Association of mortality and hospitalization with achievement of adult hemoglobin targets in adolescents maintained on hemodialysis

Cardiovascular and renal safety outcomes of hypoxia-inducible factor prolyl-hydroxylase inhibitor roxadustat for anemia patients with chronic kidney disease: a systematic review and meta-analysis

This systematic review and meta-analysis were conducted to evaluate the cardiac and kidney-related adverse effects of roxadustat for the treatment of anemia in CKD patients. 18 trials with a total of 8806 participants were identified for analysis. We employed a fixed-effects model for analysis. The pooled result revealed no significant difference in the risk of occurrence of cardiac disorders when comparing CKD patients receiving roxadustat with the placebo (RR = 1.049; CI [0.918 to 1.200]) or ESA (RR = 1.066; CI [0.919 to 1.235]), in both dialysis-dependent (DD) (RR = 1.094; CI [0.925 to 1.293]) or non-dialysis-dependent (NDD) (RR = 1.036; CI [0.916 to 1.171]) CKD patients. No significant difference was observed in the risk of kidney-related adverse events when comparing roxadustat with the placebo (RR = 1.088; CI [0.980 to 1.209]) or ESA (RR = 0.968; CI [0.831 to 1.152]), in DD (RR = 2.649; CI [0.201 to 34.981]) or NDD (RR = 1.053; CI [0.965 to 1.149]) CKD patients. A high risk of hyperkalemia was observed in the roxadustat group in DD (RR = 0.939; CI [0.898 to 0.981]). Incidence of hypertension was higher in the roxadustat for NDD patients (RR = 1.198; CI [1.042 to 1.377]), or compared to the placebo (RR = 1.374; CI [1.153 to 1.638]). In summary, the risk of cardiac or kidney-related events observed in the roxadustat was not significantly increase whether in DD or NDD patients. However, attention must be paid to the occurrence of hyperkalemia for DD patients and hypertension in NDD patients using roxadustat.

Assessment of the hematological profile of children with chronic kidney disease on follow-up at St. Paul's Hospital Millennium Medical College and Tikur Anbessa Specialized Hospital in Addis Ababa, Ethiopia

BACKGROUND

Chronic kidney disease (CKD) is a major public health issue with an increasing incidence and prevalence worldwide. In CKD, hematological parameters are influenced, and the effect increases with CKD stage. Thus, the aim of this study was to assess hematological profile of children with CKD on follow up at Tikur Anbessa Specialized Hospital and St. Paul's Hospital Millennium Medical College in Addis Ababa, Ethiopia.

METHODS

A cross-sectional study was carried out from March 1 to June 30, 2021 among 238 children with CKD. EDTA tubes were used to collect 4 ml blood samples, which were then examined by Beckman Coulter automated hematology analyzer. SPSS Version 20 was used for statistical analysis, and a bivariate and multivariate regression model were applied to assess correlations. Mean and standard deviation was used to determine hematological profiles.

RESULTS

The total number of patients in the study were 238, with 42 (59.7%) of them being men. The majority of the patients (81%) had CKD stage 1. Mean ± standard deviation determined for white blood cell (WBC) parameters in (thousand/µL); WBC, Neutrophil, Lymphocytes, Eosinophil, Monocytes and Basophil were 8.93 ± 3.32, 4.6 ± 8.31, 2.79 ± 1.62, 0.31 ± 0.51, 0.50 ± 3.03 and 0.03 ± 0.24, respectively. For some of red blood cell (RBC) parameters; RBC (million/ µL), Hemoglobin (Hgb) (g/dL), Hematocrit (Hct) (%) and Mean cell volume (fl.) were 4.73 ± 0.87, 12.82 ± 2.76, 38.28 ± 7.53 and 80.32 ± 7.89, respectively. For the platelet count (PLT) (thousand/µL) and Mean Platelet volume (MPV) (fL) 349.34 ± 130.18 and 9.03 ± 4.31 were determined, respectively. This study also found hematologic parameters such as RBC, HGB, HCT and MPV were found to be positively correlated with eGFR with a P-value < 0.05 for all parameters.

CONCLUSION

The study found that the majority of study participants were in stages 1 to 3 based on their estimated glomerular filtration rate (eGFR). Some of hematological parameters found to have positive correlation with eGFR. There is a need to improve multiple aspects of CKD management, including routine hematological tests for children with chronic kidney disease.

Improving Clinical Care for Children With CKD: A Report From a National Kidney Foundation Scientific Workshop

Development of clinical guidelines and recommendations to address the care of pediatric patients with chronic kidney disease (CKD) has rarely included the perspectives of providers from a variety of health care disciplines or the patients and parents themselves. Accordingly, the National Kidney Foundation hosted an in-person, one and a half-day workshop that convened a multidisciplinary group of physicians, allied health care professionals, and pediatric patients with CKD and their parents, with the goal of developing key clinical recommendations regarding best practices for the clinical management of pediatric patients living with CKD. The key clinical recommendations pertained to 5 broad topics: addressing the needs of patients and parents/caregivers; modifying the progression of CKD; clinical management of CKD-mineral and bone disorder and growth retardation; clinical management of anemia, cardiovascular disease, and hypertension; and transition and transfer of pediatric patients to adult nephrology care. This report describes the recommendations generated by the participants who attended the workshop.

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.

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.

