Risk for anemia in pediatric chronic kidney disease patients: a report of NAPRTCS

A cost-effective innovation in anaemia management for paediatric patients with haemodialysis-dependent chronic kidney disease

BACKGROUND

Paediatric patients undergoing haemodialysis typically require intravenous (IV) iron therapy to replenish iron stores. Upon establishing our home haemodialysis service, the need for an efficient IV iron administration method prompted exploration beyond the conventional use of iron sucrose, which is associated with anaphylaxis and requires frequent infusions. Ferric carboxymaltose has a favourable safety profile and corrects iron deficiency with less frequent infusions. We aimed to establish if ferric carboxymaltose was a viable alternative in this patient group.

METHODS

This single-centre, uncontrolled retrospective cohort study assessed the effectiveness of ferric carboxymaltose in maintaining laboratory parameters (haemoglobin level, transferrin saturation and reticulocyte haemoglobin content) within target range in our home haemodialysis population. Secondly, we conducted a comparative analysis to establish maintenance efficacy of ferric carboxymaltose, versus iron sucrose over a 12-month period. Finally, we performed a cost-effectiveness analysis of IV iron therapy, considering cost per dose and per month of treatment.

RESULTS

Following ferric carboxymaltose infusion, we observed significant increases in haemoglobin level, transferrin saturation and reticulocyte haemoglobin content, which was maintained at 3-month post-infusion. Ferric carboxymaltose demonstrated comparable efficacy to iron sucrose in maintaining laboratory parameters. Strikingly, ferric carboxymaltose treatment was associated with significantly decreased number of infusions per month (~ tenfold) and a significant cost-saving (~ fivefold).

CONCLUSIONS

This study underscores the clinical efficacy and economic benefits of ferric carboxymaltose as a viable treatment for iron deficiency anaemia in paediatric patients who are haemodialysis-dependent and highlights the potential for significant improvements in healthcare delivery, in terms of reducing frequency of hospital visits for this patient population.

Resistance to Epoetin-Stimulating Agents in Children Receiving Renal Replacement Therapy

The incidence of anemia increases with the stage of chronic kidney disease (CKD). Erythropoietin (EPO) deficiency is a common cause of anemia in CKD. Erythropoietin-stimulating agents (ESAs) are the mainstay of the treatment. Treatment can be challenging due to erythropoietin resistance (ER), which can be assessed using the erythropoietin resistance index (ERI). Our aim was to investigate the factors contributing to high ERI levels in children receiving renal replacement therapy (RRT). Thirty-three children receiving RRT for at least 3 months were included. The mean ERI value was 15.7 IU/kg/w/g/dL. A significant association was observed between serum phosphorus levels and ERI (P = .016, r = 0.41). The mean parathormone (PTH) level was also higher in the high ERI group (599 ± 351 vs 392 ± 320 pg/mL, P = .088). An association, approaching statistical significance, was found between ERI and hypertension (P = .06, r = 0.32). Our study indicated a potential relationship between hyperphosphatemia, possibly secondary hyperparathyroidism, and ERI in children undergoing RRT.

Compassionate use of roxadustat for treatment of refractory renal anemia in an infant

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) have played an important role in the treatment of renal anemia in children, but cannot improve hemoglobin to target level in some cases. Roxadustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, can stimulate endogenous erythropoietin production and regulate iron metabolism even in patients with kidney failure. However, roxadustat has not yet been approved for use in children.

CASE-DIAGNOSIS/TREATMENT

We report a case of refractory renal anemia in an 80-day-old boy, who was hyporesponsive to ESAs even in combination with iron supplementation and transfusion. Compassionate use of roxadustat successfully corrected the intractable anemia. Hyperkalemia is a manageable adverse event of concern during follow-up.

CONCLUSION

The successful experience in this case may inform the clinical utility of roxadustat for refractory renal anemia in children, which should be further confirmed by well-designed prospective clinical trials.

Novel anemia therapies in chronic kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Anemia is common in patients with chronic kidney disease and is associated with a high burden of morbidity and adverse clinical outcomes. In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) published a guideline for the diagnosis and management of anemia in chronic kidney disease. Since then, new data from studies assessing established and emerging therapies for the treatment of anemia and iron deficiency have become available. Beginning in 2019, KDIGO planned 2 Controversies Conferences to review the new evidence and its potential impact on the management of anemia in clinical practice. Here, we report on the second of these conferences held virtually in December 2021, which focused on a new class of agents-the hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs). This report provides a review of the consensus points and controversies from this second conference and highlights areas that warrant prioritization for future research.

Anemia and Associated Risk Factors in Pediatric Patients

Anemia is the most common hematologic abnormality identified in children and represents a major global health problem. A delay in diagnosis and treatment might place patients with anemia at risk for the development of rare but serious complications, including chronic and irreversible cognitive impairment. Identified risk factors contributing to the development of anemia in children include the presence of nutritional deficiencies, environmental factors, chronic comorbidities, and congenital disorders of hemoglobin or red blood cells. Pediatricians, especially those in the primary care setting, serve a particularly critical role in the identification and care of those children affected by anemia. Prompt recognition of these risk factors is crucial for developing appropriate and timely therapeutic interventions and prevention strategies.

Fibroblast growth-factor 23 and vitamin D are associated with iron deficiency and anemia in children with chronic kidney disease

BACKGROUND

This cross-sectional study investigates the association of fibroblast growth-factor 23 (FGF23) and other bone mineral parameters with iron status and anemia in pediatric chronic kidney disease (CKD).

METHODS

Serum calcium, phosphorus, 25-hydroxyvitamin D (25(OH)D), intact parathormone, c-terminal FGF23, a-Klotho, iron (Fe), ferritin, unsaturated iron-binding capacity, and hemoglobin (Hb) were measured in 53 patients from 5 to 19 years old with GFR < 60 mL/min/1.73 m2. Transferrin saturation (TSAT) was calculated.

RESULTS

Absolute (ferritin ≤ 100 ng/mL, TSAT ≤ 20%) and functional iron deficiency (ferritin > 100 ng/mL, TSAT ≤ 20%) were observed in 32% and 7.5% of patients, respectively. In CKD stages 3-4 (36 patients), lnFGF23 and 25(OH)D were correlated with Fe (rs =  - 0.418, p = 0.012 and rs = 0.467, p = 0.005) and TSAT (rs =  - 0.357, p = 0.035 and rs = 0.487, p = 0.003) but not to ferritin. In this patient group, lnFGF23 and 25(OH)D were correlated with Hb z-score (rs =  - 0.649, p < 0.001 and rs = 0.358, p = 0.035). No correlation was detected between lnKlotho and iron parameters. In CKD stages 3-4, in multivariate backward logistic regression analysis, including bone mineral parameters, CKD stage, patient age, and daily alphacalcidol dose as covariates, lnFGF23 and 25(OH)D were associated with low TSΑΤ (15 patients) (OR 6.348, 95% CI 1.106-36.419, and OR 0.619, 95% CI 0.429-0.894, respectively); lnFGF23 was associated with low Hb (10 patients) (OR 5.747, 95% CI 1.270-26.005); while the association between 25(OH)D and low Hb did not reach statistical significance (OR 0.818, 95% CI 0.637-1.050).

