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Interest in using bedside C-reactive protein (CRP) and ferritin levels to identify patients with hyperinflammatory sepsis who might benefit from anti-inflammatory therapies has piqued with the COVID-19 pandemic experience. Our first objective was to identify patterns in CRP and ferritin trajectory among critically ill pediatric sepsis patients. We then examined the association between these different groups of patients in their inflammatory cytokine responses, systemic inflammation, and mortality risks.A prospective, observational cohort study.Children with sepsis and organ failure in nine pediatric intensive care units in the United States.Two hundred and fifty-five children were enrolled. Five distinct clinical multi-trajectory groups were identified. Plasma CRP (mg/dL), ferritin (ng/mL), and 31 cytokine levels were measured at two timepoints during sepsis (median Day 2 and Day 5). Group-based multi-trajectory models (GBMTM) identified groups of children with distinct patterns of CRP and ferritin.Group 1 had normal CRP and ferritin levels ( n = 8; 0% mortality); Group 2 had high CRP levels that became normal, with normal ferritin levels throughout ( n = 80; 5% mortality); Group 3 had high ferritin levels alone ( n = 16; 6% mortality); Group 4 had very high CRP levels, and high ferritin levels ( n = 121; 11% mortality); and Group 5 had very high CRP and very high ferritin levels ( n = 30; 40% mortality). Cytokine responses differed across the five groups, with ferritin levels correlated with macrophage inflammatory protein 1α levels and CRP levels reflective of many cytokines.Bedside CRP and ferritin levels can be used together to distinguish groups of children with sepsis who have different systemic inflammation cytokine responses and mortality risks. These data suggest future potential value in personalized clinical trials with specific targets for anti-inflammatory therapies.

Purpose Our understanding of inborn errors of immunity is increasing; however, their contribution to pediatric sepsis is unknown. Methods We used whole-exome sequencing (WES) to characterize variants in genes related to monogenic immunologic disorders in 330 children admitted to intensive care for severe sepsis. We defined candidate variants as rare variants classified as pathogenic or potentially pathogenic in QIAGEN’s Human Gene Mutation Database or novel null variants in a disease-consistent inheritance pattern. We investigated variant correlation with infection and inflammatory phenotype. Results More than one in two children overall and three of four African American children had immunodeficiency-associated variants. Children with variants had increased odds of isolating a blood or urinary pathogen (blood: OR 2.82, 95% CI: 1.12–7.10, p = 0.023, urine: OR: 8.23, 95% CI: 1.06–64.11, p = 0.016) and demonstrating increased inflammation with hyperferritinemia (ferritin $$\ge 500$$ ≥ 500 ng/mL, OR: 2.16, 95% CI: 1.28–3.66, p = 0.004), lymphopenia (lymphocyte count p = 0.027), thrombocytopenia (platelet count p = 0.013), and CRP greater than 10 mg/dl (OR: 1.71, 95% CI: 1.10–2.68, p = 0.017). They also had increased odds of requiring extracorporeal membrane oxygenation (ECMO, OR: 4.19, 95% CI: 1.21–14.5, p = 0.019). Conclusion Herein, we describe the genetic findings in this severe pediatric sepsis cohort and their microbiologic and immunologic significance, providing evidence for the phenotypic effect of these variants and rationale for screening children with life-threatening infections for potential inborn errors of immunity.