Effects of changes in adult erythropoietin dosing guidelines on erythropoietin dosing practices, anemia, and blood transfusion in children on hemodialysis: findings from North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS)

BACKGROUND

While adult hemodialysis (HD) patients have increased morbidity with higher target hemoglobin levels, similar findings have not been demonstrated in pediatric patients. We evaluated changes in transfusions, anemia frequency, and erythropoietin (epo) dosing among pediatric HD patients before, during, and after implementation of federal dialysis payment policies regarding epo dosing for adult HD patients.

METHODS

This is a retrospective cohort study of pediatric HD patients enrolled in NAPRTCS. We evaluated need for transfusion, anemia, median hemoglobin, and median epo dose 6 months after starting HD in 3 eras: baseline (2003-2007), implementation (2008-2011), and post implementation (2012-2016). We used multivariate logistic regression models to evaluate potential differences in transfusion across the eras.

RESULTS

Six months after dialysis initiation, 12.6% of patients required transfusion pre-implementation, 17.9% during implementation, and 15.5% post implementation. Anemia occurred in 17.4% of patients pre, 23.5% during, and 23.8% post implementation, with median hemoglobin levels of 11.9 g/dL pre, 11 g/dL during, and 11 g/dL post implementation. Epo use was high across all 3 eras, but epo dosing decreased during and post implementation, despite more anemia during these periods. Odds of transfusion in implementation era compared with pre-implementation was 1.75 (95% CI 1.11-2.77) and odds of transfusion in post implementation era compared with pre was 1.19 (95% CI 0.71-1.98), controlling for age, race, gender, and prior transplant status.

CONCLUSIONS

During and following implementation of adult epo dosing guidelines, transfusion and anemia frequency increased in pediatric HD patients. Ideal target hemoglobin levels for pediatric dialysis patients warrant further study.

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.

Vitamin D insufficiency, hemoglobin, and anemia in children with chronic kidney disease

BACKGROUND

25-Hydroxyvitamin D (25OHD) deficiency is common in children with chronic kidney disease (CKD). It has been associated with an increased risk for anemia in both healthy US children and in adults with CKD. This association has not been explored in children with CKD.

METHODS

Children aged 1-16 enrolled in the Chronic Kidney Disease in Children (CKiD) study with mild to moderate kidney dysfunction, and with 25OHD measured at baseline (n = 580), were included in the analysis. The cross-sectional associations between 25OHD and hemoglobin (g/dL) and anemia were assessed. Anemia was defined as hemoglobin < 5th percentile for age and sex.

RESULTS

Overall 334 (57.59%) children were vitamin D insufficient/deficient and 137 (23.62%) were anemic. Of those who were vitamin D insufficient/deficient, 95 (28.44%) were anemic. In the overall cohort, the odds of being anemic was 1.9 times higher (95% CI, 1.22-3.04, p < 0.01) in vitamin D insufficient/deficient vs sufficient children, when adjusting for covariates (age, sex, race [black, white, or other], body mass index (BMI), iohexol GFR (iGFR), erythropoietin stimulation agent (ESA) use, iron supplementation use, and underlying cause of CKD). Stratified by race, the odds of being anemic was 2.39 times higher (95% CI, 1.41-4.05, p = 0.001) in vitamin D insufficient/deficient vs vitamin D sufficient white children. The association between vitamin D status and anemia was not significant in black children.

CONCLUSIONS

The data support our hypothesis that vitamin D insufficiency/deficiency increases the odds of anemia in children with CKD. The effect was strong and significant among white, but not black, children.

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.

Darbepoetin Alfa in Young Infants With Renal Failure: Single Center Experience, a Case Series and Review of the Literature

Background: Anemia treatment in infants with advanced or chronic kidney disease (CKD) represents an important challenge to nephrologists. The use of darbepoetin alfa, a novel erythropoiesis stimulating agent, has largely replaced recombinant human erythropoietin in older children and in adults with CKD. However, studies reporting the use of darbepoetin alfa in infants below 1 year of age are rare. Case presentation: We report the data of three infants with advanced stage kidney failure, aged 1, 4, and 7 months, who were treated with darbepoetin alfa and followed for 18-41 months. Hemoglobin levels increased in all three patients, reaching the target levels of 10.7-12 g/dl by 11, 19, and 22 weeks respectively, without any documented adverse effects. Patients younger than 1 year of age required a larger darbepoetin alfa dosage (ranged from 1.2 to 2.9 μg/kg per month) as compared to older children. A review of the literature found only three studies using darbepoetin alfa successfully in such young infants, with similar dosage and clinical success. Conclusion: In these three patients with advanced kidney disease, darbepoetin alfa was effective in correcting anemia with no observed side effects. It reinforces its potential use in very young patients with advanced CKD.

Clinical outcomes and survival in pediatric patients initiating chronic dialysis: a report of the NAPRTCS registry

BACKGROUND

The 2011 annual report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) registry comprises data on 6482 dialysis patients over the past 20 years of the registry.

METHODS

The study compared clinical parameters and patient survival in the first 10 years of the registry (1992-2001) with the last decade of the registry (2002-2011).

