Survival advantage of pediatric recipients of a first kidney transplant among children awaiting kidney transplantation

Reduced ATG-F dosage for induction in pediatric renal transplantation: a single-center experience

Rabbit antithymocyte globulin (ATG-F) is an extensively used induction agent. To our knowledge, no study to date has assessed reduced ATG-F dosage in children undergoing renal transplantation. This was a retrospective analysis of pediatric renal recipients in the Department of Kidney Transplantation, The First Affiliated Hospital of Zhengzhou University, from May 2007 to February 2013. Thirty-nine children underwent renal transplantation including 25 living related and 14 cardiac deceased donor transplantation. Each recipient received ATG-F 1.5 mg/kg/d once daily for 4 days. Of the 39 recipients, five (12.8%) showed delayed graft function, including one of 25 recipients (4%) of living donor and four of 14 recipients (28.6%) of deceased donor transplantation (p < 0.05). Six of the 39 recipients (15.4%) showed acute rejection on renal biopsy. Follow-up in these children ranged from 6 to 87 months. The one-, three-, and five-yr recipients and grafts survival rates postoperation were each 94.9% and 97.3%, 97.3%, and 94.6%, respectively. The incidence of postoperative infection was 35.9% (14/39), and did not differ significantly in the living related and deceased donor groups (p > 0.05). Low-dose ATG-F can be safely used as an immune induction agent in pediatric renal transplantation.

National trends over 25 years in pediatric kidney transplant outcomes

OBJECTIVE

To investigate changes in pediatric kidney transplant outcomes over time and potential variations in these changes between the early and late posttransplant periods and across subgroups based on recipient, donor, and transplant characteristics.

METHODS

Using multiple logistic regression and multivariable Cox models, graft and patient outcomes were analyzed in 17,446 pediatric kidney-only transplants performed in the United States between 1987 and 2012.

RESULTS

Ten-year patient and graft survival rates were 90.5% and 60.2%, respectively, after transplantation in 2001, compared with 77.6% and 46.8% after transplantation in 1987. Primary nonfunction and delayed graft function occurred in 3.3% and 5.3%, respectively, of transplants performed in 2011, compared with 15.4% and 19.7% of those performed in 1987. Adjusted for recipient, donor, and transplant characteristics, these improvements corresponded to a 5% decreased hazard of graft loss, 5% decreased hazard of death, 10% decreased odds of primary nonfunction, and 5% decreased odds of delayed graft function with each more recent year of transplantation. Graft survival improvements were lower in adolescent and female recipients, those receiving pretransplant dialysis, and those with focal segmental glomerulosclerosis. Patient survival improvements were higher in those with elevated peak panel reactive antibody. Both patient and graft survival improvements were most pronounced in the first posttransplant year.

CONCLUSIONS

Outcomes after pediatric kidney transplantation have improved dramatically over time for all recipient subgroups, especially for highly sensitized recipients. Most improvement in graft and patient survival has come in the first year after transplantation, highlighting the need for continued progress in long-term outcomes.

Likelihood of children with end-stage kidney disease in Europe to live with a functioning kidney transplant is mainly explained by nonmedical factors

BACKGROUND

Registry data can be used to assess associations between medical and health-policy factors and the likelihood of children on renal replacement therapy (RRT) to live with a functioning kidney transplant in Europe.

METHODS

A survey questionnaire was distributed among renal registry representatives in 38 European countries, and additional data was obtained from the European Society for Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association (ESPN/ERA-EDTA) registry.

RESULTS

Thirty-two countries with a pediatric RRT program responded. The median percentage of children by country on RRT with a functioning transplant was 62 % (interquartile range 39-77). One per million population increase in donation rate from deceased donors was associated with a 5 % increase in the percentage of functioning transplants; the existence of an intermediate and high pediatric priority policy doubled and tripled this percentage, respectively, compared with no priority, whereas an increase in living donor pediatric kidney transplant rate of one per million children was associated with a 14 % higher percentage of functioning transplants. The percentage of functioning transplants was also strongly associated with the gross domestic product (GDP).

CONCLUSION

Considerable variations exist in the percentages of prevalent pediatric RRT populations with functioning renal transplants across Europe. A macroeconomic indicator such as GDP is the most important determinant of these international differences. Efforts should be made for living donation programs and pediatric allocation priority to increase access to kidney transplantation for children.

