Growth after renal transplantation

Pediatric Kidney Transplantation in an Under-resourced Country: A Single-Center Experience

OBJECTIVES

Kidney transplant is the optimal method for managing children with end-stage kidney disease. This study aimed to present the experience and results of the pediatric kidney transplant program at our center.

MATERIALS AND METHODS

A single-center observational study was conducted at Children's University Hospital in Damascus, Syria. We reviewed the medical records of all kidney transplants performed between April 2018 and December 2022. All patients were under 14 years old when they underwent kidney transplant. All donors were living, as an effective deceased donor program is currently not an option in Syria.

RESULTS

From April 2018 to December 2022, 33 pediatric kidney transplants were performed at our center. Most recipients were boys (n = 24; 72.7%), and 9 were girls (27.3%). Median age was 10 years (range, 4.5-14 y). The most frequent underlying diseases for kidney failure were renal dysplasia-hypoplasia (42.5%), reflux nephropathy (18.2%), and neurogenic bladder with posterior urethral valves (12%). In 10 patients, kidney transplant was performed preemptively (30.3%). Initial graft function was observed in all grafts (100%). During observation time (5 years), 28 patients (85%) retained adequate graft function. The 1-year graft and patient survival rates were 91%.

CONCLUSIONS

Syria is still suffering from the consequences of the war, affecting organ transplantation in many ways. The good 1-year graft and patient survival in our center was encouraging. However, we admit that the number of patients was small and the follow-up duration was also not long enough; future research is needed to improve long-term outcomes.

Growth in Children After a Kidney Transplant: A Retrospective, Observational Single-Center Study

BACKGROUND

Kidney transplantation (KTX) is the best treatment for children with end-stage kidney disease (ESKD). It greatly improves their quality of life. Children's growth is one of the chronic issues that is known to be compromised during ESKD; therefore, catch-up growth is usually expected to be seen after KTX.

OBJECTIVES

We aimed to evaluate children's catchup growth after KTX and assess the impact of children's age at the time of KTX on catchup growth.

PATIENTS AND METHODS

We performed a retrospective analysis of weight and height data for children pre-KTX, at 12 months, and 24 months post KTX. We stratified them into five percentile categories for weight and height and counted the number of KTX patients in each category at the same three time points. We also stratified them into three different age groups: two to five, six to 10, and 11 to 12 years, and estimated the mean and standard deviation of both weight and height of each one.

RESULTS

Between 2009 and 2019, we identified 37 children who underwent KTX. The mean weight pre-KTX was 21 kg. It increased to 28 and 34 kg post KTX at 12 and 24 months, respectively. The mean height pre-KTX was 115 cm. It increased to 126 and 134 cm post KTX at 12 and 24 months, respectively. There was a significant crossing of both weight and height percentiles when we stratified them based on different initial percentiles. There was a significant change in both weight and height when we stratified them into three age groups: two to five, six to 10, and 11 to 14 years.

CONCLUSION

The growth patterns of children after a KTX can vary among children. However, our retrospective observational study showed positive results, suggesting gradual improvement in weight and height gain post KTX. Factors such as age at the time of KTX, duration of kidney disease, medication regimens, and overall health status can influence a child's growth trajectory. Close monitoring, proper nutrition, and a multidisciplinary approach are essential in supporting a child's growth after a KTX. Our findings are limited by the small sample size and retrospective design, therefore a well-structured prospective study with a large sample size is required.

Growth after pediatric kidney transplantation: a 25-year study in a pediatric kidney transplant center

OBJECTIVES

Growth failure is one of the major complications of pediatric chronic kidney disease. Even after a kidney transplant (KT), up to 50 % of patients fail to achieve the expected final height. This study aimed to assess longitudinal growth after KT and identify factors influencing it.

METHODS

A retrospective observational study was performed. We reviewed the clinical records of all patients who underwent KT for 25 years in a single center (n=149) and performed telephone interviews. Height-for-age and body mass index (BMI)-for-age were examined at KT, 3 months, 6 months, 1 year, and 5 years post-transplant and at the transition to adult care. We evaluated target height, disease duration before KT, need and type of dialysis, recombinant human growth hormone pretransplant use, nutritional support, glomerular filtration rate (GFR), and cumulative corticosteroid dose.

RESULTS

At transplant, the average height z-score was -1.38, and height z-scores showed catch-up growth at 6 months (z-score -1.26, p=0.006), 1 year (z-score -1.15, p<0.001), 5 years after KT (z-score -1.08, p<0.001), and on transition to adult care (z-score -1.22, p=0.012). Regarding BMI z-scores, a significant increase was also detected at all time points (p<0.001). After KT, GFR was significantly associated with height z-score (p=0.006) and BMI z-score (p=0.006). The height in transition to adult care was -1.28 SD compared to the target height.

CONCLUSIONS

Despite the encouraging results regarding catch-up growth after KT in this cohort, results remain far from optimum, with a lower-than-expected height at the time of transition.

Time from kidney failure onset to transplantation and its impact on growth in pediatric patients

BACKGROUND

In children with kidney failure, the longer the duration of dialysis the greater the impact on growth deficit, quality of life, and life expectancy. The aim of this research is to test whether there was a shortening of treatment time from kidney failure to transplantation in pediatric patients and whether this time interval impacted height.

METHODS

Observational retrospective cohort study from 2005 to 2018. The first outcome variable was time to transplantation in years, while the second was height/age standard deviation score (SDS) at transplantation. Cox regression models were used to analyze time from disease to transplantation and linear regression was employed to test the association of the year of kidney failure onset with height.

RESULTS

A total of 780 children were evaluated and 517 underwent kidney transplantation after a median time of 1.9 years (IQR = 1.0-4.0). The variables significantly associated with time to transplant were: year of kidney failure onset (HR = 1.07; 95% CI: 1.05-1.10; p < .001), age at kidney failure onset <12 years (HR = 0.59; 95% CI: 0.49-0.71; p < .001), living in different state as transplant center (HR = 0.63; 95% CI: 0.53-0.77; p < .001), and undergoing blood transfusion before transplantation (HR = 0.63; 95% CI: 0.53-0.75; p < .001). Regarding growth, for each 1-year increase in the epoch of kidney failure onset, a 0.05 SDS raise in height/age is expected (p < .001).

CONCLUSION

Children with recent kidney failure onset had significantly lower time to the outcome and this reduction was associated with a less severe growth deficit.

Children Are Not Small Adults: Similarities and Differences in Renal Transplantation Between Adults and Pediatrics

Kidney transplantation is the treatment of choice for all patients with end-stage kidney disease, including pediatric patients. Graft survival in pediatrics was lagging behind adults, but now is comparable with the adult cohort. Although many of the protocols have been adopted from adults, there are issues unique to pediatrics that one should be aware of to take care of this population. These issues include recipient size consideration, increased incidence of viral infections, problems related to growth, common occurrence of underlying urological issues, and psychosocial issues. This article addresses the similarities and differences in renal transplantation, from preparing a patient for transplant, the transplant process, to post-transplant complications.

Get to the heart of pediatric kidney transplant recipients: Evaluation of left- and right ventricular mechanics by three-dimensional echocardiography

Background

Kidney transplantation (KTX) markedly improves prognosis in pediatric patients with end-stage kidney failure. Still, these patients have an increased risk of developing cardiovascular disease due to multiple risk factors. Three-dimensional (3D) echocardiography allows detailed assessment of the heart and may unveil distinct functional and morphological changes in this patient population that would be undetectable by conventional methods. Accordingly, our aim was to examine left- (LV) and right ventricular (RV) morphology and mechanics in pediatric KTX patients using 3D echocardiography.

Materials and methods

Pediatric KTX recipients (n = 74) with median age 20 (14–26) years at study enrollment (43% female), were compared to 74 age and gender-matched controls. Detailed patient history was obtained. After conventional echocardiographic protocol, 3D loops were acquired and measured using commercially available software and the ReVISION Method. We measured LV and RV end-diastolic volumes indexed to body surface area (EDVi), ejection fraction (EF), and 3D LV and RV global longitudinal (GLS) and circumferential strains (GCS).