While acute kidney injury (AKI) is a common complication in COVID-19, data on post-AKI kidney function recovery and the clinical factors associated with poor kidney function recovery is lacking.A retrospective multi-centre observational cohort study comprising 12,891 hospitalized patients aged 18 years or older with a diagnosis of SARS-CoV-2 infection confirmed by polymerase chain reaction from 1 January 2020 to 10 September 2020, and with at least one serum creatinine value 1-365 days prior to admission. Mortality and serum creatinine values were obtained up to 10 September 2021.Advanced age (HR 2.77, 95%CI 2.53-3.04, p 0.0001), severe COVID-19 (HR 2.91, 95%CI 2.03-4.17, p 0.0001), severe AKI (KDIGO stage 3: HR 4.22, 95%CI 3.55-5.00, p 0.0001), and ischemic heart disease (HR 1.26, 95%CI 1.14-1.39, p 0.0001) were associated with worse mortality outcomes. AKI severity (KDIGO stage 3: HR 0.41, 95%CI 0.37-0.46, p 0.0001) was associated with worse kidney function recovery, whereas remdesivir use (HR 1.34, 95%CI 1.17-1.54, p 0.0001) was associated with better kidney function recovery. In a subset of patients without chronic kidney disease, advanced age (HR 1.38, 95%CI 1.20-1.58, p 0.0001), male sex (HR 1.67, 95%CI 1.45-1.93, p 0.0001), severe AKI (KDIGO stage 3: HR 11.68, 95%CI 9.80-13.91, p 0.0001), and hypertension (HR 1.22, 95%CI 1.10-1.36, p = 0.0002) were associated with post-AKI kidney function impairment. Furthermore, patients with COVID-19-associated AKI had significant and persistent elevations of baseline serum creatinine 125% or more at 180 days (RR 1.49, 95%CI 1.32-1.67) and 365 days (RR 1.54, 95%CI 1.21-1.96) compared to COVID-19 patients with no AKI.COVID-19-associated AKI was associated with higher mortality, and severe COVID-19-associated AKI was associated with worse long-term post-AKI kidney function recovery.Authors are supported by various funders, with full details stated in the acknowledgement section.

Pediatric encephalitis has significant morbidity and mortality, yet 50% of cases are unexplained. Host genetics plays a role in encephalitis' development; however, the contributing variants are poorly understood. One child with anti-NMDA receptor encephalitis and ten with unexplained encephalitis underwent whole genome sequencing to identify rare candidate variants in genes known to cause monogenic immunologic and neurologic disorders, and polymorphisms associated with increased disease risk. Using the professional Human Genetic Mutation Database (Qiagen), we divided the candidate variants into three categories: monogenic deleterious or potentially deleterious variants (1) in a disease-consistent inheritance pattern; (2) in carrier states; and (3) disease-related polymorphisms. Six patients (55%) had a deleterious or potentially deleterious variant in a disease-consistent inheritance pattern, five (45%) were heterozygous carriers for an autosomal recessive condition, and six (55%) carried a disease-related polymorphism. Finally, seven (64%) had more than one variant, suggesting possible polygenetic risk. Among variants identified were those implicated in atypical hemolytic uremic syndrome, common variable immunodeficiency, hemophagocytic lymphohistiocytosis, and systemic lupus erythematosus. This preliminary study shows genetic variation related to inborn errors of immunity in acute pediatric encephalitis. Future research is needed to determine if these variants play a functional role in the development of unexplained encephalitis.

OBJECTIVE: To provide guidance on the management of multisystem inflammatory syndrome in children (MIS-C), a condition characterized by fever, inflammation, and multiorgan dysfunction that manifests late in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and to provide recommendations for children with hyperinflammation during coronavirus disease 2019 (COVID-19), the acute, infectious phase of SARS-CoV-2 infection. METHODS: A multidisciplinary task force was convened by the American College of Rheumatology (ACR) to provide guidance on the management of MIS-C associated with SARS-CoV-2 and hyperinflammation in COVID-19. The task force was composed of 9 pediatric rheumatologists, 2 adult rheumatologists, 2 pediatric cardiologists, 2 pediatric infectious disease specialists, and 1 pediatric critical care physician. Preliminary statements addressing clinical questions related to MIS-C and hyperinflammation in COVID-19 were developed based on evidence reports. Consensus was built through a modified Delphi process that involved 2 rounds of anonymous voting and 2 webinars. A 9-point scale was used to determine the appropriateness of each statement (median scores of 1-3 for inappropriate, 4-6 for uncertain, and 7-9 for appropriate), and consensus was rated as low, moderate, or high based on dispersion of the votes along the numeric scale. Approved guidance statements were those that were classified as appropriate with moderate or high levels of consensus, as prespecified prior to voting. RESULTS: The ACR task force approved a total of 128 guidance statements addressing the management of MIS-C and hyperinflammation in pediatric COVID-19. These statements were refined into 40 final clinical guidance statements, accompanied by a flow diagram depicting the diagnostic pathway for MIS-C. CONCLUSION: Our understanding of SARS-CoV-2-related syndromes in the pediatric population continues to evolve. The guidance provided in this "living document" reflects currently available evidence, coupled with expert opinion, and will be revised as further evidence becomes available.

