate muscle wasting or weakness. Dit onderzoek beoogt de ontwikkeling en validering van een geautomatiseerd detectiesysteem van ongewenste incidenten (adverse events) gebaseerd op triggers ontwikkeld door het Insitute of Healthcare Improvement (IHI). Bijkomend wensen we de mogelijkheid tot detectie van ongewenste incidenten te evalueren door prevalentie, klinische relevantie en vermijdbaarheid te vergelijken met vier welomschreven detectiemethodes voor ongewenste indicenten: Global Trigger Tool (IHI), Patient Safety Indicatoren (AHRQ), Potentially Preventable Complications (3M) en vrijwillige incidentmeldingssystemen (PiMS). Als een secundaire doelstelling wordt gestreefd naar het ontwikkelen van een kernset aan indicatoren die klinisch relevant zijn en routinematig kunnen worden opgevolgd in een toekomstig kwaliteitsbeleid. ispartof: Journal of the Endocrine Society vol:7 issue:3 ispartof: location:United States status: Published online

PURPOSE: Withholding parenteral nutrition (PN) early in critical illness, late-PN, has shown to prevent infections despite a higher peak C-reactive protein (CRP). We investigated whether the accentuated CRP rise was caused by a systemic inflammatory effect mediated by cytokines or arose as a consequence of the different feeding regimens, and whether it related to improved outcome with late-PN. METHODS: This secondary analysis of the EPaNIC-RCT first investigated, with multivariable linear regression analyses, determinants of late-PN-induced CRP rise and its association with cytokine responses (IL-6, IL-10, TNF-α) in matched early-PN and late-PN patients requiring intensive care for ≥ 3 days. Secondly, with multivariable logistic regression and Cox proportional-hazard analyses, we investigated whether late-PN-induced CRP rises mediated infection prevention and enhanced recovery or reflected an adverse effect counteracting such benefits of late-PN. RESULTS: CRP peaked on day 3, higher with late-PN [216(152-274)mg/l] (n = 946) than with early-PN [181(122-239)mg/l] (n = 946) (p

Critically ill patients have low circulating 25-hydroxyvitamin D (25OHD), vitamin D binding protein (DBP), and 1,25-dihydroxyvitamin D [1,25(OH)2D]. Low 25OHD is associated with poor outcomes, possibly explained by its effect on bone and immunity. In this prospective, randomized double-blind, placebo-controlled study, we investigated the feasibility of normalizing 25OHD in prolonged (>10 days) critically ill patients and the effects thereof on 1,25(OH)2D, bone metabolism, and innate immunity. Twenty-four patients were included and compared with 24 matched healthy subjects. Patients were randomized to either intravenous bolus of 200 μg 25OHD followed by daily infusion of 15 μg 25OHD for 10 days, or to placebo. Parameters of vitamin D, bone and mineral metabolism, and innate immune function were measured. As safety endpoints, ICU length of stay and mortality were registered. Infusion of 25OHD resulted in a sustained increase of serum 25OHD (from median baseline 9.2 –16.1 ng/ml at day 10), which, however, remained below normal levels. There was no increase in serum 1,25(OH)2D but a slight increase in serum 24,25(OH)2D. Mineral homeostasis, innate immunity and clinical safety endpoints were unaffected. Thus, intravenous 25OHD administration during critical illness increased serum 25OHD concentrations, though less than expected from data in healthy subjects, which suggests illness-induced alterations in 25OHD metabolism and/or increased 25OHD distribution volume. The increased serum 25OHD concentrations were not followed by a rise in 1,25(OH)2D nor were bone metabolism or innate immunity affected, which suggests that low 25OHD and 1,25OHD levels are part of the adaptive response to critical illness.

PURPOSE: Increased systemic cortisol availability during adult critical illness is determined by reduced binding-proteins and suppressed breakdown rather than elevated ACTH. Dynamics, drivers and prognostic value of hypercortisolism during pediatric critical illness remain scarcely investigated. METHODS: This preplanned secondary analysis of the PEPaNIC-RCT (N = 1440), after excluding 420 children treated with corticosteroids before PICU-admission, documented (a) plasma ACTH, (free)cortisol and cortisol-metabolism at PICU-admission, day-3 and last PICU-day, their prognostic value, and impact of withholding early parenteral nutrition (PN), (b) the association between corticosteroid-treatment and these hormones, and (c) the association between corticosteroid-treatment and outcome. RESULTS: ACTH was normal upon PICU-admission and low thereafter (p ≤ 0.0004). Total and free cortisol were only elevated upon PICU-admission (p ≤ 0.0003) and thereafter became normal despite low binding-proteins (p

Graphical abstract, Highlights • Exposure of critically ill children to DEHP in the PICU decreased over the years. • Reduced DEHP exposure in the PICU did not result in improved long-term attention. • Whether alternative plasticizers are neurodevelopmentally safe remains unclear., Background Children who have been critically ill face long-term developmental impairments. Iatrogenic exposure to di(2-ethylhexyl)phthalate (DEHP), a plasticizer leaching from plastic indwelling medical devices used in the pediatric intensive care unit (PICU), has been associated with the pronounced attention deficit observed in children 4 years after critical illness. As concerns about DEHP toxicity increased, governmental authorities urged the phase out of DEHP in indwelling medical devices and replacement with alternative plasticizers. We hypothesized that exposure to DEHP decreased over the years, attenuating the pronounced long-term attention deficit of these vulnerable children. Methods We compared plasma concentrations of 3 oxidative DEHP metabolites (5cx-MEPP, 5OH-MEHP, 5oxo-MEHP) on the last PICU day in 216 patients who participated in the Tight Glucose Control study (2004–2007) and 334 patients who participated in the PEPaNIC study (2012–2015) and survived PICU stay. Corresponding minimal exposures to these metabolites (plasma concentration multiplied with number of days in PICU) were also evaluated. In patients with 4-year follow-up data, we compared measures of attention (standardized reaction times and consistency). Comparisons were performed with univariable analyses and multivariable linear regression analyses adjusted for baseline risk factors. Results In the PEPaNIC patients, last PICU day plasma concentrations of 5cx-MEPP, 5OH-MEHP, 5oxo-MEHP and their sum, and corresponding minimal exposures, were reduced to 17–69% of those in the Tight Glucose Control study (p

Critically ill patients are thought to develop maladaptive glucocorticoid-resistance which convinces many clinicians to administer stress doses of glucocorticoids to overcome this state of glucocorticoid-resistance. However, supportive data arises mainly from whole blood cells. It is currently not known if the observed changes in regulators and markers of glucocorticoid signaling and activity are also present in other cell and tissue types with a role in critical illness. We quantified regulators and markers of glucocorticoid signaling and activity in several cell and tissue types in critically ill humans and animals and in healthy controls. We found that throughout critical illness, glucocorticoid activity appeared suppressed in neutrophils, but upregulated in monocytes and skeletal muscle. Also in vital tissues GRα-signaling was altered in a tissue-specific, largely time-independent manner. Increasing systemic glucocorticoid availability increased glucocorticoid activity in adipose tissue, diaphragm and lung, whereas in immune cells and other tissues regulatory pathways counteracted. These data argue against glucocorticoid-treatable generalized glucocorticoid resistance and rather point towards an adaptive response in each specific cell or tissue type to optimally guide the beneficial actions of glucocorticoids to the tissues that need it while protecting collateral undesirable effects in tissue that are harmed by elevated systemic glucocorticoid availability. Presentation: Monday, June 13, 2022 11:45 a.m. - 12:00 p.m.