CONCLUSIONS

In pediatric CKD stages 3-4, iron deficiency and anemia are associated with increased FGF23, independently of Klotho. Vitamin D deficiency might contribute to iron deficiency in this population. A higher resolution version of the Graphical abstract is available as Supplementary information.

Association between serum biomarkers and oral health status in children with chronic kidney disease: A cross-sectional study

OBJECTIVES

The aim of this study was to investigate the association between serum biomarkers and oral health parameters in children with chronic kidney disease (CKD).

MATERIALS AND METHODS

Serum hemoglobin, blood urea nitrogen, serum creatinine, calcium, parathormone, magnesium, and phosphorus levels were measured in 62 children with CKD aged between 4 and 17 years. Intraoral examinations of the patients were performed by two different pediatric dentists. Dental caries was assessed using the decayed-missing-filled-teeth (DMFT/dmft) indexes, and oral hygiene was assessed using the debris (DI), calculus (CI), and simplified oral hygiene (OHI-S) indexes. Spearman's rho coefficient and generalized linear modeling were used to examine the association between serum biomarkers and oral health parameters.

RESULTS

The results of the study showed that there were negative and statistically significant correlations between serum hemoglobin and creatinine levels and dmft scores in pediatric patients with CKD (p = 0.021 and p = 0.019, respectively). Furthermore, blood urea nitrogen levels and DI and OHI-S scores (p = 0.047 and p = 0.050, respectively); serum creatinine levels and DI, CI, and OHI-S scores (p = 0.005, p = 0.047, p = 0.043, respectively); and parathormone levels and CI and OHI-S scores (p = 0.001 and p = 0.017, respectively) were found to be positively and statistically significantly related.

CONCLUSIONS

There are associations between various serum biomarker levels and dental caries and oral hygiene parameters in pediatric patients with CKD.

CLINICAL RELEVANCE

The impact of changes in serum biomarkers on oral and dental health is important for dentists' and medical professionals' approaches to patients' oral and systemic health.

A longitudinal analysis of the effect of anemia on executive functions in children with mild to moderate chronic kidney disease

BACKGROUND

Children with chronic kidney disease (CKD) are at risk for cognitive dysfunction. The aim of this study was to investigate associations between executive functions (EF), anemia, and iron deficiency.

METHODS

A total of 688 children > 6 years of age enrolled in the Chronic Kidney Disease in Children (CKiD) study who underwent evaluation for EF were included. Hemoglobin (Hgb) was characterized as low (1st-5th percentile) or very low (< 1st percentile) compared to normative values for age, sex, and race irrespective of erythropoiesis-stimulating agent (ESA) usage. Longitudinal analysis was conducted using consecutive visit pairs, with anemia status defined as new onset, resolved, or persistent. Linear mixed models with random intercept were used and adjusted for key covariates.

RESULTS

Anemia was present in 41% of children, and median Hgb was 11.8 gm/dl. New onset anemia was associated with lower digit span total score (- 0.75, 95% CI - 1.36, - 0.15, p = 0.01). Persistent anemia was associated with lower scores on color-word inhibition/switching (β =  - 0.98; 95% CI - 1.78, - 0.18, p = 0.02). Errors of omission were significantly higher (worse) in those with persistent anemia (β = 2.67, 95% CI 0.18, 5.17, p = 0.04). Very low Hgb levels were significantly associated with lower color-word inhibition/switching scores (β =  - 1.33, 95% CI - 2.16, - 0.51; p = 0.002). Anemia and low GFR were associated with lower category fluency scores compared to non-anemic subjects with higher GFR (β =  - 1.09, 95% CI - 2.09, - 0.10, p = 0.03).

CONCLUSIONS

The presence of anemia, in addition to its severity and duration in children with CKD, is associated with poorer scores on select measures of EF. A higher resolution version of the Graphical abstract is available as Supplementary information.

Comparison of darbepoetin alpha and recombinant human erythropoietin for treatment of anemia in pediatric chronic kidney disease: a non-inferiority trial from India

To determine whether or not Darbepoetin alpha (DA) was non-inferior to recombinant human erythropoietin (rHuEPO) in the treatment of anemia in children with chronic kidney disease (CKD) stage 3-5 (on or not on dialysis). This was a randomized, open-label, two-arm, parallel group, active-controlled, non-inferiority trial conducted at a tertiary care center in New Delhi, India. Fifty patients of either gender (aged 1-18 years) with CKD stage 3-5 (on or not on dialysis) who had baseline hemoglobin (Hb) between 9 and 12 g/dL and were on stable erythropoietin therapy for at least 8 weeks were randomized (1:1) to either continue rHuEPO or switch to DA therapy for a period of 28 weeks. Doses were titrated in the initial 23 weeks to maintain the Hb between 11 and 12 g/dL, and efficacy was assessed between weeks 24 and 28. The primary efficacy outcome was the mean change in Hb between baseline and the evaluation period. In the intention-to-treat population (n = 50), the adjusted between-group difference in mean Hb change between the baseline and the evaluation period was 0.131 g/dL (95% CI: - 0.439 to 0.719, p = 0.629). The lower limit of the two-sided 95% CI for the difference in the mean change in Hb between the two treatment groups was well above the pre-specified non-inferiority margin of - 1.0 g/dL. Similar pattern of non-inferiority was seen for per protocol population. The safety profile of DA and rHuEPO was also comparable (injection site pain:rHuEPO-3, DA-7; p-0.296).   Conclusion: DA is non-inferior to rHuEPO for the treatment of anemia of CKD (stage 3-5) in pediatric population with a comparable safety profile.   Trial registration: ClinicalTrials.gov Identifier: NCT04959578 (retrospectively registered), Date: July 13, 2021. What is Known: • Limited studies showing darbepoetin alpha is effective in children as an erythropoiesis stimulating agent. • No RCT from Indian subcontinent addressing this topic. What is New: • Darbepoetin alpha is non inferior to recombinant human erythropoietin for treatment of anemia in children with CKD stage 3-5 (on or not on dialysis) with safety comparable to recombinant human erythropoietin. • A cost reduction of approximately 8.6% per patient by shifting to darbepoetin alpha.

Physical performance capacity after pediatric kidney transplant and clinical parameters associated with physical performance capacity

BACKGROUND

History of chronic kidney disease and kidney transplantation is known to influence physical performance capacity. The aim of this study was to compare the physical performance of pediatric kidney transplant recipients to healthy controls and to find possible correlations between clinical parameters and physical performance capacity.

METHODS

Twenty-four pediatric kidney transplant recipients (62.5% boys) were tested at a median age of 10.8 years. Physical performance capacity was tested with a test set including six different components assessing muscle endurance, strength, speed, and flexibility. The control group consisted of 273 healthy age-matched schoolchildren. Clinical parameters were collected as part of routine follow-up protocol. The majority of patients (62.5%) had congenital nephrotic syndrome of Finnish type (CNS) as primary diagnosis, and therefore, the results of CNS recipients were compared to the other disease groups.