Sepsis is a heterogenous and imprecise syndrome that includes multiple phenotypes, some of which are amenable to specific therapies. Developing new therapies for sepsis will require focusing on subsets of patients. Key to improving care is evaluating patients for sepsis mimics and treatable diseases whose manifestations lead to a clinical classification of sepsis. Because sepsis is common, it is easy to overlook unusual causes of organ failure and succumb to confirmation bias about the nature of an illness. Careful attention to medical and family histories, focused diagnostic testing, and subspecialty input can help identify potentially treatable diseases masquerading as typical sepsis.

To provide guidance on the management of Multisystem Inflammatory Syndrome in Children (MIS-C), a condition characterized by fever, inflammation, and multiorgan dysfunction that manifests late in the course of SARS-CoV-2 infection. Recommendations are also provided for children with hyperinflammation during COVID-19, the acute, infectious phase of SARS-CoV-2 infection.The Task Force is composed of 9 pediatric rheumatologists and 2 adult rheumatologists, 2 pediatric cardiologists, 2 pediatric infectious disease specialists, and 1 pediatric critical care physician. Preliminary statements addressing clinical questions related to MIS-C and hyperinflammation in COVID-19 were developed based on evidence reports. Consensus was built through a modified Delphi process that involved anonymous voting and webinar discussion. A 9-point scale was used to determine the appropriateness of each statement (median scores of 1-3 for inappropriate, 4-6 for uncertain, and 7-9 for appropriate). Consensus was rated as low, moderate, or high based on dispersion of the votes. Approved guidance statements were those that were classified as appropriate with moderate or high levels of consensus, which were prespecified before voting.The guidance was approved in June 2020 and updated in November 2020 and October 2021, and consists of 41 final guidance statements accompanied by flow diagrams depicting the diagnostic pathway for MIS-C and recommendations for initial immunomodulatory treatment of MIS-C.Our understanding of SARS-CoV-2-related syndromes in the pediatric population continues to evolve. This guidance document reflects currently available evidence coupled with expert opinion, and will be revised as further evidence becomes available.

ObjectiveThrombotic microangiopathy induced Thrombocytopenia Associated Multiple Organ Failure and hyperinflammatory Macrophage Activation Syndrome are important causes of late pediatric sepsis mortality that are often missed or have delayed diagnosis. Our objective is to derive computable 24-hour sepsis phenotypes to facilitate enrollment in early precise anti-inflammatory trials targeting mortality from these conditions.DesignMachine learning analysis using consensus k-means clustering.SettingNine pediatric intensive care units.Patients404 children with severe sepsis.Interventions24-hour computable phenotypes derived using 25 bedside variables including C-reactive protein and ferritin.Measurements and Main ResultsFour computable phenotypes (PedSep-A, B, C, and D) are derived. Compared to the overall population mean, PedSep-A has the least inflammation (median C-reactive protein 7.3 mg/dL, ferritin 125 ng/mL), younger age, less chronic illness, and more respiratory failure (n = 135; 2% mortality); PedSep-B (median C-reactive protein 13.2 mg/dL, ferritin 225 ng/ mL) has organ failure with intubated respiratory failure, shock, and Glasgow Coma Scale score < 7 (n = 102, 12% mortality); PedSep-C (median C-reactive protein 15.2 mg/dL, ferritin 405 ng/mL) has elevated ferritin, lymphopenia, more shock, more hepatic failure and less respiratory failure (n = 110; mortality 10%); and, PedSep D (median C-reactive protein 13.1 mg/dL ferritin 610 ng/mL), has hyperferritinemic, thrombocytopenic multiple organ failure with more cardiovascular, respiratory, hepatic, renal, hematologic, and neurologic system failures (n = 56, 34% mortality). PedSep-D has highest likelihood of Thrombocytopenia Associated Multiple Organ Failure (Adj OR 47.51 95% CI [18.83-136.83], p < 0.0001) and Macrophage Activation Syndrome (Adj OR 38.63 95% CI [13.26-137.75], p CONCLUSIONS AND RELEVANCEMachine learning identifies four computable phenotypes (www.pedsepsis.pitt.edu). Membership in PedSep-D appears optimal for enrollment in early anti-inflammatory trials targeting Thrombocytopenia Associated Multiple Organ Failure and Macrophage Activation Syndrome.Author’s CommentQuestionCan machine learning methods derive 24-hour computable pediatric sepsis phenotypes that facilitate early identification of patients for enrollment in precise anti-inflammatory therapy trials?FindingsFour distinct phenotypes (PedSep-A, B, C, and D) were derived by assessing 25 bedside clinical variables in 404 children with sepsis. PedSep-D patients had a thrombotic microangiopathy and hyperinflammatory macrophage activation biomarker response, and improved survival odds associated with combined methylprednisolone plus intravenous immunoglobulin therapy.MeaningFour novel computable 24-hour phenotypes are identifiable (www.pedsepsis.pitt.edu) that could potentially facilitate enrollment in early precise anti-inflammatory trials targeting thrombotic microangiopathy and macrophage activation in pediatric sepsis.