Introduction In critically ill adults, high plasma free cortisol in face of suppressed plasma ACTH coincides with high plasma pro-opiomelanocortin (POMC), the ACTH precursor (1). Further augmenting the systemic glucocorticoid availability with hydrocortisone treatment further lowered plasma ACTH, while plasma POMC remained unaffected (2). The dynamics of POMC in relation to ACTH and free cortisol prior to intensive care unit (ICU) admission are unknown, as well as the impact hereon of glucocorticoid treatment. Also, elevated plasma POMC concentrations have not yet been confirmed in pediatric ICU (PICU) patients. In pediatric cardiac surgery-induced critical illness, we hypothesized that plasma POMC is elevated and that plasma ACTH transiently rises per-operatively and becomes suppressed once free cortisol has risen on PICU day 1 and 2. In addition, we hypothesized that in patients receiving glucocorticoids per-operatively, plasma ACTH is further suppressed while plasma POMC is unaffected. Methods From 53 children aged 0-36 months, who underwent cardiac surgery and were admitted to the PICU, blood samples were taken prior to surgery (pre-operatively, available samples N=51), during surgery (per-operatively, N=47), on the following morning (PICU day 1, N=40) and the day hereafter (PICU day 2, N=24). Blood samples were also collected from 24 age- and gender-matched healthy children. To investigate the impact of synthetic glucocorticoid treatment on the endogenous plasma hormone concentrations, patients were categorized into steroid-naive (total N=38) and steroid-treated patients (total N=15). Plasma hormone concentrations were quantified with highly-specific ELISA (POMC), RIA (ACTH, cortisol, CBG) or colorimetric assays (albumin). Cross reactivity with synthetic glucocorticoids within the used cortisol RIA is minimal ( Results Plasma POMC was increased pre-operatively (p0.05), irrespective of steroid treatment. Plasma ACTH in patients was never higher than in healthy children. While in steroid-naive patients, plasma ACTH became suppressed only by PICU day 1 (p0.05). Conclusion Pre-operatively high plasma POMC, not followed by increased ACTH, suggests a centrally-activated HPA-axis already prior to surgery and an immature pituitary processing of POMC into ACTH. Systemic glucocorticoid availability is elevated from surgery onwards, likely driven by ACTH-independent mechanisms. Further increasing systemic glucocorticoid availability exogenously with glucocorticoid administration accelerates the suppression of plasma ACTH. The long-term impact of early glucocorticoid treatment in critically ill children remains to be investigated. References (1) Téblick A. et al. Critical Care 2021. (2) Téblick A. et al. Endocrinology 2022. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m., Saturday, June 11, 2022 1:42 p.m. - 1:47 p.m.

Background Muscle weakness is a complication of critical illness which hampers recovery. In critically ill mice, supplementation with the ketone body 3-hydroxybutyrate has been shown to improve muscle force and to normalize illness-induced hypocholesterolemia. We hypothesized that altered cholesterol homeostasis is involved in development of critical illness-induced muscle weakness and that this pathway can be affected by 3-hydroxybutyrate. Methods In both human critically ill patients and septic mice, the association between circulating cholesterol concentrations and muscle weakness was assessed. In septic mice, the impact of 3-hydroxybutyrate supplementation on cholesterol homeostasis was evaluated with use of tracer technology and through analysis of markers of cholesterol metabolism and downstream pathways. Results Serum cholesterol concentrations were lower in weak than in non-weak critically ill patients, and in multivariable analysis adjusting for baseline risk factors, serum cholesterol was inversely correlated with weakness. In septic mice, plasma cholesterol correlated positively with muscle force. In septic mice, exogenous 3-hydroxybutyrate increased plasma cholesterol and altered cholesterol homeostasis, by normalization of plasma mevalonate and elevation of muscular, but not hepatic, expression of cholesterol synthesis genes. In septic mice, tracer technology revealed that 3-hydroxybutyrate was preferentially taken up by muscle and metabolized into cholesterol precursor mevalonate, rather than TCA metabolites. The 3-hydroxybutyrate protection against weakness was not related to ubiquinone or downstream myofiber mitochondrial function, whereas cholesterol content in myofibers was increased. Conclusions These findings point to a role for low cholesterol in critical illness-induced muscle weakness and to a protective mechanism-of-action for 3-hydroxybutyrate supplementation.

INTRODUCTION: Non-thyroidal illness (NTI), which occurs with fasting and in response to illness, is characterized by thyroid hormone inactivation with low triiodothyronine (T3) and high reverse T3 (rT3), followed by suppressed thyrotropin (TSH). Withholding supplemental parenteral nutrition early in pediatric critical illness (late-PN), thus accepting low/no macronutrient intake up to day 8 in the pediatric intensive care unit (PICU), accelerated recovery compared to initiating supplemental parenteral nutrition early (early-PN). Whether NTI is harmful or beneficial in pediatric critical illness and how it is affected by a macronutrient deficit remains unclear. This study investigated the prognostic value of NTI, the impact of late-PN on NTI, and whether such impact explains or counteracts the outcome benefit of late-PN in critically ill children. METHODS: This preplanned secondary analysis of the Early versus Late Parenteral Nutrition in the Pediatric Intensive Care Unit randomized controlled trial quantified serum TSH, total thyroxine (T4), T3, and rT3 concentrations in 982 patients upon PICU admission versus 64 matched healthy children and in 772 propensity score-matched early-PN and late-PN patients upon admission and at day 3 or last PICU day for shorter PICU stay. Associations between thyroid hormone concentrations upon admission and outcome, as well as impact of late-PN on NTI in relation with outcome, were assessed with univariable analyses and multivariable logistic regression, linear regression, or Cox proportional hazard analysis, adjusted for baseline risk factors. RESULTS: Upon PICU admission, critically ill children revealed lower TSH, T4, T3, and T3/rT3 and higher rT3 than healthy children (p