Results

Both LVEDVi (67 ± 17 vs. 61 ± 9 ml/m2; p &lt; 0.01) and RVEDVi (68 ± 18 vs. 61 ± 11 ml/m2; p &lt; 0.01) were significantly higher in KTX patients. LVEF was comparable between the two groups (60 ± 6 vs. 61 ± 4%; p = NS), however, LVGLS was significantly lower (−20.5 ± 3.0 vs. −22.0 ± 1.7%; p &lt; 0.001), while LVGCS did not differ (−29.7 ± 4.3 vs. −28.6 ± 10.0%; p = NS). RVEF (59 ± 6 vs. 61 ± 4%; p &lt; 0.05) and RVGLS (−22.8 ± 3.7 vs. −24.1 ± 3.3%; p &lt; 0.05) were significantly lower, however, RVGCS was comparable between the two groups (−23.7 ± 4.5 vs. −24.8 ± 4.4%; p = NS). In patients requiring dialysis prior to KTX (n = 64, 86%) RVGCS showed correlation with the length of dialysis (r = 0.32, p &lt; 0.05).

Conclusion

Pediatric KTX patients demonstrate changes in both LV and RV morphology and mechanics. Moreover, the length of dialysis correlated with the contraction pattern of the right ventricle.

Evaluation of height centile growth patterns compared with parental-adjusted target height following kidney transplantation

BACKGROUND

Early steroid withdrawal (ESW) improves growth following kidney transplant (KT). It is not known whether these children achieve target height within mid-parental height range post-KT.

METHODS

Retrospective analysis of growth patterns of KT recipients following ESW in our center between 2009 and 2020 had minimum follow-up period of 12 months.

RESULTS

Forty-eight (female 29.2%) KT recipients, median age 5.3 years at first KT, were included. At KT, 29 (60.4%) recipients had normal height (SDS≥-1.88) and in 23 (47.9%), the height was within their target height (parental-adjusted height SDS within ±1.55). The proportion of children achieving normal height at 1-, 2-, 3-, and 5-years post-KT (median 5.5 years) were 75%, 83.3%, 86.5%, and 88% respectively. The proportion of children achieving target height measured at the same intervals was 68.8%, 73.8%, 73%, and 80%, respectively. Children <6 years were most growth impaired at KT but were most likely to achieve target height within first-year post-KT (72%; p = .023). All 19 children with short stature at KT received dialysis. Three children received growth hormone post-KT. Children who did not achieve target height post-KT (n = 14), five had eGFR <60 mL/min/1.73 m² , and eight were on corticosteroid therapy at latest follow-up.

CONCLUSIONS

Although vast majority of children achieved normal height post-KT following ESW during the first 5 years post-KT, 20% of these children had not achieved their target height post-KT.

Preliminary Evaluation of Sedentary Lifestyle in Italian Children after Solid Transplant: What Role Could Physical Activity Play in Health? It Is Time to Move

BACKGROUND

Advances in the medical-surgical field have significantly increased survival after solid organ transplantation in the pediatric population. However, these patients are predisposed to the development of long-term complications (e.g., cardiovascular disease). The therapeutic role of physical activity (PA) to counteract these complications is well known. The purpose of the study was to investigate the level of PA in a pediatric population after solid organ transplantation.

METHODS

In the first 4 weeks at the beginning of the school year, the Physical Activity Questionnaire for Older Children and Adolescents was administered to young patients who had previously undergone solid transplants at our institute.

RESULTS

Questionnaires of 49 patients (57.1% female, mean age 13.2 ± 3.5 years) were analyzed and 32.7% of subjects did not perform any exercise during school physical education classes. Only 24% practiced a moderate quantity of exercise in the previous week (2-3 times/week) and 72% engaged in sedentary behaviors during weekends.

CONCLUSIONS

Preliminary data confirmed that young recipients are still far from meeting the minimum indications of the World Health Organization on PA and sedentary behavior. It will be necessary to increase their involvement in PA programs in order not only to increase their life expectancy but also to improve their quality of life.

Early corticosteroid withdrawal is associated with improved adult height in pediatric kidney transplant recipients

BACKGROUND

Catch-up growth after pediatric kidney transplantation (kTx) is usually insufficient to reach normal adult height. We aimed to analyze the effect of pre-transplant recombinant human growth hormone (rhGH) and corticosteroid withdrawal on linear growth in the first year after kidney transplantation and identify factors associated with final height (FH).

METHODS

Patients who underwent kTx between 1996 and 2018 at below 18 years old in five Belgian and Dutch centers were included. We analyzed the differences between height Z-scores at kTx and 1 year post-transplant (Δ height Z-score) in children with and without corticosteroids at 1 year (CS + /CS -) and with and without rhGH treatment before kTx (rhGH + /rhGH -). Univariable and multivariable linear regression analysis was applied to identify factors associated with height Z-score at 1 year post-kTx, Δ height Z-score, and FH Z-score.

RESULTS

A total of 177 patients were included, with median age 9.3 years at kTx. Median height Z-scores pre-kTx and 1 year later in the CS - /rhGH - , CS + /rhGH - , CS - /rhGH + , and CS + /rhGH + groups were - 1.42/ - 0.80, - 0.90/ - 0.62, - 1.35/ - 1.20, and - 1.30/ - 1.60 (p = 0.001). CS use 1 year post-kTx was the only factor associated with Δ height (p = 0.003) on multivariable analysis. CS use at 1 year was the only variable associated with FH (p = 0.014) in children with pre-transplant height Z-score below - 1 (n = 52).

CONCLUSIONS

Increase in height Z-score in the first year post-kTx was highest in the CS - /rhGH - group and lowest in the CS + /rhGH + group. The use of corticosteroids at 1 year post-kTx is associated with catch-up growth and in children with pre-transplant height Z-score below - 1 also with final height. A higher resolution version of the Graphical abstract is available as Supplementary information.

Treatment optimization of maintenance immunosuppressive agents in pediatric renal transplant recipients

Introduction: Graft survival in pediatric kidney transplant patients has increased significantly within the last three decades, correlating with the discovery and utilization of new immunosuppressants as well as improvements in patient care. Despite these developments in graft survival for patients, there is still improvement needed, particularly in long-term care in pediatric patients receiving grafts from deceased donor patients. Maintenance immunosuppressive therapies have narrow therapeutic indices and are associated with high inter-individual and intra-individual variability.Areas covered: In this review, we examine the impact of pharmacokinetic variability on renal transplantation and its association with age, genetic polymorphisms, drug-drug interactions, drug-disease interactions, renal insufficiency, route of administration, and branded versus generic drug formulation. Pharmacodynamics are outlined in terms of the mechanism of action for each immunosuppressant, potential adverse effects, and the utility of pharmacodynamic biomarkers.Expert opinion: Acquiring abetter quantitative understanding of immunosuppressant pharmacokinetics and pharmacodynamic components should help clinicians implement treatment regimens to maintain the balance between therapeutic efficacy and drug-related toxicity.

Bone evaluation in paediatric chronic kidney disease: clinical practice points from the European Society for Paediatric Nephrology CKD-MBD and Dialysis working groups and CKD-MBD working group of the ERA-EDTA

Mineral and bone disorder (MBD) is widely prevalent in children with chronic kidney disease (CKD) and is associated with significant morbidity. CKD may cause disturbances in bone remodelling/modelling, which are more pronounced in the growing skeleton, manifesting as short stature, bone pain and deformities, fractures, slipped epiphyses and ectopic calcifications. Although assessment of bone health is a key element in the clinical care of children with CKD, it remains a major challenge for physicians. On the one hand, bone biopsy with histomorphometry is the gold standard for assessing bone health, but it is expensive, invasive and requires expertise in the interpretation of bone histology. On the other hand, currently available non-invasive measures, including dual-energy X-ray absorptiometry and biomarkers of bone formation/resorption, are affected by growth and pubertal status and have limited sensitivity and specificity in predicting changes in bone turnover and mineralization. In the absence of high-quality evidence, there are wide variations in clinical practice in the diagnosis and management of CKD-MBD in childhood. We present clinical practice points (CPPs) on the assessment of bone disease in children with CKD Stages 2-5 and on dialysis based on the best available evidence and consensus of experts from the CKD-MBD and Dialysis working groups of the European Society for Paediatric Nephrology and the CKD-MBD working group of the European Renal Association-European Dialysis and Transplant Association. These CPPs should be carefully considered by treating physicians and adapted to individual patients' needs as appropriate. Further areas for research are suggested.