In complex diseases, causal structure learning across biological variables is critical to identify modifiable triggers or potential therapeutic agents. A limitation of existing causal learning methods is that they cannot identify indirect causal relations, those that would interact through latent mediating variables. We developed the first computational method that identifies both direct and indirect causalities, causal inference using deep-learning variable-selection (causalDeepVASE). To accurately identify indirect causalities and incorporate them with direct causalities, causalDeepVASE develops a deep neural network approach and extends a flexible causal inference method. In simulated and biological data of various contexts, causalDeepVASE outperforms existing methods in identifying expected or validated causal relations. Further, causalDeepVASE facilitates a systematic understanding of complex diseases. For example, causalDeepVASE uniquely identified a possible causal relation between IFNγ and creatinine suggested in a polymicrobial sepsis model. In future biomedical studies, causalDeepVASE can facilitate the identification of driver genes and therapeutic agents.

We hypothesized that serum biomarkers of inflammation including chemokine, cytokine, pituitary hormones, and growth factors following cardiac arrest in children would independently associate with 6-month neurologic outcome.In this prospective observational single center study of children with in-hospital and out-of-hospital cardiac arrest surviving to intensive care unit admission, serum was obtained twice per 24 h period between 0 h and 96 h and once at approximately 196 h post-cardiac arrest. Inflammatory mediators, hormones, and growth factors were analyzed by Luminex Multiplex Bead Immunoassay. We recorded demographics, resuscitation characteristics, and Pediatric Cerebral Performance Category (PCPC) at 6 months. We analyzed the association and area under the curve (AUC) of biomarker levels with favorable (PCPC 1-3) or unfavorable (PCPC 4-6, or 1 increase from baseline) outcome.Forty-two children (50% female; median age of 2.5 [IQR: 0.4-10.2]) were enrolled and 18 (42%) died prior to 6-month follow up. Receiver operator curves for initial levels of ciliary neurotrophic factor (CNTF, AUC 0.84, 95% CI 0.73-0.96, p 0.001) and interleukin (IL-17, AUC 0.84, 95% CI 0.73-0.97, p 0.001) best classified favorable versus unfavorable 6-month outcome. In multivariable analysis, initial levels of CNTF and IL-17 remained associated with 6-month PCPC. Peak levels of interferon-γ-inducible protein 10 (IP-10), CNTF, and hepatocyte growth factor (HGF) were also independently associated with outcome.Increased serum concentrations of CNTF and IL-17 associated with unfavorable 6-month neurologic outcome of children surviving cardiac arrest. Further investigation of the prognostic utility and roles of CNTF and IL-17 in the pathophysiology of post-cardiac arrest syndrome are warranted. This project is registered with clinicaltrials.gov (NCT00797680) as "Duration of Hypothermia for Neuroprotection after Pediatric Cardiac Arrest: A Randomized, Controlled Trial".