RESULTS

There was a significant increase in hemodialysis as the initiating dialysis modality in the most recent cohort (42% vs. 36%, p < 0.001). Patients in the later cohort were less likely to have a hemoglobin <10 g/dl [odds ratio (OR) 0.68; confidence interval (CI) 0.58-0.81; p < 0.001] and height z-score <2 standard deviations (SD) below average (OR 0.68, CI 0.59-0.78, p < 0.0001). They were also more likely to have a parathyroid hormone (PTH) level two times above the upper limits of normal (OR 1.39, CI 1.21-1.60, p < 0.0001). Although hypertension was common regardless of era, patients in the 2002-2011 group were less likely to have blood pressure >90th percentile (OR 1.39, CI 1.21-1.60, p < 0.0001), and a significant improvement in survival at 36 months after dialysis initiation was observed in the 2002-2011 cohort compared with the 1992-2001 cohort (95% vs. 90%, respectively). Cardiopulmonary causes were the most common cause of death in both cohorts. Young age, growth deficit, and black race were poor predictors of survival.

CONCLUSIONS

The survival of pediatric patients on chronic dialysis has improved over two decades of dialysis registry data, specifically for children <1year.

Posttransplant Anemia as a Prognostic Factor of Mortality in Kidney-Transplant Recipients

Background. Findings on the association between posttransplant anemia (PTA) and mortality in posttransplant patients are scarce. This study explored whether PTA shortly after kidney transplantation (KT) predicts mortality at up to 10 years' follow-up, stratified for chronic kidney disease (CKD) stages. Methods. PTA was divided into 3 categories according to the hemoglobin (Hb) value: severe (Hb < 10 g/dl), mild (10.0 g/dl ≤ Hb < 11.9 g/dl), or no PTA (Hb ≥ 12 g/dl). CKD stages were estimated using the CKD-EPI formula and divided into 2 groups: CKD1-2 and CKD3-5. Cox regression, stratified according to CKD, was performed to identify whether different categories of PTA predicted mortality in KT recipients. Results. Age, being female, and both mild and severe PTA contributed significantly to the Cox regression model on mortality in CKD1-2. In the Cox regression model for mortality in CKD3-5, age and severe PTA contributed significantly to this model. Conclusion. PTA shortly after KT increased the risk of mortality at up to 10 years' follow-up. Even mild PTA is associated with a 6-fold higher risk of mortality and severe PTA with a 10-fold higher risk of mortality in CKD1-2. Clinical evaluation and treatment of anemia might reduce the higher risk of mortality in patients with PTA in early stages of CKD after KT.

Hemoglobin of 12 g/dl and above is not associated with increased cardiovascular morbidity in children on hemodialysis

In adults on chronic hemodialysis, achieving a hemoglobin concentration of 12g/dl and above with erythropoiesis stimulating agents leads to increased cardiovascular events and mortality, but this may not be true in children. Therefore, we conducted a retrospective cohort study of pediatric patients (under 18) from the Centers for Medicare and Medicaid Services End Stage Renal Disease (ESRD) Clinical Performance Measures (CPM) project (2000 to 2008) merged with the United States Renal Data System. Hemoglobin was determined from the Clinical Performance Measures data, and beginning annually on January 1st of the next year, patients were followed for up to 1 year. We determined the outcomes (mortality, hospitalization, and cardiovascular events) during follow-up by hemoglobin group at baseline. Models were adjusted for demographic and clinical characteristics of 1569 children studied. The hemoglobin 12 g/dl and above group was older, had fewer years of ESRD, and was more often transplanted. Inpatient and outpatient visits for congestive heart failure, cardiomyopathy, and valvular heart disease were most common in the hemoglobin under 10g/dl group and the frequency of these diagnoses decreased with increasing hemoglobin. The hazard ratio of all-cause mortality (0.33, 95% confidence interval 0.14-0.81) and the adjusted relative rate of all-cause hospitalizations (0.81, 0.74-0.89) were significantly lower in the hemoglobin 12 g/dl and above group. Cardiovascular hospitalizations were significantly higher in the hemoglobin under 10g/dl group (1.31, 1.05-1.64). Thus, in children on hemodialysis, hemoglobin 12g/dl and above is not associated with increased cardiovascular visits, mortality, or all-cause and cardiovascular-related hospitalizations.

Lessons learned from the ESPN/ERA-EDTA Registry

End-stage renal disease (ESRD) in children is a medically challenging condition. Due to its rarity and special features, methodologically sound collaborative studies are required. In 2007, a new European registry of pediatric renal replacement therapy (RRT), the ESPN/ERA-EDTA Registry, was launched. In recent years, the Registry has provided comprehensive data on incidence, prevalence, patient characteristics, RRT modalities, and mortality in pediatric ESRD, along with relevant insights into cardiovascular risk, anemia, nutrition and growth, transplantation outcomes, and rare diseases. In this review, we describe the study design and structure underlying the ESPN/ERA-EDTA Registry, summarize the major research findings from more than 20 publications, and discuss current limitations and the future challenges to overcome.

PROGRESSION OF CHRONIC KIDNEY DISEASE AFTER ACUTE KIDNEY INJURY

The incidence of chronic kidney disease (CKD) in children and adults is increasing. Cardiologists have become indispensable members of the care provider team for children with CKD. This is partly due to the high incidence of CKD in children and adults with congenital heart disease, with current estimates of 30-50%. In addition, the high incidence of acute kidney injury (AKI) due to cardiac dysfunction or following pediatric cardiac surgery that may progress to CKD is also well documented. It is now apparent that AKI and CKD are uniquely intertwined as interconnected syndromes. Furthermore, the well-known long-term cardiovascular morbidity and mortality associated with CKD require the joint attention of both nephrologists and cardiologists. Children with both congenital heart disease and CKD are increasingly surviving to adulthood, with synergistically negative medical, financial, and quality of life impact. An improved understanding of the epidemiology, mechanisms, early diagnosis, and preventive measures is of importance to cardiologists, nephrologists, scientists, economists, and policy makers alike. Herein, we report the current definitions, epidemiology, and complications of CKD in children, with an emphasis on children with congenital heart disease. We then focus on the clinical and experimental evidence for the progression of CKD after episodes of AKI commonly encountered in children with heart disease, and explore the role of novel biomarkers for the prediction of CKD progression.

