Mycophenolic Acid Pharmacokinetics and Relapse in Children with Steroid-Dependent Idiopathic Nephrotic Syndrome.

Background And Objectives: Therapeutic drug monitoring of mycophenolic acid can improve clinical outcome in organ transplantation and lupus, but data are scarce in idiopathic nephrotic syndrome. The aim of our study was to investigate whether mycophenolic acid pharmacokinetics are associated with disease control in children receiving mycophenolate mofetil for the treatment of steroid-dependent nephrotic syndrome.

Design, Setting, Participants, & Measurements: This was a retrospective multicenter study including 95 children with steroid-dependent nephrotic syndrome treated with mycophenolate mofetil with or without steroids.

Label-free quantitative urinary proteomics identifies the arginase pathway as a new player in congenital obstructive nephropathy.

Obstructive nephropathy is a frequently encountered situation in newborns. In previous studies, the urinary peptidome has been analyzed for the identification of clinically useful biomarkers of obstructive nephropathy. However, the urinary proteome has not been explored yet and should allow additional insight into the pathophysiology of the disease.

The HNF1B score is a simple tool to select patients for HNF1B gene analysis.

HNF1B-related disease is an emerging condition characterized by an autosomal-dominant inheritance, a 50% rate of de novo mutations, and a highly variable phenotype (renal involvement, maturity-onset diabetes of the young type 5, pancreatic hypoplasia, and urogenital tract and liver test abnormalities). Given the current lack of pathognomonic characteristics and the wide overlap with other conditions, a genetic test is the diagnostic gold standard. However, pre-genetic screening is mandatory because genetic testing has substantial costs.

[HNF1B-related disease: paradigm of a developmental gene and unexpected recognition of a new renal disease].

HNF1B encodes for a transcription factor involved in the early development of the kidney, pancreas, liver and genital tract. Mutations in HNF1B are dominantly inherited and consist of whole-gene deletion, or small mutation. De novo mutation occurs in half of tested kindreds.

Long-term outcome of children treated with rituximab for idiopathic nephrotic syndrome.

Background: Rituximab (RTX) has recently showed promising results in the treatment of steroid-dependent idiopathic nephrotic syndrome (SDNS).

Methods: This was a retrospective multicenter study of 18 children treated with RTX for SDNS, with a mean follow-up of 3.2 years.

Protocol biopsies in pediatric renal transplant recipients on cyclosporine versus tacrolimus-based immunosuppression.

Background: Protocol biopsies can detect subclinical rejection and early signs of calcineurin inhibitor-induced nephrotoxicity.

Methods: In a prospective study, protocol biopsies 3 and 12 months after transplant in transplanted children from two centers were studied. One center used cyclosporine (CsA)-based immunosuppression and the other center used tacrolimus.

Should SIX2 be routinely tested in patients with isolated congenital abnormalities of kidneys and/or urinary tract (CAKUT)?

Mutations of the transcription factor SIX2 have been associated with renal hypodysplasia, renal cysts or vesicoureteric reflux. Here, we aimed at confirming the role and the prevalence of SIX2 mutations in a large cohort of 125 individuals with various congenital abnormalities of kidneys and urinary tract. Despite extensive sequencing of all exons and intron-exon boundaries, we failed to detect any SIX2 variation suggesting that SIX2 molecular analysis should not yet be recommended in clinical practice but restricted to research programs.

Urinary proteome analysis at 5-year followup of patients with nonoperated ureteropelvic junction obstruction suggests ongoing kidney remodeling.

Purpose: Severe ureteropelvic junction obstruction is treated surgically. However, for milder cases most clinical teams adopt a watchful waiting approach and only operate in the presence of significant decline of renal function combined with severe hydronephrosis. Little is known about the long-term consequences of ureteropelvic junction obstruction.

A 17q12 chromosomal duplication associated with renal disease and esophageal atresia.

Chromosomal imbalance of the 17q12 region (which includes the HNF1B transcription factor) has recently emerged as a frequent condition. 17q12 deletion was found in patients with various renal abnormalities, diabetes mellitus (MODY type 5), genital tract or liver test abnormalities, while 17q12 duplication was identified in a subset of patients with autism, mental retardation, epilepsy and/or schizophrenia but no renal disorder. We report here two first-degree relatives carrying a 17q12 duplication and harboring various renal abnormalities (bilateral hypoplastic kidneys with vesico-ureteric reflux or multicystic dysplatic kidney with contralateral hyperechogenic kidney).

