Clinical practice recommendations for primary hyperoxaluria: an expert consensus statement from ERKNet and OxalEurope.

Primary hyperoxaluria (PH) is an inherited disorder that results from the overproduction of endogenous oxalate, leading to recurrent kidney stones, nephrocalcinosis and eventually kidney failure; the subsequent storage of oxalate can cause life-threatening systemic disease. Diagnosis of PH is often delayed or missed owing to its rarity, variable clinical expression and other diagnostic challenges. Management of patients with PH and kidney failure is also extremely challenging. However, in the past few years, several new developments, including new outcome data from patients with infantile oxalosis, from transplanted patients with type 1 PH (PH1) and from patients with the rarer PH types 2 and 3, have emerged. In addition, two promising therapies based on RNA interference have been introduced. These developments warrant an update of existing guidelines on PH, based on new evidence and on a broad consensus. In response to this need, a consensus development core group, comprising (paediatric) nephrologists, (paediatric) urologists, biochemists and geneticists from OxalEurope and the European Rare Kidney Disease Reference Network (ERKNet), formulated and graded statements relating to the management of PH on the basis of existing evidence. Consensus was reached following review of the recommendations by representatives of OxalEurope, ESPN, ERKNet and ERA, resulting in 48 practical statements relating to the diagnosis and management of PH, including consideration of conventional therapy (conservative therapy, dialysis and transplantation), new therapies and recommendations for patient follow-up.

The development of a population physiologically based pharmacokinetic model for mycophenolic mofetil and mycophenolic acid in humans using data from plasma, saliva, and kidney tissue.

BACKGROUND: Mycophenolic acid (MPA) is used widely to prevent graft rejection in kidney-transplant patients. Therapeutic drug monitoring (TDM) in plasma requires an invasive procedure that is inconvenient, especially in pediatric patients. TDM in saliva is a more convenient non-invasive alternative compared with plasma. METHODS: A population physiologically based pharmacokinetic (Pop-PBPK) model of mycophenolate mofetil (MMF) and MPA with enterohepatic recycling was built and verified using previously published plasma, saliva, and kidney biopsy data in healthy and kidney-transplant adult patients. The verified model was then used to predict experimentally observed plasma and saliva MMF and MPA TDM data in Jordanian pediatric kidney transplant patients measured using LC-MS/MS. A correlation was established between plasma and saliva exposures in pediatrics. RESULTS: The developed LCMS was sensitive to both MMF and MPA in plasma and saliva. The developed Pop-PBPK model predicted well the previously reported MMF and MPA levels in plasma, saliva, and kidney tissue and those observed in the current study (more than 75% of observed data points were within 90% predictive interval of population simulations). A statistically significant correlation was found between plasma and saliva exposures for both MMF (Pop-PBPK predicted and observed) and MPA (Pop-PBPK predicted). CONCLUSION: Both MPA and MMF can be classified as class III compounds in the Salivary Excretion Classification System. Saliva is an alternative body fluid to plasma that can be used for TDM of MPA and MMF in kidney-transplant patients in pediatrics. Exposure to MPA and MMF in plasma, saliva, and kidney tissue was reliably predicted using the developed Pop-PBPK model.

A multiple methods approach to determine adherence with prescribed mycophenolate in children with kidney transplant.

AIMS: The aim of this study was, to use a multiple methods approach, including, for the first time, dried blood spot (DBS) sampling with population pharmacokinetic interpretation, to assess adherence to mycophenolate in children with kidney transplant. A second aim was to identify patient/parental factors that influenced adherence and to link adherence behaviour to clinical outcomes. METHODS: A convenience sample of 33 children with kidney transplant (age ≤ 18 years) who had been prescribed mycophenolate for at least 3 months were recruited from participating outpatient clinics in the UK and Jordan. Medication adherence was determined via self-report questionnaires, medication refill data from dispensing records, and via mycophenolic acid concentrations in plasma and DBS samples obtained from children during a clinic visit. RESULTS: Through triangulation of results from the different methodological approaches a total of 12 children (36.4%) were deemed to be nonadherent with their prescribed mycophenolate treatment. Logistic regression analysis indicated that nonadherence was significantly associated with the presence of mycophenolate side effects. Poor adherence was positively linked to measures of poor clinical outcomes (hospitalisation and the need for kidney biopsy). CONCLUSIONS: Despite the imperative regarding medication adherence to help prevent organ rejection, a significant proportion of children are not fully adherent with their therapy. Side-effects appear to be an important factor leading to nonadherence. Measurement of mycophenolate in DBS samples, coupled with the use of population pharmacokinetics modelling, was a convenient direct approach to assessing adherence in children with kidney transplant and has the potential to be introduced into routine practice.