Mortality after pediatric kidney transplantation in England--a population-based cohort study

The aim of this study was to explore mortality after pediatric kidney transplantation in England over the last decade. We used data from HES to select all kidney transplant procedures performed in England between April 2001 and March 2012. Data linkage analysis was performed with the ONS to identify all deaths occurring among this study cohort. Data for 1189 pediatric recipients were compared to 17 914 adult recipients (number of deaths, 33 vs. 2052, respectively, p < 0.001), with median follow-up 4.4 yr (interquartile range 2.2-7.3 yr). There was no difference in mortality within the pediatric cohort; age 0-1 (n = 25, patient survival 100.0%), age 2-5 (n = 198, patient survival 96.0%), age 6-12 (n = 359, patient survival 97.5%), and age 13-18 (n = 607, patient survival 97.4%), respectively (p = 0.567). The most common causes of death were renal (n = 8, 24.2%), infection (n = 6, 18.2%), and malignancy (n = 5, 15.2%). All deaths from malignancy were secondary to PTLD. In a fully adjusted Cox regression model, only white ethnicity was significantly associated with risk of pediatric mortality post-kidney transplantation (hazard ratio 2.7, 95% confidence interval [1.0-7.3], p = 0.047). To conclude, this population-based cohort study confirms low mortality after pediatric kidney transplantation with short follow-up.

Order of donor type in pediatric kidney transplant recipients requiring retransplantation

BACKGROUND

Living-donor kidney transplantation (KT) is encouraged for children with end-stage renal disease due to superior long-term graft survival compared with deceased-donor KT. Despite this, there has been a steady decrease in the use of living-donor KT for pediatric recipients. Due to their young age at transplantation, most pediatric recipients eventually require retransplantation, and the optimal order of donor type is not clear.

METHODS

Using the Scientific Registry of Transplant Recipients, we analyzed first and second graft survival among 14,799 pediatric (<18 years old) recipients undergoing KT between 1987 and 2010.

RESULTS

Living-donor grafts had longer survival compared with deceased-donor grafts, similarly among both first (adjusted hazard ratio [aHR], 0.78; 95% confidence interval [CI], 0.73-0.84; P<0.001) and second (aHR, 0.74; 95% CI, 0.64-0.84; P<0.001) transplants. Living-donor second grafts had longer survival compared with deceased-donor second grafts, similarly after living-donor (aHR, 0.68; 95% CI, 0.56-0.83; P<0.001) and deceased-donor (aHR, 0.77; 95% CI, 0.63-0.95; P=0.02) first transplants. Cumulative graft life of two transplants was similar regardless of the order of deceased-donor and living-donor transplantation.

CONCLUSIONS

Deceased-donor KT in pediatric recipients followed by living-donor retransplantation does not negatively impact the living-donor graft survival advantage and provides similar cumulative graft life compared with living-donor KT followed by deceased-donor retransplantation. Clinical decision-making for pediatric patients with healthy, willing living donors should consider these findings in addition to the risk of sensitization, aging of the living donor, and deceased-donor waiting times.

Disparities in policies, practices and rates of pediatric kidney transplantation in Europe

We aimed to provide an overview of kidney allocation policies related to children and pediatric kidney transplantation (KTx) practices and rates in Europe, and to study factors associated with KTx rates. A survey was distributed among renal registry representatives in 38 European countries. Additional data were obtained from the ESPN/ERA-EDTA and ERA-EDTA registries. Thirty-two countries (84%) responded. The median incidence rate of pediatric KTx was 5.7 (range 0-13.5) per million children (pmc). A median proportion of 17% (interquartile range 2-29) of KTx was performed preemptively, while the median proportion of living donor KTx was 43% (interquartile range 10-52). The median percentage of children on renal replacement therapy (RRT) with a functioning graft was 62%. The level of pediatric prioritization was associated with a decreased waiting time for deceased donor KTx, an increased pediatric KTx rate, and a lower proportion of living donor KTx. The rates of pediatric KTx, distribution of donor source and time on waiting list vary considerably between European countries. The lack of harmonization in kidney allocation to children raises medical and ethical issues. Harmonization of pediatric allocation policies should be prioritized.

