Persistent Increase in Serum Ferritin Levels despite Converting to Permanent Vascular Access in Pediatric Hemodialysis Patients: Pediatric Nephrology Research Consortium Study.

Our objective was to examine serum ferritin trends after conversion to permanent vascular access (PVA) among children who started hemodialysis (HD) using tunneled cuffed catheters (TCC). Retrospective chart reviews were completed on 98 subjects from 20 pediatric HD centers. Serum ferritin levels were collected at the creation of PVA and for two years thereafter. There were 11 (11%) arteriovenous grafts (AVG) and 87 (89%) arteriovenous fistulae (AVF). Their mean TCC use was 10.4 ± 17.3 months. Serum ferritin at PVA creation was elevated at 562.64 ± 492.34 ng/mL, increased to 753.84 ± 561.54 ng/mL (p = < 0.001) in the first year and remained at 759.60 ± 528.11 ng/mL in the second year (p = 0.004). The serum ferritin levels did not show a statistically significant linear association with respective serum hematocrit values. In a multiple linear regression model, there were three predictors of serum ferritin during the first year of follow-up: steroid-resistant nephrotic syndrome as primary etiology (p = 0.035), being from a center that enrolled >10 cases (p = 0.049) and baseline serum ferritin level (p = 0.017). Increasing serum ferritin after conversion to PVA is concerning. This increase is not associated with serum hematocrit trends. Future studies should investigate the correlation of serum transferrin saturation and ferritin levels in pediatric HD patients.

Conversion to permanent vascular access is associated with improved markers of hemodialysis efficacy in children: Pediatric nephrology research consortium study.

BACKGROUND AND OBJECTIVES: Arteriovenous fistulae (AVF) and grafts (AVG) are preferred permanent vascular access (PVA) for chronic hemodialysis (HD) patients. Our objective was to examine the change in markers of HD efficacy after successful establishment of a PVA among children who started HD with a tunneled cuffed catheter (TCC). MATERIALS AND METHODS: Retrospective chart reviews were completed on patients from 20 pediatric dialysis centers. All patients used TCC prior to AVF/AVG, and each patient acted as his/her own control. Data on markers of HD efficacy (single-pool Kt/V, urea reduction ratio (URR), serum albumin and hematocrit (Hct)) were collected at the creation of AVF/AVG and for 2 years thereafter. Statistical methods included hypothesis testing and statistical modeling after adjusting for relevant demographic variables. RESULTS: First PVA was created in 98 individual children: 87 (89%) were AVF and 11 (11%) were AVG. The mean TCC vintage prior to AVF/AVG was 10.4 ± 17.3 months. At 1-year follow-up, Kt/V improved by 0.15 ± 0.06 (p = 0.02) and URR improved by 4.54 ± 1.17% (p < 0.0001). Furthermore, PVA was associated with improved serum albumin by 0.31 ± 0.07 g/dL (p < 0.0001) and Hct by 2.80 ± 0.65% (p < 0.0001) at 1 year. These HD efficacy markers remained statistically significant at 2nd-year follow-up. These observations were further supported by the adjusted models. Conversion to AVF was associated with statistically significant improvement in all four markers of HD efficacy at 1-year follow-up. This trend was not demonstrated for subjects who were converted to AVG. CONCLUSION: Switching to PVA was associated with improved markers of HD efficacy, single-pool Kt/V, URR, serum albumin, and Hct. This improvement was mostly demonstrated at 1 year and maintained for the 2nd year. The potential differential impact of the type of PVA on the trajectory of markers of HD efficacy should be further investigated.

Predictors of time to first cannulation for arteriovenous fistula in pediatric hemodialysis patients: Midwest Pediatric Nephrology Consortium study.