PURPOSE: To investigate the effect of Neuromuscular Electrical Stimulation (NMES) on muscle thickness, strength and morphological and molecular markers of the quadriceps. MATERIALS AND METHODS: Adult critically ill patients with an expected prolonged stay received unilateral quadriceps NMES sessions for 7 consecutive days. Before and after the intervention period, quadriceps thickness was measured with ultrasound. After the intervention period, strength was assessed in cooperative patients and muscle biopsies were taken. Multivariable regression was performed to identify factors affecting muscle thickness loss. RESULTS: Muscle thickness decreased less in the stimulated leg (-6 ± 16% versus -12 ± 15%, p = 0.014, n = 47). Strength was comparable. Opioid administration, minimal muscle contraction and more muscle thickness loss in the non-stimulated muscle were independently associated with better muscle thickness preservation. Stimulated muscles showed a shift towards larger myofibers and higher MyHC-I gene expression. NMES did not affect gene expression of other myofibrillary proteins, MuRF-1 or atrogin-1. Signs of myofiber necrosis and inflammation were comparable for both muscles. CONCLUSIONS: NMES attenuated the loss of muscle mass, but not of strength, in critically ill patients. Preservation of muscle mass was more likely in patients receiving opioids, patients with a minimal muscle contraction during NMES and patients more prone to lose muscle mass. TRIAL REGISTRATION: clinicaltrials.govNCT02133300. ispartof: JOURNAL OF CRITICAL CARE vol:62 pages:65-71 ispartof: location:United States status: published

Background Circulating growth-differentiation factor-15 (GDF15), a cellular stress marker, abruptly increases during critical illness, but its later time course remains unclear. GDF15 physiologically controls oral intake by driving aversive responses to nutrition. Early parenteral nutrition (PN) in ICU patients has overall been shown not beneficial. We hypothesized that low GDF15 can identify patients who benefit from early PN, tolerate enteral nutrition (EN), and resume spontaneous oral intake. Methods In secondary analyses of the EPaNIC-RCT on timing of PN initiation (early PN versus late PN) and the prospective observational DAS study, we documented the time course of circulating GDF15 in ICU (N = 1128) and 1 week post-ICU (N = 72), compared with healthy subjects (N = 65), and the impact hereon of randomization to early PN versus late PN in propensity score-matched groups (N = 564/group). Interaction between upon-admission GDF15 and randomization for its outcome effects was investigated (N = 4393). Finally, association between GDF15 and EN tolerance in ICU (N = 1383) and oral intake beyond ICU discharge (N = 72) was studied. Results GDF15 was elevated throughout ICU stay, similarly in early PN and late PN patients, and remained high beyond ICU discharge (p p ≤ 0.002). Lower GDF15 was only weakly related to gastrointestinal tolerance (p p = 0.05). Conclusion In critically ill patients, high GDF15 reflected poor prognosis and may contribute to aversive responses to nutrition. However, the potential of GDF15 as “ready-to-feed indicator” appears limited. Trial registration ClinicalTrials.gov, NCT00512122, registered 31 July 2007, https://www.clinicaltrials.gov/ct2/show/NCT00512122 (EPaNIC trial) and ISRCTN, ISRCTN 98806770, registered 11 November 2014, http://www.isrctn.com/ISRCTN98806770 (DAS trial)

Aim: Pediatric intensive care relies on plastic indwelling medical devices softened by phthalates. Phthalates leach into the circulation and concerns about toxicity were raised. Exceeding a certain threshold of di(2-ethylhexyl)phthalate (DEHP) exposure in the pediatric intensive care unit (PICU) has been associated with an attention deficit 4 years later (1). Moreover, DEHP and its metabolites have endocrine disrupting properties. Critically ill children reveal the non-thyroidal illness syndrome (2) and unexplained relatively low cortisol (3). Whether DEHP exposure in PICU has endocrine disruptive effects is unknown. We investigated whether DEHP exposure in the PICU, exceeding the previously identified “toxic” threshold for attention, is independently associated with thyroid- and HPA-axis alterations upon PICU discharge. Methods: In this preplanned secondary analysis of the PEPaNIC RCT (N=1440) (4), plasma DEHP metabolite concentrations (MEHP, 5OH-MEHP, 5cx-MEPP, 5oxo-MEHP) were quantified for all patients with a last PICU day sample (N=920). Minimal DEHP exposure was defined as the product of the total DEHP metabolite concentrations on the last PICU day and duration of PICU stay, with 0.551 µmol/L.days identified as “toxic” threshold (1). Serum TSH, total T4, total T3 and rT3 concentrations were quantified for patients with an available last day sample (N=913). For patients with a last day plasma sample and who did not receive corticosteroids (N=391), plasma ACTH, total cortisol, albumin and CBG concentrations were quantified and free cortisol calculated. Multivariable linear regression analyses, adjusted for baseline risk factors and for duration of PICU stay, assessed whether exceeding the previously determined threshold of toxic DEHP exposure was independently associated with the hormone levels on the last PICU day. Main results: Median total DEHP metabolite concentration was 0.101 (IQR 0.049 - 0.279) µmol/L on the last PICU day. Minimal DEHP exposure was 0.337 (IQR 0.161 - 0.880) µmol/l.days, and 328 patients (35.7%) exceeded the toxic threshold. Exceeding this threshold was independently associated with lower total T4 (P=0.002), total T3 (P=0.02) and total cortisol (P=0.001), and higher rT3 (P=0.01) concentrations on the last PICU day, but not with TSH, ACTH or free cortisol. Conclusion: Critically ill children had DHEP metabolites in plasma upon PICU discharge and more than a third were exposed to toxic levels. Toxic DEHP exposure was an independent contributor to the severity of the non-thyroidal illness phenotype and to lower cortisol upon PICU discharge. Future research should assess whether such endocrine-disruptive impact of DHEP exposure in the PICU plays a role in the long-term developmental legacy of critical illness in children. 1 Verstraete et al Intensive Care Med 2016 2 Jacobs et al Thyroid 2019 3 Jacobs et al Intensive Care Med 2019 4 Fivez et al N Engl J Med 2016

