Objective. To document more fully the characteristics of chronic recurrent multifocal osteomyelitis (CRMO) in pediatric patients, to collect data on the outcomes and management of the disease, and to define prognostic factors.Methods. One hundred seventy-eight patients were included (123 female patients and 55 male patients), with a mean ؎ SD age at diagnosis of 10.9 ؎ 2.9 years. Inclusion criteria were a diagnosis of CRMO, evidence of at least one lesion of osteitis confirmed by imaging, and development of the syndrome before age 18 years.Results. Longitudinal clinical and imaging studies revealed that only 12 of 178 CRMO patients (7%) had unifocal lesions at the last medical visit. We were able to apply the clinical chronic nonbacterial osteomyelitis score to 110 of 178 patients (62%), which indicated that bone biopsy could have been avoided in 27 cases (25%). At the last medical visit, disease was in remission in only 73 of 171 patients (43%) (41% receiving therapy) after a mean ؎ SD of 47.9 ؎ 38.9 months; 44 of 171 patients (26%) experienced sequelae. Using cluster analysis, the CRMO cohort was separated into 3 homogeneous phenotypes (severe, mild, and intermediate). Patients with the severe phenotype had the worst prognosis. This group was entirely composed of male patients, most of whom had the multifocal form of CRMO and inflammatory syndrome. Patients with the mild phenotype had the best prognosis. This group was primarily composed of female patients with a unifocal form of CRMO and infrequent clavicle involvement and inflammatory syndrome. Patients with the intermediate phenotype had a good prognosis but greater reliance on treatment. This group primarily included female patients with multifocal lesions and inflammatory syndrome.Conclusion. This is the largest CRMO cohort described in the literature to date. Clinical evolution and imaging investigations confirmed the multifocal pattern of the disease. Three distinct subgroups of CRMO patients were distinguished, with very different prognoses.

The aim of this study was to develop a population pharmacokinetic model of tacrolimus in pediatric kidney transplant patients, identify factors that explain variability, and determine dosage regimens. Pharmacokinetic samples were collected from 50 de novo pediatric kidney transplant patients (age 2-18 years) who were on tacrolimus treatment. Population pharmacokinetic analysis of tacrolimus was performed using NONMEM, and the impact of variables (demographic and clinical factors, and CYP3A4-A5, ABCB1, and ABCC2 polymorphisms) was tested. The pharmacokinetic data were described by a two-compartment model that incorporated first-order absorption and lag time. The apparent oral clearance (CL/F) was significantly related to body weight (allometric scaling); in addition, it was higher in patients with low hematocrit levels and lower in patients with CYP3A5*3/*3. The population pharmacokinetic-pharmacogenetic model developed in de novo pediatric kidney transplant patients demonstrated that, in children, tacrolimus dosage should be based on weight, hematocrit levels, and CYP3A5 polymorphism. Individualization of therapy will enable the optimization of tacrolimus exposure, with resultant beneficial effects on kidney function in the initial post-transplantation period.

We confirmed in a large cohort of ante/ neonatal BS that deafness, transient hyperkalaemia and severe hypokalaemic hypochloraemic alkalosis orientate molecular investigations to BSND, KCNJ1 and CLCNKB genes, respectively. Chronic renal failure is a rare event, associated in this cohort with three genotypes and not always associated with nephrocalcinosis.

No abstract

The objective was to develop a population pharmacokinetic-pharmacogenetic model of mycophenolic acid following administration of mycophenolate mofetil (MMF) in de novo pediatric renal-transplant patients and identify factors that explain variability. The pharmacokinetic samples were collected from 89 de novo pediatric renal-transplant patients treated with MMF and studied during the first 60 postoperative days. All patients were genotyped for UGT1A8-A9, UGT2B7, and ABCC2. Population pharmacokinetic analysis was performed with the NONMEM and was validated using bootstrap visual predictive check. The pharmacokinetic data were best described by a 2-compartment model with Erlang distribution to describe the absorption phase. The covariate analysis identified body weight as an individual factor influencing central volume of distribution and concomitant immunosuppressive medication and identified body weight and UGT2B7 802C>T genotype as individual factors influencing apparent oral clearance (CL/F) of MMF. CL/F in cyclosporine-MMF-treated patients was 33% higher than in tacrolimus-MMF-treated patients. The CL/F was significantly lower in patients with UGT2B7 802 C/C genotype compared with patients with UGT2B7 802 C/T and 802T/T genotypes, and this effect was independent of concomitant immunosuppressive medication or body weight. The population pharmacokinetic-pharmacogenetic model of mycophenolic acid was validated. Body weight, concomitant medication, and UGT2B7 genotype contribute significantly to the interindividual variability of MMF disposition in pediatric renal-transplant patients.