Kidney transplantation in children weighing less than 15 kg: extraperitoneal surgical access-experience with 62 cases

Small children are a challenging group in whom to perform KT. This retrospective study analyzed the results of 62 KTs in children weighing <15 kg, performed between 1998 and 2010, using extraperitoneal access and anastomosis of the renal vessels of donors to the aorta and IVC or iliac vessels of the recipients. Thirty-two (51.6%) grafts were LRDTs and 30 (48.4%) were DDRTs-28 of them pediatric. The mean age at KT was 3.7 ± 2.2 yr (1-12), and the mean weight was 12.3 ± 2.1 kg (5.6-14.9). Ten children weighed <10 kg, and five (8.1%) children presented previous thrombosis of the venous system. At one and five yr, patient survival was 93.2% and 84.2%, and graft survival was 85.2% and 72.7%. There were no differences between the rates for LRDT and DDRT. There were six vascular complications (four vascular thromboses, one laceration, and one renal artery stenosis) and two perirenal collections. Extraperitoneal access is a valid KT technique in children weighing <15 kg.

Living unrelated renal transplantation: a good match for the pediatric candidate?

BACKGROUND/PURPOSE

Living donor kidney transplantation is encouraged for children with end-stage renal disease given the superior survival of living donor grafts, but pediatric candidates are also given preference for kidneys from younger deceased donors.

METHODS

Death-censored graft survival of pediatric kidney-only transplants performed in the U.S. between 1987-2012 was compared across living related (LRRT) (n=7741), living unrelated (LURT) (n=618), and deceased donor renal transplants (DDRT) (n=8945) using Kaplan-Meier analysis, multivariable Cox proportional hazards models, and matched controls analysis.

RESULTS

As expected, HLA mismatch was greater among LURT compared to LRRT (p<0.001). Unadjusted graft survival was lower, particularly long-term, for LURT compared to LRRT (p=0.009). However, LURT graft survival was still superior to DDRT graft survival, even when compared only to deceased donors under age 35 (p=0.002). The difference in graft survival between LURT and LRRT was not seen when adjusting for HLA mismatch, year of transplantation, and donor and recipient characteristics using a Cox model (aHR=1.04, 95% CI: 0.87-1.24, p=0.7) or matched controls (HR=1.02, 95% CI: 0.82-1.27, p=0.9).

CONCLUSION

Survival of LURT grafts is superior to grafts from younger deceased donors and equivalent to LRRT grafts when adjusting for other factors, most notably differences in HLA mismatch.

Long-term critical issues in pediatric renal transplant recipients: a single-center experience

Data on long-term outcomes after pediatric renal transplantation (Tx) are still limited. We report on a 20-year single-center experience. Medical charts of all consecutive pediatric Tx performed between 1987 and 2007 were reviewed. Data of patients who had been transferred to adult units were extracted from the French databases of renal replacement therapies. Outcomes were assessed using Kaplan-Meier and Cox models. Two hundred forty Tx were performed in 219 children (24.1% pre-emptive and 17.5% living related donor Tx). Median age at Tx was 11.1 years and median follow-up was 10.4 years. Patient survival was 94%, 92%, and 91% at 5, 10, and 15 years post-Tx, respectively. Overall, transplant survival was 92%, 82%, 72%, and 59% at 1, 5, 10, and 15 years post-Tx, respectively. The expected death-censored graft half-life was 20 years. Sixteen patients developed malignancies during follow-up. Median height at 18 years of age was 166 cm in boys and 152 cm in girls with 68% of patients being in the normal range. The proportion of socially disadvantaged young people was higher than in general population. Excellent long-term outcomes can be achieved in pediatric renal Tx, but specific problems such as malignancies, growth, and social outcome remain challenging.

