Inflammation and nutrition in children with chronic kidney disease

Interferon-γ induces combined pyroptotic angiopathy and APOL1 expression in human kidney disease

Elevated interferon (IFN) signaling is associated with kidney diseases including COVID-19, HIV, and apolipoprotein-L1 (APOL1) nephropathy, but whether IFNs directly contribute to nephrotoxicity remains unclear. Using human kidney organoids, primary endothelial cells, and patient samples, we demonstrate that IFN-γ induces pyroptotic angiopathy in combination with APOL1 expression. Single-cell RNA sequencing, immunoblotting, and quantitative fluorescence-based assays reveal that IFN-γ-mediated expression of APOL1 is accompanied by pyroptotic endothelial network degradation in organoids. Pharmacological blockade of IFN-γ signaling inhibits APOL1 expression, prevents upregulation of pyroptosis-associated genes, and rescues vascular networks. Multiomic analyses in patients with COVID-19, proteinuric kidney disease, and collapsing glomerulopathy similarly demonstrate increased IFN signaling and pyroptosis-associated gene expression correlating with accelerated renal disease progression. Our results reveal that IFN-γ signaling simultaneously induces endothelial injury and primes renal cells for pyroptosis, suggesting a combinatorial mechanism for APOL1-mediated collapsing glomerulopathy, which can be targeted therapeutically.

Screening for protein energy wasting in children with chronic kidney disease using dual energy x-ray absorptiometry as an additional tool

BACKGROUND

The current diagnosis of protein energy wasting (PEW) is based on scoring systems that lack precision in measuring muscle deficits. We undertook this cross-sectional study to determine the prevalence of PEW in children with chronic kidney disease (CKD) using a scoring system that included dual energy x-ray absorptiometry (DEXA) for measuring lean body mass (LBM) and to determine the prevalence of selected markers in PEW.

METHODS

Thirty CKD and 20 healthy children (1-18 years) were evaluated for (1) reduced dietary protein intake (DPI); (2) BMI < fifth centile for height age (BMI/HA); (3) serum albumin < 3.8 g/dl, cholesterol < 100 mg/dl, or CRP > 3 mg/L; (4) LBM < fifth centile for height age [LBMr] on DEXA. PEW was scored as minimal-one parameter positive in 2/4 categories; standard-one parameter positive in 3/4 categories; or modified-standard plus height < 2 SD.

RESULTS

Twenty children with CKD (66.7%) had PEW, (5/9) 55% in CKD 3, and (15/21) 71% in advanced CKD; minimal 12, standard 1, and modified 7. LBMr was seen in 20 (100%), reduced DPI in 16 (80%), and BMI/HA in 6 (30%) children with PEW. LBMr had 100% sensitivity and BMI/HA 100% specificity. LBMr was seen in 8 who had no other criteria for PEW. None of the parameters were positive in controls (p < 0.01).

CONCLUSIONS

PEW prevalence in CKD was high. Both prevalence and severity were higher in advanced CKD. LBMr was a highly sensitive marker to detect PEW. LBMr seen in some children with CKD who were negative for other markers could represent subclinical PEW.

Proposed Response Parameters for Twelve-Month Drug Trial in Juvenile Systemic Sclerosis: Results of the Hamburg International Consensus Meetings

OBJECTIVE

Juvenile systemic sclerosis (SSc) is an orphan disease, associated with high morbidity and mortality. New treatment strategies are much needed, but clearly defining appropriate outcomes is necessary if successful therapies are to be developed. Our objective here was to propose such outcomes.

METHODS

This proposal is the result of 4 face-to-face consensus meetings with a 27-member multidisciplinary team of pediatric rheumatologists, adult rheumatologists, dermatologists, pediatric cardiologists, pulmonologists, gastroenterologists, a statistician, and patients. Throughout the process, we reviewed the existing adult data in this field, the more limited pediatric literature for juvenile SSc outcomes, and data from 2 juvenile SSc patient cohorts to assist in making informed, data-driven decisions. The use of items for each domain as an outcome measure in an open label 12-month clinical trial of juvenile SSc was voted and agreed upon using a nominal group technique.

RESULTS

After voting, the domains agreed on were global disease activity, skin, Raynaud's phenomenon, digital ulcers, musculoskeletal, cardiac, pulmonary, renal, and gastrointestinal involvement, and quality of life. Fourteen outcome measures had 100% agreement, 1 item had 91% agreement, and 1 item had 86% agreement. The domains of biomarkers and growth/development were moved to the research agenda.

