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Markus J Kemper

Publications and source records attributed to Markus J Kemper.

At least 19 recordsLinked to original sources
PubMed2007

Prognosis of antenatally diagnosed oligohydramnios of renal origin.

Although clinical outcome data on fetuses with oligohydramnios of renal origin are scarce, prognosis is regarded as poor due to a high risk of renal dysfunction and pulmonary hypoplasia. This review aims to summarize the current knowledge and clinical experience with patients presenting antenatally with renal oligohydramnios. By reviewing the underlying mechanisms, complications, and outcome data, we hope to further improve antenatal counseling and postnatal care. We conclude that prognosis of ROH has changed in recent years. While early data before the introduction of sophisticated neonatal intensive care and renal replacement therapy indicated a poor prognosis, nowadays, a much more optimistic prognosis of children after renal oligohydramnios can be expected from the recent publications in the literature.

Female↗
PubMed2006

Antenatal oligohydramnios of renal origin: long-term outcome.

BACKGROUND: Prognosis of fetuses with renal oligohydramnios (ROH) is often still regarded as poor. Neonatal complications and the long-term follow-up of fetuses with ROH in two pediatric centres are described. Method. 23 fetuses (16 males, 7 females) were included as patients. Primary diseases included congenital anomalies of the kidney and urinary tract (n = 16), autosomal recessive polycystic kidney disease (n = 4) and renal tubular dysgenesis (n = 3). The analysis includes retrospective chart review. RESULTS: Seven children died (30%), the majority (n = 4, 17%) within the neonatal period due to pulmonary hypoplasia and renal insufficiency. Fourteen patients (61%) required postnatal mechanical ventilation for a median of 4 (range 1-60) days; 11 infants had an associated pneumothorax. All 16 surviving children have chronic kidney disease (CKD) at a current median age of 5.7 years (range 0.5-14.5), managed conservatively in eight patients [median glomerular filtration rate 51 (range 20-78) ml/min/1.73 m(2)]. Eight patients reached end-stage renal disease at a median age of 0.3 years (range 2 days to 8.3 years), including one patient with pre-emptive kidney transplantation. Five of the patients requiring dialysis underwent successful renal transplantation at a median age of 3.5 years (range 2.5-4). Growth was impaired in seven children requiring growth hormone treatment. Cognitive and motor development was normal in 12 (75%) of the 16 patients and showed a delay in four children, including two with associated syndromal features. CONCLUSION: ROH is not always associated with a poor prognosis and long-term outcome in survivors is encouraging. The high incidence of neonatal complications and long-term morbidity due to CKD requires a multidisciplinary management of these children.

Adolescent↗
PubMed2006

High prevalence of febrile urinary tract infections after paediatric renal transplantation.

BACKGROUND: Adult data suggest that urinary tract infections occur frequently after renal transplantation (RTx) and contribute to mortality and graft loss; data in children are limited. Therefore, we evaluated prevalence, short and long-term morbidity and confounding factors of febrile UTI (fUTI) after paediatric RTx. METHODS: In a retrospective cross-sectional study of three centres, we analysed data on 110 children followed for 4.9+/-3.4 years after successful transplantation. RESULTS: 40/110 (36%) patients had at least one fUTI at a median time of 0.98 years (range 0.02-8.96) after RTx; 11 patients (28%) had recurrent fUTI. Serum creatinine (SCr) rose significantly from 1.15+/-1.13 to 1.83+/-1.69 mg/dl, (P<0.001) during the fUTI, declining to baseline values after treatment. At the last followed-up calculated mean, GFR was comparable between fUTI and non-fUTI groups (75+/-26 vs 71+/-22 ml/min/1.73 m2). During fUTI mean, C-reactive protein (CRP) increased to 123+/-75 mg/l. Febrile UTI were significantly more frequent in girls compared to boys (22/44 vs 18/66, P<0.05) but occurred significantly earlier in boys than in girls [median 0.63 (range 0.02-4.15) vs 1.07 (0.04-8.96) years after RTx; P<0.02]. Also, patients with urinary tract malformations (UTMs) and neurogenic bladder as underlying diagnosis and those with urological surgery prior to transplantation had an increased risk for fUTI. CONCLUSION: fUTI is a frequent complication with significant short-term morbidity especially in girls and children with UTMs, neurogenic bladder and those with urological surgery. Long-term follow-up and prospective studies confirming specific risk factors, preventive measures and impact on graft survival are necessary.