Long-term outcome of deceased donor renal transplantation in pediatric recipients: a single-center experience from a developing country

RTx is best treatment for children with ESRD. Data scarcity on DDRTx outcome in children prompted us to review our experience. This study was undertaken to evaluate patient/graft survival, function vis-a-vis SCr, rejection episodes, and mortality in DDRTx performed in 37 children between 1998 and 2011. The most common recipient diseases leading to ESRD were congenital anomalies of kidney and urinary tract (48.6%) and chronic glomerulonephritis (18.9%). Mean recipient age was 13.8 ± 3.1 yr; 67.5% (n = 25) were men. Mean donor age was 38.8 ± 18.6 yr; 48.5% (n = 18) were men. Mean dialysis duration pre-transplantation was 15.5 ± 3.5 months. All recipients received r-ATG, and triple immunosuppression. Over a mean follow-up of 3.93 ± 3.5 yr, patient and graft survival rates were 72.9% (n = 27) and 83.7% (n = 31), respectively, with a mean SCr of 1.1 mg/dL; 21.6% (n = 8) of patients had acute rejection episodes; 24.3% (n = 9) of patients had DGF. A total of 27% (n = 10) patients died, mainly owing to infections (n = 6) and cardiovascular disease (n = 3). DDRTx is a viable option for children and achieves acceptable graft function with patient/graft survival over long-term follow-up, encouraging use of this approach.

Epidemiology of chronic kidney disease in children

In the past 30 years there have been major improvements in the care of children with chronic kidney disease (CKD). However, most of the available epidemiological data stem from end-stage renal disease (ESRD) registries and information on the earlier stages of pediatric CKD is still limited. The median reported incidence of renal replacement therapy (RRT) in children aged 0-19 years across the world in 2008 was 9 (range: 4-18) [corrected] per million of the age-related population). [corrected] The prevalence of RRT in 2008 ranged from 18 to 100 per million of the age-related population. Congenital disorders, including congenital anomalies of the kidney and urinary tract (CAKUT) and hereditary nephropathies, are responsible for about two thirds of all cases of CKD in developed countries, while acquired causes predominate in developing countries. Children with congenital disorders experience a slower progression of CKD than those with glomerulonephritis, resulting in a lower proportion of CAKUT in the ESRD population compared with less advanced stages of CKD. Most children with ESRD start on dialysis and then receive a transplant. While the survival rate of children with ERSD has improved, it remains about 30 times lower than that of healthy peers. Children now mainly die of cardiovascular causes and infection rather than from renal failure.

[Kidney transplantation in childhood: from milimeter to centimeters]

Graft survival is worse in recipient aged less than 5 years due to the greater risk of vascular thrombosis. Thrombosis may be prevented by the choice of the donor, method of surgery, perioperative hemodynamic optimisation and preventive anti-coagulation. Normal growth is a major objective of the management of transplanted children. The mean final height increased during the 20 last years to be between -1.63 and -0.92 SDS depending on age and period of the transplantation.

Change in mortality risk over time in young kidney transplant recipients

Mortality risk for kidney transplant recipients may change with increasing accumulated exposure to the "transplantation milieu." We sought to characterize changes over time in mortality rate and in age-, sex- and race-standardized mortality ratios (SMR) relative to the general population, and to estimate the association between increasing time since first transplant and mortality risk. A total of 18 911 patients who received a first transplant at <21 years old (1983-2006), and whose data were recorded in the USRDS, were studied. There were 2713 deaths over a median follow-up of 8.9 (interquartile range 4.0-14.5; maximum 23) years. Among those with graft function, mortality was highest in the first post transplant year; beyond the first year of the first transplant, age-adjusted mortality rates and SMRs decreased slightly over follow-up. Cause of death was cardiovascular for 34.6%, infection for 19.5%, malignancy for 5.8%, other for 21.4% and unknown for 18.7%. For every 1-year time increment after the end of the first post transplant year, age-adjusted all-cause and cardiovascular mortality rates fell by 1% (p = 0.06) and 16% (p = 0.007), respectively; infection-related mortality rate did not change over time (p = 0.5). These results suggest that exposure to the transplantation milieu has no cumulative negative effects on cardiovascular health over the long term.

Late graft loss among pediatric recipients of DCD kidneys

BACKGROUND AND OBJECTIVES

Kidney transplantation from donors after cardiac death (DCD) provides similar graft survival to donors after brain death (DBD) in adult recipients. However, outcomes of DCD kidneys in pediatric recipients remain unclear, primarily because of limited sample sizes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We identified 137 pediatric (<18 years old) recipients of DCD kidneys between 1994 and 2010 using Scientific Registry of Transplant Recipients data and compared outcomes with 6059 pediatric recipients of DBD kidneys during the same time period, accounting for donor, recipient, and transplant characteristics using time-varying Cox regression and matched controls. Long-term follow-up (4 years or beyond) was available for 31 DCD recipients.