Using a non-invasive method in chronic hemodialysis pediatric patients to estimate hemoglobin

BACKGROUND

Maintaining hemoglobin (Hgb) levels within a target range is difficult. Non-invasive hematocrit monitoring (NIVH) continuously monitors both the hematocrit and percent change in intravascular blood volume in real time. Based on the data reported here, NIVH can be utilized as a tool for anemia management in pediatric hemodialysis patients.

METHODS

Monthly, mid-week pre-dialysis, Hgb levels were obtained for 12 consecutive months. Concurrent with monthly Hgb, hematocrit was recorded at the start of the dialysis treatment using NIVH. Hgb (oHgb) was calculated using the adult equation Hgb = 0.3112*HCT + 0.71, and a linear regression model was used to derive a pediatric specific equation (pHgb = 0.28*CRIT Hct + 2.5).

RESULTS

A total of 310 observations were obtained from 47 patients. The mean actual hemoglobin (mHgb) was 11.14 ± 1.4, and the mean derived hemoglobin from the adult equation, oHgb, was 10.3 ± 1.3 (p = 0.0001). For the target hemoglobin of 10-12 gm/dl, the adult equation was 72 % sensitive and 63 % specific, whereas the pediatric equation was 93 % sensitive and 70 % specific.

CONCLUSIONS

The newly derived pediatric equation (pHgb = 0.28*CRIT Hct + 2.5) improved the prediction capability compared to the standard equation with lower false-negative and false-positive rates.

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.

Association of higher erythropoiesis stimulating agent dose and mortality in children on dialysis

BACKGROUND

Higher doses of erythropoiesis-stimulating agents (ESA) have been associated with an increased risk of adverse outcomes in adults with chronic kidney disease (CKD) and end-stage kidney disease (ESRD), but to our knowledge no trials have been performed in children. We examined the association between ESA dose and all-cause mortality in a prevalent pediatric dialysis population.

METHODS

Retrospective cohort study utilizing national data on all prevalent dialysis patients aged <18 years from the Centers for Medicare and Medicaid Services' 2005 ESRD Clinical Performance Measures (CPM) project, linked to 18-month mortality records from the United States Renal Data System. Multivariate Cox proportional hazards regression was performed to determine the risk of mortality by mean weekly ESA dose.

RESULTS

Eight-hundred and twenty-nine children were included in the analysis; 7 % died during follow-up. A higher proportion of patients receiving ESA doses in the highest category (erythropoietin ≥350 units/kg/week or darbepoetin ≥1.5 units/kg/week) died (50 % vs 28 %, p = 0.002), and also demonstrated a trend toward lower hemoglobin (11.0 vs 11.4 g/dL, p = 0.05). In multivariate analysis, patients receiving the highest dose of ESA demonstrated an increased risk of mortality (hazard ratio 3.37; p value <0.01).

CONCLUSION

Higher ESA dose is independently associated with mortality in children on chronic dialysis.

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.

Comorbidities in chronic pediatric peritoneal dialysis patients: a report of the International Pediatric Peritoneal Dialysis Network

BACKGROUND, OBJECTIVES, AND METHODS: Hospitalization and mortality rates in pediatric dialysis patients remain unacceptably high. Although studies have associated the presence of comorbidities with an increased risk for death in a relatively small number of pediatric dialysis patients, no large-scale study had set out to describe the comorbidities seen in pediatric dialysis patients or to evaluate the impact of those comorbidities on outcomes beyond the newborn period. In the present study, we evaluated the prevalence of comorbidities in a large international cohort of pediatric chronic peritoneal dialysis (CPD) patients from the International Pediatric Peritoneal Dialysis Network registry and began to assess potential associations between those comorbidities and hospitalization rates and mortality.

RESULTS

Information on comorbidities was available for 1830 patients 0 - 19 years of age at dialysis initiation. Median age at dialysis initiation was 9.1 years [interquartile range (IQR): 10.9], median follow-up for calculation of hospitalization rates was 15.2 months (range: 0.2 - 80.9 months), and total follow-up time in the registry was 2095 patient-years. At least 1 comorbidity had been reported for 602 of the patients (32.9%), with 283 (15.5%) having cognitive impairment; 230 (12.6%), motor impairment; 167 (9.1%), cardiac abnormality; 76 (4.2%), pulmonary abnormality; 212 (11.6%), ocular abnormality; and 101 (5.5%), hearing impairment. Of the 150 patients (8.2%) that had a defined syndrome, 85% had at least 1 nonrenal comorbidity, and 64% had multiple comorbidities. The presence of at least 1 comorbidity was associated with a higher hospitalization rate [hospital days per 100 observation days: 1.7 (IQR: 5.8) vs 1.2 (IQR: 3.9), p = 0.001] and decreased patient survival (4-year survival rate: 73% vs 90%, p < 0.0001).

