Amniotic fluid peptides predict postnatal kidney survival in developmental kidney disease.

Although a rare disease, bilateral congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of end stage kidney disease in children. Ultrasound-based prenatal prediction of postnatal kidney survival in CAKUT pregnancies is far from accurate. To improve prediction, we conducted a prospective multicenter peptidome analysis of amniotic fluid spanning 140 evaluable fetuses with CAKUT. We identified a signature of 98 endogenous amniotic fluid peptides, mainly composed of fragments from extracellular matrix proteins and from the actin binding protein thymosin-ß4. The peptide signature predicted postnatal kidney outcome with an area under the curve of 0.96 in the holdout validation set of patients with CAKUT with definite endpoint data. Additionally, this peptide signature was validated in a geographically independent sub-cohort of 12 patients (area under the curve 1.00) and displayed high specificity in non-CAKUT pregnancies (82 and 94% in 22 healthy fetuses and in 47 fetuses with congenital cytomegalovirus infection respectively). Change in amniotic fluid thymosin-ß4 abundance was confirmed with ELISA. Knockout of thymosin-ß4 in zebrafish altered proximal and distal tubule pronephros growth suggesting a possible role of thymosin ß4 in fetal kidney development. Thus, recognition of the 98-peptide signature in amniotic fluid during diagnostic workup of prenatally detected fetuses with CAKUT can provide a long-sought evidence base for accurate management of the CAKUT disorder that is currently unavailable.

The ANTENATAL multicentre study to predict postnatal renal outcome in fetuses with posterior urethral valves: objectives and design.

BACKGROUND: Posterior urethral valves (PUV) account for 17% of paediatric end-stage renal disease. A major issue in the management of PUV is prenatal prediction of postnatal renal function. Fetal ultrasound and fetal urine biochemistry are currently employed for this prediction, but clearly lack precision. We previously developed a fetal urine peptide signature that predicted in utero with high precision postnatal renal function in fetuses with PUV. We describe here the objectives and design of the prospective international multicentre ANTENATAL (multicentre validation of a fetal urine peptidome-based classifier to predict postnatal renal function in posterior urethral valves) study, set up to validate this fetal urine peptide signature. METHODS: Participants will be PUV pregnancies enrolled from 2017 to 2021 and followed up until 2023 in >30 European centres endorsed and supported by European reference networks for rare urological disorders (ERN eUROGEN) and rare kidney diseases (ERN ERKNet). The endpoint will be renal/patient survival at 2 years postnatally. Assuming α = 0.05, 1-ß = 0.8 and a mean prevalence of severe renal outcome in PUV individuals of 0.35, 400 patients need to be enrolled to validate the previously reported sensitivity and specificity of the peptide signature. RESULTS: In this largest multicentre study of antenatally detected PUV, we anticipate bringing a novel tool to the clinic. Based on urinary peptides and potentially amended in the future with additional omics traits, this tool will be able to precisely quantify postnatal renal survival in PUV pregnancies. The main limitation of the employed approach is the need for specialized equipment. CONCLUSIONS: Accurate risk assessment in the prenatal period should strongly improve the management of fetuses with PUV.

A capillary electrophoresis coupled to mass spectrometry pipeline for long term comparable assessment of the urinary metabolome.

Although capillary electrophoresis coupled to mass spectrometry (CE-MS) has potential application in the field of metabolite profiling, very few studies actually used CE-MS to identify clinically useful body fluid metabolites. Here we present an optimized CE-MS setup and analysis pipeline to reproducibly explore the metabolite content of urine. We show that the use of a beveled tip capillary improves the sensitivity of detection over a flat tip. We also present a novel normalization procedure based on the use of endogenous stable urinary metabolites identified in the combined metabolome of 75 different urine samples from healthy and diseased individuals. This method allows a highly reproducible comparison of the same sample analyzed nearly 130 times over a range of 4 years. To demonstrate the use of this pipeline in clinical research we compared the urinary metabolome of 34 newborns with ureteropelvic junction (UPJ) obstruction and 15 healthy newborns. We identified 32 features with differential urinary abundance. Combination of the 32 compounds in a SVM classifier predicted with 76% sensitivity and 86% specificity UPJ obstruction in a separate validation cohort of 24 individuals. Thus, this study demonstrates the feasibility to use CE-MS as a tool for the identification of clinically relevant urinary metabolites.

Adolescents with partial growth hormone (GH) deficiency develop alterations of body composition after GH discontinuation and require follow-up.

It is now a consensus to resume GH treatment in adolescents with severe GH deficiency (GHD) at retesting to prevent the occurrence of adult GHD syndrome. However, we do not have any data on the follow-up of adolescents with nonsevere GHD at completion of treatment. This report presents preliminary data from a 1-yr prospective study that includes the first 91 patients retested. Anthropometric data, IGF-I and IGF binding protein-3 levels, glycemia and insulinemia, lipid profile, and body composition using dual x-ray absorptiometry and abdominal computed tomography scan were recorded at completion of GH treatment and 1 yr later. Body composition was significantly different at both evaluations, with increased total body fat and decreased lean body mass in the partial GHD group vs. the normal group. Moreover, these alterations worsened after 1 yr without GH in the partial GHD group, whereas there were no modifications in the normal group. We did not find any metabolic alterations such as elevated triglyceride, total cholesterol, or insulin levels. Adolescents with reconfirmed partial GHD exhibit alterations in body composition after 1 yr without GH, whereas those retested normal do not. These changes are similar to those described in severe GHD, although less marked, and justify a precise follow-up.

Wrist anomalies in Turner syndrome compared with Leri-Weill dyschondrosteosis: a new feature in Turner syndrome.

UNLABELLED: We analysed bone age radiographs in 102 girls with Turner syndrome and compared the findings with 93 control girls and nine girls with Leri-Weill syndrome. Various signs were analysed: radial bowing or Madelung deformity, maximal/minimal height of the radial epiphysis, brachymetacarpia of the 4th digit, carpal and epiphyseal angle, as well as a new sign the distal radio-ulnar physeal disparity. Two values differed significantly between the Turner group and the control group, the first being the epiphyseal angle which has already been reported to be greater in Turner syndrome, and the second being the new sign we have been able to describe. Turner patients had an increased distance between the ulnar and radial metaphysis, or "distal radio-ulnar physeal disparity", the ulnar being shorter. Furthermore, in 27% of cases the medial extremity of the ulnar epiphysis was flattened and passed below the distal extremity of the radius, whose medial part projected over the distal extremity of the ulna, thus reproducing in reverse the characteristic feature of Leri-Weill syndrome. In the growth hormone-treated Turner patients, we found a significant correlation between distal radio-ulnar physeal disparity and growth velocity expressed in cm/year (r = 0.28; P < 0.002) or in SDS/bone age (r = 0.21; P < 0.03) during the first year of treatment. CONCLUSION: the value of this new sign requires further investigation.