Child↗
PubMed2006

Hyperuricemia and gout following pediatric renal transplantation.

Hyperuricemia and gout are common complications in adult renal transplant recipients. In pediatric recipients, however, hyperuricemia seems to be rare, but data are scarce. Thirty-two children (21 males, 11 females) were investigated for a median time of 4.8 years (range: 0.4-11.2 years) following renal transplantation. The median age of this pediatric study group was 13.9 years (range: 5.7-20.3 years), and the calculated glomerular filtration rate (GFR) was 61 ml/min per 1.73 m(2) (range:12-88 ml/min per 1.73 m(2)). All patients were given calcineurin inhibitors, with 22 and ten children receiving cyclosporine A (CSA) and tacrolimus (TAC), respectively. The median plasma uric acid was 385 micromol/l (range: 62-929 micromol/l); 15 children (47%) were above the age-related normal range. Only one patient experienced gouty arthritis. There was a significant correlation between plasma uric acid concentration and both time span after transplantation and plasma creatinine, and an inverse correlation to GFR (p<0.05). No significant correlation was found between plasma uric acid and body mass index (BMI). Plasma uric acid concentrations were neither different among CSA- and TAC-treated children, nor did they correlate with drug exposure or blood trough levels of CSA or TAC. Plasma uric acid concentration was not different when compared to children with chronic renal failure (CRF) of a similar degree in native kidneys. We conclude that hyperuricemia is common among pediatric renal transplant recipients and rather a consequence of chronic renal transplant dysfunction than the use of calcineurin inhibitors. Gout, however, is rare.

Adolescent↗
PubMed2006

Body growth after combined liver-kidney transplantation in children with primary hyperoxaluria type 1.

BACKGROUND: Children with primary hyperoxaluria type 1 (PH1) often develop severe growth failure, which is related to metabolic and endocrine consequences of chronic renal failure, and/or oxalate deposition in bone and cartilage. Combined liver and kidney transplantation (LKT) corrects the underlying metabolic defect and restores renal function in these children. METHODS: We therefore analyzed longitudinal growth of 24 children with PH1 who underwent LKT at nine European centers. Mean age at LKT was 8.9 years, and mean duration of follow-up was 5.7 years. RESULTS: After LKT mean standardized height tended to increase from -1.79 SD to -1.47 SD until last observation. Mean adult height amounted to 167 cm and 158 cm in boys and girls, respectively. At last observation, seven out of 24 patients were stunted. Within the whole study population, the degree of catch-up growth after LKT was positively associated with degree of stunting at the time of LKT and negatively associated with prednisolone dosage explaining together 39% of the overall variability. CONCLUSIONS: Combined LKT does not induce true catch-up growth in the majority of children with PH1. Due to the preexisting growth retardation at the time of LKT, one third of patients end up with a reduced final height.

Body Height↗
PubMed2006

The centrosomal protein nephrocystin-6 is mutated in Joubert syndrome and activates transcription factor ATF4.

The molecular basis of nephronophthisis, the most frequent genetic cause of renal failure in children and young adults, and its association with retinal degeneration and cerebellar vermis aplasia in Joubert syndrome are poorly understood. Using positional cloning, we here identify mutations in the gene CEP290 as causing nephronophthisis. It encodes a protein with several domains also present in CENPF, a protein involved in chromosome segregation. CEP290 (also known as NPHP6) interacts with and modulates the activity of ATF4, a transcription factor implicated in cAMP-dependent renal cyst formation. NPHP6 is found at centrosomes and in the nucleus of renal epithelial cells in a cell cycle-dependent manner and in connecting cilia of photoreceptors. Abrogation of its function in zebrafish recapitulates the renal, retinal and cerebellar phenotypes of Joubert syndrome. Our findings help establish the link between centrosome function, tissue architecture and transcriptional control in the pathogenesis of cystic kidney disease, retinal degeneration, and central nervous system development.

Activating Transcription Factor 4↗
PubMed2006

A de novo mutation in the AGXT gene causing primary hyperoxaluria type 1.