Care of Pediatric Solid Organ Transplant Recipients: An Overview for Primary Care Providers

As the number of living pediatric solid organ transplant (SOT) recipients continues to grow, there is an increased likelihood that primary care providers (PCPs) will encounter pediatric SOT recipients in their practices. In addition, as end-stage organ failure is replaced with chronic medical conditions in transplant recipients, there is a need for a comprehensive approach to their management. PCPs can significantly enhance the care of immunosuppressed hosts by advising parents of safety considerations and avoiding adverse drug interactions. Together with subspecialty providers, PCPs are responsible for ensuring that appropriate vaccinations are given and can play an important role in the diagnosis of infections. Through early recognition of rejection and posttransplant complications, PCPs can minimize morbidity. Growth and development can be optimized through frequent assessments and timely referrals. Adherence to immunosuppressive regimens can be greatly improved through reinforcement at every encounter, particularly among adolescents. PCPs can also improve long-term outcomes by easing the transition of pediatric SOT recipients to adult providers. Although guidelines exist for the primary care management of adult SOT recipients, comprehensive guidance is lacking for pediatric providers. In this evidence-based overview, we outline the main issues affecting pediatric SOT recipients and provide guidance for PCPs regarding their management from the first encounter after the transplant to the main challenges that arise in childhood and adolescence. Overall, PCPs can and should use their expertise and serve as an additional layer of support in conjunction with the transplant center for families that are caring for a pediatric SOT recipient.

Growth Patterns After Kidney Transplantation in European Children Over the Past 25 Years: An ESPN/ERA-EDTA Registry Study

BACKGROUND

Improved management of growth impairment might have resulted in less growth retardation after pediatric kidney transplantation (KT) over time. We aimed to analyze recent longitudinal growth data after KT in comparison to previous eras, its determinants, and the association with transplant outcome in a large cohort of transplanted children using data from the European Society for Paediatric Nephrology/European Renal Association and European Dialysis and Transplant Association Registry.

METHODS

A total of 3492 patients transplanted before 18 years from 1990 to 2012 were included. Height SD scores (SDS) were calculated using recent national or European growth charts. We used generalized equation models to estimate the prevalence of growth deficit and linear mixed models to calculate adjusted mean height SDS.

RESULTS

Mean adjusted height post-KT was -1.77 SDS. Height SDS was within normal range in 55%, whereas 28% showed moderate, and 17% severe growth deficit. Girls were significantly shorter than boys, but catch-up growth by 5 years post-KT was observed in both boys and girls. Children <6 years were shortest at KT and showed the greatest increase in height, whereas there was no catch-up growth in children transplanted >12.

CONCLUSIONS

Catch-up growth post-KT remains limited, height SDS did not improve over time, resulting in short stature in nearly half of transplanted children in Europe.

Liver Transplant for Posthepatectomy Liver Failure in Hepatoblastoma

OBJECTIVES

Predicting the risk of posthepatectomy liver failure is important when performing extended hepatectomy. However, there is no established method to evaluate liver function and improve preoperative liver function in pediatric patients.

MATERIALS AND METHODS

We show the clinical features of pediatric patients who underwent living donor liver transplant for posthepatectomy liver failure in hepatoblastoma. The subjects were 4 patients with hepatoblastoma who were classified as Pretreatment Extent of Disease III, 2 of whom had distal metastasis (chest wall and lung).

RESULTS

Hepatic right trisegmentectomy was performed in 3 patients and extended left hepatectomy in 1 patient. The median alpha-fetoprotein level at the diagnosis of hepatoblastoma was 986300 ng/mL (range, 22500-2726350 ng/mL), and the median alpha-fetoprotein level before hepatectomy was 8489 ng/mL (range, 23-22500 ng/mL). The remnant liver volume after hepatectomy was 33.3% (range, 20% to 34.9%). Four patients had cholangitis after hepatectomy and progressed to posthepatectomy liver failure. The peak serum total bilirubin after hepatectomy was 11.4 mg/dL (range, 8.7-14.6 mg/dL). Living donor liver transplant was performed for these 4 patients with posthepatectomy liver failure, and they did not have a recurrence.

CONCLUSIONS

When the predictive remnant liver volume by computed tomography-volumetry before extended hepatectomy for patients with hepatoblastoma is less than 40%, the possibility of posthepatectomy liver failure should be recognized.

[Clinical features of catch-up growth after kidney transplantation in children]

OBJECTIVE

To study the clinical features of catch-up growth of body height after kidney transplantation in children and related influencing factors.

METHODS

A retrospective analysis was performed from the chart review data of 15 children who underwent kidney transplantation in Guangzhou Women and Children's Medical Center from July 2017 to November 2019. According to whether the increase in height standard deviation score (ΔHtSDS) in the first year after kidney transplantation reached ≥0.5, the children were divided into a catch-up group with 8 children and a non-catch-up group with 7 children. According to whether final HtSDS was ≥-2, the children were divided into a standard group with 6 children and a non-standard group with 9 children. The features of catch-up growth of body height and related influencing factors were compared between groups.

RESULTS

The data showed that median ΔHtSDS was 0.8 in the first year after transplantation, which suggested catch-up growth of body height. There was a significant difference in HtSDS between the non-catch-up and catch-up groups (P<0.05). Baseline HtSDS before transplantation was positively correlated with HtSDS at the end of follow-up (r=0.622, P<0.05) and was negatively correlated with ∆HtSDS in the first year after transplantation (r=-0.705, P<0.05). Age of transplantation and mean dose of glucocorticoid (GC) per kg body weight were risk factors for catch-up growth after kidney transplantation (OR=1.23 and 1.74 respectively; P<0.05), while baseline HtSDS and use of antihypertensive drugs were independent protective factors for catch-up growth (OR=0.08 and 0.18 respectively; P<0.05); baseline HtSDS and ΔHtSDS in the first year after kidney transplantation were influencing factors for final HtSDS (β=0.984 and 1.271 respectively; P<0.05).

CONCLUSIONS

Kidney transplantation should be performed for children as early as possible, growth retardation before transplantation should be improved as far as possible, and multiple treatment methods (including the use of GC and antihypertensive drugs) should be optimized after surgery, in order to help these children achieve an ideal body height.

Innovative Three-Dimensional Microscopic Analysis of Uremic Growth Plate Discloses Alterations in the Process of Chondrocyte Hypertrophy: Effects of Growth Hormone Treatment

Chronic kidney disease (CKD) alters the morphology and function of the growth plate (GP) of long bones by disturbing chondrocyte maturation. GP chondrocytes were analyzed in growth-retarded young rats with CKD induced by adenine intake (AD), control rats fed ad libitum (C) or pair-fed with the AD group (PF), and CKD rats treated with growth hormone (ADGH). In order to study the alterations in the process of GP maturation, we applied a procedure recently described by our group to obtain high-quality three-dimensional images of whole chondrocytes that can be used to analyze quantitative parameters like cytoplasm density, cell volume, and shape. The final chondrocyte volume was found to be decreased in AD rats, but GH treatment was able to normalize it. The pattern of variation in the cell cytoplasm density suggests that uremia could be causing a delay to the beginning of the chondrocyte hypertrophy process. Growth hormone treatment appears to be able to compensate for this disturbance by triggering an early chondrocyte enlargement that may be mediated by Nkcc1 action, an important membrane cotransporter in the GP chondrocyte enlargement.

Growth characterization in a cohort of renal allograft recipients

INTRODUCTION

Growth retardation is a common problem in children with CKD. This study aims to describe growth, prevalence of short stature before RTx, catch-up growth after RTx, and associated factors.

