Publications by authors named "Markus J Kemper"

Background: X-linked hypophosphatemia (XLH) is a rare inherited phosphate-wasting disorder associated with bone and dental complications. Health-related quality of life (HRQoL) is reduced in XLH patients on conventional treatment with phosphate supplements and active vitamin D, while information on patients treated with burosumab is rare.

Methods: HRQoL was assessed in 63 pediatric XLH patients participating in a prospective, observational study and patient registry in Germany using the KIDSCREEN-52 survey instrument and standardized qualitative interviews.

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Background: Infantile nephropathic cystinosis (INC) is a rare lysosomal storage disorder, mostly and often firstly affecting the kidneys, together with impaired disharmonious growth and rickets, eventually resulting in progressive chronic kidney disease (CKD). With the introduction of cysteamine therapy, most pediatric patients reach adulthood with no need for kidney replacement therapy. Still, detailed changes in INC patients' clinical and morphological presentation over the past decades have not yet been thoroughly investigated.

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Background: Kidney transplantation (KTx) from small donors is associated with inferior graft survival in registry studies, whereas single-center studies show favorable results.

Methods: We compared 175 pediatric KTx from small donors ≤20 kg (SDKTx) with 170 age-matched recipients from adult donors (ADKTx) from 20 centers within the Cooperative European Paediatric Renal Transplant Initiative registry. Graft survival and estimated glomerular filtration rate (eGFR) were analyzed by Cox regression and mixed models.

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Background: Shiga toxin-producing E. coli-hemolytic uremic syndrome (STEC-HUS) is associated with high morbidity and relevant mortality. Previous small studies showed that volume expansion could improve the course and outcome of STEC-HUS.

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Background: Early onset focal segmental glomerular sclerosis (FSGS) in the kidney allograft in patients without FSGS in the native kidney is a rare disorder in children. It usually occurs mostly beyond the first year after kidney transplantation and often leads to graft loss. Standardized treatment protocols have not yet been established.

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Background: Infantile nephropathic cystinosis (INC) is a systemic lysosomal storage disease causing intracellular cystine accumulation, resulting in renal Fanconi syndrome, progressive kidney disease (CKD), rickets, malnutrition, and myopathy. An INC-specific disproportionately diminished trunk length compared to leg length poses questions regarding the functionality of the trunk.

Methods: Thus, we prospectively investigated thoracic dimensions and proportions, as well as their clinical determinants in 44 pediatric patients with INC with CKD stages 1-5 and 97 age-matched patients with CKD of other etiology between the ages of 2-17 years.

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Context: Burosumab has been approved for the treatment of children and adults with X-linked hypophosphatemia (XLH). Real-world data and evidence for its efficacy in adolescents are lacking.

Objective: To assess the effects of 12 months of burosumab treatment on mineral metabolism in children (aged <12 years) and adolescents (aged 12-18 years) with XLH.

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Introduction: Combined or sequential liver and kidney transplantation (CLKT/SLKT) restores kidney function and corrects the underlying metabolic defect in children with end-stage kidney disease in primary hyperoxaluria type 1 (PH1). However, data on long-term outcome, especially in children with infantile PH1, are rare.

Methods: All pediatric PH1-patients who underwent CLKT/SLKT at our center were analyzed retrospectively.

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Patients with primary hyperoxaluria type I (PH I) are prone to develop early kidney failure. Systemic deposition of calcium-oxalate (CaOx) crystals starts, when renal function declines and plasma oxalate increases. All tissue, but especially bone, heart and eyes are affected.

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Almost 2 years into the pandemic and with vaccination of children significantly lagging behind adults, long-term pediatric humoral immune responses to SARS-CoV-2 are understudied. The C19.CHILD Hamburg (COVID-19 Child Health Investigation of Latent Disease) Study is a prospective cohort study designed to identify and follow up children and their household contacts infected in the early 2020 first wave of SARS-CoV-2.