Background In two recent randomized controlled trials, withholding parenteral nutrition early in critical illness improved outcome as compared to early up-to-calculated-target nutrition, which may be explained by beneficial effects of fasting. Outside critical care, fasting-mimicking diets were found to maintain fasting-induced benefits while avoiding prolonged starvation. It is unclear whether critically ill patients can develop a fasting response after a short-term nutrient interruption. In this randomized crossover pilot study, we investigated whether 12-h nutrient interruption initiates a metabolic fasting response in prolonged critically ill patients. As a secondary objective, we studied the feasibility of monitoring autophagy in blood samples. Methods In a single-center study in 70 prolonged critically ill patients, 12-h up-to-calculated-target feeding was alternated with 12-h fasting on day 8 ± 1 in ICU, in random order. Blood samples were obtained at the start of the study, at the crossover point, and at the end of the 24-h study period. Primary endpoints were a fasting-induced increase in serum bilirubin and decrease in insulin requirements to maintain normoglycemia. Secondary outcomes included serum insulin-like growth factor I (IGF-I), serum urea, plasma beta-hydroxybutyrate (BOH), and mRNA and protein markers of autophagy in whole blood and isolated white blood cells. To obtain a healthy reference, mRNA and protein markers of autophagy were assessed in whole blood and isolated white blood cells of 23 matched healthy subjects in fed and fasted conditions. Data were analyzed using repeated-measures ANOVA, Fisher’s exact test, or Mann–Whitney U test, as appropriate. Results A 12-h nutrient interruption significantly increased serum bilirubin and BOH and decreased insulin requirements and serum IGF-I (all p ≤ 0.001). Urea was not affected. BOH was already increased from 4 h fasting onwards. Autophagic markers in blood samples were largely unaffected by fasting in patients and healthy subjects. Conclusions A 12-h nutrient interruption initiated a metabolic fasting response in prolonged critically ill patients, which opens perspectives for the development of a fasting-mimicking diet. Blood samples may not be a good readout of autophagy at the tissue level. Trial registration ISRCTN, ISRCTN98404761. Registered 3 May 2017.

BACKGROUND: Early use of parenteral nutrition in the paediatric intensive care unit (PICU) negatively affects development of executive functions, externalising behaviour, and visual-motor integration 2 years later, compared with omitting parenteral nutrition until PICU day 8 (late parenteral nutrition). The molecular basis of this finding is uncertain. We aimed to test the hypothesis that DNA methylation changes occur during critical illness and that early parenteral nutrition (or a specific macronutrient component hereof) contributes to these changes, which could explain its negative effects on neurocognitive development. METHODS: This pre-planned secondary analysis of the multicentre PEPaNIC trial (2012-18) included all patients with a last PICU day blood sample (n=825, aged 0-17 years at PICU admission) who were randomly allocated (1:1) to early parenteral nutrition or late parenteral nutrition, as compared with 352 demographically matched healthy children. Investigators were masked to treatment allocation. We used the Infinium Human MethylationEPIC BeadChip to determine the genome-wide peripheral blood leukocyte DNA methylation of 865 859 CpG sites, yielding high-quality results for 403 patients allocated to early parenteral nutrition and for 411 patients allocated to late parenteral nutrition. Applying a false discovery rate of less than 0·05, DNA methylation of patients on the last PICU day was compared with that of healthy children, after excluding all CpG sites differentially methylated upon PICU admission, because these reflected pre-admission conditions and altered leukocyte composition. We used bootstrapped multivariable linear and non-linear regression analyses to assess the effect of early parenteral nutrition versus late parenteral nutrition on illness-induced alterations in DNA methylation and to what extent differentially methylated CpG sites explained impaired neurocognitive development 2 years later. FINDINGS: During PICU stay, 159 CpG sites were methylated differently in patients admitted to the PICU than in healthy children, with mean effect sizes of 2·6% (SD 2·5) up to 21·6% (p

Background A genome-wide study identified de novo DNA methylation alterations in leukocytes of children at paediatric intensive care unit (PICU) discharge, offering a biological basis for their impaired long-term development. Early parenteral nutrition (early-PN) in PICU, compared with omitting PN in the first week (late-PN), explained differential methylation of 23% of the affected CpG-sites. We documented the time course of altered DNA methylation in PICU and the impact hereon of early nutritional management. Results We selected 36 early-PN and 36 late-PN matched patients, and 42 matched healthy children. We quantified DNA methylation on days 3, 5 and 7 for the 147 CpG-sites of which methylation was normal upon PICU admission in this subset and altered by critical illness at PICU discharge. Methylation in patients differed from healthy children for 64.6% of the 147 CpG-sites on day 3, for 72.8% on day 5 and for 90.5% on day 7 as revealed by ANOVA at each time point. Within-patients methylation time course analyses for each CpG-site identified different patterns based on paired t test p value and direction of change. Rapid demethylation from admission to day 3 occurred for 76.2% of the CpG-sites, of which 67.9% remained equally demethylated or partially remethylated and 32.1% further demethylated beyond day 3. From admission to day 3, 19.7% of the CpG-sites became hypermethylated, of which, beyond day 3, 34.5% remained equally hypermethylated or partially demethylated again and 65.5% further hypermethylated. For 4.1% of the CpG-sites, changes only appeared beyond day 3. Finally, for the CpG-sites affected by early-PN on the last PICU day, earlier changes in DNA methylation were compared for early-PN and late-PN patients, revealing that 38.9% were already differentially methylated by day 3, another 25.0% by day 5 and another 13.9% by day 7. Conclusions Critical illness- and early-PN-induced changes in DNA methylation occurred mainly within 3 days. Most abnormalities were at least partially maintained or got worse with longer time in PICU. Interventions targeting aberrant DNA methylation changes should be initiated early.

Context Changes in the GH axis during critical illness resemble fasting in healthy adults and contribute to hypercatabolism, which potentially affects outcome. Accepting macronutrient deficits by withholding parenteral nutrition (PN) during the first week in the intensive care unit (ICU; late PN) reduced complications and accelerated recovery as compared with early use of PN (early PN). Objective To investigate how late PN affects the GH axis in relation to its clinical outcome benefits. Design Preplanned subanalysis of the Early Parenteral Nutrition Completing Enteral Nutrition in Adult Critically Ill Patients randomized controlled trial. Participants A total of 1128 patients for time-course study, 20 patients investigated for nocturnal GH pulsatility, and 600 patients investigated for muscle weakness, with early PN and late PN patients having comparable baseline characteristics. Intervention Withholding PN during the first ICU week (late PN) vs early PN. Main Outcome Measures Changes in serum GH, IGF-I, IGF-binding protein (IGFBP) 3, and IGFBP1 concentrations from ICU admission to day 4 or last ICU day for patients with a shorter ICU stay (d4/LD) and association in multivariable analyses with likelihood of earlier live ICU discharge, risk of new infection, and muscle weakness. Results Late PN attenuated a rise in serum GH and IGF-I (P < 0.0001), did not affect IGFBP3, and attenuated a decrease in IGFBP1 concentrations from admission to d4/LD (P < 0.0001) as compared with early PN. Late PN decreased nonpulsatile (P = 0.005), but not pulsatile, GH secretion. Adjusting the multivariable models for the observed GH axis alterations increased the independent benefit of late PN for all outcomes. GH axis alterations induced by late PN were independently associated with adverse outcomes (P ≤ 0.03). Conclusion Accepting macronutrient deficits early during critical illness further suppressed the GH axis, which statistically attenuated its clinical outcome benefits.