METHODS

We retrospectively reviewed 74 renal allograft recipients who underwent RTx at Fundación Cardioinfantil, Colombia, between January 2008 and September 2016 with follow-up for 2 years afterwards. Pre-RTx Height_SDS and demographic characteristics were compared between children with normal and short stature. Post-RTx Height_SDS at 1 and 2 years post-RTx and FAH, when available, were retrieved. Children were classified into catch-up growth and no catch-up growth groups depending on whether or not Height_SDS increased ≥0.5 per year within the first 2 years post-RTx. Possible associated factors were compared.

RESULTS

Seventy-four patients were included. Mean age at RTx was 11 ± 4.0 years, and 43.2% (32/74) were females. Mean Height_SDS for the entire study population at pre-RTx was -2.8 ± 1.5. Before RTx, 68.9% (51/74) had short stature, and 44.6% (33/74) had severe short stature. 37.2% presented catch-up growth post-RTx. Time on dialysis was associated with short pre-RTx stature (OR 1.66; 95% CI [1.15-2.39]; P = .006) and catch-up growth (OR 2.15; 95% CI [1.15-3.99]; P = .016). 44.59% (33/74) reached FAH, and 48.4% (16/33) presented short FAH.

CONCLUSIONS

Growth continues to be suboptimal after RTx. Given that pre-RTx height is a significantly associated factor, it is important to plan early interventions in terms of growth improvement in these children.

Growth plate alterations in chronic kidney disease

Growth retardation is a major feature of chronic kidney disease (CKD) of onset in infants or children and is associated with increased morbidity and mortality. Several factors have been shown to play a causal role in the growth impairment of CKD. All these factors interfere with growth by disturbing the normal physiology of the growth plate of long bones. To facilitate the understanding of the pathogenesis of growth impairment in CKD, this review discusses cellular and molecular alterations of the growth plate during uremia, including structural and dynamic changes of chondrocytes, alterations in their process of maturation and hypertrophy, and disturbances in the growth hormone signaling pathway.

Linear Growth in Pediatric Kidney Transplant Population

Introduction: Growth retardation is one of the main complications of chronic kidney disease (CKD) in children and induces a negative impact on quality of life. Materials and Methods: Retrospective analysis of all consecutive patients younger than 18 years old who received a first KT in our center between 2008 and 2018. Results: 95 first KT recipients, median age at KT of 7.83 years. At the time of KT, 65.52% of males and 54.05% females showed normal height. After transplantation, linear growth improved from -1.53 at transplant to -1.37 SDS height at the last visit. We detected a different linear growth pattern according to patient age at KT. Children younger than 3 years old exhibited the most significant growth retardation at baseline and the greatest linear growth over time (-2.29 vs. -1.82 SDS height), whereas catch-up was not observed in older patients. Multivariate analysis showed that use of corticosteroids was negatively related to SDS height at 1 year after transplantation and final SDS height only was positively associated with SDS height at KT. 44.2 and 22.1% patients received rhGH treatment before and after KT. 71.88% patients reached adulthood with normal final height. Conclusions: In our study, pediatric KT recipients exhibited a normal height in more than half of cases at KT and in more than two thirds at the final adult height. Only children younger than 6 years old presented a relevant growth catch-up after KT. Treatment with rhGH was used before and after KT with significant improvement in height.

Growth of pediatric recipients after renal transplantation from small pediatric deceased donors weighing less than 15 kg

RTx is currently the best treatment for children with ESRD. This study retrospectively analyzed the outcomes of growth after RTx using the pediatric-to-pediatric allocation strategy and some factors that may affect it. From March 2012 to August 2016, 8 en bloc and 38 single pediatric RTxs were performed at our center using organs from small pediatric deceased donors (weight < 15 kg). Growth before and after RTx was analyzed according to the height-for-age z-score at RTx, the 3-year follow-up, and adulthood and compared between the procedures. The chi-square test and multiple linear regression analysis were used for statistical analyses. Overall, 79.2% of children were diagnosed with chronic nephritis before RTx; 14.6% of cases were due to congenital urinary tract malformation, and 6.3% of cases were due to unknown causes. All grafts and patients survived postoperatively. The mean estimated GFRs were 92.7 ± 28.6 mL/min/1.73 m² , 100.9 ± 32.3 mL/min/1.73 m² , and 110.1 ± 34.8 mL/min/1.73 m² at 1, 2, and 3 years' postoperatively, respectively. The children's postoperative growth and development, particularly during the first year postoperatively, improved but were negatively correlated with age and the height-for-age z-score before RTx. The growth of children after RTx was moderate and accelerated during prepubescence. The rate of post-RTx growth during the first year postoperatively was unrelated to the recipient's sex or duration of dialysis (P > 0.05) but was negatively correlated with age at RTx (r = -0.349, P = 0.043). Future studies on the long-term outcomes are still needed.

A Cross-Sectional Study of Growth and Metabolic Bone Disease in a Pediatric Global Cohort Undergoing Chronic Hemodialysis

OBJECTIVE

We sought to assess worldwide differences among pediatric patients undergoing hemodialysis. Because practices differ widely regarding nutritional resources, treatment practice, and access to renal replacement therapy, investigators from the Pediatric Investigation and Close Collaboration to examine Ongoing Life Outcomes, the pediatric subset of the MONitoring Dialysis Outcomes Cohort (PICCOLO MONDO) performed this cross-sectional study. We hypothesized that growth would be better in developed countries, possibly at the expense of bone mineral disease.

STUDY DESIGN

In this cross-sectional study, we analyzed growth by height z score and recommended age-specific bone mineral metabolism markers from 225 patients <18 years of age maintained on hemodialysis, between the years of 2000 to 2012 from 21 countries in different regions.

RESULTS

The patients' median age was 16 (IQR 14-17) years, and 45% were females. A height z score less than the third percentile was noted in 34% of the cohort, whereas >66% of patients reported normal heights, with patients from North America having the greatest proportion (>80%). More than 70% of the entire cohort had greater than the age-recommended levels of phosphorus, particularly in the Asia-Pacific and North America, where we also observed the greatest body mass index z score (0.99 ± 1.6) and parathyroid hormone levels (557.1 [268.4-740.5]). Below-recommended parathyroid hormone levels were noted in 26% and elevated levels in 61% of the entire sample, particularly in the Asia Pacific region. Lower-than-recommended calcium levels were noted in 36% of the entire cohort, particularly in Latin America.

CONCLUSIONS

We found regional differences in growth- and age-adjusted bone mineral metabolism markers. Children from North America had the best growth, received the most dialysis, but also had the worst phosphate control and body mass index z scores.

Pediatric kidney transplantation is different from adult kidney transplantation

Kidney transplantation (KT) is the gold standard for renal replacement therapy in pediatric patients with end-stage renal disease. Recently, it has been observed that the outcome of pediatric KT is nearly identical to that in adults owing to the development and application of a variety of immunosuppressants and newer surgical techniques. However, owing to several differences in characteristics between children and adults, pediatric KT requires that additional information be learned and is associated with added concerns. These differences include post-KT complications, donor-recipient size mismatch, problems related to growth, and nonadherence to therapy, among others. This review was aimed at elucidating the clinical characteristics of pediatric KT that differ from those observed in adults.

Growth hormone treatment improves final height and nutritional status of children with chronic kidney disease and growth deceleration

PURPOSE

Growth retardation is a common complication of chronic kidney disease (CKD) in children. Treatment with recombinant human growth hormone (rhGH) has been used to help short children with CKD to attain a height more in keeping with their age group, but the scientific evidence regarding the effect of rhGH on final height is scarce.

METHODS

Final heights of children with CKD receiving rhGH treatment (cases) were compared with final heights of a matched cohort of children with CKD that did not receive rhGH therapy (controls).

RESULTS

Sixty-eight rhGH-treated cases (44 boys) were compared with 92 untreated controls (60 boys). Mean duration of rhGH therapy was 4.2 ± 0.9 years; rhGH dose was 0.3 ± 0.07 mg/kg/week. Height SDS at baseline was lower in rhGH-treated patients than in controls (-2.00 ± 1.02 versus -0.96 ± 1.11, p < 0.001). Baseline height SDS was significantly lower than target height SDS in both groups. Height SDS significantly improved from baseline to final height attainment in rhGH-treated patients, while it slightly decreased in controls (mean SDS variation 0.69 ± 1.05 in rhGH-treated cases versus -0.15 ± 1.2 in controls). Final height SDS was -1.25 ± 1.06 in rhGH-treated cases and -1.06 ± 1.17 in controls (p = 0.29). Target adjusted final height SDS was -0.91 ± 1.03 in rhGH-treated cases and -0.61 ± 1.17 in controls (p = 0.1).

