Cardiac dysfunction and ferritin as early markers of severity in pediatric sepsis

Potential biomarkers used for risk estimation of pediatric sepsis-associated organ dysfunction and immune dysregulation

Pediatric sepsis is a serious issue globally and is a significant cause of illness and death among infants and children. Refractory septic shock and multiple organ dysfunction syndrome are the primary causes of mortality in children with sepsis. However, there is incomplete understanding of mechanistic insight of sepsis associated organ dysfunction. Biomarkers present during the body's response to infection-related inflammation can be used for screening, diagnosis, risk stratification/prognostication, and/or guidance in treatment decision-making. Research on biomarkers in children with sepsis can provide information about the risk of poor outcomes and sepsis-related organ dysfunction. This review focuses on clinically used biomarkers associated with immune dysregulation and organ dysfunction in pediatric sepsis, which could be useful for developing precision medicine strategies in pediatric sepsis management in the future. IMPACT: Sepsis is a complex syndrome with diverse clinical presentations, where organ dysfunction is a key factor in morbidity and mortality. Early detection of organ complications is vital in sepsis management, and potential biomarkers offer promise for precision medicine in pediatric cases. Well-designed studies are needed to identify phase-specific biomarkers and improve outcomes through more precise management.

Gasdermins in sepsis

Sepsis is a hyper-heterogeneous syndrome in which the systemic inflammatory response persists throughout the course of the disease and the inflammatory and immune responses are dynamically altered at different pathogenic stages. Gasdermins (GSDMs) proteins are pore-forming executors in the membrane, subsequently mediating the release of pro-inflammatory mediators and inflammatory cell death. With the increasing research on GSDMs proteins and sepsis, it is believed that GSDMs protein are one of the most promising therapeutic targets in sepsis in the future. A more comprehensive and in-depth understanding of the functions of GSDMs proteins in sepsis is important to alleviate the multi-organ dysfunction and reduce sepsis-induced mortality. In this review, we focus on the function of GSDMs proteins, the molecular mechanism of GSDMs involved in sepsis, and the regulatory mechanism of GSDMs-mediated signaling pathways, aiming to provide novel ideas and therapeutic strategies for the diagnosis and treatment of sepsis.

Control variables of serum ferritin concentrations in hospitalized newborn infants: an observational study

Both iron excess and deficiency are deleterious to cellular and organ homeostasis. Serum ferritin levels serve as a biomarker of iron storage; however, their distribution and determinants in sick newborn infants remain unclear. This study aimed to investigate the reference range and independent variables of serum ferritin in hospitalized newborn infants. All newborn infants who were hospitalized at a tertiary neonatal center within 24 h of birth were retrospectively reviewed for the period of April 2015 through March 2017. Serum ferritin levels were assessed using venous blood samples obtained at admission and their independent variables were explored. The study population comprised 368 infants (36.2 ± 2.8 weeks gestation and 2319 ± 623 g at birth), whose median serum ferritin level was 149 µg/L (inter-quartile range: 81-236). The multivariable model used to explain serum ferritin values comprised hemoglobin, lactate dehydrogenase, blood pH, and maternal hypertensive disorders in pregnancy (all p < 0.01, adjusted for sex and birth weight). Serum ferritin values in hospitalized newborn infants were comparable to those previously reported using umbilical cord blood. Our novel findings indicated the association between blood pH, lactate dehydrogenase, and ferritin levels, suggesting the influence of antenatal hypoxia-ischemia and stress to serum ferritin levels.