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Background: Pulse wave velocity (PWV) is a measure of arterial stiffness. We investigated PWV and blood pressure (BP) to determine to what extent BP changes contribute to arterial stiffness, and secondly, to identify influencing factors on BP in children after kidney transplantation.

Methods: Seventy children ≥ 2.

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Background: Long-term outcomes after multiple courses of rituximab among children with frequently relapsing, steroid-dependent nephrotic syndrome (FRSDNS) are unknown.

Methods: A retrospective cohort study at 16 pediatric nephrology centers from ten countries in Asia, Europe, and North America included children with FRSDNS who received two or more courses of rituximab. Primary outcomes were relapse-free survival and adverse events.

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Children with infantile nephropathic cystinosis (INC), an inherited lysosomal storage disease resulting in cystine accumulation in all body cells, are prone to progressive chronic kidney disease (CKD), impaired growth and reduced weight gain; however, systematic anthropometric analyses are lacking. In this prospective multicenter study we investigated linear growth, body proportion, body mass index (BMI), upper arm fat area (UFA) and biochemical parameters in 43 pediatric INC patients with CKD stages 1 to 5 and 49 age-matched CKD controls, with 193 annual measurements. INC patients showed more impaired height than CKD controls (-1.

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Idiopathic nephrotic syndrome is the most frequent glomerular disease in children in most parts of the world. Children with steroid-sensitive nephrotic syndrome (SSNS) generally have a good prognosis regarding the maintenance of normal kidney function even in the case of frequent relapses. The course of SSNS is often complicated by a high rate of relapses and the associated side effects of repeated glucocorticoid (steroid) therapy.

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Background: Hemoconcentration has been identified as a risk factor for a complicated course in Shiga toxin-producing E. coli-hemolytic uremic syndrome (STEC-HUS). This single-center study assesses hemoconcentration and predictors at presentation in STEC-HUS treated from 2009-2017.

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Context: Children with nephropathic cystinosis (NC) show persistent hypophosphatemia, due to Fanconi syndrome, as well as mineral and bone disorders related to chronic kidney disease (CKD); however, systematic analyses are lacking.

Objective: To compare biochemical parameters of bone and mineral metabolism between children with NC and controls across all stages of CKD.

Design: Cross-sectional multicenter study.

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Rituximab is an effective treatment for steroid-dependent/ frequently-relapsing nephrotic syndrome (SDFRNS) in children. However, the optimal rituximab regimen remains unknown. To help determine this we conducted an international, multicenter retrospective study at 11 tertiary pediatric nephrology centers in Asia, Europe and North America of children 1-18 years of age with complicated SDFRNS receiving rituximab between 2005-2016 for 18 or more months follow-up.

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Steroid sensitive nephrotic syndrome is one of the most common pediatric glomerular diseases. Unfortunately, it follows a relapsing and remitting course in the majority of cases, with 50% of all cases relapsing once or even more often. Most children with idiopathic nephrotic syndrome respond initially to steroid therapy, nevertheless repeated courses for patients with relapses induce significant steroid toxicity.

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In primary hyperoxaluria type 1 (PH1), systemic oxalate deposition (oxalosis) in end-stage renal disease (ESRD) is associated with high morbidity and mortality, particularly in children with infantile oxalosis (IO). Combined liver and kidney transplantation (CLKT) is the only curative treatment option in these patients. After CLKT, systemic oxalosis decreases continuously, although only insufficient data are available regarding oxalate retinopathy (ROx), leading to severe visual impairment.

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Background: Cardiovascular comorbidity is of increasing importance after transplantation. Metabolic syndrome (MS) contributes to the risk for cardiovascular sequelae. Our aim was to assess the risk for MS in pediatric solid organ and stem cell transplant recipients by comparing them with matched untransplanted peers in a multicenter study.

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Introduction: Idiopathic nephrotic syndrome is the most common glomerular disease in childhood with an incidence of 1.8 cases per 100 000 children in Germany. The treatment of the first episode implies two aspects: induction of remission and sustainment of remission.

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