RESULTS

The physical performance capacity in pediatric kidney transplant recipients was lower compared to healthy controls. Surprisingly, no statistically significant correlation was found between graft function and physical performance capacity. The CNS patients scored worse than patients with other diagnoses in all test domains except for sit-and-reach and shuttle run, but the differences did not reach statistical significance.

CONCLUSION

The physical performance of pediatric kidney transplant recipients is reduced, especially in those with congenital nephrotic syndrome. Clinical parameters, including graft function, did not predict physical performance capacity, suggesting that the reduced physical performance seems to be of multivariable cause. A higher resolution version of the Graphical abstract is available as Supplementary information.

Calcitriol levels and the stage of chronic kidney disease in children

Background Kidney damage in chronic kidney disease (CKD) disrupts the 1?-hydroxylase enzyme, preventing the conversion of vitamin D into the active form of calcitriol. To our knowledge, no previous studies have assessed calcitriol levels in children with CKD. Decreased vitamin D levels may occur at an early stage of the disease, so it is important to evaluate calcitriol levels in children with early stage CKD. Objective To assess calcitriol levels in children with CKD according to disease stage and other characteristics. Methods This cross-sectional study was conducted on 43 pediatric CKD patients at Dr. M Djamil Hospital, Padang, Indonesia. We recorded patient characteristics and performed laboratory tests, including routine hematology, blood urea nitrogen (BUN), creatinine, uric acid, electrolytes, calcium, and calcitriol levels. Based on estimated glomerular filtration rate (GFR), patients were grouped into either early-stage (stages I and II), or advanced-stage (stages III to V) CKD. Univariate and multivariate analyses were conducted to determine the association between calcitriol levels with disease stage and other characteristics. Results The overall mean calcitriol level of our subjects was 108.77 (SD 10.79) pmol/L. Mean levels at each CKD stage from I to V were 164.28 (SD 160.90), 94.14 (SD 50.63), 72.16 (SD 13.18), 62.92 (SD 4.87), and 67.51 (SD 4.87) pmol/L, respectively. Calcitriol levels did not differ significantly by CKD stage (P=0.114) when each stage from I to V was considered separately. There was no significant difference in calcitriol levels by growth characteristics (P=0.944), etiology (P=0.311), or anemic status (P=0.104). However, low calcitriol levels were found in all subjects with advanced stage CKD, compared to 63.6% subjects with early stage CKD  (P=0.004). Mean calcitriol levels were significantly lower in CKD stage IV (P=0.049) and stage V (P=0.027) compared to stage I. Conclusions The decrease in calcitriol level occurs at an early stage in CKD. Calcitriol levels are significantly lower in advanced stage than in early stage CKD.

Chronic kidney disease causes and outcomes in children: Perspective from a LMIC setting

Background and objective

Chronic kidney disease (CKD) constitutes a major public health challenge, with a global prevalence of 15–74.7 cases /million children. Preventing CKD in children, slowing its progression and management of complications are essential, especially in challenged health systems in low middle income countries (LMIC). We conducted a retrospective review to assess the underlying cause and stage of CKD at presentation and clinical outcomes in children and adolescents at the Indus Hospital and Health Network (IHHN) in Karachi, Pakistan.

Methods

Children 0–16 years with CKD stage 1 and/or higher at presentation were included. Data including demographics, clinical status and lab results at presentation and during follow-up, surgical intervention if any, kidney function at last visit and outcome at last follow-up was recorded.

Results

A total of 229 children diagnosed with CKD are included in our study. The median age at diagnosis was 10 years with male: female ratio of 1.8:1. Only 5% children presented in stage 1 CKD. The rate of adverse outcomes is 4.5 times higher in children with CKD stage 3–5 compared to early CKD. Congenital anomaly of kidney and urinary tract (CAKUT) was the underlying cause in 49% children. Children with glomerular disease had comparatively worse outcome. Proteinuria, hypertension, anemia and bone disease were associated with high morbidity and mortality.

Conclusion

The true epidemiology of childhood CKD is unknown in Pakistan. Our cohort showed better CKD outcomes in children diagnosed early with appropriate surgical and medical follow-up. Prompt diagnosis, treatment and prevention of progression can be life-saving in our setting. CKD registry data can inform policy changes that can prevent poor outcomes.

Use of erythropoiesis-stimulating agents in children with chronic kidney disease: a systematic review

Background

Erythropoiesis-stimulating agents (ESAs) revolutionized the management of anaemia in chronic kidney disease (CKD) when introduced in the late 1980s. A range of ESA types, preparations and administration modalities now exist, with newer agents requiring less frequent administration. Although systematic reviews and meta-analyses have been published in adults, no systematic review has been conducted investigating ESAs in children.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-analyses statement for the conduct of systematic reviews was used. All available literature on outcomes relating to ESAs in children with CKD was sought. A search of the MEDLINE, CINAHL and Embase databases was conducted by two independent reviewers. Inclusion criteria were published trials in English, children with chronic and end-stage kidney disease and use of any ESA studied against any outcome measure. An assessment of risk of bias was carried out in all included randomized trials using the criteria from the Cochrane Handbook for Systematic Reviews of Interventions. Two tables were used for data extraction for randomized and observational studies. Study type, participants, inclusion criteria, case characteristics, follow-up duration, ESA type and dosage, interventions and outcomes were extracted by one author.

Results

Of 965 identified articles, 58 were included covering 54 cohorts. Six were randomized trials and 48 were observational studies. A total of 38 studies assessed the efficacy of recombinant human erythropoietin (rHuEPO), 11 of darbepoetin alpha (DA) and 3 of continuous erythropoietin receptor activator (CERA), with 6 studies appraising secondary outcome measures exclusively. Recruitment to studies was a consistent challenge. The most common adverse effect was hypertension, although confounding effects often limited direct correlation. Two large cohort studies demonstrated a greater hazard of death independently associated with high ESA dose. Secondary outcome measures included quality of life measures, growth and nutrition, exercise capacity, injection site pain, cardiovascular function, intelligent quotient, evoked potentials and platelet function.

Conclusions

All ESA preparations and modes of administration were efficacious, with evidence of harm at higher doses. Evidence supports individualizing treatments, with strong consideration given to alternate treatments in patients who appear resistant to ESA therapy. Further research should focus on randomized trials comparing the efficacy of different preparations, treatment options in apparently ESA-resistant cohorts and clarification of meaningful secondary outcomes to consolidate patient-relevant indices.