CONCLUSIONS

Long-term rhGH therapy is able to reduce the linear growth deceleration of children with CKD, and ultimately to improve their final height, reducing the difference with target height.

Immunosuppressive therapy for kidney transplantation in children and adolescents: systematic review and economic evaluation

BACKGROUND

End-stage renal disease is a long-term irreversible decline in kidney function requiring kidney transplantation, haemodialysis or peritoneal dialysis. The preferred option is kidney transplantation followed by induction and maintenance immunosuppressive therapy to reduce the risk of kidney rejection and prolong graft survival.

OBJECTIVES

To systematically review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect,(®) Novartis Pharmaceuticals) and rabbit antihuman thymocyte immunoglobulin (Thymoglobuline,(®) Sanofi) as induction therapy and immediate-release tacrolimus [Adoport(®) (Sandoz); Capexion(®) (Mylan); Modigraf(®) (Astellas Pharma); Perixis(®) (Accord Healthcare); Prograf(®) (Astellas Pharma); Tacni(®) (Teva); Vivadex(®) (Dexcel Pharma)], prolonged-release tacrolimus (Advagraf,(®) Astellas Pharma); belatacept (BEL) (Nulojix,(®) Bristol-Myers Squibb), mycophenolate mofetil (MMF) [Arzip(®) (Zentiva), CellCept(®) (Roche Products), Myfenax(®) (Teva), generic MMF is manufactured by Accord Healthcare, Actavis, Arrow Pharmaceuticals, Dr Reddy's Laboratories, Mylan, Sandoz and Wockhardt], mycophenolate sodium, sirolimus (Rapamune,(®) Pfizer) and everolimus (Certican,(®) Novartis Pharmaceuticals) as maintenance therapy in children and adolescents undergoing renal transplantation.

DATA SOURCES

Clinical effectiveness searches were conducted to 7 January 2015 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science [via Institute for Scientific Information (ISI)], Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (HTA) (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted to 15 January 2015 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Databases (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations Database (via Wiley Online Library) and EconLit (via EBSCOhost).

REVIEW METHODS

Titles and abstracts were screened according to predefined inclusion criteria, as were full texts of identified studies. Included studies were extracted and quality appraised. Data were meta-analysed when appropriate. A new discrete time state transition economic model (semi-Markov) was developed; graft function, and incidences of acute rejection and new-onset diabetes mellitus were used to extrapolate graft survival. Recipients were assumed to be in one of three health states: functioning graft, graft loss or death.

RESULTS

Three randomised controlled trials (RCTs) and four non-RCTs were included. The RCTs only evaluated BAS and tacrolimus (TAC). No statistically significant differences in key outcomes were found between BAS and placebo/no induction. Statistically significantly higher graft function (p < 0.01) and less biopsy-proven acute rejection (odds ratio 0.29, 95% confidence interval 0.15 to 0.57) was found between TAC and ciclosporin (CSA). Only one cost-effectiveness study was identified, which informed NICE guidance TA99. BAS [with TAC and azathioprine (AZA)] was predicted to be cost-effective at £20,000-30,000 per quality-adjusted life year (QALY) versus no induction (BAS was dominant). BAS (with CSA and MMF) was not predicted to be cost-effective at £20,000-30,000 per QALY versus no induction (BAS was dominated). TAC (with AZA) was predicted to be cost-effective at £20,000-30,000 per QALY versus CSA (TAC was dominant). A model based on adult evidence suggests that at a cost-effectiveness threshold of £20,000-30,000 per QALY, BAS and TAC are cost-effective in all considered combinations; MMF was also cost-effective with CSA but not TAC.

LIMITATIONS

The RCT evidence is very limited; analyses comparing all interventions need to rely on adult evidence.

CONCLUSIONS

TAC is likely to be cost-effective (vs. CSA, in combination with AZA) at £20,000-30,000 per QALY. Analysis based on one RCT found BAS to be dominant, but analysis based on another RCT found BAS to be dominated. BAS plus TAC and AZA was predicted to be cost-effective at £20,000-30,000 per QALY when all regimens were compared using extrapolated adult evidence. High-quality primary effectiveness research is needed. The UK Renal Registry could form the basis for a prospective primary study.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013544.

FUNDING

The National Institute for Health Research HTA programme.

Special Considerations in Pediatric Kidney Transplantation

Universally accepted as the treatment of choice for children needing renal replacement therapy, kidney transplantation affords children the opportunity for an improved quality of life over dialysis therapy. Immunologic and surgical advances over the last 15 years have improved the pediatric patient and kidney graft survival. Unique to pediatrics, congenital genitourinary anomalies are the most common primary diseases leading to kidney failure, many with urological issues. Early urological evaluation for post-transplant bladder dysfunction and emphasis on immunization adherence are the mainstays of pediatric pretransplant and post-transplant evaluations. A child's height can be challenging, sometimes requiring an intra-abdominally placed graft, particularly if the patient is <20 kg. Maintenance immunosuppression regimens are similar to adult kidney graft recipients, although distinctive pharmacokinetics may change dosing intervals in children from twice a day to thrice a day. Viral infections and secondary malignancies are problematic for children relative to adults. Current trends to reduce/remove corticosteroid therapy from post-transplant protocols have produced improved linear growth with less steroid toxicity; although these studies are still ongoing, graft function and survival are considered acceptable. Finally, all children with a kidney transplant need a smooth transition to adult clinics. Future research in pertinent psychosocial aspects and continued technological advances will only serve to optimize the transition process. Although some aspects of kidney transplantation are similar in children and adults, for instance immunosuppression and immunosuppressive regimens, and rejection mechanisms and their diagnosis using the Banff criteria, there are important differences this review will focus on and which continue to drive innovation.

Graft Growth and Podocyte Dedifferentiation in Donor-Recipient Size Mismatch Kidney Transplants

Background

Kidney transplantation is the treatment choice for patients with end-stage renal diseases. Because of good long-term outcome, pediatric kidney grafts are also accepted for transplantation in adult recipients despite a significant mismatch in body size and age between donor and recipient. These grafts show a remarkable ability of adaptation to the recipient body and increase in size in a very short period, presumably as an adaptation to hyperfiltration.

Methods

We investigated renal graft growth as well as glomerular proliferation and differentiation markers Kiel-67, paired box gene 2 and Wilms tumor protein (WT1) expression in control biopsies from different transplant constellations: infant donor for infant recipient, infant donor for child recipient, infant donor for adult recipient, child donor for child recipient, child donor for adult recipient, and adult donor for an adult recipient.

Results

We detected a significant increase in kidney graft size after transplantation in all conditions with a body size mismatch, which was most prominent when an infant donated for a child. Podocyte WT1 expression was comparable in different transplant conditions, whereas a significant increase in WT1 expression could be detected in parietal epithelial cells, when a kidney graft from a child was transplanted into an adult. In kidney grafts that were relatively small for the recipients, we could detect reexpression of podocyte paired box gene 2. Moreover, the proliferation marker Kiel-67 was expressed in glomerular cells in grafts that increased in size after transplantation.

Conclusions

Kidney grafts rapidly adapt to the recipient size after transplantation if they are transplanted in a body size mismatch constellation. The increase in transplant size is accompanied by an upregulation of proliferation and dedifferentiation markers in podocytes. The different examined conditions exclude hormonal factors as the key trigger for this growth so that most likely hyperfiltration is the key trigger inducing the rapid growth response.

The Long-term Outcome of Pediatric Kidney Transplantation in Iran: Results of a 25-year Single-Center Cohort Study

BACKGROUND

Kidney transplantation is the optimal treatment for end-stage renal disease in children. However, long-term graft survival has not significantly improved among pediatric patients.