CONCLUSION

We reached consensus on multiple domains and items that should be assessed in an open label, 12-month clinical juvenile SSc trial as well as a research agenda for future development.

Screening of key genes in the pathogenesis of muscle atrophy in CKD-PEW children based on RNA sequencing

BACKGROUND

In children with CKD, Protein Energy Wasting (PEW) is common, which affects the outcome of children and is an important cause of poor prognosis. We are aiming to explore the pathogenesis of muscle wasting in CKD-PEW children.

METHODS

Blood samples of 32 children diagnosed with chronic kidney disease (CKD) and protein energy wasting (PEW) in our hospital from January 2016 to June 2021 were collected. RNA sequencing and bioinformatics analysis were performed.

RESULTS

Based on GO (Gene Ontology) functional enrichment analysis, KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis and differential gene expression analysis, a total of 25 CKD-PEW related genes were obtained including CRP, IL6, TNF, IL1B, CXCL8, IL12B, IL12A, IL18, IL1A, IL4, IL10, TGFB2, TGFB1, TGFB3, ADIPOQ, NAMPT, RETN, RETNLB, LEP, CD163, ICAM1, VCAM1, SELE, NF-κB1, NF-κB2. The most significantly differentially expressed gene was NF-κB2 (adjusted P = 2.81 × 10-16), and its expression was up-regulated by 3.92 times (corresponding log2FoldChange value was 1.979). Followed by RETN (adjusted P = 1.63 × 10-7), and its expression was up-regulated by 8.306 times (corresponding log2FoldChange value was 2.882). SELE gene were secondly significant (adjusted P = 5.81 × 10-7), and its expression was down-regulated by 22.05 times (corresponding log2FoldChange value was -4.696).

CONCLUSIONS

A variety of inflammatory factors are involved in the pathogenesis of CKD-PEW in children, and chronic inflammation may lead to the development of muscle atrophy in CKD-PEW. It is suggested for the first time that NF-κB is a key gene in the pathogenesis of muscle wasting in CKD-PEW children, and its increased expression may play an important role in the pathogenesis of muscle wasting in children with CKD-PEW.

Effect of L-Carnitine Supplementation on Inflammatory Markers and Serum Glucose in Hemodialysis Children: A Randomized, Placebo-Controlled Clinical Trial

OBJECTIVES

Chronic inflammation is present in a high proportion of the chronic kidney disease (CKD) population, which can increase the risk of cardiovascular disease. Moreover, it is known as the leading cause of death in these patients. In addition, change in glucose metabolism is another common problem among CKD population. In this regard, it was found that insulin resistance and inflammation can perpetuate each other and simultaneously cause atherosclerosis. Because some studies have previously shown the positive effects of L-carnitine on reducing inflammation and controlling blood sugar, in the present study, we examined the effects of L-carnitine supplementation on serum inflammatory markers, fasting blood sugar (FBS), free carnitine (FC), albumin levels, and quality of life score among children on hemodialysis.

METHOD

Twenty-four children on hemodialysis (aged between 6 and 18 years) were enrolled in this randomized clinical trial study. Thereafter, 12 patients received 50 mg/kg of L-carnitine and 12 patients received placebo for a 10-week period. Afterward, we determined serum FC, interleukin-6 (IL-6), high-sensitivity C-reactive protein, FBS, and albumin and Pediatrics Quality of Life scores once at the baseline and once after performing intervention for 10 weeks. Moreover, the one-way repeated measures analysis was used to evaluate the effects of L-carnitine supplementation.

RESULTS

Although oral L-carnitine supplementation led to the decreased high-sensitivity C-reactive protein, this change was not significant compared with the placebo. Also, L-carnitine supplementation has significantly reduced serum levels of IL-6 and FBS, which has also raised serum FC and Pediatrics Quality of Life scores compared with the placebo. Notably, no significant change was observed in serum albumin levels.

CONCLUSION

Given the significant reductions in IL-6 and FBS levels, L-carnitine supplementation appeared to have some positive effects on the inflammation, blood glucose control, and prevention of cardiovascular events in these patients, as well as the improvement of quality of life. In this regard, L-carnitine therapy with a longer duration is recommended to obtain more effective results.