Increased systemic cortisol availability during adult critical illness is determined by reduced binding-proteins and suppressed breakdown rather than elevated ACTH. Dynamics, drivers and prognostic value of hypercortisolism during pediatric critical illness remain scarcely investigated.This preplanned secondary analysis of the PEPaNIC-RCT (N = 1440), after excluding 420 children treated with corticosteroids before PICU-admission, documented (a) plasma ACTH, (free)cortisol and cortisol-metabolism at PICU-admission, day-3 and last PICU-day, their prognostic value, and impact of withholding early parenteral nutrition (PN), (b) the association between corticosteroid-treatment and these hormones, and (c) the association between corticosteroid-treatment and outcome.ACTH was normal upon PICU-admission and low thereafter (p ≤ 0.0004). Total and free cortisol were only elevated upon PICU-admission (p ≤ 0.0003) and thereafter became normal despite low binding-proteins (p 0.0001) and persistently suppressed cortisol-metabolism (p ≤ 0.03). Withholding early-PN did not affect this phenotype. On PICU-day-3, high free cortisol and low ACTH independently predicted worse outcome (p ≤ 0.003). Also, corticosteroid-treatment initiated in PICU, which further suppressed ACTH (p 0.0001), was independently associated with poor outcomes (earlier live PICU-discharge: p 0.0001, 90-day mortality: p = 0.02).In critically ill children, systemic cortisol availability is elevated only transiently, much lower than in adults, and not driven by elevated ACTH. Further ACTH lowering by corticosteroid-treatment indicates active feedback inhibition at pituitary level. Beyond PICU-admission-day, low ACTH and high cortisol, and corticosteroid-treatment, predicted poor outcome. This suggests that exogenously increasing cortisol availability during acute critical illness in children may be inappropriate. Future studies on corticosteroid-treatment in critically ill children should plan safety analyses, as harm may be possible.

Background Invasive fungal infections (IFI) are difficult to diagnose, especially in critically ill patients. As the mannose receptor (MR) is shed from macrophage cell surfaces after exposure to fungi, we investigate whether its soluble serum form (sMR) can serve as a biomarker of IFI. Methods This is a secondary analysis of the multicentre randomised controlled trial (EPaNIC, n = 4640) that investigated the impact of initiating supplemental parenteral nutrition (PN) early during critical illness (Early-PN) as compared to withholding it in the first week of intensive care (Late-PN). Serum sMR concentrations were measured in three matched patient groups (proven/probable IFI, n = 82; bacterial infection, n = 80; non-infectious inflammation, n = 77) on the day of antimicrobial initiation or matched intensive care unit day and the five preceding days, as well as in matched healthy controls (n = 59). Independent determinants of sMR concentration were identified via multivariable linear regression. Serum sMR time profiles were analysed with repeated-measures ANOVA. Predictive properties were assessed via area under the receiver operating curve (aROC). Results Serum sMR was higher in IFI patients than in all other groups (all p

Background: Critically ill patients often develop multiple organ failure accompanied by profound metabolic and endocrine alterations. The pathogenesis is incompletely understood, but the development of cellular stress, including endoplasmic reticulum (ER) stress, might play a pivotal role (1). Indeed, markers of ER stress have been observed in critical illness, both in animal models and human patients, correlating with organ dysfunction (1). ER stress normally activates the unfolded protein response (UPR). The UPR follows a distinct temporal pattern, aimed at restoring ER homeostasis in the short term, but inducing apoptosis whenever ER stress becomes too severe or prolonged. During critical illness, the temporal activation pattern in liver has only been partially studied. In addition, the potential implications for liver function and metabolism are currently unknown. Methods: We quantified the hepatic expression of crucial markers of the 3 UPR branches and of key hepatic transcription factors in a clinically relevant fluid-resuscitated mouse model of sepsis. Mice were sacrificed at 10 hrs, 30 hrs or 3 days after cecal ligation and puncture in comparison with healthy pair-fed mice (n=15 per group per time point). We quantified the same markers in postmortem liver biopsies from patients admitted to the intensive care unit with sepsis (n=64), who died after a median ICU stay of 10 days (IQR 6-20 days), in comparison with matched patients undergoing elective restorative rectal surgery (n=18). Results: In septic mice, the UPR showed a distinct temporal pattern. In the acute phase (10-30 hrs), the PERK, IRE1α and ATF6 branches were all activated (p˂0.01). In the prolonged phase (3 days), the PERK and ATF6 branches were attenuated and only the IRE1α branch remained activated (p˂0.0001). The UPR activation in the acute phase coincided with a significant downregulation of key hepatic transcription factors important for normal liver function and metabolism, including Shp, FXR, Lrh1, PXR, Hnf6 and Foxa2 (p˂0.01). Several transcription factors remained significantly downregulated in the prolonged phase. ALT as liver damage marker correlated directly with several UPR markers and inversely with several transcription factors in the acute phase, but not in the prolonged phase. In postmortem liver biopsies of patients with sepsis, we only observed an upregulation of the IRE1α branch of the UPR, consistent with the pattern in prolonged critically ill mice. Also in patients, this coincided with a repression of several key hepatic transcription factors. Conclusion: The present findings suggest that patients admitted to the intensive care unit with sepsis develop a state of chronic ER stress in the liver, which might hamper normal hepatic function at least in part through the downregulation of key transcription factors. References: 1. Thiessen SE et al. BBA-Mol Basis Dis 2017, 1863, 2534-45

Background: The activity of the growth hormone (GH) axis is altered by critical illness. In the acute phase, GH resistance, as reflected by increased GH and decreased insulin-like growth factor-I (IGF-I), mimics fasting-induced changes in health. Although early full feeding in ICU has long been assumed to prevent muscle wasting and weakness, the EPaNIC RCT observed fewer complications and faster recovery with accepting the macronutrient deficit in the first ICU week, as compared with early full feeding, including less acquired muscle weakness [1,2]. We previously observed that accepting the early macronutrient deficit attenuated rather than aggravated the rise in GH as compared with early full feeding [3]. We have now further characterized its impact on the GH axis, in relation to the risk of acquiring muscle weakness in ICU. Methods: This was a preplanned sub-analysis of the EPaNIC RCT. For 10 matched patients per group, serum GH was quantified every 10 min between 9 PM and 6 AM, followed by deconvolution analyses to estimate GH secretion. For 564 patients per group, matched for baseline characteristics, and for all patients investigated for muscle weakness (n=600), serum IGF-I, IGF binding protein 3 (IGFBP3) and IGFBP1 were measured upon ICU admission, at day 4 (if still in ICU), and on the last ICU day (LD). Matched healthy subjects (n=65) were included as controls. Groups were compared with Wilcoxon test or repeated-measures ANOVA. Associations between changes in concentrations from baseline to day 4 or LD for patients with shorter ICU stay (d4/LD) and risk of muscle weakness were assessed with nominal logistic regression analysis, adjusted for baseline risk factors, baseline hormone concentrations and randomization. Results: Upon ICU admission, patients revealed low IGF-I and IGFBP3 and high IGFBP1 as compared with controls (p