Ferritin in pediatric critical illness: a scoping review

This scoping review aimed to elucidate and summarize the predictive role of serum ferritin in critical pediatric illness. The Preferred Reporting Items for Systematic reviews and Meta-Analyses methodology was employed to conduct a scoping review of 5 databases (MEDLINE, CENTRAL, ProQuest, ScienceDirect, and Epistemonikos) from the date of inception through January 24, 2022. Primary research studies involving subjects aged <18 years and serum ferritin levels were screened and reviewed independently following an a priori defined protocol. Of the 1,580 retrieved studies, 66 were analyzed. Summary statistics of serum ferritin levels for overall and condition-specific studies were reported in 30 (45.4%) and 47 studies (71.2%), respectively. The normal range was defined in 16 studies (24.2%), whereas the threshold was determined in 43 studies (65.1%). A value of <500 ng/mL was most often the upper limit of the normal range. Serum ferritin as a numerical variable (78.9%) was usually significantly higher (80.8%) in the predicted condition than in controls, while as a categorical variable with preset thresholds, ferritin was a significant predictor in 84.6% of studies. A total of 22 predictive thresholds predicted mortality (12 of 46 [26.1%]), morbidity (18 of 46 [39.1%]), and specific (16 of 46 [34.8%]) outcomes in 15 unique conditions. Increased precision in serum ferritin measures followed by close attention to the threshold modeling strategy and reporting can accelerate the translation from evidence to clinical practice.

Role of Serum Ferritin and PRISM-III in Predicting Mortality in Children with Acute Encephalitis Syndrome in Northern India

The aim of this study was to evaluate the role of serum ferritin (SF) and PRISM-III (Pediatric Risk of Mortality) score in predicting mortality in critically ill children aged 6 months to 15 years diagnosed with acute encephalitis syndrome (AES) admitted to the pediatric intensive care unit (PICU). This prospective observational study was conducted in the PICU of a tertiary teaching hospital in Northern India between July 2018 and June 2019. The primary outcome was to determine the association of admission SF levels with mortality. Secondary outcomes included estimating the prevalence of hyperferritinemia and comparing SF with PRISM-III scores in predicting mortality. Etiology could be established in 85.5% (n = 219) of the 256 children enrolled. Scrub typhus accounted for nearly two-thirds of the cases (60.5%), while dengue and Japanese encephalitis were the next common diagnoses. The median [interquartile range] SF at admission was significantly higher among the nonsurvivors than survivors: 514 [260–1,857] and 318 [189–699] µg/L, respectively (p = 0.029). SF and PRISM-III independently predicted mortality in AES. However, both had poor discriminatory power with area under receiver operating curve (95% confidence interval) of 0.61 (0.51–0.72) and 0.67 (0.56–0.77), respectively. Elevated SF and higher PRISM-III scores independently predicted mortality in children admitted to PICU with AES.

Protective role of matrine in sepsis-associated cardiac dysfunction through regulating the lncRNA PTENP1/miR-106b-5p axis

BACKGROUND

Matrine has attractive cardioprotective effects in some diseases. This study aimed to evaluate the therapeutic potential of matrine against cardiac dysfunction induced by sepsis in vivo and in vitro, and further explore the related mechanisms.

METHODS

Cecal ligation and puncture (CLP) was used to induce a sepsis mice model, and H9C2 cells treated with lipopolysaccharide (LPS) were used as a cardiac myoblast injury model. The evaluation of cardiac function of mice was performed by measuring cardiac function biomarker levels and hemodynamic indicators. An ELISA method was used to examine inflammatory cytokine levels. H9C2 cell viability was measured using MTT assay. The expression of non-coding RNAs that might be involved in matrine function was analyzed using real-time quantitative PCR.

RESULTS

Matrine could significantly improve the cardiac function and attenuate the inflammatory response of the mice model, and could increase H9C2 viability and inhibit inflammation in the cell model. By matrine administration, the expression of PTENP1 was downregulated, but miR-106b-5p expression was upregulated both in vivo and in vitro. The cardioprotective effects of matrine in mice and cell models could be reversed by the overexpression of PTENP1 or the knockdown of miR-106b-5p, and the overexpression of miR-106b-5p could significantly abolish the effects of PTENP1 on cardiac function and inflammation.