OBJECTIVE

To investigate the determinants of long-term graft survival among Iranian pediatric recipients of kidney transplantation.

METHODS

In a single-center cohort study, we studied 314 pediatric kidney transplantations performed from 1989 to 2013 at Dr. Shariati Hospital, Tehran, Iran. Different variables were collected for each patient and graft survival rates were calculated.

RESULTS

After a mean±SD follow-up period of 15.8±4.0 years, the mean±SD graft survival rate was 14.5±0.5 years; the 1-, 5-, 10-, and 20-year mean graft survival rates were 90%, 81%, 62%, and 62%, respectively. The corresponding patient survival rates were 100%, 99.4%, 97.8%, and 96.5%, respectively. Pre-emptive transplantation (p=0.006), and living graft donation (p=0.002) led to higher graft survival, while acute rejection (p=0.002), and primary disease of primary hyperoxaluria (p=0.001) led to lower graft survival. Chronic rejection was the most frequent cause of graft loss.

CONCLUSION

Short-term graft survival still outpaces the long-term outcome. Modifying the mentioned determinants, with more intense immunosuppression for greater prevention of acute and chronic rejection, and increased rate of pre-emptive transplantation and living donor transplantation, long-term graft survival may significantly improve in future.

Is Kidney Transplantation a Better State of CKD? Impact on Diagnosis and Management

Patients with CKD are at increased risk for cardiovascular events, hospitalizations, and mortality. Kidney transplantation (KTx) is the preferred treatment for end-stage kidney disease. Although comorbidities including anemia and bone and mineral disease improve or are even halted after KTx, kidney transplant recipients carry higher cardiovascular mortality risk than the general population, as well as an increased risk of infections, malignancies, fractures, and obesity. When comparing CKD with CKD after transplantation (CKD-T), the rate of decline of estimated glomerular filtration rate (eGFR) is significantly lower in CKD-T. Higher rate of decline of eGFR has been associated with increased risk of mortality. However, due to the significant increased risk of mortality due to cardiovascular events, infections, and malignancies, many kidney transplant recipients may not benefit of decline in the rate of eGFR. Patients with CKD-T are a unique subset of patients with multiple traditional and transplant-specific risk factors. Proper management and appropriate preventive health measures may improve long-term patient and allograft survival in patients with CKD-T.

Renal transplantation in infants

Renal transplantation (RTx) has become an accepted mode of therapy in infants with severe renal failure. The major indications are structural abnormalities of the urinary tract, congenital nephrotic syndrome, polycystic diseases, and neonatal kidney injury. Assessment of these infants needs expertise and time as well as active treatment before RTx to ensure optimal growth and development, and to avoid complications that could lead to permanent neurological defects. RTx can be performed already in infants weighing around 5 kg, but most operations occur in infants with a weight of 10 kg or more. Perioperative management focuses on adequate perfusion of the allograft and avoidance of thrombotic and other surgical complications. Important long-term issues include rejections, infections, graft function, growth, bone health, metabolic problems, neurocognitive development, adherence to medication, pubertal maturation, and quality of life. The overall outcome of infant RTx has dramatically improved, with long-term patient and graft survivals of over 90 and 80 %, respectively.

The consequences of pediatric renal transplantation on bone metabolism and growth

PURPOSE OF REVIEW

During childhood, growth retardation, decreased final height and renal osteodystrophy are common complications of chronic kidney disease (CKD). These problems remain present in patients undergoing renal transplantation, even though steroid-sparing strategies are more widely used. In this context, achieving normal height and growth in children after transplantation is a crucial issue for both quality of life and self-esteem. The aim of this review is to provide an overview of pathophysiology of CKD-mineral bone disorder (MBD) in children undergoing renal transplantation and to propose keypoints for its daily management.

RECENT FINDINGS

In adults, calcimimetics are effective for posttransplant hyperparathyroidism, but data are missing in the pediatric population. Fibroblast growth factor 23 levels are associated with increased risk of rejection, but the underlying mechanisms remain unclear. A recent meta-analysis also demonstrated the effectiveness of rhGH therapy in short transplanted children.

SUMMARY

In 2013, the daily clinical management of CKD-MBD in transplanted children should still focus on simple objectives: to optimize renal function, to develop and promote steroid-sparing strategies, to provide optimal nutritional support to maximize final height and avoid bone deformations, to equilibrate calcium/phosphate metabolism so as to provide acceptable bone quality and cardiovascular status, to correct all metabolic and clinical abnormalities that can worsen both bone and growth (mainly metabolic acidosis, anemia and malnutrition), promote good lifestyle habits (adequate calcium intake, regular physical activity, no sodas consumption, no tobacco exposure) and eventually to correct native vitamin D deficiency (target of 25-vitamin D >75 nmol/l).

Identification of subgroups by risk of graft failure after paediatric renal transplantation: application of survival tree models on the ESPN/ERA-EDTA Registry

BACKGROUND

Identification of patient groups by risk of renal graft loss might be helpful for accurate patient counselling and clinical decision-making. Survival tree models are an alternative statistical approach to identify subgroups, offering cut-off points for covariates and an easy-to-interpret representation.

METHODS

Within the European Society of Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association (ESPN/ERA-EDTA) Registry data we identified paediatric patient groups with specific profiles for 5-year renal graft survival. Two analyses were performed, including (i) parameters known at time of transplantation and (ii) additional clinical measurements obtained early after transplantation. The identified subgroups were added as covariates in two survival models. The prognostic performance of the models was tested and compared with conventional Cox regression analyses.

RESULTS

The first analysis included 5275 paediatric renal transplants. The best 5-year graft survival (90.4%) was found among patients who received a renal graft as a pre-emptive transplantation or after short-term dialysis (<45 days), whereas graft survival was poorest (51.7%) in adolescents transplanted after long-term dialysis (>2.2 years). The Cox model including both pre-transplant factors and tree subgroups had a significantly better predictive performance than conventional Cox regression (P < 0.001). In the analysis including clinical factors, graft survival ranged from 97.3% [younger patients with estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m(2) and dialysis <20 months] to 34.7% (adolescents with eGFR <60 mL/min/1.73 m(2) and dialysis >20 months). Also in this case combining tree findings and clinical factors improved the predictive performance as compared with conventional Cox model models (P < 0.0001).

CONCLUSIONS

In conclusion, we demonstrated the tree model to be an accurate and attractive tool to predict graft failure for patients with specific characteristics. This may aid the evaluation of individual graft prognosis and thereby the design of measures to improve graft survival in the poor prognosis groups.

Corticosteroid-free Kidney Transplantation Improves Growth: 2-Year Follow-up of the TWIST Randomized Controlled Trial

BACKGROUND

Corticosteroid withdrawal (CW) after pediatric kidney transplantation potentially improves growth while avoiding metabolic and other adverse events. We have recently reported the results of a 196 subject randomized controlled trial comparing early CW (tacrolimus, mycophenolate mofetil (MMF), daclizumab, and corticosteroids until day 4) with tacrolimus, MMF, and corticosteroid continuation (CC). At 6 months, CW subjects showed better growth with no adverse impact on acute rejection or graft survival (Am J Transplant 2010; 10: 828-836). This 2-year investigator-driven follow-up study aimed to determine whether improved growth persisted in the longer term.

METHODS

Data regarding growth, graft outcomes and adverse events were collected at 1 year (113 patients) and 2 years (106 patients) after transplantation. The primary endpoint, longitudinal growth calculated as delta height standard deviation score, was analyzed using a mixed model repeated measures model.

RESULTS

Corticosteroid withdrawal subjects grew better at 1 year (difference in adjusted mean change, 0.25; 95% confidence interval, 0.10, 0.40; P = 0.001). At 2 years, growth remained numerically better in CW subjects (0.20 (-0.01, 0.41); P = 0.06), and significantly better in prepubertal subjects (0.50 (0.16, 0.84); P = 0.004). Bacterial and viral infection was significantly more common in CW subjects at 1 year only. Corticosteroid withdrawal and CC subjects received similar exposure to both tacrolimus and MMF at 1 and 2 years. No significant difference in patient or graft survival, rejection, estimated glomerular filtration rate, or other adverse events was detected.