Background: Children who have suffered from critical illnesses that required treatment in a paediatric intensive care unit (PICU) have long-term physical and neurodevelopmental impairments. The mechanisms underlying this legacy remain largely unknown. In patients suffering from chronic diseases hallmarked by inflammation and oxidative stress, poor long-term outcome has been associated with shorter telomeres. Shortened telomeres have also been reported to result from excessive food consumption and/or unhealthy nutrition. We investigated whether critically ill children admitted to the PICU have shorter-than-normal telomeres, and whether early parenteral nutrition (PN) independently affects telomere length when adjusting for known determinants of telomere length.Methods: Telomere length was quantified in leukocyte DNA from 342 healthy children and from 1148 patients who had been enrolled in the multicenter, randomised controlled trial (RCT), PEPaNIC. These patients were randomly allocated to initiation of PN within 24 h (early PN) or to withholding PN for one week in PICU (late PN). The impact of early PN versus late PN on the change in telomere length from the first to last PICU-day was investigated with multivariable linear regression analyses.Results: Leukocyte telomeres were 6% shorter than normal upon PICU admission (median 1.625 (IQR 1.446–1.825) telomere/single-copy-gene ratio (T/S) units vs. 1.727 (1.547–1.915) T/S-units in healthy children (P P = 0.01). Other independent determinants of telomere length identified in this model were age, gender, baseline telomere length and fraction of neutrophils in the sample from which the DNA was extracted. Telomere shortening with early PN was independent of post-randomisation factors affected by early PN, including longer length of PICU stay, larger amounts of insulin and higher risk of infection.Conclusions: Shorter than normal leukocyte telomeres are present in critically ill children admitted to the PICU. Early initiation of PN further shortened telomeres, an effect that was independent of other determinants. Whether such telomere-shortening predisposes to long-term consequences of paediatric critical illness should be further investigated in a prospective follow-up study.Trial registration: ClinicalTrials.gov, NCT01536275. Registered on 16 February 2012.

RATIONALE: Critical illness is hallmarked by muscle wasting and disturbances in glucose, lipid, and amino acid homeostasis. Circulating concentrations of glucagon, a catabolic hormone that affects these metabolic pathways, are elevated during critical illness. Insight in the nutritional regulation of glucagon and its metabolic role during critical illness is lacking. OBJECTIVES: To evaluate whether macronutrient infusion can suppress plasma glucagon during critical illness and study the role of illness-induced glucagon abundance in the disturbed glucose, lipid, and amino acid homeostasis and in muscle wasting during critical illness. METHODS: In human and mouse studies, we infused macronutrients and manipulated glucagon availability up and down to investigate its acute and chronic metabolic role during critical illness. MEASUREMENTS AND MAIN RESULTS: In critically ill patients, infusing glucose with insulin did not lower glucagon, whereas parenteral nutrition containing amino acids increased glucagon. In critically ill mice, infusion of amino acids increased glucagon and up-regulated markers of hepatic amino acid catabolism without affecting muscle wasting. Immunoneutralizing glucagon in critically ill mice only transiently affected glucose and lipid metabolism, did not affect muscle wasting, but drastically suppressed markers of hepatic amino acid catabolism and reversed the illness-induced hypoaminoacidemia. CONCLUSIONS: These data suggest that elevated glucagon availability during critical illness increases hepatic amino acid catabolism, explaining the illness-induced hypoaminoacidemia, without affecting muscle wasting and without a sustained impact on blood glucose. Furthermore, amino acid infusion likely results in a further breakdown of amino acids in the liver, mediated by increased glucagon, without preventing muscle wasting. Clinical trial registered with www.clinicaltrials.gov (NCT 00512122). ispartof: AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE vol:196 issue:9 pages:1131-1143 ispartof: location:United States status: published

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress, which activates the unfolded protein response (UPR), mediate critical illness-induced organ failure, often affecting the liver. Autophagy is known to alleviate both and suppressed or insufficiently activated autophagy in prolonged illness has shown to associate with organ failure. Whether insufficient autophagy contributes to organ failure during critical illness by affecting these underlying mechanisms is incompletely understood. In this study, we investigated whether the inability to acutely activate hepatic autophagy during critical illness aggravates liver damage by increasing hepatic mitochondrial dysfunction and affecting the UPR. In a mouse model of critical illness, induced by surgery and sepsis, we investigated the impact of inactivating hepatic autophagy on markers of hepatic mitochondrial function, the UPR and liver damage in acute (1 day) and prolonged (3 days) critical illness. Hepatic autophagy inactivation during critical illness acutely worsened mitochondrial dysfunction and time-dependently modulated the hepatic UPR. Furthermore, autophagy inactivation aggravated markers of liver damage on both time points. In conclusion, the inability to acutely activate autophagy in liver during critical illness worsened hepatic mitochondrial damage and dysfunction, partially prohibited acute UPR activation and aggravated liver damage, indicating that autophagy is crucial in alleviating critical illness-induced organ failure. ispartof: Scientific Reports vol:7 issue:1 ispartof: location:England status: published

Background:Critically ill children are susceptible to nosocomial infections, which contribute to adverse outcome. Deficiencies within the innate immunity lectin pathway of complement activation are implicated in a child's vulnerability to infections in conditions such as cancer, but the role during critical illness remains unclear. We hypothesized that low upon-admission levels of the pathway proteins are in part genetically determined and associated with susceptibility to infectious complications and adverse outcome.Methods:We studied protein levels of mannose-binding lectin (MBL), H-ficolin and M-ficolin, three MBL-associated-serine proteases (MASPs) and MBL-associated protein (MAp44), and relation with functional genetic polymorphisms, in 130 healthy children and upon-ICU-admission in 700 critically ill children of a randomized study on glycemic control.Results:Levels of MASP-1, MASP-2, MASP-3 and MAp44 were lower and those of M-ficolin higher in ICU patients upon-admission than in matched healthy controls. Only a low upon-admission MASP-3 level was independently associated with risk of new ICU infections and prolonged ICU stay, after correction for other risk factors. Upon-admission MASP-3 varied with age, illness severity and genetic variation.Conclusion:Low upon-admission MASP-3 levels in critically ill children were independently associated with subsequent acquisition of infection and prolonged ICU stay. The biological explanation needs further investigation.Pediatric Research (2013); doi:10.1038/pr.2013.180. ispartof: Pediatric Research vol:75 issue:1 pages:99-108 ispartof: location:United States status: published