CONCLUSION

All the data revealed that matrine can alleviate sepsis-related cardiac dysfunction by enhancing cardiac myoblast viability and attenuating inflammatory responses through the PTENP1/miR-106b-5p axis.

Renal Involvement in Pediatric Patients with COVID-19: An Up-to-date Review

BACKGROUND

In pediatric patients, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection has been mostly associated with mild symptoms. However, as in adults, renal involvement has been reported in children and adolescents with Coronavirus Disease 2019 (COVID-19).

OBJECTIVE

This review aimed to report data about renal involvement in pediatric COVID-19 patients. The focuses were on the pathophysiology of acute kidney injury in Pediatric Inflammatory Multisystem Syndrome Temporally Associated (PIMS-TS) with SARS-CoV-2 and the possible impact of SARS-CoV-2 infection upon kidney function, as well as data concerning patients with previous kidney diseases, including Nephrotic Syndrome and Chronic Renal Disease. The implications for COVID-19 outcomes in pediatric patients were also discussed.

METHODS

This integrative review searched for articles on renal involvement in pediatric COVID-19 patients. The databases evaluated were PubMed and Scopus.

RESULTS

The emergence of PIMS-TS with SARS-CoV-2 has shown that pediatric patients are at risk of severe COVID-19, with multi-organ involvement and dysfunction. In addition to intense inflammation, several systems are affected in this syndrome, collectively creating a combination of factors that results in acute kidney injury. Several studies have proposed that kidney cells, including the podocytes, might be at risk of direct infection by SARS-CoV-2, as high levels of ACE2, the virus receptor, are expressed on the membrane of such cells. Some cases of glomerular diseases triggered by SARS-CoV-2 infection and relapses of previous renal diseases have been reported.

CONCLUSION

Further studies are necessary to establish risk factors for renal involvement in pediatric COVID-19 and to predict disease outcomes.

Biomarkers in pediatric sepsis: a review of recent literature

Sepsis remains the leading cause of death in infants and children worldwide. Prompt diagnosis and monitoring of infection is pivotal to guide therapy and optimize outcomes. No single biomarker has so far been identified to accurately diagnose sepsis, monitor response and predict severity. We aimed to assess existing evidence of available sepsis biomarkers, and their utility in pediatric population. C-reactive protein and procalcitonin remain the most extensively evaluated and used biomarkers. However, biomarkers related to endothelial damage, vasodilation, oxidative stress, cytokines/chemokines and cell bioproducts have also been identified, often with regard to the site of infection and etiologic pathogen; still, with controversial utility. A multi-biomarker model driven by genomic tools could establish a personalized approach in future disease management.

Prediction of Poor Outcomes for Septic Children According to Ferritin Levels in a Middle-Income Setting

OBJECTIVES

To evaluate serum ferritin measured within 48 hours of admission as a prognostic marker and examine the association with unfavorable outcomes in a population of pediatric patients with sepsis and high prevalence of iron deficiency anemia in which this biomarker is routinely measured.

DESIGN

Retrospective cohort study.

SETTING

PICU of a tertiary care teaching hospital in a middle-income country in South America.

PATIENTS

All patients 6 months to 18 years old (n = 350) admitted with a diagnosis of sepsis, suspected or proven, were eligible for inclusion. Exclusion criteria were length of PICU stay less than 8 hours and inherited or acquired disorder of iron metabolism that could interfere with serum ferritin levels.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Three-hundred twelve patients had their ferritin levels measured within 48 hours, and only 38 did not. The prevalence of iron deficiency anemia (hemoglobin < 11 g/dL and mean corpuscular volume < 80 fl was 40.3%. The median of the highest serum ferritin level within 48 hours was 150.5 ng/mL (interquartile range, 82.25-362 ng/mL), being associated with mortality (p < 0.001; Exp(B), 5.170; 95% CI, 2.619-10.205). A 10-fold increase in ferritin level was associated with a five-fold increase in mortality. There was a monotonic increase in mortality with increasing ferritin levels (p < 0.05). Regarding the discriminatory power of ferritin for mortality, the area under the receiver operating characteristic curve was 0.787 (95% CI, 0.737-0.83; p < 0.0001).