Diabetes Mellitus After Pediatric Kidney Transplant.

OBJECTIVES: Kidney transplant is the best renal replacement therapy for pediatric patients with end-stage renal disease; however, this procedure is not without complications. A major complication is the development of new-onset diabetes mellitus, which affects the outcomes of transplant in terms of kidney and patient survival. In this study, our objective was to calculate the percentage of pediatric patients who developed new-onset diabetes mellitus or transient hyperglycemia after kidney transplant, compare our data with international data, and discuss the related factors that predispose to diabetes. MATERIALS AND METHODS: A retrospective study was conducted by reviewing the medical records of pediatric patients who had transplant procedures or were followed at the Royal Medical Services (Amman, Jordan) from 2007 to 2017. RESULTS: Our study cohort included 104 patients. The average follow-up time was 4 years and 7 months, with a maximum follow-up of 9 years. Ten patients developed posttransplant hyperglycemia, with 8 developing early hyperglycemia (during the first 3 months posttransplant). In 40% of patients, this complication was transient, and patients stopped insulin after immunosuppressant medications were decreased. However, 60% of patients continued to have diabetes, with 20% having late-onset diabetes and treatment with oral hypoglycemic agent. CONCLUSIONS: Pretransplant awareness of risk factors of new-onset diabetes mellitus after transplant and close monitoring of hyperglycemia during the posttransplant period are mandatory. Transient hyperglycemia after kidney transplant is common, and kidney transplant does not alleviate the high risk of diabetes in patients with chronic kidney disease.

Pediatric focal segmental glomerulosclerosis in Jordan: A tertiary hospital experience.

Our objective is to study the demographical data, clinical course and outcome of children with primary focal segmental glomerulosclerosis (FSGS) in Jordan. A retrospective chart review of patients with a diagnosis of FSGS at a tertiary care hospital from the period July 2010 to July 2016 was conducted. A total of 99 patients were analyzed. The mean age of presentation was 3.71 ± 2.59 years, 66% were male. At presentation, 66.6% of patients were steroid-resistant, 10% had a steroid dependant course and 20.2% had familial FSGS. Cyclosporine was used in 66.6% of children with a response rate of 46.9%. Long-term follow-up showed complete remission in 29.3%, partial remission in 31.3%, end-stage renal disease in 22.2%, and death in 11.1%. There is a high prevalence of familial FSGS in our Jordanian cohort with a high rate of progression to end-stage kidney disease.

Renal Impairment and Complication After Kidney Transplant at Queen Rania Abdulla Children's Hospital.

OBJECTIVES: Kidney transplant is the treatment of choice for end-stage renal disease, but it is not without complications. We review the medical cause of significant renal impairment and complications that developed after kidney transplant in pediatric patients who required hospital admission and intervention and/or who were followed between 2007 and 2016. MATERIALS AND METHODS: A retrospective noninterventional chart review study was conducted in pediatric patients who received a kidney transplant and/or followed at the nephrology clinic at Queen Rania Abdulla Children's Hospital between 2007 and 2016. RESULTS: In this study, 101 pediatric patients received a total of 103 transplants. Forty-eight patients (47%) experienced deterioration of kidney function out of a total of 53 episodes of complications; 37 of these episodes occurred early (0-6 mo after transplant), and 26 episodes occurred late. The causes of kidney function deterioration were surgical complications, acute tubular necrosis, cell- or antibody-mediated rejection, diabetes mellitus, urinary leak, recurrence of original disease, and chronic allograft nephropathy. Thirteen patients experienced graft loss; 50% of these losses were secondary to noncompliance to immunosuppressant medication treatment after transplant. A total of six patients died; 2 (23%) of these deaths occurred in the first week after transplant, whereas the other 4 patients died over a period of 10 years. CONCLUSIONS: Pediatric kidney transplant is not without complications; however, most of these complications are treatable and reversible. The most serious complications leading to graft loss and death occur early, in the first week after transplant. Improving immunosuppressant compliance after transplant would prevent 50% of graft losses.