OBJECTIVE: Hemophagocytic lymphohistiocytosis (HLH) poses significant challenges due to limited tools to guide clinical decisions in a population at high risk of death. We sought to assess whether disseminated intravascular coagulation (DIC) and hepatobiliary dysfunction (HBD), significant comorbidities seen in critical care settings, would identify HLH patients with increased risk of mortality. DESIGN: Retrospective chart review. SETTING: Single-center pediatric intensive care unit PATIENTS: All patients admitted to a tertiary care children’s hospital diagnosed with HLH from 2005 – 2012 INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: Forty-three patients were diagnosed with HLH with median age of 61 months. The 5-year overall survival was 51% (22/43). Univariate analyses revealed ferritin levels > 10,000 (ng/mL), international normalized ratio >1.5, or platelet counts < 100,000/mcL at initiation of dexamethasone were individually associated with mortality. Development of DIC, HBD or both increased the likelihood of death in HLH patients (relative risk; 95% confidence interval) (6; 1.4 – 34; p

Post-hoc subgroup analysis of the negative trial of interleukin-1β receptor antagonist (IL1RA) for septic shock suggested that patients with features of macrophage activation syndrome (MAS) experienced a 50% relative risk reduction for mortality with treatment. Here we seek a genetic basis for this differential response. From 1341 patients enrolled in the ProCESS trial of early goal directed therapy for septic shock, we selected 6 patients with MAS features and the highest ferritin, for whole exome sequencing (mean 24,030.7 ηg/ml, ±SEM 7,411.1). In total 11 rare (minor allele frequency

Understanding of ferritin biology has traditionally centered on its role in iron storage and homeostasis, with low ferritin levels indicative of deficiency and high levels indicative of primary or secondary hemochromatosis. However, further work has shown that iron, redox biology and inflammation are inexorably linked. During infection, increased ferritin levels represent an important host defense mechanism that deprives bacterial growth of iron and protects immune cell function. It may also be protective, limiting the production of free radicals and mediating immunomodulation. Additionally, hyperferritinemia is a key acute-phase reactants, used by clinicians as an indication for therapeutic intervention, aimed at controlling inflammation in high-risk patients. One school of thought maintains that hyperferritinemia is an ‘innocent bystander’ biomarker of uncontrolled inflammation that can be used to gauge effectiveness of intervention. Other schools of thought maintain that ferritin induction could be a protective negative regulatory loop. Others maintain that ferritin is a key mediator of immune dysregulation, especially in extreme hyperferritinemia, via direct immune-suppressive and pro-inflammatory effects. There is a clear need for further investigation of the role of ferritin in uncontrolled inflammatory conditions both as a biomarker and mediator of disease because its occurrence identifies patients with high mortality risk and its resolution predicts their improved survival.

Poor outcomes in COVID-19 correlate with clinical and laboratory features of cytokine storm syndrome. Broad screening for cytokine storm and early, targeted antiinflammatory therapy may prevent immunopathology and could help conserve limited health care resources. While studies are ongoing, extrapolating from clinical experience in cytokine storm syndromes may benefit the multidisciplinary teams caring for patients with severe COVID-19.

OBJECTIVES: Genetic disorders are a leading contributor to mortality in the neonatal and pediatric intensive care unit (ICU) in the United States. Although individually rare, there are over 6200 single gene diseases, which may preclude a genetic diagnosis prior to ICU admission. Rapid whole genome sequencing (rWGS) is an emerging method of diagnosing genetic conditions in time to affect ICU management of neonates; however its clinical utility has yet to be adequately demonstrated in critically ill children. This study evaluates next-generation sequencing in pediatric critical care. DESIGN: Retrospective cohort study SETTING: Single-center PICU in a tertiary children’s hospital PATIENTS: Children 4 months to 18 years admitted to the PICU who were nominated between July 2016 and May 2018. INTERVENTIONS: rWGS with targeted phenotype-driven analysis was performed on patients and their parents, when parental samples were available. MEASUREMENTS AND MAIN RESULTS: A molecular diagnosis was made by rWGS in 17 of 38 children (45%). In four of the 17 patients (24%), the genetic diagnoses led to a change in management while in the PICU, including genome-informed changes in pharmacotherapy and transition to palliative care. Nine of the 17 diagnosed children (53%) had no dysmorphic features or developmental delay. Eighty-two percent of diagnoses affected the clinical management of the patient and/or family after PICU discharge, including avoidance of biopsy, administration of factor replacement, and surveillance for disorder-related sequelae. CONCLUSIONS: This study demonstrates a retrospective evaluation for undiagnosed genetic disease in the PICU and clinical utility of rWGS in a portion of critically ill children. Further studies are needed to identify PICU patients who will benefit from rWGS early in PICU admission when the underlying etiology is unclear.