CONCLUSIONS

Serum ferritin at lower thresholds predicts mortality in children with sepsis admitted to the ICU in a middle-income country with high prevalence of iron deficiency anemia.

Ferritin: An Inflammatory Player Keeping Iron at the Core of Pathogen-Host Interactions

Iron is an essential element for virtually all cell types due to its role in energy metabolism, nucleic acid synthesis and cell proliferation. Nevertheless, if free, iron induces cellular and organ damage through the formation of free radicals. Thus, iron levels must be firmly controlled. During infection, both host and microbe need to access iron and avoid its toxicity. Alterations in serum and cellular iron have been reported as important markers of pathology. In this regard, ferritin, first discovered as an iron storage protein, has emerged as a biomarker not only in iron-related disorders but also in inflammatory diseases, or diseases in which inflammation has a central role such as cancer, neurodegeneration or infection. The basic research on ferritin identification and functions, as well as its role in diseases with an inflammatory component and its potential as a target in host-directed therapies, are the main considerations of this review.

Serum Ferritin Predicts Neither Organ Dysfunction Nor Mortality in Pediatric Sepsis Due to Tropical Infections

Objective: To evaluate serial ferritin levels measured in the initial 72 h of admission as a biomarker for new and progressive multi organ dysfunction syndrome (NPMODS) and mortality (unfavorable outcomes) in critically ill children with sepsis due to tropical infections. Material and Methods: In this prospective observational study from a tertiary care teaching hospital in India, children 3 month to 12 years with a diagnosis of acute febrile illness and any two features suggesting tropical infections [cytopenia (platelet count <1,00,000/cu.mm, total leucocyte count <4,000/cu.mm), hepatomegaly and/or splenomegaly, lymphadenopathy, systemic signs (rash, edema), respiratory distress, and encephalopathy not accounted by localized infection] were eligible for inclusion. Children with known or suspected disorder of iron metabolism were excluded. Primary outcome was to determine the association of serial ferritin levels with mortality and NPMODS. Secondary outcomes included estimation of the prevalence of hyperferritinemia and comparison of risk prediction scores with serial ferritin measurement in predicting unfavorable outcomes. Measurements and Main Results: In the 202 children enrolled, diagnosis could be established in 133 (65.8%) children. Scrub typhus and dengue were the most common infections. Median (IQR) ferritin measured at admission (n = 183) and on day 3 (n = 120) of hospital stay were 798 (378, 3,205) μg/L and 429 (213,680) μg/L, respectively. Majority (n = 180, 89.1%) had MODS at admission defined as per International pediatric sepsis consensus conference. NPMODS occurred in 47 (23.3%) children of whom 37 (18.3%) died. Children with three or less organ dysfunctions had lower mortality. Neither admission ferritin values nor the percentage change over 72 h was different between children with favorable and unfavorable outcomes. Pediatric Risk of Mortality (PRISM-III) and daily Pediatric Logistic Organ Dysfunction score (dPELOD2 score) were significantly different in those with unfavorable outcomes. Admission ferritin levels and percentage change in 72 h had poor discriminatory power for mortality with AUC of 0.53 (0.53, 0.67) and 0.50 (0.50, 0.64), respectively. dPELOD2 had the best discriminatory power for mortality with AUC of 0.89 (0.89, 0.95). Conclusions: Serial ferritin estimation predicted neither organ dysfunction nor mortality in pediatric sepsis with tropical infections. dPELOD-2 and PRISM-III predicted unfavorable outcomes better than ferritin. The current diagnostic criteria for MODS overestimated organ dysfunctions in tropical infections and hence may need modification with further validation in this epidemiological cohort.