Epidemiology of Chronic Kidney Disease in Children: A Report from Lithuania

Background and Objectives: The data on the prevalence of chronic kidney disease (CKD) in the pediatric population are limited. The prevalence of CKD ranges from 56 to 74.7 cases per million of the age-related population (pmarp). The most common cause of CKD among children is congenital anomalies of the kidney and urinary tract (CAKUT). With progressing CKD, various complications occur, and end-stage renal disease (ESRD) can develop. The aim of the study was to determine the causes, stage, prevalence, and clinical signs of CKD and demand for RRT (renal replacement therapy) among Lithuanian children in 2017 and to compare the epidemiological data of CKD with the data of 1997 and 2006. Materials and Methods: The data of 172 Lithuanian children who had a diagnosis of CKD (stage 2–5) in 1997 (n = 41), in 2006 (n = 65), and in 2017 (n = 66) were retrospectively analyzed. Physical development and clinical signs of children who had CKD (stage 2–5) in 2017 were assessed. Results: The prevalence of CKD stages 2–5 was 48.0 pmarp in 1997; 88.7 in 2006; and 132.1 in 2017 (p < 0.01). Congenital and hereditary diseases of the kidney in 1997 accounted for 66% of all CKD causes; in 2006, for 70%; and in 2017, for 79%. In 2017, children with CKD stages 4 or 5 (except transplanted children) had hypertension (87.5%) and anemia (50%) (p < 0.01). Children under ≤2 years with CKD were at a 3-fold greater risk of having elevated blood pressure (OR = 3.375, 95% CI: 1.186–9.904). Conclusions: There was no change in the number of children with CKD in Lithuania; however, the prevalence of CKD increased due to reduced pediatric population. CAKUT remains the main cause of CKD at all time periods. Among children with CKD stages 4 or 5, there were more children with hypertension and anemia. In children who were diagnosed with CKD at an early age hypertension developed at a younger age.

Low-Dose Maintenance Intravenous Iron Therapy Can Prevent Anemia in Children with End-Stage Renal Disease Undergoing Chronic Hemodialysis

Iron deficiency anemia is common in children with end-stage renal disease (ESRD) on long-term hemodialysis receiving erythropoiesis-stimulating agents. One approach to maintain the iron profile and hemoglobin levels is maintenance therapy with regular low doses of intravenous (IV) iron after initial iron repletion therapy; however, evidence for the benefits of this approach is lacking. This study evaluated the effect of IV iron maintenance therapy on anemia in children on regular hemodialysis. This retrospective cohort study included 41 pediatric ESRD patients with normal hemoglobin and iron status who underwent regular hemodialysis at the Pediatric Dialysis Unit of Cipto Mangunkusumo Hospital, Indonesia, between January 2015 and April 2019. Among these, 21 received IV iron maintenance therapy with two doses of 2 mg/kg of IV iron sucrose every 2 weeks (the treatment group) and 20 did not (the comparison group). Changes in hemoglobin and transferrin saturation were assessed after 6 weeks of observation and compared between the two groups. There was a significant reduction in the mean hemoglobin level compared with the baseline level in the comparison group (21 g/L; 95% CI, 9.3–33 g/L; p=0.001) but not in the treatment group (0.7 g/L; 95% CI, −6.6–8 g/L; p=0.84). The risk of anemia was lower in the treatment group (relative risk = 0.42; 95% CI, 0.22–0.79; p=0.003). Although majority of the patients had high baseline ferritin level, this study indicates that in our setting, ferritin may not be a reliable parameter to review the iron status, as it can be affected by chronic inflammation. Hence, the decision to start IV iron maintenance therapy in patients with hyperferritinemia should consider the patient's clinical condition and morbidity. To conclude, the coadministration of IV iron maintenance therapy is beneficial for maintaining hemoglobin levels and preventing anemia in children with ESRD who are undergoing regular hemodialysis, have achieved the target hemoglobin levels, and have normal iron status.

Glomerular disease patients have higher odds not to reach quality targets in chronic dialysis compared with CAKUT patients: analyses from a nationwide German paediatric dialysis registry

BACKGROUND

Paediatric dialysis patients still suffer from high morbidity rates. To improve this, quality assurance programs like the German QiNKid (Quality in Nephrology for Children)-Registry have been developed. In our study, the significance of underlying renal disease on a range of clinical and laboratory parameters impacting morbidity and mortality was analysed. Our aim was to evaluate whether or not disease-specific dialysis strategies should be considered in planning dialysis for a patient.

METHODS

Inclusion criteria were defined as follows: (1) CAKUT (congenital anomalies of the kidney and urinary tract) or glomerular disease patient, (2) < 18 years of age, (3) haemodialysis or peritoneal dialysis patient. Only measurements obtained from day 90 to 365 after the date of the first dialysis in the registry were analysed. Laboratory (serum albumin, haemoglobin, ferritin, calcium, phosphate, parathyroid hormone) and clinical parameters (height, blood pressure) were analysed using mixed effects models accounting for the correlation of repeated measures in individual patients.

RESULTS

The study cohort comprised n = 167 CAKUT and n = 55 glomerular disease patients. Glomerular disease patients had significantly higher odds of hypoalbuminemia (OR 13.90, 95% CI 1.35-159.99; p = 0.0274), anaemia (OR 3.31, 95% CI 1.22-9.13; p = 0.0197), hyperphosphatemia (OR 9.69, 95% CI 2.65-37.26; p = 0.0006) and diastolic hypertension (OR 3.38, 95% CI 1.20-9.79; p = 0.0212).

CONCLUSIONS

Glomerular disease patients might require more intensive dialysis regimens. The evaluation of hydration status should be given more attention, since conditions differing between the cohorts can be linked to overhydration. The QiNKid-Registry allows monitoring of the quality of paediatric dialysis in a nationwide cohort.

Estimated GFR at Dialysis Initiation and Mortality in Children and Adolescents

RATIONALE & OBJECTIVE

The association of estimated glomerular filtration rate (eGFR) at dialysis therapy initiation with mortality among adult dialysis patients has been greatly debated, with some studies showing no benefit from early dialysis therapy initiation. However, this association has not been well investigated in pediatric dialysis patients. The objective of this study was to evaluate the mortality risk associated with eGFR at dialysis therapy initiation in children and adolescents with kidney failure.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

9,963 incident dialysis patients aged 1 to 17 years in the US Renal Data System registry (1995-2016).

PREDICTOR

eGFRs at dialysis therapy initiation calculated using the pediatric-specific bedside Schwartz equation (<5, 5-<7, 7-<9, 9-<12, and ≥12mL/min/1.73m²).

OUTCOME

Time to all-cause death.

ANALYTICAL APPROACH

Cox proportional hazards regression adjusted for case-mix variables, height, body mass index, hemoglobin level, and serum albumin level.

RESULTS

Median eGFR was 7.8 (IQR, 5.6-10.5) mL/min/1.73m² and median age was 13 (IQR, 9-16) years. 696 deaths were observed during the median follow-up of 1.4 (IQR, 0.7-2.7) years, and overall crude mortality rate was 31 per 1,000 patient-years. There appeared to be a trend toward higher mortality risk across higher eGFRs at dialysis therapy initiation. Compared with eGFRs of 7 to <9mL/min/1.73m², eGFRs <5 and ≥12mL/min/1.73m² were associated with lower and higher mortality, with adjusted HRs of 0.57 (95% CI, 0.43-0.74) and 1.31 (95% CI, 1.05-1.65), respectively. In age-stratified analysis, there were consistent relationships among patients 6 years and older while the eGFR-mortality association was attenuated among patients younger than 6 years (P_interaction = 0.002).

LIMITATIONS

Possible errors in eGFRs due to methods for serum creatinine measurement. Unmeasured confounders related to eGFR at dialysis therapy initiation.

CONCLUSIONS

Higher eGFR at dialysis therapy initiation was associated with higher mortality risk. Further studies of eGFR at initiation are needed in pediatric dialysis patients, especially among those younger than 6 years.