BACKGROUND: Critically ill children are prone to nosocomial infections, which may lead to adverse outcome. Low serum concentrations upon admission to the pediatric intensive care unit (PICU) of the mannan-binding lectin (MBL)-associated serine protease (MASP)-3 protein of the lectin pathway of complement activation have been associated with risk of infection and prolonged need for intensive care. We hypothesized that also a low upon-admission concentration of collectin-L1 (CL-L1), a novel member of this pathway, is independently associated with these adverse outcomes.METHODS: We quantified the serum concentrations of CL-L1 in 81 healthy children and in 700 critically ill children upon PICU admission.RESULTS: CL-L1 concentrations were significantly lower in the critically ill children as compared with the healthy children. However, corrected for baseline characteristics, risk factors and several lectin pathway proteins, a higher CL-L1 concentration upon PICU admission was independently associated with an increased risk of acquiring a new infection and with a prolonged time to PICU discharge. In contrast, a low MASP-3 concentration remained independently associated with these adverse outcomes.CONCLUSION: A high serum CL-L1 concentration in critically ill children upon PICU admission is associated with an increased risk of infection and prolonged need of intensive care, and counteracts the protective effect of having a high MASP-3 concentration.

Although preventing excessive hyperglycemia during critical illness may provide clinical neuroprotection, it remains debated whether normoglycemia is without risk for the brain.To address this question, we compared the neuropathological alterations in microglia, astrocytes, and neurons, with uncontrolled hyperglycemia, moderately controlled hyperglycemia, and normoglycemia during human critical illness. We further investigated the time course in an animal model.We analyzed brain specimens from patients who died in the intensive care unit and from critically ill rabbits randomized to hyper- or normoglycemia. PATIENTS/OTHER PARTICIPANTS: We compared 10 critically ill patients randomized to normoglycemia (104 ±9 mg/dl) or moderate hyperglycemia (173 ±32 mg/dl), and five patients with uncontrolled hyperglycemia (254 ±83 mg/dl) with 16 controls (out of hospital sudden deaths). Critically ill rabbits were randomized to hyperglycemia (315 ±32 mg/dl) or normoglycemia (85 ±13 mg/dl) and studied after 3 and 7 d.Insulin was infused to control blood glucose.Patients with uncontrolled hyperglycemia showed 3.7-6-fold increased microglial activation, 54-95% reduced number and activation of astrocytes, more than 9-fold increased neuronal and glial apoptosis, and a 1.5-2-fold increase in damaged neurons in hippocampus and frontal cortex (all P ≤ 0.05). Most of these abnormalities were attenuated with moderate hyperglycemia and virtually absent with normoglycemia. Frontal cortex of hyperglycemic rabbits that had been critically ill for 3 d only revealed microglial activation, followed after 7 d by astrocyte and neuronal abnormalities similar to those observed in patients, all prevented by normoglycemia.Preventing hyperglycemia with insulin during critical illness reduced neuropathological abnormalities, with microglial activation being the earliest preventable event. Whether these pathological findings associate with neurological outcome remains unknown.

Muscle weakness contributes to prolonged rehabilitation and adverse outcome of critically ill patients. Distinction between a neurogenic and/or myogenic underlying problem is difficult using routine diagnostic tools. Preferential loss of myosin has been suggested to point to a myogenic component. We evaluated markers of muscle atrophy and denervation, and the myosin/actin ratio in limb and abdominal wall skeletal muscle of prolonged critically ill patients and matched controls in relation to insulin therapy and known risk factors for intensive care unit-acquired weakness.Secondary analysis of two large, prospective, single-center randomized clinical studies.University hospital surgical and medical intensive care unit.Critically ill patients and matched controls.Intensive care unit patients had been randomized to blood glucose control to 80-110 mg/dL with insulin infusion or conventional glucose management, where insulin was only administered when glucose levels rose above 215 mg/dL.As compared with controls, rectus abdominis and vastus lateralis muscle of critically ill patients showed smaller myofiber size, decreased mRNA levels for myofibrillar proteins, increased proteolytic enzyme activities, and a lower myosin/actin ratio, virtually irrespective of insulin therapy. Increased forkhead box O1 action may have played a role. Most alterations were more severe in patients treated with corticosteroids. Duration of corticosteroid treatment, independent of duration of intensive care unit stay or other risk factors, was a dominant risk factor for a low myosin/actin ratio. The immature acetylcholine receptor subunit γ messenger RNA expression was elevated in vastus lateralis, independent of the myosin/actin ratio.Both limb and abdominal wall skeletal muscles of prolonged critically ill patients showed downregulation of protein synthesis at the gene expression level as well as increased proteolysis. This affected myosin to a greater extent than actin, resulting in a decreased myosin/actin ratio. Muscle atrophy was not ameliorated by intensive insulin therapy, but possibly aggravated by corticosteroids.

Critical illness induces swelling, enlargement, and dysfunction of mitochondria, which in liver, but not in muscle, is aggravated by excessive hyperglycemia. We previously demonstrated impaired autophagic clearance of damaged mitochondria in fed prolonged critically ill patients. Impaired fusion/fission-mediated repair and/or renewal through biogenesis may further accentuate mitochondrial abnormalities.We studied mitochondrial fusion/fission and biogenesis and how these are affected by preventing hyperglycemia with insulin during critical illness.Patients admitted to a university hospital surgical/medical intensive-care unit participated in a randomized study.We studied adult prolonged critically ill patients vs. controls.Tolerating hyperglycemia up to 215 mg/dl was compared with intensive insulin therapy targeting normoglycemia (80-110 mg/dl).In liver and skeletal muscle, we quantified levels of several proteins involved in mitochondrial fusion/fission and biogenesis.Key players in mitochondrial fusion/fission and biogenesis were up-regulated in postmortem liver (1.4- to 3.7-fold) and rectus abdominis (1.2- to 4.2-fold) but not in in vivo or postmortem vastus lateralis biopsies of critically ill patients. Maintaining normoglycemia with insulin attenuated the hepatic response in the mitochondrial fusion/fission process but did not affect the markers of mitochondrial biogenesis in liver or muscle.Our observations suggest tissue-dependent attempts of compensatory activation of mitochondrial repair mechanisms during critical illness. Considering the previously observed persistent mitochondrial damage, this activation may be insufficient and contribute to mitochondrial dysfunction. Suppressed activation of fusion/fission when excessive hyperglycemia is prevented with insulin may reflect reduced need for diluting (less) damage during normoglycemia or, alternatively, a suppressive effect of insulin on repair.