CONCLUSION

Early CW effectively and safely improves growth up to 2 years after transplantation, particularly in prepubertal children.

Single-center experience in pediatric renal transplantation using thymoglobulin induction and steroid minimization

Our center has offered thymoglobulin induction with steroid minimization to our pediatric renal transplant patients for the last 10 yr. Steroid minimization or avoidance has shown favorable results in survival, kidney function, and growth in previous studies of pediatric patients. We report our experience with this protocol over the past 10 yr with respect to patient/graft survival, acute rejection episodes, renal function, linear growth, bone density, cardiovascular risk factors, and opportunistic infections. A retrospective chart review was performed for pediatric renal transplant patients on the steroid-minimized protocol between January 2002 and December 2011 on an intention to treat basis. Patient demographics, height, weight, serum creatinine, iGFR, biopsies, and survival data were collected. Height and weight z-scores were calculated with EpiInfo 7, using the CDC 2000 growth charts. Survival was calculated using Kaplan-Meier analysis. eGFR was calculated using the original and modified Schwartz equations. Forty-four pediatric patients were identified, aged 13 months to 19 yr. Five-yr survival was 95.5% for males and 94.4% for females. Only five patients had biopsy-proven ACR, two of which were at more than 12 months post-transplantation. Height delta z-scores from transplant to one, three, and five yr were 0.34, 0.38, and 0.79, respectively. Weight delta z-scores from transplant to one, three, and five yr were 0.87, 0.79, and 0.84, respectively. Mean original Schwartz eGFR was 84.3 ± 15.8 mL/min/1.73 m(2) , modified Schwartz eGFR was 59.3 ± 11.5 mL/min/1.73 m(2) , and iGFR was 64.2 ± 8.5 mL/min/1.73 m(2) at three yr. Of 18 subjects who had a bone density exam, none had a z-score less than -2 on DEXA exam at one-yr post-transplantation. Fifty-one percent of patients were on antihypertensives at the time of transplant compared with 43% at one-yr post-transplantation. Three yr post-transplantation, the average LDL was <100 mg/dL, and average total cholesterol was <200 mg/dL. There were no clinical episodes of EBV or CMV infection. A steroid-minimized protocol with thymoglobulin induction is safe and provides favorable improvement in linear growth, stable graft function, stable or improved cardiovascular risk factors, and normal bone density in pediatric renal transplant patients.

Growth, chronic kidney disease and pediatric kidney transplantation: is it useful to use recombinant growth hormone in Colombian children with renal transplant?

Kidney transplantation has become the best treatment for children with chronic kidney disease (CKD). In recent times, knowledge concerning the effect of CKD and kidney transplantation over the normal growth rate has increased; now it is known that 40% of children with CKD do not reach the expected height for age. Growth retardation has been associated with the type of nephropathy, metabolic and endocrine disorders that are secondary to kidney disease, immunosuppressive therapy with glucocorticoids, and suboptimal function of renal allograft. Nowadays, we know better the role of the growth hormone/insulin-like growth factor 1 axis in growth retardation we can see it in children with CKD or recipients of renal allograft. Several studies have shown that administration of recombinant growth hormone (rhGH) has a positive effect on the longitudinal growth of children and teenagers who have received a kidney transplant. On the other hand, there have been reported side effects associated with using rhGH; however, these are not statistically significant. In this article, we show a small review about growth in children with CKD and/or recipients of renal allografts the growth pattern of three children who were known by the Transplant Group of National University of Colombia, and the results obtained with the use of rhGH in one of these cases. We want to show the possibility of achieving a secure use of rhGH in children with CKD and its use as a therapeutic option for treating the growth retardation in children with kidney transplantation, and set out the need of typifying the growth pattern of Colombian children with CKD and/or who are recipients of renal allografts through multicenter studies to propose and analyze the inclusion of rhGH in the therapeutic scheme of Colombian children with these two medical conditions. rhGH could be a useful tool for treating children with CKD or kidney transplantation who have not reached the expected longitudinal growth for age. However, it is necessary to know the growth pattern standards for Colombian children with CKD or kidney transplant in Bogotá-Colombia to include the rhGH in clinical protocols for treatment of these patients.

Long-term experience of steroid-free pediatric renal transplantation: effects on graft function, body mass index, and longitudinal growth

Increased focus on the potential negative side effects of steroid usage in pediatric transplantation has led to steroid minimization or steroid-free transplantation. In this study, we report results after complete steroid avoidance in renal transplantation in the period 1994-2009. We evaluate the effects of complete steroid avoidance on allograft function, BMI, and linear growth. The majority of transplanted children were induced with antithymocyte globulin and immunosuppressed with a calcineurin inhibitor and mycophenolate mofetil. Steroids were given only when rejection occurred or due to comorbidities. Anthropometric data were collected from 65 transplantations in 60 children. Patient survival was 93%; graft survival was 81% after five yr (N = 42) and 63% after 10 yr (N = 16). Acute rejection within the first year of transplantation was 9%. The distribution of the children's BMI before transplantation was normal; the mean BMI-SDS was 0.21 before transplantation, and this value remained stable during the next five yr. Post-transplantation the children demonstrated significant improved growth as the mean height-SDS increased significantly from -1.7 to -1.1. Catch-up growth was most pronounced in the youngest (< six yr). Steroid-free immunosuppression in pediatric renal transplantation is safe and protects against steroid-induced obesity and short stature.

Adult height in patients with advanced CKD requiring renal replacement therapy during childhood

BACKGROUND AND OBJECTIVES

Growth and final height are of major concern in children with ESRD. This study sought to describe the distribution of adult height of patients who started renal replacement therapy (RRT) during childhood and to identify determinants of final height in a large cohort of RRT children.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 1612 patients from 20 European countries who started RRT before 19 years of age and reached final height between 1990 and 2011 were included. Linear regression analyses were performed to calculate adjusted mean final height SD score (SDS) and to investigate its potential determinants.

RESULTS

The median final height SDS was -1.65 (median of 168 cm in boys and 155 cm in girls). Fifty-five percent of patients attained an adult height within the normal range. Adjusted for age at start of RRT and primary renal diseases, final height increased significantly over time from -2.06 SDS in children who reached adulthood in 1990-1995 to -1.33 SDS among those reaching adulthood in 2006-2011. Older age at start of RRT, more recent period of start of RRT, cumulative percentage time on a functioning graft, and greater height SDS at initiation of RRT were independently associated with a higher final height SDS. Patients with congenital anomalies of the kidney and urinary tract and metabolic disorders had a lower final height than those with other primary renal diseases.

CONCLUSIONS

Although final height remains suboptimal in children with ESRD, it has consistently improved over time.

Growth and maturation improvement in children on renal replacement therapy over the past 20 years

BACKGROUND

The attainment of normal growth and maturation remains a major challenge in the management of children and adolescents requiring renal replacement therapy (RRT).

METHODS

We compared growth and maturation in 384 German children with RRT who were followed between 1998 and 2009 with 732 children who were enrolled in the European Dialysis and Transplant Association (EDTA) Registry from 1985 to 1988; of these children, 78 and 88 %, respectively, were transplanted.

RESULTS

The data on the German patients included in the EDTA registry did not differ significantly from those of the patients from other European countries. Overall, the mean height standard deviation score (SDS) has improved over the past 20 years from -3.03 to -1.80 (p < 0.001). Until the age of 6 years, the difference in height SDS was not significant, whereas it improved significantly in adolescence (-3.40 vs. -1.52; p < 0.001). Significant improvements in the delay of the pubertal growth spurt, age at menarche, bone maturation and body mass index (BMI) were noted in the recent German group compared to the EDTA group (each p < 0.001).

CONCLUSIONS

Our findings demonstrate a marked improvement of growth and maturation in paediatric patients on RRT during the past 20 years.

Factors affecting growth and final adult height after pediatric renal transplantation

BACKGROUND

Growth retardation is a common problem for children with chronic kidney disease. Although renal transplantation (RTx) resolves endocrine metabolic and uremic disturbances, growth continues to be suboptimal. This study aims to describe changes in height from diagnosis to final adult height (FAH) in Korean renal allograft recipients and determine factors associated with posttransplantation growth.