Genetic associations of hemoglobin in children with chronic kidney disease in the PediGFR Consortium

BACKGROUND

Genome-wide association studies (GWAS) in healthy populations have identified variants associated with erythrocyte traits, but genetic causes of hemoglobin variation in children with CKD are incompletely understood.

METHODS

The Pediatric Investigation of Genetic Factors Linked with Renal Progression (PediGFR) Consortium comprises three pediatric CKD cohorts: Chronic Kidney Disease in Children (CKiD), Effect of Strict Blood Pressure Control and ACE Inhibition on the Progression of CRF in Pediatric Patients (ESCAPE), and Cardiovascular Comorbidity in Children with CKD (4C). We performed cross-sectional and longitudinal association studies of single-nucleotide polymorphisms (SNPs) in 1125 patients.

RESULTS

Children of European (n = 725) or Turkish (n = 400) ancestry (EA or TA) were included. In cross-sectional analysis, two SNPs (rs10758658 and rs12718597) previously associated with RBC traits were significantly associated with hemoglobin levels in children of EA and TA. In longitudinal analysis, SNP rs2540917 was nominally associated with hemoglobin in EA and TA children.

CONCLUSIONS

SNPs associated with erythrocyte traits in healthy populations were marginally significant for an association with hemoglobin. Further analyses/replication studies are needed in larger CKD cohorts to investigate SNPs of unknown significance associated with hemoglobin. Functional studies will be required to confirm that the observed associations between SNPs and clinical phenotype are causal.

Anemia and Iron Deficiency in Children with Chronic Kidney Disease (CKD): Data from the Know-Ped CKD Study

Children with chronic kidney disease (CKD) are at high risk of anemia, an important risk factor for cardiovascular disease and poor quality of life. The present study used baseline data from the Korean cohort study for Outcome in patients With Pediatric Chronic Kidney Disease (KNOW-PedCKD). A Total of 437 patients was included in the analyses excluding missing data. The characteristics of patients with and without anemia and those of patients with and without iron deficiency were compared. Logistic regression analysis and Pearson correlation were conducted to evaluate associated risk factors and correlations in children with CKD. Anemia in children with CKD was associated with older age, low body weight and body mass index (BMI) z-score, birth age, preceding glomerulonephritis, decreased estimated glomerular filtration rate (eGFR), low levels of serum albumin and calcium, high levels of serum intact parathyroid hormone (iPTH), and serum phosphorus. Anemia was correlated positively with changes in the BMI z-score, body weight, and serum albumin and cholesterol levels, but correlated negatively with serum calcium, iPTH, ferritin levels, and transferrin saturation. Iron deficiency in children with CKD was associated with young age, low hemoglobin and serum ferritin levels, high BMI z-scores, and low levels of serum iPTH. This is the first nationwide cohort study of anemia in Korean children with CKD and the first prospective pediatric CKD cohort study in Asia. The study results demonstrated that anemia and iron deficiency are affected by various factors, including age, BMI, and levels of serum iPTH. To improve the retrospective outcome of affected children, it is important to understand the effect of each of these factors and to attempt an early intervention to prevent anemia and iron deficiency by regular measurement of these parameters in children at risk.

HIF stabilizers in the management of renal anemia: from bench to bedside to pediatrics

Anemia is a common complication of chronic kidney disease (CKD) in adult and pediatric patients. It has traditionally been treated with erythropoietin therapy and iron supplementation, with great success. With the discovery of the major transcription factor hypoxia inducible factor (HIF) for the erythropoietin gene in 1992, molecules were created that inhibit the HIF prolyl-hydroxylase enzyme. This new class of drug-called HIF stabilizers, or HIF prolyl-hydroxylase inhibitors-prevents the proteasomal degradation of HIF-α, thereby inducing upregulation of the erythropoietin gene. This new strategy for treating CKD anemia is already in phase III clinical trials in adults, and the potential advantages of this therapy are that it is orally active (thereby avoiding injections), and patients are exposed to lower circulating levels of erythropoietin. The long-term safety of this strategy, however, requires elucidation in these trials, particularly since there are many other hypoxia-sensitive genes, notably, angiogenic factors such as vascular endothelial growth factors (VEGF), as well as glycolytic enzymes. As with all new therapies, it is only once a positive benefit: risk profile has been ascertained in adults that the treatment will translate across into pediatrics. Specific issues in the pediatric CKD population are discussed in this review.

Measurement of iron status in chronic kidney disease

Anemia is a common complication of chronic kidney disease (CKD) in children, and dysregulation of iron homeostasis plays a central role in its pathogenesis. Optimizing iron status is a prerequisite for effective treatment of anemia. Insufficient iron can lead to inappropriate escalation of the erythropoiesis-stimulating agent (ESA) dose, which is associated with adverse outcomes. Excess iron supplementation also has negative sequelae including free radical tissue damage and increased risk of systemic infection. Notwithstanding the importance of optimizing bioavailable iron for erythropoiesis for children with advanced CKD, achieving this remains challenging for pediatric nephrologists due to the historical lack of practical and robust measures of iron status. In recent years, novel techniques have come to the fore to facilitate accurate and practical assessment of iron balance. These measures are the focus of this review, with emphasis on their relevance to the pediatric CKD population.

Anemia in chronic kidney disease

Anemia is common and associated with adverse outcomes in children with chronic kidney disease (CKD). Many factors contribute to declining hemoglobin as CKD progresses, but impaired production of erythropoietin by failing kidneys is a central cause. Hepcidin-mediated iron restriction also contributes to anemia by downregulating both intestinal iron absorption and release of stored iron for erythropoiesis. The core components of anemia management remain erythropoiesis-stimulating agents (ESA) and iron supplementation, but despite these therapies, a substantial number of children remain anemic. Although escalating ESA dose to target higher hemoglobin has been associated with adverse outcomes in adults, no trials have investigated this association in children, and maintaining hemoglobin levels in a narrow range with conservative ESA dosing is challenging. Judicious use of iron supplementation can enhance the response to ESAs, but the iron storage markers most commonly used in clinical practice have limitations in distinguishing which patients will benefit most from additional iron. Several novel anemia therapies, including hypoxia-inducible factor stabilizers, prolyl hydroxylase inhibitors, and dialysate-delivered iron supplements, have been developed and may offer options for alternative anemia management. However, the safety and efficacy of these agents in children with CKD has yet to be assessed.

De novo weekly and biweekly darbepoetin alfa dosing in pediatric patients with chronic kidney disease

BACKGROUND

Darbepoetin alfa is a commonly prescribed erythropoiesis-stimulating agent (ESA) for correcting anemia in pediatric chronic kidney disease (CKD) patients. However, little information exists on its use in ESA-naïve patients. This study evaluated the efficacy and safety of darbepoetin alfa in pediatric patients initiating ESA therapy.