Congenital ureteropelvic junction obstruction: human disease and animal models.

Ureteropelvic junction (UPJ) obstruction is the most frequently observed cause of obstructive nephropathy in children. Neonatal and foetal animal models have been developed that mimic closely what is observed in human disease. The purpose of this review is to discuss how obstructive nephropathy alters kidney histology and function and describe the molecular mechanisms involved in the progression of the lesions, including inflammation, proliferation/apoptosis, renin-angiotensin system activation and fibrosis, based on both human and animal data.

Acute neurological involvement in diarrhea-associated hemolytic uremic syndrome.

Background And Objectives: Neurologic involvement is the most threatening complication of diarrhea-associated hemolytic uremic syndrome (D+HUS).

Design, Setting, Participants, & Measurements: We report a retrospective multicenter series of 52 patients with severe initial neurologic involvement that occurred in the course of D+HUS.

Results: Verotoxigenic Escherichia coli infection was documented in 24.

Blockade of the kinin B1 receptor ameloriates glomerulonephritis.

Severe inflammation characterizes rapidly progressive glomerulonephritides, and expression of the kinin B1 receptor (B1R) associates with inflammation. Delayed B1R blockade reduces renal inflammation in a model of unilateral ureteral obstruction, but whether B1R modulates the pathophysiology of glomerulonephritides is unknown. Here, we observed an association of B1R protein expression and inflammation, in both glomeruli and the renal interstitium, in biopsies of patients with glomerulonephritides, Henoch-Schönlein purpura nephropathy, and ANCA-associated vasculitis.

Spectrum of HNF1B mutations in a large cohort of patients who harbor renal diseases.

Background And Objectives: Hepatocyte nuclear factor 1beta (HNF1beta) is a transcription factor that is critical for the development of kidney and pancreas. In humans, mutations in HNF1B lead to congenital anomalies of the kidney and urinary tract, pancreas atrophy, and maturity-onset diabetes of the young type 5 and genital malformations.

Design, Setting, Participants, & Measurements: We report HNF1B screening in a cohort of 377 unrelated cases with various kidney phenotypes (hyperechogenic kidneys with size not more than +3 SD, multicystic kidney disease, renal agenesis, renal hypoplasia, cystic dysplasia, or hyperuricemic tubulointerstitial nephropathy not associated with UMOD mutation).

Cryptosporidiosis in paediatric renal transplantation.

Diarrhoea in transplantation may be secondary to infectious agents and immunosuppressive drugs. The use of combined immunosuppressive drugs increases the incidence of infectious diarrhoea. We retrospectively collected all diarrhoea episodes during a 3-year period in 199 pediatric renal transplant recipients, including 47 patients receiving a kidney transplant during this period.

The human urinary proteome reveals high similarity between kidney aging and chronic kidney disease.

Aging induces morphological changes of the kidney and reduces renal function. We analyzed the low molecular weight urinary proteome of 324 healthy individuals from 2-73 years of age to gain insight on human renal aging. We observed age-related modification of secretion of 325 out of over 5000 urinary peptides.

Steroid-responsive nephrotic syndrome in a child with juvenile idiopathic arthritis.

Renal disease is rare in children with juvenile idiopathic arthritis, although a number of associated nephropathies have been described, including mesangial glomerulonephritis. We report the presence of mesangial glomerulonephritis, revealed by a nephrotic syndrome, in a paediatric patient with juvenile idiopathic arthritis. Short-term steroid treatment induced a rapid remission of the nephrotic syndrome, but the presence of anti-nuclear antibodies, 1:320 in a homogeneous pattern, irregular deposits of C1q in a renal biopsy, and a mother with episodes of cutaneous lupus suggested an uncertain renal evolution for this infant.

Anomalies of the TCF2 gene are the main cause of fetal bilateral hyperechogenic kidneys.

Prenatal discovery of fetal bilateral hyperechogenic kidneys is very stressful for pregnant women and their family, and accurate diagnosis of the cause of the moderate forms of this pathology is very difficult. Hepatocyte nuclear factor-1beta that is encoded by the TCF2 gene is involved in the embryonic development of the kidneys. Sixty-two pregnancies with fetal bilateral hyperechogenic kidneys including 25 fetuses with inaccurate diagnosis were studied.