Primary hyperoxaluria type 1 is caused by mutations in the alanine-glyoxylate aminotransferase (AGXT) gene. In cases in which no mutation was identified, linkage analysis can be used to confirm or exclude the diagnosis in other siblings. We present a family in which a sibling of the index case predicted to have primary hyperoxaluria type 1 by means of linkage analysis failed to show hyperoxaluria during the following 7 years, putting the diagnosis into question. Whole-gene sequence analysis identified 2 causative mutations in the index case, of which only 1, c.646A (Gly216Arg), was inherited. The other sequence change, c.33_34insC, was a de novo mutation occurring on the paternal allele. This particular mutation is a relatively common cause of primary hyperoxaluria type 1. It occurs in a run of 8 cytosines and therefore potentially is susceptible to polymerase slippage. This case illustrates 2 important points. First, biochemical confirmation of a genetic diagnosis should always be made in siblings diagnosed by using genetic tests. Second, de novo mutations should be considered as a potential, albeit rare, cause of primary hyperoxaluria type 1.

Child, Preschool↗
PubMed2006

Long-term evaluation of cyclosporine and tacrolimus based immunosuppression in pediatric liver transplantation.

Both calcineurin inhibitors (CNIs), cyclosporine and tacrolimus, are widely used in pediatric liver transplant recipients and currently data are limited with regards to long-term results using the one drug or the other in comparable low doses. We conducted the present study to assess the advantages and disadvantages of both drugs in children at least five yr post-liver transplantation. A total of 129 children were enrolled in the study. Thirty-eight of the children were switched to tacrolimus monotherapy for different reasons [steroid resistant graft rejection (n = 15), chronic rejection (n = 5), severe acute rejection (n = 4), repetitive acute graft rejection (n = 5), dysfunction of the transplant (n = 3), insufficient CsA metabolism (n = 3), hypertrichosis (n = 2), and CsA toxicity (n = 1)], four patients had primary tacrolimus therapy, and 87 patients are receiving cyclosporine. Mean trough levels were 5.3 +/- 2.3 ng/mL (tacrolimus) and 73.6 +/- 44.5 micro/L (cyclosporine), respectively at least five yr post-orthotopic liver transplantation (OLT). There was no significant difference in the calculated glomerular filtration rate between children on cyclosporine and tacrolimus (142.7 + 39.5 mL/min/1.73 m(2) vs. 151.1 +/- 44.1 mL/min/1.73 m(2)). The incidence of arterial hypertension was 7.1% vs. 9.2%, that of hepatotoxicity was 0% vs. 2.3%. Cosmetic changes were found in more than one-third of the patients on cyclosporine and in 4.8% of the patients receiving tacrolimus. Quality of life was excellent in both groups (self assessment). The impact of CNIs on chronic graft dysfunction cannot be assessed by our present study. We conclude from the results that cyclosporine and tacrolimus are both excellent drugs for maintenance immunosuppression in the long-term course following pediatric liver transplantation. However, this retrospective analysis is limited by the bias between children on CsA as compared with patients receiving tacrolimus. A prospective randomized controlled trial is needed in order to assess which CNI is the best for children following OLT.

Calcineurin Inhibitors↗
PubMed2006

Angiotensin converting enzyme gene polymorphisms do not predict the course of idiopathic nephrotic syndrome in Swiss children.

AIM: Contradictory reports exist about a correlation of angiotensin I converting enzyme (ACE) gene polymorphisms to the outcome of idiopathic nephrotic syndrome (INS) in children. We investigated the frequency of ACE polymorphisms and their impact on the clinical course of INS in children in a Swiss hospital. METHODS: The ACE gene polymorphism (I, insertion; D, deletion) was assessed in 32 children - 22 with steroid-sensitive INS and 10 with steroid-resistant INS - with a median age at onset of INS of 2.9 years (range 1.1-15.0). Polymerase chain reaction amplification was performed on genomic DNA isolated from blood leucocytes. Results were correlated to clinical course and renal morphology. RESULTS: The ACE genotype was I/I, I/D and D/D in two, 12 and eight patients, respectively, with steroid-sensitive INS, and in one, eight and one patient, respectively, with steroid resistance. Renal morphology, available in 25 patients showed minimal change glomerulopathy in 17 patients (14 steroid-sensitive; three steroid-resistant) and focal segmental glomerulosclerosis in eight (one steroid-sensitive; seven steroid-resistant). There was no significant correlation between ACE genotype and steroid responsiveness, histology or outcome. ACE genotype was I/I, I/D and D/D in none, 12 and five patients, respectively, with minimal change glomerulopathy, and in one, five and two patients, respectively, with focal segmental glomerulosclerosis. Six patients with steroid-resistant nephrotic syndrome went into end stage renal disease; ACE genotype was I/I in one and I/D in five, but none were D/D. CONCLUSION: In contrast to previous reports, ACE gene polymorphism is irrelevant for clinical outcome, steroid responsiveness or morphology in Swiss children with INS.