Living Kidney Donor Cancellation at King Hussein Medical Center.

OBJECTIVES: Living-related kidney donation is the main source of renal grafts in Jordan, since kidneys from deceased donors are scarce. Although the Jordanian community accepts the idea of kidney donation to family members, not all potential donors manage to complete the required psychologic and medical evaluations. We review the causes of kidney-donation cancellation and suggest options to increase the number of available organs. MATERIALS AND METHODS: We performed a retrospective chart review of all potential living-related kidney donors at King Hussein Medical Center between January 2008 and June 2016. RESULTS: Of 642 potential donors, 366 (57%) were male and 276 (43%) were female, ranging in age from 18 to 66 years with a mean age of 37 years. A total of 384 (59.8%) eventually donated a kidney. A donor issue was the cause of cancellation in 143 (22.3%), whereas 47 (32.9%) had a risk for renal impairment after donation (eg, hematuria, proteinuria, stones, multiple renal cysts, scarred kidney, congenital malformation, recurrent urinary tract infection), and 30 (21%) had blood group or immunologic incompatibilities. Fifteen (10.5%) withdrew during the evaluation process, 13 (9%) had hypertension, 10 (7%) had a high body mass index, 8 (5.6%) were diabetic or prediabetic, 7 (4.9%) were surgically unsuitable, 4 (2.8%) had hepatitis B virus infection, 4 (2.8%) were pregnant, 3 (2.1%) had significant cardiovascular disease, 1 (0.7%) had splenomegaly with lymph node enlargement, and 1 (0.7%) had thyroiditis. CONCLUSIONS: Cancellation of kidney donation in Jordan is mainly for medical reasons, the most common being renal issues. Paired donation between blood group and immunologically incompatible duos may increase the number of organs available, as may good psychologic assessment and counseling of those likely to change their mind. Support should be provided for donors who drop out of donation for any cause, especially for renal and vascular issues.

Acute kidney injury in critically ill child.

Acute kidney injury (AKI) is a common and serious complication in patients in the Pediatric Intensive Care Unit (PICU). We conducted this study to estimate the incidence and the mortality rate of AKI in critically ill children as well as to describe some other related factors. A retrospective study was conducted at PICU of Queen Rania Abdulla Children Hospital, Amman, Jordan for the period extending from May 2011 to June 2013. The medical records of all patients admitted during this period, and their demographic data were reviewed. Patients with AKI were identified, and management and outcomes were reviewed and analyzed. AKI was evaluated according to modified RIFLE criteria. Of the 372 patients admitted to PICU, 64 (17.2%) patients developed AKI. Of these 64 patients who had AKI, 28 (43.7%) patients reached RIFLE max of risk, 21 (32.8%) patients reached injury, and 15 (23.4%) reached failure. Mean Pediatric Risk of Mortality II score at admission was significantly higher in patients with AKI than those without P <0.001. The age ranged between one month and 14 years with the median age as 5.4 year. Thirty-five (54.7%) were males. Sepsis was the most common cause of AKI. The mortality rate in critically ill children without AKI was 58.7%, whereas increased in children with AKI to 73.4%. The mortality rate in patients who received renal replacement therapy was 71.4% and was higher (81.5%) in patients who received mechanical ventilation (95%, [confidence interval (CI)] 79.3-83.4%) and was significantly higher in patients with multi-organ system dysfunction 90.3% (95%, [CI] 88.7-92.5%). The incidence of AKI in critically ill children is high and increased their mortality rate and higher mortality seen in the younger age group, especially those below one year. High mortality rate was associated with multi-organ system dysfunction and the need for mechanical ventilation.

The clinical pattern of primary hyperoxaluria in pediatric patient at Queen Rania Abdulla Children Hospital.