RESULTS

Pediatric recipients of DCD kidneys experienced a significantly higher rate of delayed graft function (22.0% versus 12.3%; P = 0.001), although lower than reported delayed graft function rates of DCD grafts in adults. Although DCD and DBD graft survival was equal in the early postoperative period, graft loss among pediatric recipients of DCD kidneys exceeded their DBD counterparts starting 4 years after transplantation. This effect was statistically significant in a multivariate Cox model (hazard ratio = 2.03; 95% confidence interval, 1.21 to 3.39; P = 0.007) and matched-controls analysis (hazard ratio = 2.36; 95% confidence interval, 1.11 to 5.03; P = 0.03).

CONCLUSIONS

A significant increase in DCD graft loss starting 4 years after transplantation motivates a cautious approach to the use of DCD kidneys in children, in whom long-term graft survival is of utmost importance.

The effect of timing of the first kidney transplantation on survival in children initiating renal replacement therapy

BACKGROUND

Controversy exists concerning the timing of the first kidney transplantation for children who need to start renal replacement therapy (RRT). Our aim was to estimate the effect of timing of the first transplantation on patient survival in children, for the first time also taking into account the mortality on dialysis before transplantation.

METHODS

We included 2091 patients who started RRT between the age of 3 and 18 years in the period 1988-2007, from 13 European renal registries. A multistate model was used to simulate patient survival assuming (i) pre-emptive transplantation, (ii) transplantation after 1 or 2 years on dialysis and (iii) remaining on dialysis.

RESULTS

Over the 20-year period, the highest 8-year survival probabilities were achieved in children transplanted pre-emptively {living donor (LD): 95.9% [95% confidence interval (CI): 93.1-98.8], deceased donor (DD): 95.3% (95% CI: 90.9-99.9)} rather than after 2 years of dialysis [LD: 94.2% (95% CI: 91.6-96.8), DD: 93.4% (95% CI: 91.0-95.9)], although these differences were not statistically significant.

CONCLUSIONS

Even after taking mortality on dialysis into account, the potentially negative effect of postponing transplantation for 1 or 2 years was relatively small and not statistically significant. Therefore, if pre-emptive transplantation is not possible, starting RRT with a short period of dialysis and receiving a transplant thereafter seems an acceptable alternative from the perspective of patient survival.

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.

Media appeals by pediatric patients for living donors and the impact on a transplant center

Little is published regarding the effect of advertising for kidney donors on transplant centers. At our center, families of nine children used media appeals. Per candidate, there were 8 to 260 potential donor calls, 92 (11.6%) were medically ineligible, 326 (41.1%) voluntarily did not proceed or an alternate donor had been approved, 38 (4.8%) were ABO incompatible, and 327 (41.1%) had positive crossmatch or unsuitable human leukocyte antigens. Media appeals resulted in four living donor transplants and five nondirected donors to other candidates, and we made directed changes in our center. The ethical debate of advertising for organ donors continues.

Good outcome of kidney transplants in recipients of young donors: a NAPRTCS data analysis

NAPRTCS data were analyzed to assess outcome of TX recipients from YDs (<5 yr) in comparison with IDs (6-35 yr) and ODs (36-55 yr). Of 9854 TX in NAPRTCS (1987-2003), 469 were YD. Patient survival (PS) and graft survival (GS) were compared between DD TX after 1995; 81YD, 1324 ID, and 429 OD and eGFR were compared among functioning grafts (YD 31, ID 439, OD 174) at three yr. PS was comparable in all groups; GS at one, two, and three yr in TX of YD (91.1%, 83.8%, 79.7%), ID (93.5%, 89.7%, 83.6%), and OD (92.2%, 87.2%, 82.4%) was comparable. The eGFR in YD was comparable to ID but better than OD (86.5 vs. 79.7 vs. 67.2 mL/min/1.73 m2, p 0.139 and<0.0003). Primary graft non-function was more frequent in TX from YD than ID and OD (3.7% vs. 0.3 and 0.7%, p=0.004); the incidence of vascular thrombosis was similar. The aforementioned data show that pediatric recipients of YD had equivalent patient and graft survival. Although primary graft non-function was higher, eGFR of functioning grafts was comparable to ID. With further improvements in care, kidneys from YD may present a viable option for transplantation.