METHODS

One-hundred sixteen pediatric ESA-naïve subjects (aged 1-18 years) with CKD stages 3-5D and hemoglobin (Hb) <10 g/dl from 43 centers in the US, Europe, and Mexico were randomized by age (three groups) and dialysis status (yes vs. no) to receive darbepoetin alfa once weekly (QW) or every 2 weeks (Q2W) subcutaneously (not on dialysis and peritoneal dialysis subjects) and intravenously (hemodialysis subjects). The drug was titrated to achieve Hb levels of 10.0-12.0 g/dl over 25 weeks. Patient- and parent-reported health-related outcomes were measured by the Pediatric Quality of Life Inventory (PedsQL™) in children ≥2 years.

RESULTS

In both groups, mean Hb concentrations increased to ≥11.0 g/dl over the first 3 months of treatment and remained stable within the 10.0-12.0 g/dl target range. The median time to achieve hemoglobin ≥10 g/dl was slightly longer for subjects <12 years (QW and Q2W, both 28 days) vs. those ≥12 years (23 and 22 days, respectively). Adverse event profiles were similar between groups, with QW, four (7%) and Q2W, five (9%). PedsQL™ scores showed modest increases.

CONCLUSIONS

Darbepoetin alfa can be safely administered either QW or Q2W to ESA-naïve pediatric patients with CKD-related anemia to achieve Hb targets of 10.0-12.0 g/dl.

Pilot study of the effect of cholecalciferol supplementation on hepcidin in children with chronic kidney disease: Results of the D-fense Trial

BACKGROUND

Hepcidin is a key mediator of the anemia of chronic kidney disease (CKD). There is emerging evidence that 25-hydroxyvitamin D (25D) regulates hepcidin production.

METHODS

A randomized controlled trial of daily vitamin D supplementation for 12 weeks was performed with the aim to test the effects of 4000 versus 400 IU of cholecalciferol on serum hepcidin levels in children with non-dialysis CKD recruited at a tertiary care children's hospital. Hepcidin was quantified using a validated competitive enzyme-linked immunosorbent assay. 25D levels were measured using the chemiluminescence Liaison 25(OH)D assay system. Co-variables included hemoglobin, C-reactive protein, ferritin, and serum calcium and phosphorus for safety monitoring.

RESULTS

A total of 34 subjects were randomized to either the intervention or control group, of whom 26.5% were female and 23.5% were African American. The mean age of the study cohort was 10.9 [standard deviation (SD) 5.8] years, the mean baseline glomerular filtration rate was 60 (SD 17.6) ml/min/1.73 m², and mean baseline 25D level was 29.7 (SD 11.5) ng/ml. At baseline, 50% of subjects were 25D deficient. There were no significant differences in baseline characteristics between the intervention and control groups. Treatment with 4000 IU cholecalciferol was not associated with significant change in hepcidin level at 4 or 12 weeks, and multivariable generalized estimating equation regression demonstrated no significant difference in change in hepcidin over the treatment period in either arm. The median C-reactive protein level decreased significantly at 12 weeks in the intervention group.

CONCLUSIONS

These results do not suggest that daily nutritional vitamin D supplementation modifies serum hepcidin levels in children with CKD. Further study will be required to determine whether supplementation may be effective in children with more advanced CKD or those on dialysis.

Chronic kidney disease in children

Chronic kidney disease (CKD) is a major health problem worldwide. Although relatively uncommon in children, it can be a devastating illness with many long-term consequences. CKD presents unique features in childhood and may be considered, at least in part, as a stand-alone nosologic entity. Moreover, some typical features of paediatric CKD, such as the disease aetiology or cardiovascular complications, will not only influence the child's health, but also have long-term impact on the life of the adult that they will become. In this review we will focus on the unique issues of paediatric CKD, in terms of aetiology, clinical features and treatment. In addition, we will discuss factors related to CKD that start during childhood and require appropriate treatments in order to optimize health outcomes and transition to nephrologist management in adult life.

Chronic Kidney Disease in Children: Recent Update

The incidence of end stage of renal disease (ESRD) in US children age 0-19 years is 12.9 per million/year (2012). The economic and social burden of diagnosing, treating and preventing chronic kidney disease (CKD) in children and adults remains substantial. Advances in identifying factors that predict development of CKD and its progression, as well as advances in the management of co-morbid conditions including anemia, cardiovascular disease, growth, mineral and bone disorder, and neurocognitive function are discussed. Despite recent reports from retrospective registry data analysis and multi-center prospective studies which have significantly advanced our knowledge of CKD, and despite advances in the understanding of the pathogenesis, diagnosis and treatment of CKD much work remains to be done to improve the long term outcome of this disease.

The Growth Attainment, Hematological, Iron Status and Inflammatory Profile of Guatemalan Juvenile End-Stage Renal Disease Patients

Background

Stunting, anemia and inflammation are frequently observed in children with end-stage renal disease (ESRD).

Objectives

To assess anthropometric, hematological and inflammatory data and to study their potential interrelationship in Guatemalan juveniles undergoing hemodialysis (HD) and peritoneal dialysis (PD).

Methods

54 juveniles 7–20 years of age were recruited in FUNDANIER, Guatemala City: 27 on HD and 27 PD. Hemoglobin, serum iron, transferrin, serum transferrin receptor (sTfR), serum ferritin, transferrin saturation and iron-binding capacity, white blood cell count (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), as well as IL-6, IL-1 and TNF-α, weight and height were determined by standard methods. Hepcidin–25 (Hep-25) was assessed by weak cation exchange time-of-flight mass-spectrometry.

Results

92% and 55% of HD and PD children, respectively, were stunted and 95% and 85% were anemic. Among iron status biomarkers, serum ferritin was massively increased and significantly higher in the HD group compared to the PD group. Hep-25 was also greatly elevated in both groups. 41% of HD patients showed increments in three or more inflammatory biomarkers, while it was 2 or less in all PD subjects.

Conclusions

The degree of stunting, the prevalence and severity of anemia in Guatemalan juvenile ESRD far exceed the national statistics for this low-income Central American country. Ferritin and Hep-25 concentrations were elevated, with the latter to an extraordinary magnitude. Additional biomarkers of inflammation not directly related to iron status were elevated as well. The role of both disease- and environment-related factors in combination best explains the magnitude of the biomarker abnormalities.

Hepcidin and risk of anemia in CKD: a cross-sectional and longitudinal analysis in the CKiD cohort

BACKGROUND

Hepcidin, a key iron regulatory protein, is elevated in patients with chronic kidney disease (CKD). Its role in the development and progression of the anemia of CKD in children remains poorly defined.

METHODS

Cross-sectional and longitudinal study in children aged 1-16 years with stage 2-4 CKD in the Chronic Kidney Disease in Children (CKiD) cohort (n = 133) with hepcidin measured at baseline and hemoglobin (HGB) measured annually at follow-up. Anemia was defined as HGB <5th percentile for age/sex OR treatment with an erythropoiesis-stimulating agent (ESA).