Age of Onset↗
PubMed2005

Transplantation of infant en bloc kidneys into paediatric recipients.

En bloc renal transplantation (EBT) from infant donors is an option for children with end-stage renal failure. Owing to potential complications, EBT is not performed in all paediatric nephrology centres. We evaluated the perioperative and long-term course of five children undergoing EBT. Primary diagnosis was atypical (diarrhoea-negative) haemolytic uraemic syndrome (n=2), interstitial nephropathy (two siblings) and branchio-oto-renal syndrome (n=1). Recipient and donor ages ranged between 5.9 and 11.1 years and 0.3 and 2.5 years, respectively. Follow-up time after EBT was 2.1-13.2 years. Perioperative complications included (1) a renal artery thrombosis, with immediate intraoperative reconstruction and primary non-functioning of the graft, with recovery after 10 days, and (2) a vesico-ureteric obstruction, successfully managed with temporary insertion of a JJ-catheter. All grafts had good long-term function. Absolute glomerular filtration rate (GFR; millilitres/minute) increased in all patients, whereas relative GFR (millilitres/minute per 1.73 m(2) body surface area) remained stable during the follow-up period in all but one. Kidney size increased significantly, with maximal growth during the first year after EBT; magnetic resonance imaging (MRI) showed normal structure and vasculature. EBT is a safe and effective option for young children with end-stage renal failure. Absolute GFR and graft size increase and adapt to the children's growing body mass.

Age Factors↗
PubMed2005

The role of preemptive liver transplantation in primary hyperoxaluria type 1.

In primary hyperoxaluria the deficiency or mistargeting of hepatic alanine-glyoxylate aminotransferase (AGT) leads to the overproduction of oxalate resulting in hyperoxaluria and renal damage due to urolithiasis and/or nephrocalcinosis. Presently, the cure of the metabolic defect can be achieved only by liver transplantation. While for patients with end-stage renal disease combined hepatorenal transplantation is recommended, the concept of preemptive liver transplantation (PLTX), i.e. cure of the metabolic defect before renal damage occurs, has received considerable attention. Due to the heterogenous clinical course in PH1, optimal timing of PLTX is a matter of debate. Advocators of PLTX would consider a patient with a slowly declining GFR, reaching levels of 40-60 ml/min/1.73 m(2), as an ideal candidate, while others would continue medical treatment in these patients and opt for rapid combined liver-kidney transplantation if GFR reaches even lower levels. This review will discuss the background and rationale of PLTX and gives an update on 11 patients with PLTX who have been reported in the literature to date.

Humans↗
PubMed2005

Primary hyperoxaluria--the German experience.

BACKGROUND: Primary hyperoxaluria (PH) is a heterogeneous disease with variable age of onset and inconsistent progression into renal failure (ESRF). AIMS: In 1994 we initiated a survey within our Pediatric Nephrology working group to ascertain epidemiologic data and current practices. Updates were performed in 2000 and 2004. RESULTS: Diagnosis of PH was made in 65 patients (42 with PH type I, 3 with PH type II, 12 unclassified and 8 reported dead), which suggests a minimum prevalence of 0.7 per 1 million of the population. First symptoms were urolithiasis, nephrocalcinosis, urinary tract infection or hematuria. Diagnosis was often delayed and was made only in ESRF in 11% of patients. Measurement of urine metabolites or plasma oxalate in ESRF was performed in 76 and 57%, respectively. Determination of enzyme activity in liver biopsy (55% overall) and mutation analysis have increasingly been performed since 2000 (84.2 and 51%). Treatment included high fluid intake, pyridoxine, citrate and magnesium preparations. Pyridoxine response was reported in 21% of patients. No genotype/phenotype correlation was seen. Most patients (39) do not require renal replacement therapy, 5 patients receive chronic hemodialysis. Preemptive liver (n = 5) and combined liver-kidney transplantation (n = 9) were the preferred transplantation procedures. CONCLUSION: Despite increasing knowledge and awareness, diagnosis of PH is still too often delayed and diagnosis only made in ESRF. Most German patients, however, do currently not require renal replacement therapy. Genotype/phenotype correlations were not found. Combined liver kidney transplantation is the preferred procedure, but has its specific risks. Additional treatment options are clearly needed.