CONCLUSIONS

Nearly one third of pediatric CPD patients in a large international cohort had at least 1 comorbidity, and multiple comorbidities were frequently reported among patients with a defined syndrome. Preliminary analysis suggests an association between comorbidity and poor outcome in those patients. As this powerful international registry matures, further multivariate analyses will be important to more clearly define the impact of comorbidities on hospitalization rates and mortality in pediatric CPD patients.

Association between common iron store markers and hemoglobin in children with chronic kidney disease

BACKGROUND

Serum ferritin and transferrin saturation (TSAT) are used to assess iron status in children with chronic kidney disease (CKD), but their sensitivity in identifying those at risk of lower hemoglobin (HGB) values is unclear.

METHODS

We assessed the association of iron status markers (ferritin, TSAT, and serum iron) with age- and gender-related HGB percentile in mild-to-moderate CKD in 304 children in the Chronic Kidney Disease in Children (CKiD) Study. Standardized HGB percentile values were examined by KDOQI-recommended ferritin (≥ 100 ng/ml) and TSAT (≥ 20 %) thresholds. Regression tree methods were used to identify iron status markers and clinical characteristics most associated with lower HGB percentiles.

RESULTS

The cohort was 62 % male, 23 % African American, and 12 % Hispanic, median age 12 years, and median HGB 12.9 g/dl. 34 % had low TSAT and 93 % low ferritin as defined by KDOQI. Distribution of HGB percentile values was lower in those with ferritin ≥ 100 ng/ml, while TSAT ≥ 20 % was associated with only modest increase in HGB percentile. In regression tree analysis, lower glomerular filtration rate (GFR), serum iron <50 μg/dl and ferritin ≥ 100 ng/ml were most strongly associated with lower HGB percentile.

CONCLUSIONS

The level of GFR was significantly associated with HGB. Higher serum ferritin was associated with lower HGB in this cohort. Low serum iron in the context of normal/increased ferritin and low HGB may be a useful indicator of iron-restricted erythropoiesis.

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.

Racial disparities in access to pediatric kidney transplantation since share 35

Share 35 was enacted in 2005 to shorten transplant wait times and provide high-quality donors to children with ESRD. To investigate the possible effect of this policy on racial disparities in access to pediatric transplantation, we analyzed data from the US Renal Data System before and after Share 35. Among 4766 pediatric patients with incident ESRD, the probability of receiving a deceased-donor kidney transplant increased 46% after Share 35, with Hispanics experiencing the greatest improvements (increases of 81% for Hispanics, 45% for blacks, and 37% for whites). On average, patients received a deceased-donor kidney transplant earlier after Share 35, but this finding varied by race: 63 days earlier for whites, 90 days earlier for blacks, and 201 days earlier for Hispanics. Furthermore, a shift from living- to deceased-donor sources occurred with Share 35 for all races, with a 25% reduction in living donors for whites compared with 48% and 46% reductions for Hispanics and blacks, respectively. In summary, Share 35 seems to have attenuated racial disparities in the time to and probability of children receiving a deceased-donor kidney transplant. These changes coincided with changes in the rates of living-donor sources, which vary by race. Future studies should explore how these changes may impact racial differences in long-term graft outcomes.

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.

Metabolic abnormalities, cardiovascular disease risk factors, and GFR decline in children with chronic kidney disease

BACKGROUND AND OBJECTIVES

Metabolic abnormalities and cardiovascular disease (CVD) risk factors have rarely been systematically assessed in children with chronic kidney disease (CKD). We examined the prevalence of various CKD sequelae across the GFR spectrum.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were used from 586 children participating in the Chronic Kidney Disease in Children (CKiD) study (United States and Canada) with GFR measured by iohexol plasma disappearance. Laboratory values and CVD risk factors were compared across GFR categories and with an age-, gender-, and race-matched community sample.

RESULTS

CKiD participants were 62% male, 66% Caucasian, 23% African American, and 15% Hispanic with a median age of 11 years and a median GFR of 44 ml/min per 1.73 m(2). Compared with those with a GFR ≥ 50 ml/min per 1.73 m(2), having a GFR < 30 ml/min per 1.73 m(2) was associated with a three-fold higher risk of acidosis and growth failure and a four- to five-fold higher risk of anemia and elevated potassium and phosphate. Median GFR change was -4.3 ml/min per 1.73 m(2) and -1.5 ml/min per 1.73 m(2) per year in children with glomerular and nonglomerular diagnoses, respectively. Despite medication and access to nephrology care, uncontrolled systolic hypertension was present in 14%, and 16% had left ventricular hypertrophy. Children with CKD frequently were also shorter and had lower birth weight, on average, compared with norms.

CONCLUSIONS

Growth failure, metabolic abnormalities, and CVD risk factors are present at GFR >50 ml/min per 1.73 m(2) in children with CKD and, despite therapy, increase in prevalence two- to four-fold with decreasing GFR.