C-Reactive Protein and Ferritin Are Associated With Organ Dysfunction and Mortality in Hospitalized Children

Our objective was to determine if C-reactive protein (CRP) and ferritin values alone and in combination are associated with mortality among hospitalized children. All hospitalized patients at our institution with a CRP or ferritin assay in 2015 and 2016 were included. Area under the receiver operating curves (AUROC) were examined, optimal cut-points determined, and patients were stratified into low-, intermediate-, or high-risk groups based on elevation of zero, one, or both biomarkers. A total of 14 928 CRP and 653 ferritin values were obtained, with both obtained for 172 patients. AUROC for maximum CRP value was 0.76 (0.68-0.85) with a cut-point of 7.1 mg/dL for in-hospital mortality and 0.90 (0.83-0.98) for maximum ferritin with a cut-point of 373 ng/mL. Elevation of both ferritin and CRP was associated with the highest inpatient mortality (21.7%) and greatest organ dysfunction, followed by either biomarker alone. Additional prospective study of these biomarkers in combination is warranted.

Caspse-11-GSDMD pathway is required for serum ferritin secretion in sepsis

Ferritin is the major iron storage molecule of vertebrates, which can be detected in serum under numerous conditions, including inflammatory, neurodegenerative, and malignant diseases. Given this character, serum ferritin is frequently used as a biomarker in clinical settings. How the ferritin secreted to the serum has attracted much attention. Although some studies have found ferritin was mediated via the endoplasmic reticulum (ER)-Golgi secretion pathway or secretory lysosomes trafficking pathway under normal conditions, the secretion pathway of ferritin under pathological conditions, especially in sepsis is not very clear. In this report, we adopt a murine sepsis model to study the secretion pathway of ferritin in sepsis. We demonstrated caspase-11-GSDMD pathway and associated pyroptosis are required for secretion of ferritin in vitro and in vivo in sepsis. Moreover, our work connects pyroptosis to serum ferritin secretion and suggests a passive release process of ferritin, enhancing our understanding of the mechanism of ferritin secretion.

Incorporation of point-of-care ultrasound into morning round is associated with improvement in clinical outcomes in critically ill patients with sepsis

OBJECTIVES

Point-of-care ultrasound (POCUS) has been widely used in the intensive care unit (ICU). However, it is largely unknown whether the use of POCUS is associated with improved patient-important outcomes. The study aimed to investigate whether incorporation of POCUS during morning round on a routine basis was able to improve clinical outcomes in critically ill patients with sepsis.

DESIGN

It was a prospective observational study.

SETTING

A tertiary care emergency intensive care unit.

PATIENTS

All patients admitted to the emergency ICU from January 2016 to December 2017 were screened for potential eligibility. Sepsis was defined as infection plus signs of organ dysfunction.

INTERVENTION

The intervention group incorporated POCUS during morning round on a routine basis, and a checklist was developed to improve the compliance. The control group did not have the mandates to perform POCUS during morning round, but could use POCUS when necessary.

MEASUREMENTS

Clinical outcomes of mortality, length of stay in ICU, durations of vasopressors and mechanical ventilation were compared between the intervention and control groups. Multivariable regression model was employed to adjust for confounding factors.

MAIN RESULTS

A total of 129 subjects, including 88 in the control group and 41 in the intervention group, were included for analysis. Univariate analysis showed that the intervention group had shorter durations of mechanical ventilation (MV) (4.5 ± 1.2 vs. 5.7 ± 1.0 days; p = 0.034) and more negative fluid balance (-143 vs. 48 ml/24 h; p = 0.003) on day 3. In multivariable model, routine incorporation of POCUS was associated with lower risk of prolonged (>7 days) ICU stay (OR: 0.39, 95% CI: 0.29-0.88; p = 0.029).

CONCLUSIONS

The study showed that incorporation of POCUS during morning round on a routine basis was associated with shortened duration of MV and length of stay in ICU. The possible mechanism underlying the relationship may be via reduced fluid administration. Future randomized controlled trials are needed to validate current findings.

Hyperferritinemia and inflammation

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.