Effect of L-carnitine supplementation on lipid profile and apolipoproteins in children on hemodialysis: a randomized placebo-controlled clinical trial

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death in children with chronic kidney disease (CKD) and accounts for 40% of all deaths among pediatric patients with stage 5 chronic kidney disease (CKD 5). Dyslipidemia is common in children with CKD and is considered one of the major causes of CVD in these patients. As carnitine plays a key role in lipid metabolism and because plasma levels are reduced in hemodialysis patients, the aim of this study was to determine the effects of L-carnitine supplementation on serum lipid profiles, apolipoproteins, and free carnitine (FC) levels.

METHODS

A total of 30 children on hemodialysis (6-18 years) were enrolled and 24 completed the study. Twelve patients received 50 mg/kg/day L-carnitine, while the other 12 patients received placebo for 10 weeks. Serum FC, total cholesterol (TC), LDL-C, HDL-C, TG, Apolipoprotein B (ApoB), and Apolipoprotein A1 (ApoA1) were determined at the baseline and after the intervention. One-way repeated measures analysis was used to evaluate the effects of L-carnitine supplementation.

RESULTS

Oral L-carnitine supplementation led to decreased ApoB levels and ApoB/ApoA1 ratio, but these changes were not significant compared to placebo. Meanwhile, L-carnitine supplementation significantly reduced serum LDL-C and TC and increased serum FC compared to placebo. No significant changes were observed in serum TG and HDL-C levels.

CONCLUSION

Given the significant reduction in LDL-C and TC levels, L-carnitine supplementation had positive effects on improving hyperlipidemia in children receiving hemodialysis. For more decisive results, studies with longer duration of L-carnitine therapy on children receiving hemodialysis with significant dyslipidemia are recommended.

TRIAL REGISTRATION

We registered the present trial in the Iranian Registry of Clinical Trials website (available at: http://www.irct.ir , identifier: IRCT20170202032367N2).

Tumor necrosis factor-alpha is associated with mineral bone disorder and growth impairment in children with chronic kidney disease

BACKGROUND

Mineral and bone disorder (MBD) and growth impairment are common complications of pediatric chronic kidney disease (CKD). Chronic inflammation detrimentally affects bone health and statural growth in non-CKD settings, but the impact of inflammation on CKD-MBD and growth in pediatric CKD remains poorly understood. This study assessed associations between inflammatory cytokines with biomarkers of CKD-MBD and statural growth in pediatric CKD.

METHODS

This is a cross-sectional study of children with predialysis CKD stages II-V. Cytokines (IL-1b, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, TNF-α, interferon-γ), bone alkaline phosphatase (BAP), and procollagen type 1 N-terminal propeptide (P1NP) were measured at the same time as standard CKD-MBD biomarkers. Associations between cytokines, CKD-MBD biomarkers, and height z-score were assessed using linear regression analysis.

RESULTS

Among 63 children, 52.4% had stage 3 CKD, 76.2% non-glomerular CKD etiology, and 21% short stature. TNF-α was the only cytokine associated with parathyroid hormone (PTH) independent of glomerular filtration rate. After stratification by low, medium, and high TNF-α tertiles, significant differences in PTH, serum phosphorus, alkaline phosphatase, BAP, P1NP, and height z-score were found. In a multivariate analysis, TNF-α positively associated with phosphorus, PTH, and alkaline phosphatase and inversely associated with height z-score, independent of kidney function, age, sex, and active vitamin D analogue use.

CONCLUSIONS

TNF-α is positively associated with biomarkers of CKD-MBD and inversely associated with height z-score, indicating that inflammation likely contributes to the development of CKD-MBD and growth impairment in pediatric CKD. Prospective studies to definitively assess causative effects of inflammation on bone health and growth in children with CKD are warranted.

WITHDRAWN: Analysis of Infection Factors and Nerve Conduction Velocity in Patients with Chronic Glomerular Disease Based on Information Health Data and Electromyography

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Serum albumin and hospitalization among pediatric patients with end-stage renal disease who started dialysis therapy

BACKGROUND

Hypoalbuminemia is a strong predictor of hospitalization and mortality among adult dialysis patients. However, data are scant on the association between serum albumin and hospitalization among children new to dialysis.

METHODS

In a retrospective cohort study of children 1-17 years old with end-stage renal disease receiving dialysis therapy in a large US dialysis organization 2007-2011, we examined the association of serum albumin with hospitalization frequency and total hospitalization days using a negative binomial regression model.