BACKGROUND: Permanent vascular access (PVA) is preferred for long-term hemodialysis. Arteriovenous fistulae (AVF) have the best patency and the lowest complication rates compared to arteriovenous grafts (AVG) and tunneled cuffed catheters (TCC). However, AVF need time to mature. This study aimed to investigate predictors of time to first cannulation for AVF in pediatric hemodialysis patients. METHODS: Data on first AVF and AVG of patients at 20 pediatric dialysis centers were collected retrospectively, including demographics, clinical information, dialysis markers, and surgical data. Statistical modeling was used to investigate predictors of outcome. RESULTS: First PVA was created in 117 children: 103 (88%) AVF and 14 (12%) AVG. Mean age at AVF creation was 15.0 ± 3.3 years. AVF successfully matured in 89 children (86.4%), and mean time to first cannulation was 3.6 ± 2.5 months. In a multivariable regression model, study center, age, duration of non-permanent vascular access (NPVA), and Kt/V at AVF creation predicted time to first cannulation, with study center as the strongest predictor (p < 0.01). Time to first cannulation decreased with increasing age (p = 0.03) and with increasing Kt/V (p = 0.01), and increased with duration of NPVA (p = 0.03). Secondary failure occurred in 10 AVF (11.8%). Time to first cannulation did not predict secondary failure (p = 0.29), but longer time to first cannulation tended towards longer secondary patency (p = 0.06). CONCLUSIONS: Study center is the strongest predictor of time to first cannulation for AVF and deserves further investigation. Time to first cannulation is significantly shorter in older children, with more efficient dialysis treatments, and increases with longer NPVA duration.

Correction to: Predictors of patency for arteriovenous fistulae and grafts in pediatric hemodialysis patients.

The original version of this article unfortunately contained a mistake. The name of Vimal Chadha was presented incorrectly. The corrected author list is given above.

Predictors of patency for arteriovenous fistulae and grafts in pediatric hemodialysis patients.

BACKGROUND: Hemodialysis (HD) guidelines recommend permanent vascular access (PVA) in children unlikely to receive kidney transplant within 1 year of starting HD. We aimed to determine predictors of primary and secondary patency of PVA in pediatric HD patients. METHODS: Retrospective chart reviews were performed for first PVAs in 20 participating centers. Variables collected included patient demographics, complications, interventions, and final outcome. RESULTS: There were 103 arterio-venous fistulae (AVF) and 14 AV grafts (AVG). AVF demonstrated superior primary (p = 0.0391) and secondary patency (p = 0.0227) compared to AVG. Primary failure occurred in 16 PVA (13.6%) and secondary failure in 14 PVA (12.2%). AVF were more likely to have primary failure (odds ratio (OR) = 2.10) and AVG had more secondary failure (OR = 3.33). No demographic, clinical, or laboratory variable predicted primary failure of PVA. Anatomical location of PVA was predictive of secondary failure, with radial having the lowest risk compared to brachial (OR = 12.425) or femoral PVA (OR = 118.618). Intervention-free survival was predictive of secondary patency for all PVA (p = 0.0252) and directly correlated with overall survival of AVF (p = 0.0197) but not AVG. Study center demonstrated statistically significant effect only on intervention-free AVF survival (p = 0.0082), but not number of complications or interventions, or outcomes. CONCLUSIONS: In this multi-center pediatric HD cohort, AVF demonstrated primary and secondary patency advantages over AVG. Radial PVA was least likely to develop secondary failure. Intervention-free survival was the only predictor of secondary patency for AVF and directly correlated with overall access survival. The study center effect on intervention-free survival of AVF deserves further investigation.

UGT1A9, UGT2B7, and MRP2 genotypes can predict mycophenolic acid pharmacokinetic variability in pediatric kidney transplant recipients.

BACKGROUND: Mycophenolic acid (MPA) exposure in pediatric patients with kidney transplant receiving body surface area (BSA)-based dosing exhibits large variability. Several genetic variants in glucuronosyltransferases (UGTs) and of multidrug resistance-associated protein 2 (MRP2) have independently been suggested to predict MPA exposure in adult patients with varying results. Here, the combined contribution of these genetic variants to MPA pharmacokinetic variability was investigated in pediatric renal transplant recipients who were on mycophenolic mofetil maintenance therapy. METHODS: MPA and MPA-glucuronide concentrations from 32 patients were quantified by high-performance liquid chromatography. MPA exposure (AUC) was estimated using a 4-point abbreviated sampling strategy (predose/trough and 20 minutes, 1 hour, and 3 hours after dose) using a validated pediatric Bayesian estimator. Genotyping was performed for all of the following single nucleotide polymorphisms (SNPs): UGT1A8 830G>A(*3), UGT1A9 98T>C(*3), UGT1A9-440C>T, UGT1A9-2152C>T, UGT1A9-275T>A, UGT2B7-900A>G, and MRP2-24T>C. RESULTS: Recipients heterozygous for MRP2-24T>C who also had UGT1A9-440C>T or UGT2B7-900A>G (n = 4), and MRP2-24T>C-negative recipients having both UGT1A9-440C>T and UGT2B7-900A>G (n = 5) showed a 2.2 and 1.7 times higher dose-dependent and BSA-normalized MPA-AUC compared with carriers of no or only 1 UGT-SNP (P < 0.001 and P = 0.01, respectively) (n = 7). Dose-dependent and BSA-normalized predose MPA concentrations were 3.0 and 2.4 times higher, respectively (P < 0.001). Interindividual variability in peak concentrations could be explained by the presence of the UGT1A9-440C>T genotype (P < 0.05). CONCLUSION: Our preliminary study demonstrates that combined UGT1A9-440C>T, UGT2B7-900A>G, and MRP2-24T>C polymorphisms can be important predictors of interindividual variability in MPA exposure in the pediatric population.