METHODS

We retrospectively reviewed 63 renal allograft recipients who underwent RTx at <15 years of age with regular follow-up for >3 years afterwards. Pre- and post-RTx growth was analyzed by height Z scores (Ht_Z) at RTx, 2 and 5 years follow-up, and at FAH.

RESULTS

Ht_Z decreased from diagnosis to dialysis by -0.8 (P = .009) and from dialysis to RTx by -0.46 (P < .001). The mean baseline Ht_Z at RTx was -1.62 ± 1.36. The change in Ht_Z at 2 and 5 years after transplantation was 0.68 ± 0.88 and 0.48 ± 0.86, respectively. Both variables were negatively correlated with baseline age at RTx. Mean FAH was -1.22 ± 1.11 and was positively correlated with baseline height at RTx. Height at start of dialysis and dialysis duration were significant determinants of baseline height at RTx (P < .001).

CONCLUSIONS

Although there is significant posttransplant catch-up growth among younger recipients and among those with greater baseline height deficit, catch-up growth is not sustained and greater FAH is attained in those who are taller at RTx. Achieving greater height before dialysis and decreasing dialysis duration leads to maximal height at RTx as well as greater FAH.

Final adult height in kidney recipients who underwent highly successful transplantation as children: a single-center experience

BACKGROUND

Achieving a normal final adult height (FH) remains a challenge in the field of pediatric kidney transplantation (KTx). To examine the optimal approach to assuring normal FH following KTx, we retrospectively examined the post-transplant growth and FH of pediatric KTx recipients.

METHODS

Since the relevant factors affecting the FH of children following KTx are multifactorial and notably complex, KTx recipients with persistent good graft function and successful steroid minimization until FH attainment were selected for this study.

RESULTS

Thirteen patients were enrolled in this study. The mean estimated glomerular filtration rate was 72.1 ± 15.3 ml/min/1.73 m(2), and the mean corticosteroid dose was 0.05 ± 0.05 mg/kg on alternate days at the time of FH attainment. Despite highly successful KTx, four (30.8 %) patients (one who underwent KTx before puberty and three during puberty) showed a decrease in the height standard deviation score (hSDS) from the time of KTx until FH attainment. Moreover, of these, two male patients had an FH with an SD <-2.

CONCLUSION

FH remained suboptimal despite highly successful KTx. Not only highly successful KTx but also further treatment such as steroid avoidance, early steroid withdrawal or using rhGH might be necessary to assure a normal FH in some pubertal patients.

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.

The consequences of chronic kidney disease on bone metabolism and growth in children

Growth retardation, decreased final height and renal osteodystrophy (ROD) are common complications of childhood chronic kidney disease (CKD), resulting from a combination of abnormalities in the growth hormone (GH) axis, vitamin D deficiency, hyperparathyroidism, hypogonadism, inadequate nutrition, cachexia and drug toxicity. The impact of CKD-associated bone and mineral disorders (CKD-MBD) may be immediate (serum phosphate/calcium disequilibrium) or delayed (poor growth, ROD, fractures, vascular calcifications, increased morbidity and mortality). In 2012, the clinical management of CKD-MBD in children needs to focus on three main objectives: (i) to provide an optimal growth in order to maximize the final height with an early management with recombinant GH therapy when required, (ii) to equilibrate calcium/phosphate metabolism so as to obtain acceptable bone quality and cardiovascular status and (iii) to correct all metabolic and clinical abnormalities that can worsen bone disease, growth and cardiovascular disease, i.e. metabolic acidosis, anaemia, malnutrition and 25(OH)vitamin D deficiency. The aim of this review is to provide an overview of the mineral, bone and vascular abnormalities associated with CKD in children in terms of pathophysiology, diagnosis and clinical management.

Final height in a prospective trial of late steroid withdrawal after pediatric renal transplantation treated with cyclosporine and mizoribine

A prospective trial of corticosteroid (steroid) withdrawal after pediatric renal transplantation was started in 1990. Fifty-eight recipients with functioning grafts reached their final height. They were transplanted at a mean age of 10.7 yr. Immunosuppressive therapy with CyA, MP, and MZ was started after transplantation. MP was reduced to an alternate-day dose in 49 patients and was withdrawn in 23. Their mean height SDS was -2.4 at the time of transplantation and -2.1 at their final height. Mean final height was 157.9 cm in men and 147.6 cm in women. In 18 patients who had been withdrawn from MP for more than two yr before reaching final height, mean age at transplantation was 8.9 yr. Their mean height SDS of -2.2 at the time of transplantation increased to -1.6 at their final height (p = 0.02), and mean final height was 163.8 cm in men and 147.8 cm in women. The height SDS in all 58 patients was maintained during the immunosuppressive therapy with steroid minimization, and final height SDS increased in recipients older than five yr at transplantation with steroid withdrawal.

Pediatric renal transplantation

Although the number of children with end-stage renal disease (ESRD) in need for renal transplantation is small compared with adults, the problem associated with renal transplant in children are numerous, varied, and often peculiar. Pre-emptive transplantation has recently been growing in popularity as it avoids many of the associated long-term complications of ESRD and dialysis. Changes in immunosuppression to more potent agents over the years will have affected transplant outcome; there is also evidence that tacrolimus is more effective than cyclosporine. This review will discuss the short- and long-term complications such as acute and chronic rejection, hypertension, infections, and malignancies as well as factors related to long-term graft function. Chronic allograft nephropathy is the leading cause of renal allograft loss in pediatric renal transplant recipients. It is likely that it reflects a combination of both immune and nonimmune injury occurring cumulatively over time so that the ultimate solution will rely on several approaches. Transplant and patient survival have shown a steady increase over the years. The major causes of death after transplantation are cardiovascular disease, infection and malignancy. Transplantation in special circumstances such as children with abnormal urinary tracts and children with diseases that have the potential to recur after transplantation will also be discussed in this review. Non-compliance with therapeutic regimen is a difficult problem to deal with and affects patients and families at all ages, but particularly so at adolescence. Growth may be severely impaired in children with ESRD which may result in major consequences on quality of life and self-esteem; a better height attainment at transplantation is recognized as one of the most important factors in final height achievement. Although pediatric kidney transplantation is active in some parts of many developing countries, it is still inactive in many others and mostly relying on living donors. The lacking deceased programs in most of these countries is one of the main issues to be addressed to adequately respond to organ shortage. In conclusion, transplantation is currently the best option for children with ESRD. Although improvement in immunosuppression demonstrated excellent results and has led to greater 1-year graft survival rates, chronic graft loss remains relatively unchanged and opportunistic infectious complications remain a problem.

[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.

Pubertal development is normal in adolescents after renal transplantation in childhood

BACKGROUND

This study was conducted to evaluate the pubertal development in adolescents after renal transplantation (RTx) in childhood.

METHODS

We performed a retrospective review of medical records of 109 RTx recipients (72 males) transplanted at the median age of 4.5 years (range: 0.9-15.8 years). Data on the clinical signs of puberty, growth, bone age, medication, and graft function of 98 patients were analyzed. Furthermore, serum levels of reproductive hormones in 87 patients were assessed to evaluate the progression and outcome of pubertal development.

RESULTS

The age at the onset of puberty averaged 12.7 years (range: 9.4-16.2 years) in 55 males and 10.7 years (range: 8.9-12.7 years) in 29 females. The mean age at menarche was 12.5 years (range: 10.5-14.5 years). Twenty-two percent of the boys and none of the girls had a moderately delayed onset of puberty. Children who underwent RTx before the age of 5 years reached puberty earlier than those transplanted at later age (boys 12.3±1.2 vs. 13.4±1.5 years, P<0.01; girls 10.3±0.9 vs. 11.0±1.0 years, P>0.05). The mean length of puberty was 3.9 and 4.7 years for boys and girls, respectively. The bone age was delayed in practically all, and final height was reached at the mean age of 18.1 and 16.0 years in boys and girls, respectively. Pubertal maturation resulted in acceptable final height and reproductive hormone status in great majority of the patients.

CONCLUSION

Pubertal development was normal in all female and most male adolescents after RTx in childhood.