INTRODUCTION: Hyperoxaluria is a metabolic disorder that can lead to end stage renal disease (ESRD). It can be either inherited or acquired. Primary hyperoxaluria (PHO) is more common and characterized by an excessive production of oxalate leading to recurrent urolithiasis and progressive nephrocalcinosis. Due to the high rate of consanguineous marriage in Jordan this disease is commonly diagnosed in pediatric nephrology clinics. We aimed to demonstrate the clinical pattern and progression to ESRD in pediatric patients with hyperoxaluria at Queen Rania Abdulla Children Hospital. METHODS: Medical records of all patients followed up in the pediatric nephrology clinic with the diagnosis of PHO during the period between September 2007 and March 2013 were reviewed. RESULTS: There were 70 patients with the diagnosis of PHO, 52.9% were males. The median age at presentation was 3 years ± 3 months with the youngest child being two months old. Diagnosis was made in the first year of life in 15.7% of patients. The most common presenting symptom was hematuria, while 14% of patients were asymptomatic and detected by family screening after the diagnosis of an index case. At the time of initial presentation, 15.7% of patients had ESRD and 25% had impaired renal function. Kidney stones were found in 57% of cases and nephrocalcinosis was found in 37%. CONCLUSION: High index of suspicion is needed to diagnose PHO in children presenting with kidney stone or unexplained hematuria. Twenty-four hour urine collection for oxalate are required to make the proper diagnosis. Family screening, when appropriate, is indicated for early detection of PHO.

Hypercalcemia, hypercalciuria and nephrocalcinosis in a breast-fed term newborn: a rare presentation.

Although hypercalcemia and hypercalciuria are known to occur in breast-fed pre-term infants, to the best of our knowledge, it has never been reported in a term baby previously. We report a term male baby who was followed-up during pregnancy for having bright kidneys, but a follow-up renal ultrasound (US) after birth had revealed normal scan. Laboratory investigations revealed normal serum calcium (Ca), phosphorous (PO4) and alkaline phosphatase (ALP). The baby was being fed by breast milk. Follow-up US two months later showed early nephrocalcinosis along with hypercalcemia and hypercalciuria; by the age of three months, nephrocalcinosis was more extensive and the serum Ca level was more than 12 mg/L with hypercalciuria. Parathyroid hormone (PTH), phosphorous (PO4), ALP and thyroid function tests were all normal. Antenatal history revealed a hypothyroid mother who was maintained on L-thyroxin, calcium and vitamin D supplement during pregnancy. Her blood tests showed normal serum Ca, low PO4 and elevated PTH. The baby was diagnosed to have hypercalciuria and hypercalcemia secondary to maternal hypophosphatemia (maternal vitamin D deficiency). Breast feeding was stopped and the baby was started on formula, whereby he showed remarkable improvement both for his blood chemistry as well as his hypercalciuria.

The impact of CYP3A5 and MDR1 polymorphisms on tacrolimus dosage requirements and trough concentrations in pediatric renal transplant recipients.

Previous international studies demonstrated significant heterogeneity in the tacrolimus (TAC) dose required to attain target blood concentrations, attributed to both genetic and ethnic factors. While the majority of previous reports on adult recipients of renal, heart and liver transplants have shown a significant effect of CYP3A5FNx013 single nucleotide polymorphisms (SNPs) on TAC pharmacokinetics (PKs), the impact of multidrug resistance protein 1 (MDR1) and SNPs remains controversial. Yet, similar data of TAC in pediatric populations, in whom the intra- and inter-subject variations are likely to be even greater, is currently limited. We aimed to examine the influence of various CYP3A5 and MDR1 genotypes on TAC dose requirements and PKs in the Jordanian pediatric renal transplant population. Thirty-eight patients were genotyped for CYP3A5FNx011 and FNx013 and MDR1 C3435T. Dose-adjusted trough concentrations (C 0 /D) and daily doses (D) were compared among different CYP3A5 and MDR1 genotypes in the early and maintenance phases post-transplant. Surprisingly, there were no significant differences in D, C 0 or C 0 /D among the genotypes of CYP3A5 or MDR1 polymorphisms in either the early or the maintenance phase after transplantation, whereas after combining the C 0 /D levels of MDR1 C allele expressers, noticeably lower TAC levels were observed as compared with the TT genotype. However, the difference became not significant beyond 3 months. Based on a pharmacogenetic evaluation, the independent impact of CYP3A5 SNPs on TAC PKs was not evident, demonstrating the need for further large-scale studies.