No difference in meeting hemoglobin and albumin targets for dialyzed children with urologic disorders

Urologic disorders are the most common cause of chronic kidney disease in children. To determine whether children with urologic etiology of end-stage renal disease (ESRD) fare better than children with ESRD from other causes while on dialysis, we conducted a cross-sectional study of children <18 years receiving peritoneal and hemodialysis in the United States using data from the Centers for Medicare & Medicaid Services 2005 ESRD CPM Project. We compared baseline demographics and the study groups. In multivariate logistic regression analysis of 1,286 subjects, we assessed whether children with urologic disorders had a higher odds of meeting adult KDOQI targets for hemoglobin levels ≥11 g/dl and albumin ≥3.5 BCG/3.2 BCP g/dl. We conducted a subset analysis of 1,136 patients to examine the impact of erythropoietin on hemoglobin targets. Our results did not reveal differences in achievement of adult hemoglobin targets (adjusted OR: 1.27; p value 0.09; CI: 0.97-1.66) or in the subset analysis with erythropoietin (adjusted OR: 1.32; p value 0.06; CI: 0.98-1.78) or albumin targets (adjusted OR: 1.22; p value 0.21; CI: 0.90-1.65) in adjusted analyses. Due to our study's limitations, it is difficult to determine whether this may result from treatment prior to dialysis initiation or treatment effect of dialysis rather than underlying diagnosis.

Hospitalization rates and clinical performance measures in U.S. adolescent hemodialysis patients

The Centers for Medicare and Medicaid Services' End Stage Renal Disease (ESRD) Clinical Performance Measures (CPM) Project monitors clinical measure attainment in pediatric hemodialysis (HD) patients. Targets include hemoglobin ≥ 11 g/dL, albumin ≥ 3.5/3.2 g/dL (bromcresol green/purple), single-pooled Kt/V ≥ 1.2, and the use of subcutaneous access. We hypothesized that the achievement of multiple targets by adolescent HD patients is associated with decreased morbidity. Data on patients aged 12-18 years included in the ESRD CPM Project from 2000 to 2004 with Medicare as primary payer were linked to the U.S. Renal Data System data from October 1, 1999 to December 31, 2004. Hospitalization rates by number of targets achieved were determined with Poisson regression analysis adjusted for dialysis vintage, short stature, and race. A total of 1534 patients with 1774 patient-years of follow-up, with 580 hospitalizations, were included in the analysis. In their first year in the ESRD CPM Project, 22% of the patients achieved four targets, with 34 and 28% achieving three and two targets, respectively. Subcutaneous access was least frequently attained target; spKt/V ≥ 1.2 was the most frequently attained target. After adjustment, there was decreased hospitalization risk with increasing target attainment (incidence rate ratio 0.74, 95% confidence interval 0.67-0.80, p < 0.001). Based on this analysis, meeting adult-defined targets is associated with decreases in the hospitalization rate of adolescent HD patients. Tracking adult-defined HD measures is appropriate for assessing hospitalization risk in adolescent patients, although no evidence for a cause-and-effect relationship exists.

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

Previous studies in children with chronic kidney disease (CKD) have identified low hemoglobin as a risk factor for poor outcomes. A retrospective review of the North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS) CKD registry was performed to identify the prevalence of and risk factors for anemia among children with stage 3 CKD, including both patients with low hemoglobin and those whose hemoglobin normalized with an erythropoiesis-stimulating agent (ESA). At enrollment, 2,792 patients had stage 3 CKD. Mean age was 9.5 (+/-0.11) years, 62.1% were male, 61.3% were white, and 43.7% had structural/urologic disease. Among 1,640 of those patients with 12 month follow-up data available for multivariate analysis, 73% met the criteria for anemia. Multivariate logistic regression analysis identifying risk factors for anemia at the 12-month follow-up revealed that, after controlling for estimated glomerular filtration rate, age >2 years, male sex, earlier era of study entry, and prescription of anti-hypertensive medications are associated with an increased risk for anemia at 12 months. In addition, multivariate Cox proportional hazards regression analysis revealed that when patients with ESA-corrected hemoglobin are included in the definition, anemia is not associated with increased risk of progression to end stage renal disease (dialysis initiation or transplantation).

Risk factors for progression of chronic kidney disease

PURPOSE OF REVIEW

The present review provides an overview of the identified risk factors for chronic kidney disease (CKD) progression emphasizing the pediatric population.

RECENT FINDINGS

Over the past 10 years, there have been significant changes to our understanding and study of preterminal kidney failure. Recent refinements in the measurement of glomerular filtration rate and glomerular filtration rate estimating equations are important tools for identification and association of risk factors for CKD progression in children. In pediatric CKD, lower level of kidney function at presentation, higher levels of proteinuria, and hypertension are known markers for a more rapid decline in glomerular filtration rate. Anemia and other reported risk factors from the pregenomic era require further study and validation. Genome-wide association studies have identified genetic loci that have provided novel genetic risk factors for CKD progression.

SUMMARY

With cohort studies of children with CKD becoming mature, they have started to yield important refinements to the assessment of CKD progression. Although many of the traditional risk factors for renal progression will certainly be assessed, such cohorts will be important for evaluating novel risk factors identified by genome-wide studies.

Secondary hyperparathyroidism and anemia in children treated by hemodialysis

BACKGROUND

Many patients treated using hemodialysis remain anemic despite exogenous erythropoietin therapy, suggesting that the anemia experienced by these patients is multifactorial in cause. Iron deficiency, infection, inflammation, and malnutrition have been implicated in this process. Additionally, secondary hyperparathyroidism has been associated with anemia in adults, but few data exist about this topic in children.

STUDY DESIGN

Cross-sectional retrospective.

SETTING & PARTICIPANTS

Children treated in hemodialysis centers (N = 588) within the Centers for Medicare & Medicaid Services' 2002 Clinical Performance Measures Project.