Effectiveness of home visits to pediatric peritoneal dialysis patients.

Home visits by trained personnel to patients undergoing home dialysis are required, but little is reported about the effectiveness of such home visits. We retrospectively reviewed home visits to 22 pediatric patients undergoing continuous cycling peritoneal dialysis (PD) at home. A trained dialysis nurse completed each home visit. An average of 1.5 pertinent dialysis findings and 1 pertinent medication finding was noted for each home visit to these patients. The interdisciplinary dialysis team reviewed the home visit findings and made specific recommendations after each home visit. In addition, the training process has been enhanced to incorporate visit findings for future home PD patients. Although not statistically significant in this small number of patients, peritonitis rates declined in the 6 months after initiation of the home visit program. The average cost for a dialysis nurse to complete a home visit is less than the cost of antibiotics for 1 episode of peritonitis. Home visits are valuable for improving clinical care in pediatric patients on home PD.

Factors related to long-term renal transplant function in children.

Short-term renal allograft survival in children has improved. It is therefore important to determine the factors leading to long-term graft function. To this end, we evaluated patients in the NAPTRCS registry who were <12 years old when they received their renal transplant between 1987 and 1993. Children with 10 years of post-transplant follow-up were compared to those in whom the transplant failed within 10 years. Children with a failed transplant within 10 years of the surgery tended to be older, female, and non-Caucasian; they also manifested obstructive uropathy less often and had focal segmental glomerulosclerosis more often, and they received more deceased donor kidneys. Children with a failed renal transplant had fewer HLA donor and recipient matches, received pre-transplant dialysis compared to a preemptive transplant, required dialysis in the first week post-transplant, and required more antihypertensives the first month post-transplant. Allograft function was examined at 10 years. Patients with continued allograft function and a serum creatinine

Hajdu-Cheney syndrome: report of a case.

Hajdu-Cheney syndrome is a rare disorder characterized by short stature, joint hypermobility, distinctive craniofacial and skull abnormalities, dental anomalies, and acroosteolysis of the distal phalanges. Cystic kidneys have been associated with some cases. We report a case of a 12-year-old girl with renal failure who underwent bilateral nephrectomies. Histopathological examination revealed polycystic kidneys with numerous nodules located throughout the kidney composed of basaloid epithelial cells.

Childhood hemolytic uremic syndrome is associated with adolescent-onset diabetes mellitus.

Extra-renal manifestations of the hemolytic uremic syndrome in children are well described. Pancreatic involvement may manifest as transient hyperglycemia and permanent diabetes mellitus. Two previous case reports demonstrate short periods of "remission" between initial hyperglycemia and the development of permanent diabetes mellitus. We report an unusual case of a two-year-old Caucasian boy whose HUS-associated hyperglycemia resolved shortly after the acute phase of his illness only to recur as permanent diabetes mellitus at puberty. To our knowledge no other case is reported that demonstrates such a long interval between initial presentation and the development of permanent diabetes mellitus.

Management of childhood hypertension: a guide for primary care physicians.

Prevalence of pediatric hypertension has increased with the onset of obesity epidemic. Early detection and treatment of childhood hypertension is important due to its link with atherosclerosis in adult life. Accurate measurement of blood pressure is the key for the management and physicians should make effort to rule out the possibility of anxiety associated and white coat hypertension before the final diagnosis of hypertension. Secondary hypertension is more common in children as compared to adults but essential hypertension is also common in older children and adolescents. The younger children with severe hypertension are more likely to have secondary hypertension. Non-pharmacologic treatment should be tried before instituting the pharmacologic treatment, unless patient is symptomatic and has severe hypertension.