Kidneys from donors after cardiac death provide survival benefit

The continuing shortage of kidneys for transplantation requires major efforts to expand the donor pool. Donation after cardiac death (DCD) increases the number of available kidneys, but it is unknown whether patients who receive a DCD kidney live longer than patients who remain on dialysis and wait for a conventional kidney from a brain-dead donor (DBD). This observational cohort study included all 2575 patients who were registered on the Dutch waiting list for a first kidney transplant between January 1, 1999, and December 31, 2004. From listing until the earliest of death, living-donor kidney transplantation, or December 31, 2005, 459 patients received a DCD transplant and 680 patients received a DBD transplant. Graft failure during the first 3 months after transplantation was twice as likely for DCD kidneys than DBD kidneys (12 versus 6.3%; P=0.001). Standard-criteria DCD transplantation associated with a 56% reduced risk for mortality (hazard ratio 0.44; 95% confidence interval 0.24 to 0.80) compared with continuing on dialysis and awaiting a standard-criteria DBD kidney. This reduction in mortality translates into 2.4-month additional expected lifetime during the first 4 years after transplantation for recipients of DCD kidneys compared with patients who await a DBD kidney. In summary, standard-criteria DCD kidney transplantation associates with increased survival of patients who have ESRD and are on the transplant waiting list.

Meta-analysis of medical regimen adherence outcomes in pediatric solid organ transplantation

BACKGROUND

Adherence to the medical regimen after pediatric organ transplantation is important for maximizing good clinical outcomes. However, the literature provides inconsistent evidence regarding prevalence and risk factors for nonadherence posttransplant.

METHODS

A total of 61 studies (30 kidney, 18 liver, 8 heart, 2 lung/heart-lung, and 3 with mixed recipient samples) were included in a meta-analysis. Average rates of nonadherence to six areas of the regimen, and correlations of potential risk factors with nonadherence, were calculated.

RESULTS

Across all types of transplantation, nonadherence to clinic appointments and tests was most prevalent, at 12.9 cases per 100 patients per year (PPY). The immunosuppression nonadherence rate was six cases per 100 PPY. Nonadherence to substance use restrictions, diet, exercise, and other healthcare requirements ranged from 0.6 to 8 cases per 100 PPY. Only the rate of nonadherence to clinic appointments and tests varied by transplant type: heart recipients had the lowest rate (4.6 cases per 100 PPY vs. 12.7-18.8 cases per 100 PPY in other recipients). Older age of the child, family functioning (greater parental distress and lower family cohesion), and the child's psychological status (poorer behavioral functioning and greater distress) were among the psychosocial characteristics significantly correlated with poorer adherence. These correlations were small to modest in size (r=0.12-0.18).

CONCLUSIONS

These nonadherence rates provide benchmarks for clinicians to use to estimate patient risk. The identified psychosocial correlates of nonadherence are potential targets for intervention. Future studies should focus on improving the prediction of nonadherence risk and on testing interventions to reduce risk.

Chronic kidney disease in children: the global perspective

In contrast to the increasing availability of information pertaining to the care of children with chronic kidney disease (CKD) from large-scale observational and interventional studies, epidemiological information on the incidence and prevalence of pediatric CKD is currently limited, imprecise, and flawed by methodological differences between the various data sources. There are distinct geographic differences in the reported causes of CKD in children, in part due to environmental, racial, genetic, and cultural (consanguinity) differences. However, a substantial percentage of children develop CKD early in life, with congenital renal disorders such as obstructive uropathy and aplasia/hypoplasia/dysplasia being responsible for almost one half of all cases. The most favored end-stage renal disease (ESRD) treatment modality in children is renal transplantation, but a lack of health care resources and high patient mortality in the developing world limits the global provision of renal replacement therapy (RRT) and influences patient prevalence. Additional efforts to define the epidemiology of pediatric CKD worldwide are necessary if a better understanding of the full extent of the problem, areas for study, and the potential impact of intervention is desired.