Chronic kidney disease ten years after pediatric allogeneic hematopoietic stem cell transplantation.

Chronic kidney disease (CKD) is an important sequela of hematopoietic stem cell transplantation (HSCT), but data regarding CKD after pediatric HSCT are limited. In this single center cohort study, we evaluated the estimated glomerular filtration rate (eGFR) dynamics, proteinuria and hypertension in the first decade after HSCT and assessed risk factors for CKD in 216 pediatric HSCT survivors, transplanted 2002-2012. The eGFR decreased from a median of 148 to 116 ml/min/1.73 m2 between pre-HSCT to ten years post-HSCT. CKD (KDIGO stages G2 or A2 or more; eGFR under 90 ml/min/1.73m2 and/or albuminuria) occurred in 17% of patients. In multivariate analysis, severe prolonged stage 2 or more acute kidney injury (AKI), with an eGFR under 60ml/min/1.73m2 and duration of 28 days or more, was the main risk factor for CKD (hazard ratio 9.5, 95% confidence interval 3.4-27). Stage 2 or more AKI with an eGFR of 60ml/min/1.73m2 or more and KDIGO stage 2 or more AKI with eGFR under 60ml/min/1.73m2 but recovery within 28 days were not associated with CKD. Furthermore, hematological malignancy as HSCT indication was an independent risk factor for CKD. One third of patients had both CKD criteria, one third had isolated eGFR reduction and one third only had albuminuria. Hypertension occurred in 27% of patients with CKD compared to 4.4% of patients without. Tubular proteinuria was present in 7% of a subgroup of 71 patients with available ß2-microglobulinuria. Thus, a significant proportion of pediatric HSCT recipients developed CKD within ten years. Our data stress the importance of structural long-term monitoring of eGFR, urine and blood pressure after HSCT to identify patients with incipient CKD who can benefit from nephroprotective interventions.

Renal function in neonates with twin-twin transfusion syndrome treated with or without fetoscopic laser surgery.

The aim of this study is to investigate the short-term renal function in neonates with twin-twin transfusion syndrome (TTTS), treated with fetoscopic laser surgery (laser group) or conservatively (non-laser group). Creatinine and urea levels and urine output were recorded in the first week after birth. Primary outcome was short-term renal dysfunction, defined as a creatinine level of >100 µmol/L during the first week postpartum. We evaluated 312 twins (laser group, n = 274; non-laser group, n = 38). Median creatinine and urea levels were lower in the laser group than in the non-laser group (71 versus 82 µmol/L, p = 0.002). Short-term renal dysfunction was lower in the laser group compared to the non-laser group (7.2 versus 34.4%, p < 0.001). Within the laser group, creatinine levels were significantly higher in the subgroup with incomplete laser surgery compared to twins with successful laser surgery (76 versus 69 µmol/L, p = 0.018). No differences were found between donors and recipients except for a higher incidence of oliguria in donors in the non-laser group on day 1. CONCLUSION: Short-term renal dysfunction occurs less frequently in TTTS twins treated with fetoscopic laser coagulation, particularly after complete surgery, suggesting that laser surgery may have a protective effect on renal function. What is Known: • Antenatally, donor twins in TTTS have severe oliguria due to chronic hypovolemia and impaired renal perfusion • Postnatally, donor twins may suffer from severe renal complications, particularly in TTTS twins treated conservatively. What is New: • The incidence of short-term renal failure in TTTS twins treated with complete laser surgery is low. • After incomplete laser surgery, the incidence of short-term renal dysfunction is increased.

Pharmacokinetics of rituximab in a pediatric patient with therapy-resistant nephrotic syndrome.

BACKGROUND: Rituximab (RTX) has recently been introduced as a second-line therapy for nephrotic syndrome in children. Studies show that RTX given during the nephrotic state may be less effective than treatment during a non-nephrotic state, possibly due to loss of RTX in the urine. CASE-DIAGNOSIS/TREATMENT: We describe a 10-year-old boy with steroid-resistant nephrotic syndrome (SRNS) treated with RTX during a phase of active non-selective proteinuria. The serum half-life of RTX in this patient was less than 1 day compared to 20 days in patients without protein losses. Urinary clearance was at least 25 %, compared to approximately 0 % in control patients. However, RTX loss in the urine, as well as in pleural effusion and ascites, only partly explains the rapid drop in the serum RTX concentration of this patient. CONCLUSIONS: Serum half-life of RTX can be extremely short, partly due to excessive urinary losses in therapy-resistant nephrotic syndrome with non-selective proteinuria, as seen in our patient. These findings may help to explain the poor results of RTX treatment in patients with active proteinuria.