Inappropriate stimulation or defective negative regulation of the type I interferon response can lead to autoinflammation. In genetically uncharacterized cases of the type I interferonopathy Aicardi-Goutières syndrome, we identified biallelic mutations in LSM11 and RNU7-1, encoding components of the replication-dependent histone pre-mRNA processing complex. Mutations were associated with the misprocessing of canonical histone transcripts, and a disturbance of linker histone stoichiometry. Additionally, we observed an altered distribution of nuclear cyclic GMP-AMP synthase (cGAS), and enhanced interferon signaling mediated by the cGAS-stimulator of interferon genes (STING) pathway in patient fibroblasts. Finally, we established that chromatin without linker histone more efficiently stimulates cGAS production in vitro. We conclude that nuclear histones, as key constituents of chromatin, are essential in suppressing the immunogenicity of self-DNA.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT• MMF has been proposed as a treatment of steroid-dependent nephrotic syndrome and in the recent years, several studies have suggested its positive effect in preventing relapses. WHAT THIS PAPER ADDS• The population pharmacokinetics of MPA was first evaluated in children with idiopathic nephrotic syndrome and data fitted well with a two-compartment model with first-order absorption and lag time.• Body weight and serum albumin had a significant impact on oral clearance. • A three-point (T0, T1 and T4h) Bayesian estimator of AUC0-12 was developed. AIMSTo develop a population pharmacokinetic model for mycophenolic acid (MPA) in children with idiopathic nephrotic syndrome (INS) treated with mycophenolate mofetil (MMF), identify covariates that explain variability and determine the Bayesian estimator of the area under the concentration-time curve over 12 h (AUC0-12). METHODSThe pharmacokinetic model of MMF was described from 23 patients aged 7.4 Ϯ 3.9 years (range 2.9-14.9) using nonlinear mixed-effects modelling (NONMEM) software. A two-compartment model with lag-time and first-order absorption and elimination was developed. The final model was validated using visual predictive check. Bayesian estimator was validated using circular permutation method. RESULTSThe population pharmacokinetic parameters were apparent oral clearance 9.7 l h , lag time 0.215 h. The covariate analysis identified body weight and serum albumin as individual factors influencing the apparent oral clearance. Accurate Bayesian estimation of AUC0-12 was obtained using the combination of three MPA concentrations measured just before (T0), 1 and 4 h (T1 and T4) after drug intake with a small error of 0.298 mg h -1 ml -1 between estimated and reference AUC0-12. CONCLUSIONSThe population pharmacokinetic model of MPA was developed in children with INS. A three-point (T0, T1 and T4h) Bayesian estimator of AUC0-12 was developed and might be used to investigate the relation between MPA pharmacokinetic and pharmacodynamics in children with INS and determine if there is any indication to monitor MPA exposure in order to improve patient outcome based on individual AUC-controlled MMF dosing.

Ciliopathies are a group of hereditary disorders associated with defects in cilia structure and function. The distal appendages (DAPs) of centrioles are involved in the docking and anchoring of the mother centriole to the cellular membrane during ciliogenesis. The molecular composition of DAPs was recently elucidated and mutations in two genes encoding DAPs components (CEP164/NPHP15, SCLT1) have been associated with human ciliopathies, namely nephronophthisis and orofaciodigital syndrome. To identify additional DAP components defective in ciliopathies, we independently performed targeted exon sequencing of 1,221 genes associated with cilia and 5 known DAP protein-encoding genes in 1,255 individuals with a nephronophthisis-related ciliopathy. We thereby detected biallelic mutations in a key component of DAP-encoding gene, CEP83, in seven families. All affected individuals had early-onset nephronophthisis and four out of eight displayed learning disability and/or hydrocephalus. Fibroblasts and tubular renal cells from affected individuals showed an altered DAP composition and ciliary defects. In summary, we have identified mutations in CEP83, another DAP-component-encoding gene, as a cause of infantile nephronophthisis associated with central nervous system abnormalities in half of the individuals.