Genes that establish the circadian clock have differential expression with respect to solar time in central and peripheral tissues. Here, we find circadian-time-induced differential expression in a large number of genes not associated with circadian rhythms in two brain regions lacking overt circadian function: the dorsal vagal complex (DVC) and the central nucleus of the amygdala (CeA). These regions primarily engage in autonomic, homeostatic, and emotional regulation. However, we find striking diurnal shifts in gene expression in these regions of male Sprague Dawley rats with no obvious patterns that could be attributed to function or region. These findings have implications for the design of gene expression studies as well as for the potential effects of xenobiotics on these regions that regulate autonomic and emotional states.

To evaluate the relationship between detection of DNA viruses, ferritin, and outcomes in children with severe sepsis.We enrolled 75 pediatric patients with severe sepsis admitted to a tertiary care children's hospital. Plasma ferritin was measured within 48 hours of diagnosis and subsequently twice weekly. Herpes simplex type 1, human herpesvirus 6, Epstein-Barr virus, cytomegalovirus, and adenovirus DNAemia were assessed by polymerase chain reaction.The incidence of DNAemia was increased significantly in patients with ferritin ≥1000 ng/mL (78% vs 28%; P .05). Patients with ferritin ≥1000 ng/mL were more likely to have multiple DNA viruses detected in plasma (39% vs 4%; P .001). The number of viruses detected in plasma directly correlated with the degree of hyperferritinemia and development of combined hepatobiliary and hematologic dysfunction after we controlled for bacterial and fungal coinfections (P .05) as well as increased mortality after we controlled for severity of illness and cancer diagnosis (OR 2.6, 95% CI 1.1-6.3, P.05).Viral DNAemia was associated with hyperferritinemia and adverse outcome in pediatric severe sepsis. Prospective studies are needed to determine whether hyperferritinemia may be used to identify patients at risk of occult DNAemia.

The overall incidence of acute kidney injury (AKI) in the USA is estimated to be about 7/1000 population [1]. Older adults and children are disproportionately affected in a bimodal distribution mirroring the incidence of sepsis [2], the leading cause of AKI [3–6]. Even mild forms of AKI are associated with increased risk of hospital mortality [6, 7], and AKI may result in chronic kidney disease and life-long morbidity, shortened survival and increased costs [8]. Moreover, severity of AKI varies by etiology and sepsis-associated AKI tends to be most severe. For example, KDIGO stage 3 occurs in 20% of patients with septic shock [9]. Once acquired, the consequences of AKI are also unequally distributed. Approximately one third of patients exhibit no reversal of renal dysfunction within the first few days of AKI. Roughly 25% will never recover, and experience a fivefold increase in mortality over the ensuing year [10]. Even among patients with sepsis-associated AKI, outcomes are heterogeneous and different mechanisms may be involved [11]—indeed, no fewer than six have been proposed [12]. Renal endothelial pathology is prevalent in experimental models of sepsis [12, 13]. Endothelial injury can reduce microcirculatory flow leading to perfusion abnormalities and interstitial infiltration of inflammatory cells [13]. However, the reasons some patients exhibit these pathologic features while others do not are obscure.

What is the significance of the extensive variability observed in individual members of a single-cell phenotype? This question is particularly relevant to the highly differentiated organization of the brain. In this study, for the first time, we analyze the in vivo variability within a neuronal phenotype in terms of input type. We developed a large-scale gene-expression data set from several hundred single brainstem neurons selected on the basis of their specific synaptic input types. The results show a surprising organizational structure in which neuronal variability aligned with input type along a continuum of sub-phenotypes and corresponding gene regulatory modules. Correlations between these regulatory modules and specific cellular states were stratified by synaptic input type. Moreover, we found that the phenotype gradient and correlated regulatory modules were maintained across subjects. As these specific cellular states are a function of the inputs received, the stability of these states represents “attractor”-like states along a dynamic landscape that is influenced and shaped by inputs, enabling distinct state-dependent functional responses. We interpret the phenotype gradient as arising from analog tuning of underlying regulatory networks driven by distinct inputs to individual cells. Our results change the way we understand how a phenotypic population supports robust biological function by integrating the environmental experience of individual cells. Our results provide an explanation of the functional significance of the pervasive variability observed within a cell type and are broadly applicable to understanding the relationship between cellular input history and cell phenotype within all tissues.