Clinical evaluation of viral acute respiratory tract infections in children presenting to the emergency department of a tertiary referral hospital in the Netherlands.

BACKGROUND: The relative incidence and clinical impact of individual respiratory viruses remains unclear among children presenting to the hospital emergency department with acute respiratory tract infection (ARTI). METHODS: During two winter periods, respiratory virus real-time multiplex PCR results were evaluated from children (< 18 years) presenting to the emergency department of a tertiary referral hospital with ARTI that had been sampled within 48 hours of hospital presentation. In an attempt to identify virus-specific distinguishing clinical features, single virus infections were correlated with presenting signs and symptoms, clinical findings and outcomes using multivariate logistic regression. RESULTS: In total, 274 children with ARTI were evaluated and most were aged < 3 years (236/274, 86%). PCR detected respiratory viruses in 224/274 (81.8%) children and included 162 (59%) single and 62 (23%) mixed virus infections. Respiratory syncytial virus (RSV) and human rhinovirus (HRV) single virus infections were common among children aged < 3 years, but proportional differences compared to older children were only significant for RSV (95% CI 1.3-15). Clinical differentiation between viral ARTIs was not possible due to common shared presenting signs and symptoms and the high frequency of mixed viral infections. We observed virus-associated outcome differences among children aged < 3 years. Oxygen treatment was associated with RSV (OR 3.6) and inversely correlated with FLU (OR 0.05). Treatment with steroids (OR 3.4) or bronchodilators (OR 3.4) was associated with HRV. Severe respiratory complications were associated with HRV (OR 3.5) and inversely correlated with RSV (OR 0.24). CONCLUSIONS: Respiratory viruses are frequently detected in young children presenting to the hospital emergency department with ARTI and require PCR diagnosis since presenting signs and symptoms are not discriminant for a type of virus. RSV and HRV bear a high burden of morbidity in the pediatric clinical setting.

Perceived discomfort levels in healthy children participating in vaccine research.

When assessing the risks of a research protocol, review boards need to consider not only the possible harms but also the expected discomfort levels caused by the various study procedures. However, data on how children experience various study procedures are scarce. This study assessed perceived discomfort levels in 671 healthy children aged 0-2 years under-going vaccinations, venipunctures, and nasopharyngeal swab taking. In half of the study participants, venipunctures caused a moderate or high level of discomfort (49%). Corresponding figures for nasopharyngeal swabbing and vaccinations were 28% and 12%, respectively. Within the reported age group, increasing age was related with higher discomfort levels. In a majority of cases for all study procedures, the perceived levels of discomfort met the parents' expectations.

Discomfort in children undergoing unsedated MRI.

Magnetic resonance imaging (MRI) scans for research purposes usually do not directly benefit the children scanned, so that review boards need to assess whether the risk of harm or discomfort is minimal. This study aimed at providing empirical data on discomfort related to unsedated MRI in children aged 5-12 years. Secondary objectives were to determine whether lower age is associated with higher levels of discomfort and to investigate which other characteristics of subjects and/or procedures may be associated with higher levels of discomfort. Self-report scores, observation scores, heart rate standard deviation scores, and incremental salivary cortisol levels were obtained from 54 children aged 5-12 years with non-acute conditions undergoing diagnostic MRI. Of the 54 children, 10 scored relatively high values on the self-report score and on one or two of the other measures, and another 15 scored relatively high on the self-report score alone. Rather than an age effect, associations were found between parents' trait anxiety and observation score values and between use of contrast fluid (requiring the insertion of a venous cannula) and high incremental salivary cortisol levels. In conclusion, MRI-related discomfort may be regarded as minimal for more than half of children aged 5-12.

IDH2 mutations in patients with D-2-hydroxyglutaric aciduria.