RESULTS

Among 416 eligible patients, median (interquartile range) age was 14 (10-16) years and mean ± SD baseline serum albumin level was 3.7 ± 0.8 g/dL. Two hundred sixty-six patients (64%) were hospitalized during follow-up with an incidence rate of 2.2 (95%CI, 1.9-2.4) admissions per patient-year. There was a U-shaped association between serum albumin and hospitalization frequency; hospitalization rates (95%CI) were 2.7 (2.2-3.2), 1.9 (1.5-2.4), 1.6 (1.3-1.9), and 2.7 (1.7-3.6) per patient-year among patients with serum albumin levels < 3.5, 3.5- < 4.0, 4.0- < 4.5, and ≥ 4.5 g/dL, respectively. Case mix-adjusted hospitalization incidence rate ratios (IRRs) (95%CI) were 1.63 (1.24-2.13), 1.32 (1.10-1.58), and 1.25 (1.06-1.49) at serum albumin levels 3.0, 3.5, and 4.5 g/dL, respectively (reference: 4.0 g/dL). Similar trends were observed in hospitalization days. These associations remained robust against further adjustment for laboratory variables associated with malnutrition and inflammation.

CONCLUSIONS

Both high and low serum albumin were associated with higher hospitalization in children starting dialysis. Because the observed association is novel and not fully explainable especially for high serum albumin levels, interpreting the results requires caution and further studies are needed to confirm and elucidate this association before clinical recommendations are made.

Nutrition imbalance in Chinese chronic kidney disease children

BACKGROUND

Nutrition imbalance is common in chronic kidney disease (CKD) children. This study evaluated the nutrition status of CKD children at different stages using bioimpedance analysis (BIA) compared with anthropometry.

METHODS

Fifty-five CKD children at stages III, IV, V and 19 age- and sex-matched healthy controls were recruited. Fat, protein and mineral composition on BIA were analyzed together with anthropometry for height, weight and body mass index (BMI). Biochemistry was also checked in CKD children.

RESULTS

Of the CKD children, 23.6%, 10.9% and 56.3% were underweight, overweight/obese and stunted, respectively. On BIA, 52.7%, 70.9%, 14.5% and 40.0% of the CKD children had protein reduction, fat reduction, fat enhancement and mineral reduction, respectively. Growth retardation and nutrition reduction became remarkable at stages IV and V. Approximately 65% of healthy-weight children had nutrition reduction. In the underweight and healthy-weight groups, fat reduction rates were higher than protein reduction rate. In the overweight/obese group, fat enhancement was most notable. Mineral reduction was less remarkable.

CONCLUSIONS

The nutrition imbalance in CKD children on BIA correlated well with anthropometry and disease process, supporting BIA as an auxiliary diagnosis tool.

Biomarkers of Systemic Inflammation and Growth in Early Infancy are Associated with Stunting in Young Tanzanian Children

Stunting can afflict up to one-third of children in resource-constrained countries. We hypothesized that low-grade systemic inflammation (defined as elevations in serum C-reactive protein or alpha-1-acid glycoprotein) in infancy suppresses the growth hormone–insulin-like growth factor (IGF) axis and is associated with subsequent stunting. Blood samples of 590 children from periurban Dar es Salaam, Tanzania, were obtained at 6 weeks and 6 months of age as part of a randomized controlled trial. Primary outcomes were stunting, underweight, and wasting (defined as length-for-age, weight-for-age and weight-for-length z-scores < −2) between randomization and endline (18 months after randomization). Cox proportional hazards models were constructed to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of time to first stunting, underweight, and wasting as outcomes, with measures of systemic inflammation, insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) as exposures, adjusting for numerous demographic and clinical variables. The incidences of subsequent stunting, underweight, and wasting were 26%, 20%, and 18%, respectively. In multivariate analyses, systemic inflammation at 6 weeks of age was significantly associated with stunting (HR: 2.14, 95% CI: 1.23, 3.72; p = 0.002). Children with higher levels of IGF-1 at 6 weeks were less likely to become stunted (HR: 0.58, 95% CI: 0.37, 0.93; p for trend = 0.019); a similar trend was noted in children with higher levels of IGF-1 at 6 months of age (HR: 0.50, 95% CI: 0.22, 1.12; p for trend = 0.07). Systemic inflammation occurs as early as 6 weeks of age and is associated with the risk of future stunting among Tanzanian children.