PREDICTOR

Intact parathyroid hormone (iPTH) levels assessed in October, November, and December 2001 and categorized as quintiles.

OUTCOMES & MEASUREMENTS

Achievement of serum hemoglobin level > or = 11 g/dL was assessed using Poisson regression adjusting for sex, age, race, dialysis vintage, vascular access type, single-pool Kt/V, serum albumin level, normalized protein catabolic rate, calcium-phosphorus product, and erythropoietin alfa dose.

RESULTS

Using the second quintile (iPTH, 103-224 pg/mL) as the reference quintile, there was no association between iPTH quintile and achievement of the hemoglobin goal: quintile 1 prevalence ratio, 1.0 (95% CI, 0.9-1.2); quintile 3, 0.95 (95% CI, 0.8-1.1); quintile 4, 0.99 (95% CI, 0.8-1.2); and quintile 5, 0.97 (95% CI, 0.8-1.1). Only serum albumin level >/= 3.5 g/dL (bromocresol green assay method) or > or = 3.2 g/dL (bromocresol purple assay method) was significantly associated with meeting the hemoglobin goal: 1.4 (95% CI, 1.2-1.6).

LIMITATIONS

The simultaneous collection of iPTH and hemoglobin limits causal inference. Iron stores and iron therapy are potential confounders not accounted for in this study.

CONCLUSIONS

In the largest study of this topic in children, no association was found between iPTH level and achievement of a hemoglobin level > or = 11 g/dL. Serum albumin level was associated strongly with achievement of the hemoglobin goal.

Persistent low albumin and temporary vascular access in pediatric patients with SLE on hemodialysis

Pediatric patients with systemic lupus erythematosus (SLE) often present with significant kidney disease. In a previous cross-sectional analysis, we showed that pediatric patients with ESRD secondary to SLE have lower serum albumin levels and less permanent vascular access for hemodialysis (HD) compared to pediatric patients on HD secondary to other causes. The goal of this longitudinal study was to determine if there was an improvement in these targets over time. To this end, we performed a longitudinal analysis of patients receiving HD in the ESRD Clinical Performance Measures Project 2000-2004 study years, comparing achievement of clinical targets between pediatric patients with SLE and pediatric patients with other causes of ESRD. In the longitudinal follow-up, pediatric patients with SLE were less likely to reach target albumin levels than other children with ESRD maintained on HD [odds ratio (OR) 0.18, 95% confidence interval (CI) 0.09, 0.35] and were less likely to have arteriovenous fistulas or grafts than other pediatric patients (OR 0.45, 95% CI 0.23, 0.89). Pediatric patients with SLE maintained on HD are at particularly high risk for failing to meet some clinical targets that have been associated with improved long-term outcomes in other populations. This is true even as they remain on dialysis over time.

Clinical outcomes in pediatric hemodialysis patients in the USA: lessons from CMS' ESRD CPM Project

Although prospective randomized trials have provided important information and allowed the development of evidence-based guidelines in adult hemodialysis (HD) patients, with approximately 800 prevalent pediatric HD patients in the United States, such studies are difficult to perform in this population. Observational data obtained through the Center for Medicare & Medicaid Services' (CMS') End Stage Renal Disease (ESRD) Clinical Performance Measures (CPM) Project have allowed description of the clinical care provided to pediatric HD patients as well as identification of risk factors for failure to reach adult targets for clinical parameters such as hemoglobin, single-pool Kt/V (spKt/V) and serum albumin. In addition, studies linking data from the ESRD CPM Project and the United States Renal Data System have allowed evaluation of associations between achievement of those targets and the outcomes of hospitalization and death. The results of those studies, while unable to prove cause and effect, suggest that the adult ESRD CPM targets may assist in identifying pediatric HD patients at risk for poor outcomes.

Hemoglobin target in chronic kidney disease: a pediatric perspective

Erythropoietin has transformed the treatment of the anemia of chronic kidney disease (CKD) by preventing the need for blood transfusions and improving the quality of life in all patients, including children. Anemia in children, in the age group 1-19 years, may be defined as hemoglobin (Hgb) levels < 12.1-13.5 g/dl for boys and < 11.4-11.5 g/dl for girls, based on the National Health and Nutrition Examination Survey (NHANES) norms. The prevalence of anemia in children ranges from 31.2% in stage 1 CKD to 93.3% in stages 4 and 5 CKD. The recent publication of trials evaluating the optimal hemoglobin level in adult CKD patients has generated considerable uncertainty about the target Hgb level in children with CKD. It is unclear whether generalizing of results from these trials in adults to children is appropriate. Adequately powered, randomized, controlled studies have not been conducted on children, and none to our knowledge are currently planned. The Food and Drug Administration (FDA) offers scant guidance on the Hgb target level for children, other than implying that it should be no different from that for adults. The purpose of this editorial is to critically scrutinize whether there is a benefit to the normalization of anemia in children with CKD and whether adoption of the results from adult studies is appropriate.

Anemia and risk of hospitalization in pediatric chronic kidney disease

BACKGROUND AND OBJECTIVES

Anemia is a well known complication of chronic kidney disease (CKD); however, the prevalence of anemia within CKD stages in the pediatric population has not been established. Additionally, the associated morbidity of anemia in the pediatric CKD population has not been elucidated.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

2,779 patients ages 2 yr and older in the North American Pediatric Renal Trials and Collaborative Studies database with CKD stage II to V (excluding dialysis or previous transplant patients) were identified. Descriptive statistics and multivariate modeling using logistic regression was performed to determine the prevalence of anemia and to evaluate the correlation between baseline anemia and hospitalization.