RESULTS

Hepcidin levels correlated negatively with glomerular filtration rate (GFR; r = -0.22, p = 0.01) and positively with ferritin (r = 0.67, p < 0.001). At the lower end of the GFR spectrum at baseline (10th percentile, 27.5 mL/min/1.73 m(2)), higher hepcidin was associated with a 0.87 g/dL decrease in HGB during follow-up (95 % CI -1.69, -0.05 g/dL, p = 0.038). At higher GFR percentiles there was no significant association between baseline hepcidin and HGB during follow-up. Among 90 non-anemic subjects at baseline, 23.3 % developed incident anemia. In subjects with GFR  ≤  the median, a higher hepcidin level was associated with an increased risk of incident anemia (at the 10th percentile GFR, HR 3.471, 95 % CI 1.228, 9.810, p = 0.019; at the 25th percentile GFR, HR 2.641, 95 % CI 1.213, 5.750, p = 0.014; at the 50th percentile GFR, HR 1.953, 95 % CI 1.011, 3.772, p = 0.046). Among subjects with GFR at the 75th percentile or above, incrementally higher baseline hepcidin was not associated with increased anemia risk.

CONCLUSIONS

Higher hepcidin levels are associated with a decreased HGB and an increased risk of incident anemia, and this association is most significant among subjects with lower GFR.

Hemoglobin level and risk of hospitalization and mortality in children on peritoneal dialysis

BACKGROUND

Clinical practice guidelines for management of anemia in children with end-stage kidney disease (ESKD) remain largely opinion-based. In this study, we evaluated the risk of mortality and hospitalization by hemoglobin (Hb) level in a large prevalent population of U.S. children on peritoneal dialysis (PD).

METHODS

Hemoglobin levels in prevalent PD patients from the 2005 End Stage Renal Disease Clinical Performance Measures Project were linked with 5-year mortality and 4-year hospitalization records from the United States Renal Data System.

RESULTS

Of the 468 patients included in the study, the mean age was 11 years, 55 % were male, 67 % were white, 254 (54 %) were hospitalized, and 23 (5 %) died. Median (interquartile range) Hb levels were 11.7 (10.7-12.6) g/dl, and 30 % had Hb levels of <11 g/dl. In adjusted survival analysis, Hb thresholds of 10, 11, or 12 g/dl were not associated with a significant difference in risk of death. The incidence rate ratio (IRR) of hospitalization for patients with a mean Hb of ≥11 g/dl was 0.56 (95 % CI 0.43-0.73). Compared to a reference range of Hb of 11 to <12, Hb of ≥12 g/dl was not associated with a significant difference in hospitalization risk (IRR 0.88; 95 % CI 0.61-1.25). Using age- and sex specific cut-offs for anemia, children who were not anemic had a 27 % decreased risk of hospitalization compared to those with anemia (IRR 0.73; 95 % CI 0.55-0.97). Compared to the first erythropoiesis stimulating agent (ESA) dosing quartile, higher ESA doses were associated with an increased risk of both hospitalization and mortality.

CONCLUSIONS

U.S. children on PD with Hb levels of ≥11 g/dl were less likely to be hospitalized but had no observed difference in mortality. Children who were not anemic were also less likely to be hospitalized. Further study is necessary to elucidate whether a single optimal Hb level or a range applies to the pediatric ESKD population.

Management of anemia with erythropoietic-stimulating agents in children with chronic kidney disease

Anemia management is an important component of the care provided to children with chronic kidney disease (CKD) and influences both morbidity and mortality risk. The introduction of recombinant human erythropoietin to the treatment regimen three decades ago revolutionized the therapy and significantly decreased the need for repeated blood transfusions and exposure to associated risks. Recent data on the efficacy and complications associated with erythropoietic-stimulating agent (ESA) usage has, however, prompted a reassessment of treatment-related recommendations. This review will address these recommendations, in addition to describing pediatric outcomes associated with current ESAs and presenting information on alternative ESAs, many of which will likely soon be incorporated into clinical practice.

The development of anemia is associated to poor prognosis in NKF/KDOQI stage 3 chronic kidney disease

Background

Anemia is a common condition in CKD that has been identified as a cardiovascular (CV) risk factor in end-stage renal disease, constituting a predictor of low survival. The aim of this study was to define the onset of anemia of renal origin and its association with the evolution of kidney disease and clinical outcomes in stage 3 CKD (CKD-3).

Methods

This epidemiological, prospective, multicenter, 3-year study included 439 CKD-3 patients. The origin of nephropathy and comorbidity (Charlson score: 3.2) were recorded. The clinical characteristics of patients that developed anemia according to EBPG guidelines were compared with those that did not, followed by multivariate logistic regression, Kaplan-Meier curves and ROC curves to investigate factors associated with the development of renal anemia.

Results

During the 36-month follow-up period, 50% reached CKD-4 or 5, and approximately 35% were diagnosed with anemia (85% of renal origin). The probability of developing renal anemia was 0.12, 0.20 and 0.25 at 1, 2 and 3 years, respectively. Patients that developed anemia were mainly men (72% anemic vs. 69% non-anemic). The mean age was 68 vs. 65.5 years and baseline proteinuria was 0.94 vs. 0.62 g/24h (anemic vs. non anemic, respectively). Baseline MDRD values were 36 vs. 40 mL/min and albumin 4.1 vs. 4.3 g/dL; reduction in MDRD was greater in those that developed anemia (6.8 vs. 1.6 mL/min/1.73 m²/3 years). These patients progressed earlier to CKD-4 or 5 (18 vs. 28 months), with a higher proportion of hospitalizations (31 vs. 16%), major CV events (16 vs. 7%), and higher mortality (10 vs. 6.6%) than those without anemia. Multivariate logistic regression indicated a significant association between baseline hemoglobin (OR=0.35; 95% CI: 0.24-0.28), glomerular filtration rate (OR=0.96; 95% CI: 0.93-0.99), female (OR=0.19; 95% CI: 0.10-0.40) and the development of renal anemia.

Conclusions

Renal anemia is associated with a more rapid evolution to CKD-4, and a higher risk of CV events and hospitalization in non-dialysis-dependent CKD patients. This suggests that special attention should be paid to anemic CKD-3 patients.

Prevalence and predictors of the sub-target Hb level in children on dialysis

BACKGROUND

Anaemia is a common and potentially treatable co-morbidity of end-stage renal disease. We aimed to determine the prevalence of the sub-target haemoglobin (Hb) level among European children on dialysis and to identify factors associated with a low Hb level.

METHODS

From the European Society for Paediatric Nephrology (ESPN)/European Renal Association-European Dialysis Transplant Association (ERA-EDTA) registry, data were available on 2351 children between 1 month and 18 years of age, totalling 5546 measurements from 19 countries.

RESULTS

The mean Hb level was 10.8 g/dL (5th-95th percentiles, 7.4-13.9). Among those above 2 years of age, the mean Hb level was 10.9 g/dL (11.4% below 8.5 g/dL), while it was 10.3 g/dL among those below 2 years (11.2% below 8.0 g/dL). A total of 91.2% of the patients were on an erythropoiesis-stimulating agent (ESA). Hb levels increased with age and were higher in peritoneal dialysis compared with haemodialysis patients. Patients with congenital anomalies of the kidney and urinary tract showed the highest Hb levels, and those with cystic kidney diseases or metabolic disorders the lowest ones. Ferritin levels between 25 and 50 ng/mL were associated with the highest Hb levels. We found a weak inverse association between parathyroid hormone (PTH) and Hb. Whereas standardized blood pressure (BP) was not elevated in patients with above-target Hb, elevated systolic BP z-score was noted in those with sub-target Hb levels.