The Impact of Insulin Resistance and Chronic Kidney Disease on Inflammation and Cardiovascular Disease

There is extensive evidence showing that insulin resistance (IR) is associated with chronic low-grade inflammation. Furthermore, IR has been shown to increase the risk for cardiovascular disease (CVD), even in nondiabetic patients, and is currently considered as a “nontraditional” risk factor contributing to CVD by promoting hypertension, oxidative stress, endothelial dysfunction, dyslipidemia, and type 2 diabetes mellitus. However, chronic kidney disease (CKD) is also considered a state of low-grade inflammation. In addition, CKD is considered an IR state and has been described as an independent risk factor for the development of CVD, as even early-stage CKD is associated with an estimated 40% to 100% increase in CVD risk. There is also strong evidence indicating that inflammation per se plays a crucial role in both the initiation and progression of CVD. Given the above, the combined effect of IR and CKD may significantly increase the risk of inflammation and CVD. This review aims to focus on the complex interplay between IR, CKD, inflammation, and CVD and will present and discuss the current clinical and scientific data pertaining to the impact of IR and CKD on inflammation and CVD.

Is Dietary Protein Intake Predictive of 1-Year Mortality in Dialysis Patients?

BACKGROUND

High mortality in dialysis patients may be associated with protein-energy wasting (PEW) syndrome characterized by progressively depleted protein and energy stores. While early diagnosis and treatment of PEW can reduce mortality, clinically practical measures for its detection are lacking. Poor dietary protein intake (DPI) is associated with risk of malnutrition and PEW. However, the impact of DPI on mortality is unclear. The purpose of this study is to examine the ability of DPI to predict 1-year mortality in dialysis patients.

METHODS

This prospective, secondary study using data from the Comprehensive Dialysis Study and United States Renal Data System examined risk factors associated with 1-year mortality in dialysis patients.

RESULTS

Seventeen (7.5%) of the 227 subjects died within 1 year following baseline data collection. One year survivors were significantly younger (60 ± 13.6 versus 71 ± 12.8; P = 0.0043), had a lower Charlson Comorbidity Index score (1.6 ± 2.3 versus 4.0 ± 3.6; P = 0.0157), higher serum albumin level (3.5 ± 0.5 versus 3.3 ± 0.4; P = 0.0173) and had higher DPI (63 ± 33.7 versus 49.5 ± 21.5 g/day; P = 0.0386) than those who died. In multivariable Cox proportional hazards model analyses, only the Charlson Comorbidity Index adjusted hazard ratio for death (1.24) was significantly associated with increased mortality. The Comprehensive Dialysis Study data showed no association between DPI and 1-year mortality in dialysis patients.

CONCLUSIONS

Future studies using more precise measures should further examine the impact of DPI on mortality given the known association of DPI with PEW syndrome and the definitive link between PEW syndrome and survival in dialysis patients.

A Translational Model of Incomplete Catch-Up Growth: Early-Life Hypoxia and the Effect of Physical Activity

Advances in therapies have led to prolonged survival from many previously lethal health threats in children, notably among prematurely born babies and those with congenital heart disease. Evidence for catch‐up growth is common in these children, but in many cases the adult phenotype is never achieved. A translational animal model is required in which specific tissues can be studied over a reasonable time interval. We investigated the impact of postnatal hypoxia (HY) (12%O₂ (HY12) or 10% O₂ (HY10)) on growth in rats relative to animals raised in room air. Subgroups had access to running wheels following the HY period. Growth was fully compensated in adult HY12 rats but not HY10 rats. The results of this study indicate that neonatal hypoxia can be a useful model for the elucidation of mechanisms that mediate successful catch‐up growth following neonatal insults and identify the critical factors that prevent successful catch‐up growth.

Care of the Pediatric Patient on Chronic Dialysis

Optimal care of the pediatric end-stage renal disease (ESRD) patient on chronic dialysis is complex and requires multidisciplinary care as well as patient/caregiver involvement. The dialysis team, along with the family and patient, should all play a role in choosing the dialysis modality which best meets the patient's needs, taking into account special considerations and management issues that may be particularly pertinent to children who receive peritoneal dialysis or hemodialysis. Meticulous attention to dialysis adequacy in terms of solute and fluid removal, as well as to a variety of clinical manifestations of ESRD, including anemia, growth and nutrition, chronic kidney disease-mineral bone disorder, cardiovascular health, and neurocognitive development, is essential. This review highlights current recommendations and advances in the care of children on dialysis with a particular focus on preventive measures to minimize ESRD-associated morbidity and mortality. Advances in dialysis care and prevention of complications related to ESRD and dialysis have led to better survival for pediatric patients on dialysis.