RESULTS

The prevalence of anemia (hematocrit < 33%) increased from 18.5% in CKD stage II to 68% in CKD stage V (predialysis). Anemic children were 55% more likely to be hospitalized when compared with nonanemic children (odds ratio 1.55; 95% confidence interval 1.23 to 1.94). Similar results were obtained using hematocrit cutoffs of 36 and 39%.

CONCLUSIONS

In this pediatric predialysis CKD population, anemia increases with increasing CKD stage and is significantly associated with hospitalization risk. Hematocrit levels above 36 and 39% were not associated with increased risk of hospitalization. Further examination into the effect of correcting anemia on hospitalization rates may provide additional useful information.

Recent advances in pediatric dialysis: a review of selected articles

Important discoveries and studies that help inform us about the best methods to evaluate and manage children with end-stage renal disease (ESRD) continue to emerge. This review addresses a number of recent publications regarding important clinical issues for children with ESRD. Despite advances made in previous years, many clinical problems remain in the care of the pediatric dialysis patient. This review covers five topics of recent interest: three articles that address important patient outcome measures such as dialysis adequacy and hemoglobin; two articles that address growth failure in a chronic dialysis patients; five articles that address cardiovascular (CV) morbidity, mortality, and interventions to reduce CV risk in children; two articles that address mineral-bone disorder (MBD) and evidence that past strategies for MBD in children may have increased CV disease; and two articles that address nephrogenic systemic fibrosis, a recently described disorder in chronic kidney disease (CKD) patients that occurs in children as well as adults. Using a concise consistent format, each of the 14 key publications is summarized, and the "conclusion" for the practitioner is identified. The goal of this review is to highlight important work done in this area and focus attention on the important issues raised by each article.

Disparate outcomes in pediatric peritoneal dialysis patients by gender/race in the End-Stage Renal Disease Clinical Performance Measures project

Associations between achievement of adult Kidney Disease Outcomes Quality Initiative (KDOQI) targets for hemoglobin, adequacy and albumin, and race and gender were determined for pediatric peritoneal dialysis patients from the End-Stage Renal Disease (ESRD) Clinical Performance Measures (CPM) project for the period October 2004-March 2005. Fifty-six percent (427/761) of patients were male. Sixty-six percent (500/761) of patients were White. There were no differences in achievement of targets for adults by gender, and no differences in adequacy parameters by race. Blacks had lower mean hemoglobin levels than did Whites (11.1 +/- 1.6 g/dl vs 11.8 +/- 1.4 g/dl, P < 0.0001). Blacks were more likely to have mean hemoglobin levels < 10 g/dl (24% vs 11%, P < 0.0001) and less likely to achieve mean hemoglobin > 11 g/dl (56% vs 72%, P < 0.0001). Whites were more likely to achieve mean serum albumin levels > 4.0/3.7 g/dl [bromocresol green/bromocresol purple (BCG/BCP)] than Blacks were (35% vs 26%, P = 0.0376). In multivariate logistic regression models, White race was associated with mean hemoglobin levels > 11 g/dl [adjusted odds ratio (adj OR) 2.7, 95% confidence interval (CI) 1.7, 4.3] and mean serum albumin > 4.0/3.7 g/dl (BCG/BCP) (adj OR 1.9, 95% CI 1.3, 2.9]. Further study is needed of factors associated with anemia on peritoneal dialysis and barriers to its correction.

Serum albumin level and risk for mortality and hospitalization in adolescents on hemodialysis

BACKGROUND AND OBJECTIVES

National Kidney Foundation Dialysis Outcomes Quality Initiative practice guidelines recommend serum albumin > or = 4.0 g/dl for adults who are on hemodialysis. There is no established pediatric target for albumin and little evidence to support use of adult guidelines. This study examined the association between albumin and risk for death and hospitalization in adolescents who are on hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective cohort study linked data on patients aged 12 to 18 yr in 1999 and 2000 from the Centers for Medicare and Medicaid Services' End Stage Renal Disease Clinical Performance Measures Project with 4-yr hospitalization and mortality records in the United States Renal Data System. Albumin was categorized as < 3.5/3.2, > or = 3.5/3.2 and < 4.0/3.7, and > or = 4.0/3.7 g/dl.

RESULTS

Of 675 adolescents, 557 were hospitalized and 50 died. Albumin > or = 4.0/3.7 g/dl was associated with male gender, Hispanic ethnicity, and higher hemoglobin level. Those with albumin > or = 4.0/3.7 g/dl had fewer deaths per 100 patient-years and fewer hospitalizations per time at risk. In multivariate analysis, patients with albumin > or = 4.0/3.7 g/dl had 57% decreased risk for death. Poisson regression showed progressive decrease in hospitalization risk as albumin level increased; however, confidence intervals were similar between albumin > or = 4.0/3.7 g/dl and albumin > or = 3.5/3.2 and < 4.0/3.7 g/dl.

CONCLUSIONS

This study demonstrates decreased mortality and hospitalization risk with albumin > or = 3.5/3.2 g/dl and suggests that adolescent hemodialysis patients who are able to achieve serum albumin > or = 4.0/3.7 g/dl may have the lowest mortality risk.