Context: Responses to critical illness, such as excessive inflammation and hyperglycemia, may trigger detrimental chain reactions that damage cellular proteins and organelles. Such responses to illness contribute to the risk of (nonresolving) multiple organ dysfunction and adverse outcome. Objective: We studied autophagy as a bulk degradation pathway able to remove toxic protein aggregates and damaged organelles and how these are affected by preventing hyperglycemia with insulin during critical illness. Design and Setting: Patients participated in a randomized study, conducted at a university hospital surgical/medical intensive care unit. Patients: We studied adult prolonged critically ill patients vs. controls. Interventions: Tolerating excessive hyperglycemia was compared with intensive insulin therapy targeting normoglycemia. Main Outcome Measures: We quantified (ultra)structural abnormalities and hepatic and skeletal muscle protein levels of key players in autophagy. Results: Morphologically, both liver and muscle revealed an autophagy-deficiency phenotype. Proteins involved in initiation and elongation steps of autophagy were induced 1.3- to 6.5-fold by critical illness (P < 0.01), but mature autophagic vacuole formation was 62% impaired (P = 0.05) and proteins normally degraded by autophagy accumulated up to 97-fold (P < 0.03). Mitophagy markers were unaltered or down-regulated (P = 0.05). Although insulin preserved hepatocytic mitochondrial integrity (P = 0.05), it further reduced the number of autophagic vacuoles by 80% (P = 0.05). Conclusions: Insufficient autophagy in prolonged critical illness may cause inadequate removal of damaged proteins and mitochondria. Such incomplete clearance of cellular damage, inflicted by illness and aggravated by hyperglycemia, could explain lack of recovery from organ failure in prolonged critically ill patients. These data open perspectives for therapies that activate autophagy during critical illness.

Objectives. The relationship between inflammation, destruction and new tissue formation leading to ankylosis, determines the severity and prognosis of patients with SpA. Recent data in mice and men suggest that new cartilage and bone formation and subsequent ankylosis are uncoupled from chronic inflammation. These data challenge the hypothesis that inflammation and tissue damage trigger an excessive repair response in SpA. We tested whether inhibition of bone erosion by targeting osteoclasts, would prevent or influence joint ankylosis in a mouse model. Methods. Male DBA/1 mice from different litters were caged together at the age of 8 weeks. Treatment with zoledronic acid (ZA) (100 ng/g) or placebo was started at the age of 10 weeks and administered every 2 weeks. Clinical incidence and severity of arthritis were evaluated twice a week until the age of 26 weeks. At this point, bone density measurements were performed, mice were sacrificed and severity of arthritis was evaluated by histology. Results. Treatment with ZA did not affect incidence or clinical severity of arthritis in male DBA/1 mice. ZA treatment significantly increased bone mineral density and content as demonstrated by dual X-ray densitometry and peripheral quantitative CT. However, the treatment did not affect histomorphological appearance of arthritis or ankylosis. Conclusions. These data suggest that bone erosion at the enthesis does not necessarily precede entheseal ankylosis. Therefore, these observations further support the concept that inflammation and new tissue formation in SpA are at least partially uncoupled events and may be different therapeutic targets.

Objective Ligands and antagonists of the WNT pathway are linked to osteoporosis and osteoarthritis. In particular, polymorphisms in the FRZB gene, a secreted WNT antagonist, have been associated with osteoarthritis. The aim of this study was to examine cartilage and bone in Frzb−/− mice. Methods The Frzb gene in mice was inactivated using a Cre/loxP strategy. Three models of osteoarthritis were used: collagenase, papain, and methylated bovine serum albumin induced. Bone biology was studied using density measurements and microfocal computed tomography. Bone stiffness and mechanical loading–induced bone adaptation were studied by compression of the ulnae. Results Targeted deletion of the Frzb gene in mice increased articular cartilage loss during arthritis triggered by instability, enzymatic injury, or inflammation. Cartilage damage in Frzb−/− mice was associated with increased WNT signaling and matrix metalloproteinase 3 (MMP-3) expression and activity. Frzb−/− mice had increased cortical bone thickness and density, resulting in stiffer bones, as demonstrated by stress–strain relationship analyses. Moreover, Frzb−/− mice had an increased periosteal anabolic response to mechanical loading as compared with wild-type mice. Conclusion The genetic association between osteoarthritis and FRZB polymorphisms is corroborated by increased cartilage proteoglycan loss in 3 different models of arthritis in Frzb−/− mice. Loss of Frzb may contribute to cartilage damage by increasing the expression and activity of MMPs, in a WNT-dependent and WNT-independent manner. FRZB deficiency also resulted in thicker cortical bone, with increased stiffness and higher cortical appositional bone formation after loading. This may contribute to the development of osteoarthritis by producing increased strain on the articular cartilage during normal locomotion but may protect against osteoporotic fractures.

Objective To study the relationship between inflammation and remodeling by inhibiting tumor necrosis factor α (TNFα) in male DBA/1 mice with spontaneous arthritis, a model of spondylarthritis (SpA). Methods TNFα was inhibited using etanercept, a soluble TNF receptor. The efficacy of the dose used (25 μg/mouse) was confirmed in methylated bovine serum albumin (mBSA)–induced monarthritis, a model of inflammation-driven joint destruction. Male DBA/1 mice with spontaneous arthritis were caged together from the age of 10 weeks onward and were treated twice weekly with etanercept. The incidence and clinical severity of disease were recorded. Mice were killed at age 25 weeks, and histomorphologic analysis was performed. The presence of TNFα, NF-κB, and Smad signaling was studied using immunohistochemistry. Entheseal endochondral bone formation was modeled using micromass cultures of periosteal cells. Results Etanercept inhibited mouse TNFα in vitro and in vivo. Etanercept treatment of mBSA-induced arthritis had a significant effect on the severity of disease. Etanercept did not affect the incidence or severity of spontaneous arthritis. Pathologic analysis revealed no differences between etanercept-treated and phosphate buffered saline–treated mice. TNFα-positive cells were observed in the synovium, in vessel-associated cells, in fibrocartilage, and in new cartilage. Activation of Smad signaling was observed in earlier stages of disease than was active NF-κB signaling. TNFα inhibited chondrogenesis in the micromass model. Conclusion Inhibition of TNF did not affect the severity and incidence of joint ankylosis in a mouse model of SpA. Therefore, the process of entheseal ankylosis may be independent of TNF. New tissue formation in SpA could be considered an additional and specific therapeutic target.