Citric Acid↗
PubMed2005

Changes of lymphocyte populations in pediatric steroid-sensitive nephrotic syndrome are more pronounced in remission than in relapse.

BACKGROUND/AIM: Although clinical and immunological findings in steroid-sensitive nephrotic syndrome (SSNS) favor an immunopathogenesis, many issues remain unsolved. Comprehensive studies analyzing cellular and humoral immunity in SSNS are scarce, and few studies addressed the effect of steroids on immunological factors. METHODS: We therefore performed a cross-sectional study of T and B lymphocyte populations in 89 children during the different stages of the disease and related the findings to parameters of humoral immunity and treatment with steroids. RESULTS: In untreated relapse, an increase in the proportion of activated CD3+ lymphocytes with a concomitant reduction of CD19+ B cells was noted compared to healthy controls. Conversely, patients with steroid dependency, relapsing on alternate-day steroids, showed a decline of the absolute numbers as well as proportion of CD4+ lymphocytes but a relative increase in CD19+ B cells, compared to healthy controls. Also untreated remission was characterized by an absolute and relative decrease in CD4+ lymphocytes compared to healthy controls which was accompanied by a significant increase in the proportion of CD8+ and also activated CD3+ lymphocytes. Steroid-induced remission resulted in suppression of absolute and relative CD4+, while absolute and relative B cells were upregulated in this group compared to untreated remission. SUMMARY AND CONCLUSION: Alterations of lymphocyte populations in SSNS are not limited to relapse but seem to be more pronounced in remission and show a different profile with steroid treatment. Changes of lymphocyte populations do not only affect T but also B lymphocytes, which may be of relevance in the pathogenesis of this disorder.

Adolescent↗
PubMed2005

Children with steroid-sensitive nephrotic syndrome come of age: long-term outcome.

OBJECTIVE: Long-term outcome of steroid-sensitive idiopathic nephrotic syndrome (SSNS) in children is usually considered benign, although data on follow-up into adulthood are scarce. The aim of this study was to investigate adults who had childhood SSNS regarding their relapse rate, growth, and renal and extrarenal morbidity. STUDY DESIGN: Adult patients (n=42, 26 males) were evaluated at a median age of 28.0 (18.1 to 46.9) years and a median follow-up of 22.0 (2.9 to 39.0) years since diagnosis. RESULTS: Fourteen of 42 (33%) patients relapsed in adulthood. The number of relapses during childhood and adolescence and a complicated course-administration of steroid-sparing medication such as cyclophosphamide, chlorambucil, and cyclosporin A-were identified as risk factors. Final adult height (median SD score -0.4, range -3.3 to +1.3) and body mass index (BMI) were normal. Renal function was normal in all patients, and overall morbidity was low. Only eight patients (three males) had children. Cytotoxic therapy was identified as a major factor contributing to childlessness. CONCLUSION: Relapses in adulthood were common in pediatric patients with SSNS. Growth and renal function were normal, and overall morbidity was low. Yet, transition to an adult nephrologist is recommended for all children with relapsing SSNS.

Adrenal Cortex Hormones↗
PubMed2004

Psychosocial impact of living-related kidney transplantation on donors and partners.