Heterozygous somatic mutations in the genes encoding isocitrate dehydrogenase-1 and -2 (IDH1 and IDH2) were recently discovered in human neoplastic disorders. These mutations disable the enzymes' normal ability to convert isocitrate to 2-ketoglutarate (2-KG) and confer on the enzymes a new function: the ability to convert 2-KG to d-2-hydroxyglutarate (D-2-HG). We have detected heterozygous germline mutations in IDH2 that alter enzyme residue Arg(140) in 15 unrelated patients with d-2-hydroxyglutaric aciduria (D-2-HGA), a rare neurometabolic disorder characterized by supraphysiological levels of D-2-HG. These findings provide additional impetus for investigating the role of D-2-HG in the pathophysiology of metabolic disease and cancer.

Acceptable risks and burdens for children in research without direct benefit: a systematic analysis of the decisions made by the Dutch Central Committee.

OBJECTIVES: To evaluate whether the requirement of "minimal risk and burden" for paediatric research without direct benefit to the subjects compromises the ability to obtain data necessary for improving paediatric care. To provide evidence-based reflections on the EU recommendation that allows for a higher level of risk. DESIGN AND SETTING: Systematic analysis of the approval/rejection decisions made by the Dutch Central Committee on Research involving Human Subjects (CCMO). REVIEW METHODS: The analysis included 165 proposals for paediatric research without direct benefit that were reviewed by the CCMO between January, 2000, and July, 2007. A separate, in-depth analysis of all drug studies included 18 early phase drug studies and nine other drug studies without direct benefit. RESULTS: 11 out of 165 studies were definitively rejected because the CCMO did not regard the risk and/or burden to be minimal. In three of these 11 cases (including two early phase drug studies) the requirement of minimal risk and burden was cited as the only reason for rejection. Four other early phase drug studies also involved risks and/or burdens that were not regarded to be minimal but were nevertheless approved. CONCLUSIONS: The requirement of minimal risk and burden, aiming to protect research subjects, occasionally leads to rejection of protocols. Early phase drug studies relatively often do not comply with the requirement. Committees may find ways to approve important studies that formally should be rejected, but that is not a desirable solution. The regulatory framework should be revised to make such occasional exceptions to the requirement legitimate and transparent.

Stimulation programs for pediatric drug research--do children really benefit?

Most drugs that are currently prescribed in pediatrics have not been tested in children. Pediatric drug studies are stimulated in the USA by the pediatric exclusivity provision under the Food and Drug Administration Modernization Act (FDAMA) that grants patent extensions when pediatric labeling is provided. We investigated the effectiveness of these programs in stimulating drug research in children, thereby increasing the evidence for safe and effective drug use in the pediatric population. All drugs granted pediatric exclusivity under the FDAMA were analyzed by studying the relevant summaries of medical and clinical pharmacology reviews of the pediatric studies or, if these were unavailable, the labeling information as provided by the manufacturer. A systematic search of the literature was performed to identify drug utilization patterns in children. From July 1998 to August 2006, 135 drug entities were granted pediatric exclusivity. Most frequent drug groups were anti-depressants and mood stabilizers, ACE inhibitors, lipid-lowering preparations, HIV antivirals, and non-steroidal anti-inflammatory and anti-rheumatic drugs. The distribution of the different drugs closely matched the distribution of these drugs over the adult market, and not the drug utilization by children. Many drug studies in children have been performed since the introduction of the FDAMA. However, children infrequently use the drugs granted pediatric exclusivity. The priorities for pediatric drug research should be set by the need of the patients, not by market considerations.

A toddler with recurrent oral and genital ulcers.

In western countries, when a child presents with recurrent oral ulcers and colitis, the diagnosis of Crohn's disease is mostly made. In our patient, the diagnosis was Behçet's disease with gastrointestinal manifestations. Behçet's disease with gastrointestinal manifestations has a similar clinical presentation to Crohn's disease, but there is more organ involvement and the prognosis is more severe in the former. Because there is limited experience in the treatment of Behçet's disease in the paediatric population, successful and unsuccessful treatment modalities in both paediatric and adult populations should be reported.

Detection of respiratory pathogens by real-time PCR in children with clinical suspicion of pertussis.

The use of a multiplex respiratory real-time PCR in patients clinically suspected of pertussis increases the number of pathogens detected.