Adequacy of peritoneal dialysis in children following cardiopulmonary bypass surgery.

Acute renal failure requiring renal replacement therapy can complicate cardiopulmonary bypass in children. Peritoneal dialysis has been shown to stabilize electrolytes and improve fluid status in these patients. To assess dialysis adequacy in this setting, we prospectively measured Kt/V and creatinine clearance in five patients (6-839 days of age) requiring renal replacement therapy at our institution. Median dialysis creatinine clearance was 74.25 L/week/1.73m(2) (range 28.28-96.63 L/week/1.73m(2)). Residual renal function provided additional solute clearance as total creatinine clearance was 215.97 L/week/1.73m(2) (range 108.04-323.25 L/week/1.73m(2)). Dialysis Kt/V of >2.1 (median 4.84 [range 2.12-5.59]) was achieved in all patients. No dialysis-associated complications were observed. We conclude that peritoneal dialysis is a safe, simple method of providing adequate clearance in children who develop acute renal failure following exposure to cardiopulmonary bypass.

Nontuberculous mycobacterial exit-site infection and abscess in a peritoneal dialysis patient. A case report and review of the literature.

Nontuberculous mycobacterial infections of peritoneal dialysis catheter exit sites have rarely been reported in patients on peritoneal dialysis. We report here a case of Mycobacterium abscessus exit site infection with abdominal wall abscess formation in an adolescent on peritoneal dialysis, which required long-term antibiotic therapy, peritoneal dialysis catheter removal, and surgical debridement of the abscess. Nontuberculous mycobacteria should be considered as a possible causative organism for an exit site infection that fails to respond to usual antibiotic therapy. Nontuberculous mycobacterial exit site infections may require peritoneal dialysis catheter removal and surgical debridement.

Diabetes mellitus and the kidney in adolescents.

Diabetic nephropathy continues to be a major complication of both types I and II diabetes; renal disease in the two types of diabetes exhibits no major differences with regard to initiation, progression, or treatment. The increasing prevalence of type II diabetes among adolescents means that understanding diabetic nephropathy and its prevention and treatment strategies is increasingly important for physicians caring for this population. The most important prevention and treatment modalities for diabetic nephropathy are improved glycemic control and aggressive blood pressure control, beginning as soon as possible after the diagnosis of diabetes.

Polyoma nephropathy and progressive multifocal leukoencephalopathy in a renal transplant recipient.

Progressive multifocal leukoencephalopathy is a progressive and ultimately fatal white-matter disease of the brain that is associated with polyomavirus infection. It is uncommon in the general population, and even in the immunosuppressed patient, who is inherently at greatest risk for active infection with the virus, it is rare. The causative agent in progressive multifocal leukoencephalopathy, JC virus, has become increasingly important in recent years as its role in nephropathy in the renal transplant recipient has become better understood. We present a young renal transplant patient who developed nephropathy with renal biopsy changes consistent with polyomavirus lesions and then developed mental status changes and was diagnosed with progressive multifocal leukoencephalopathy.

"Flush before fill" in children receiving automated peritoneal dialysis.

OBJECTIVE: To evaluate the impact of the "flush before fill" technique on the frequency of peritonitis in children receiving automated peritoneal dialysis (APD). DESIGN: Randomized prospective multicenter study. SETTING: Participating pediatric dialysis programs of the Pediatric Peritoneal Dialysis Study Consortium. PATIENTS: 121 pediatric (< 21 years of age) patients that had received peritoneal dialysis for > or = 2 months and that were currently receiving APD were randomized to use (flush group) or non-use (no flush group) of the "flush before fill" option. 66 patients were followed for > or = 12 months. MAIN OUTCOME MEASURE: Peritonitis rates. RESULTS: Overall, patients enrolled in the flush group experienced a peritonitis rate of 1 infection every 16.8 patient months; patients in the no flush group experienced a rate of 1 infection every 12.6 patient months (p = 0.193). However, analysis by gender revealed the peritonitis rate of females in the flush group (1 infection every 44.7 patient months) to be significantly better than females in the no flush group (1 infection every 12.4 patient months) (p < or = 0.01). There was no difference noted in the male patients. CONCLUSION: The use of the "flush before fill" option in pediatric patients receiving APD is associated with a marked improvement in the peritonitis rate of female but not male patients. Further study is indicated to explain the gender differences.