Living-related kidney transplantation (LRKT) is an option for children with end-stage renal failure. In addition to medical concerns, there is uncertainty about the psychological impact of living-related donation on parent donors and families. A survey was conducted on the decision making process and medical and psychosocial consequences of LRKT. Between 1992 and 1999, 20 parents donated a kidney for their child. A questionnaire including 24 items was sent to parent donors and their partners. Nineteen parents and partners responded; the median time after LRKT was 3 years. Donors and partners reported an independent decision making process with no significant influence of partners, relatives, or hospital staff. Partners were more concerned about medical problems than donors themselves (P <0.02). Donors and partners cited no medical problems except sustained pain. Both reported an improved personal relationship towards the transplanted child. Donors and partners also cited an improved personal relationship. The vast majority (18/19) of couples still supported the decision for organ donation. In conclusion, there was a high degree of satisfaction with the decision making process in LRKT. The great majority of donors and partners did not report negative medical or psychological consequences. The relationship between donor, partner, and recipient child improved after LRKT.

Adolescent↗
PubMed2004

BIOKID: randomized controlled trial comparing bicarbonate and lactate buffer in biocompatible peritoneal dialysis solutions in children [ISRCTN81137991].

BACKGROUND: Peritoneal dialysis (PD) is the preferred dialysis modality in children. Its major drawback is the limited technique survival due to infections and progressive ultrafiltration failure. Conventional PD solutions exert marked acute and chronic toxicity to local tissues. Prolonged exposure is associated with severe histopathological alterations including vasculopathy, neoangiogenesis, submesothelial fibrosis and a gradual loss of the mesothelial cell layer. Recently, more biocompatible PD solutions containing reduced amounts of toxic glucose degradation products (GDPs) and buffered at neutral pH have been introduced into clinical practice. These solutions contain lactate, bicarbonate or a combination of both as buffer substance. Increasing evidence from clinical trials in adults and children suggests that the new PD fluids may allow for better long-term preservation of peritoneal morphology and function. However, the relative importance of the buffer in neutral-pH, low-GDP fluids is still unclear. In vitro, lactate is cytotoxic and vasoactive at the concentrations used in PD fluids. The BIOKID trial is designed to clarify the clinical significance of the buffer choice in biocompatible PD fluids. METHODS/DESIGN: The objective of the study is to test the hypothesis that bicarbonate based PD solutions may allow for a better preservation of peritoneal transport characteristics in children than solutions containing lactate buffer. Secondary objectives are to assess any impact of the buffer system on acid-base status, peritoneal tissue integrity and the incidence and severity of peritonitis. After a run-in period of 2 months during which a targeted cohort of 60 patients is treated with a conventional, lactate buffered, acidic, GDP containing PD fluid, patients will be stratified according to residual renal function and type of phosphate binding medication and randomized to receive either the lactate-containing Balance solution or the bicarbonate-buffered Bicavera solution for a period of 10 months. Patients will be monitored by monthly physical and laboratory examinations. Peritoneal equilibration tests, 24-h dialysate and urine collections will be performed 4 times. Peritoneal biopsies will be obtained on occasion of intraabdominal surgery. Changes in small solute transport rates, markers of peritoneal tissue turnover in the effluent, acid-base status and peritonitis rates and severity will be analyzed.

Adolescent↗
PubMed2004

SIX1 mutations cause branchio-oto-renal syndrome by disruption of EYA1-SIX1-DNA complexes.

Urinary tract malformations constitute the most frequent cause of chronic renal failure in the first two decades of life. Branchio-otic (BO) syndrome is an autosomal dominant developmental disorder characterized by hearing loss. In branchio-oto-renal (BOR) syndrome, malformations of the kidney or urinary tract are associated. Haploinsufficiency for the human gene EYA1, a homologue of the Drosophila gene eyes absent (eya), causes BOR and BO syndromes. We recently mapped a locus for BOR/BO syndrome (BOS3) to human chromosome 14q23.1. Within the 33-megabase critical genetic interval, we located the SIX1, SIX4, and SIX6 genes, which act within a genetic network of EYA and PAX genes to regulate organogenesis. These genes, therefore, represented excellent candidate genes for BOS3. By direct sequencing of exons, we identified three different SIX1 mutations in four BOR/BO kindreds, thus identifying SIX1 as a gene causing BOR and BO syndromes. To elucidate how these mutations cause disease, we analyzed the functional role of these SIX1 mutations with respect to protein-protein and protein-DNA interactions. We demonstrate that all three mutations are crucial for Eya1-Six1 interaction, and the two mutations within the homeodomain region are essential for specific Six1-DNA binding. Identification of SIX1 mutations as causing BOR/BO offers insights into the molecular basis of otic and renal developmental diseases in humans.

Amino Acid Sequence↗