CONCLUSIONS

Sub-target Hb levels remain common in children on dialysis, in spite of virtually all children being treated with ESA; although we cannot exclude under-dosing. Optimal ferritin levels seemed to be slightly lower in children (25-50 ng/mL) than those in adults. Other risk factors for sub-target Hb are dialysis modality and a high PTH level.

Anaemia treatment in chronically dialysed children: a multicentre nationwide observational study

OBJECTIVE

Erythropoiesis-stimulating agents (ESAs) are applied as a standard therapy in children with anaemia in chronic kidney disease. The aim of this study was to describe the efficacy and details of ESA treatment in a population of dialysed children in Poland.

MATERIAL AND METHODS

The study had a prospective observational design and was performed in 12 dialysis centres. The study group comprised 117 dialysed children with a mean age at enrolment of 165.33 (97.18-196.45) months.

RESULTS

Dialysed children were treated mostly with epoietin beta and darbepoietin. The mean dose of ESA was 99 (68-147) U/kg/week with a significant difference between patients on peritoneal dialysis [83 (54-115)] and haemodialysis [134 (103-186)] (p < 0.0001). The mean haemoglobin of all the time-point tests during 6 months was 10.91 ± 1.18 g/dl. The efficacy of anaemia treatment was unsatisfactory in 52% of subjects. In multivariate analysis, initial haemoglobin level <10 g/l, any infection, younger age at first dialysis, malnutrition and inadequate ESA dosage remained significant predictors of anaemia.

CONCLUSIONS

The study revealed that anaemia treatment in Polish children is unsatisfactory. Late commencement of the treatment, inadequate dosing, malnutrition and infections could constitute risk factors for therapy failure.

Cardiovascular disease in children with chronic kidney disease

More than a decade ago, cardiovascular disease (CVD) was recognized as a major cause of death in children with advanced CKD. This observation has sparked the publication of multiple studies assessing cardiovascular risk, mechanisms of disease, and early markers of CVD in this population. Similar to adults, children with CKD have an extremely high prevalence of traditional and uremia-related CVD risk factors. Early markers of cardiomyopathy, such as left ventricular hypertrophy and dysfunction, and early markers of atherosclerosis, such as increased carotid artery intima-media thickness, carotid arterial wall stiffness, and coronary artery calcification, are frequently present in these children, especially those on maintenance dialysis. As a population without preexisting symptomatic cardiac disease, children with CKD potentially receive significant benefit from aggressive attempts to prevent and treat CVD. Early CKD, before needing dialysis, is the optimal time to both identify modifiable risk factors and intervene in an effort to avert future CVD. Slowing the progression of CKD, avoiding long-term dialysis and, if possible, conducting preemptive transplantation may represent the best strategies to decrease the risk of premature cardiac disease and death in children with CKD.

Resistance to erythropoietin-stimulating agents: etiology, evaluation, and therapeutic considerations

Routine clinical and laboratory assessments facilitate diagnosis of erythropoietin (EPO) resistant anemia by allowing early identification of patients with non-adherence. Any new event that impairs response to EPO (e.g., catheter sepsis) must be promptly controlled. Because of the confounding interaction of its risk factors, initial evaluation should include nutrition, dialysis adequacy, hemorrhage, bone mineral metabolism, and inflammation. Prevention of EPO resistance is more cost effective and should include adequate dialysis and nutritional supplements. Blood loss during hemodialysis (HD) procedures should be minimized. If there is laboratory proof of iron deficit intravenous repletion is most effective. Oxidative stress may be attenuated by vitamins E and C, while optimal control of hyperparathyroidism will enhance EPO stimulation. Contaminated dialysates should be suspected if there is EPO-stimulating agents (ESA) resistance at the same time among most members of a dialysis program. Heavy metal toxicity should be suspected in high-risk patients. The impact of co-morbidities such as hemoglobinopathy, glucose 6 phosphate dehydrogenase (G6PD) deficiency and connective tissue diseases must be excluded in an appropriate setting. In conclusion, given the multiple risk factors of EPO resistance promotion of the overall health status will most likely yield an enduring benefit. Finally, there are experimental trials of gene-based (therapy) to stimulate endogenous EPO synthesis with the goal of avoiding the off-target effect of excessive dosing.

Hepcidin in anemia of chronic kidney disease: review for the pediatric nephrologist

Anemia coincident with hyporesponsiveness to erythropoiesis-stimulating agents is an ongoing and prevalent problem in children with chronic kidney disease (CKD). The recently identified iron-regulatory protein hepcidin appears likely to play a significant role in this problem. Hepcidin up-regulation in the setting of CKD, with subsequent increased serum levels, results in impaired iron absorption from the intestine and decreased iron release from body storage sites. Ultimately, in the setting of such elevated levels, a state of functional iron deficiency may develop and lead to anemia due to iron-restricted erythropoiesis. Elevated hepcidin levels are expected in the face of decreased glomerular filtration rate and inflammation. Based on current evidence, it seems likely that hepcidin represents a potentially modifiable mediator of anemia of CKD and is thus a potential target for future anemia therapy. Currently, increased removal via intensified dialysis and-/or blockade of the inflammatory pathway appear to be two viable generic strategies for reducing hepcidin levels. Goals of directly manipulating the hepcidin pathway should offer the pediatric clinician new options for treating the complex anemia associated with CKD.

Anemia in children with chronic kidney disease

Anemia is a common comorbidity in children with chronic kidney disease (CKD). This condition is associated with multiple adverse clinical consequences and its management is a core component of nephrology care. Increased morbidity and mortality, increased risk of cardiovascular disease and decreased quality of life have been associated with anemia of CKD in children. Although numerous complex factors interact in the development of this anemia, erythropoietin deficiency and iron dysregulation (including iron deficiency and iron-restricted erythropoiesis) are the primary causes. In addition to iron supplementation, erythropoietin-stimulating agents (ESAs) can effectively treat this anemia, but there are important differences in ESA dose requirements between children and adults. Also, hyporesponsiveness to ESA therapy is a common problem in children with CKD. Although escalating ESA doses to target increased hemoglobin values in adults has been associated with adverse outcomes, no studies have demonstrated this association in children. The question of appropriate target hemoglobin levels in children, and the approach by which to achieve these levels, remains under debate. Randomized, controlled studies are needed to evaluate whether normalization of hemoglobin concentrations is beneficial to children, and whether this practice is associated with increased risks.

Insights from the Chronic Kidney Disease in Children (CKiD) study

Over the last 5 years, the Chronic Kidney Disease in Children (CKiD) prospective cohort study has enrolled close to 600 children ages 1 to 16 years with mild to moderate chronic kidney disease (CKD). The main purpose of this interim report is to review the initial cross-sectional data and conclusions derived from the clinical studies conducted within CKiD in the context of findings from other pediatric CKD and end-stage renal disease (ESRD) registry and cohort studies. In particular, special emphasis was placed on studying four aspects of chronic kidney disease in children, including the identification of risk factors related to disease progression, the impact of CKD on neurocognition and quality of life (QoL), the cardiovascular morbidity associated with CKD, and identifying the causes and effects of growth failure in the context of mild to moderate kidney failure.