Urinary Extracellular Vesicles as a Source of NGAL for Diabetic Kidney Disease Evaluation in Children and Adolescents With Type 1 Diabetes Mellitus.

Background: Tubular damage has a role in Diabetic Kidney Disease (DKD). We evaluated the early tubulointerstitial damage biomarkers in type-1 Diabetes Mellitus (T1DM) pediatric participants and studied the correlation with classical DKD parameters. Methods: Thirty-four T1DM and fifteen healthy participants were enrolled. Clinical and biochemical parameters [Glomerular filtration Rate (GFR), microalbuminuria (MAU), albumin/creatinine ratio (ACR), and glycated hemoglobin A1c (HbA1c)] were evaluated. Neutrophil gelatinase-associated lipocalin (NGAL), Hypoxia-inducible Factor-1α (HIF-1α), and Nuclear Factor of Activated T-cells-5 (NFAT5) levels were studied in the supernatant (S) and the exosome-like extracellular vesicles (E) fraction from urine samples. Results: In the T1DM, 12% had MAU >20 mg/L, 6% ACR >30 mg/g, and 88% had eGFR >140 ml/min/1.72 m2. NGAL in the S (NGAL-S) or E (NGAL-E) fraction was not detectable in the control. The NGAL-E was more frequent (p = 0.040) and higher (p = 0.002) than NGAL-S in T1DM. The T1DM participants with positive NGAL had higher age (p = 0.03), T1DM evolution (p = 0.03), and serum creatinine (p = 0.003) than negative NGAL. The NGAL-E correlated positively with tanner stage (p = 0.0036), the median levels of HbA1c before enrollment (p = 0.045) and was independent of ACR, MAU, and HbA1c at the enrollment. NFAT5 and HIF-1α levels were not detectable in T1DM or control. Conclusion: Urinary exosome-like extracellular vesicles could be a new source of early detection of tubular injury biomarkers of DKD in T1DM patients.

Impaired phosphorylation of JAK2-STAT5b signaling in fibroblasts from uremic children.

BACKGROUND: Chronic kidney disease (CKD) in children is characterized by severe growth failure. The growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis in uremic animals shows a post-receptor impaired phosphorylation of Janus kinase 2/signal transducer and activator of transcription (JAK-STAT) proteins. The objective of our study was to characterize the intracellular phosphorylation of JAK-STAT signaling in fibroblasts from children with CKD on chronic peritoneal dialysis (PD). METHODS: Serum GH-binding protein (GHBP), IGF-1 and IGFBP3 were measured in 15 prepubertal CKD stage-5 children on PD. Cytoplasmic JAK2, cytoplasmic/nuclear STAT5b and nuclear IGFBP3, acid-labile subunit (ALS) and IGF-1 mRNA expression were quantified in fibroblasts obtained from skin biopsies before and after stimulation with 200 ng/ml recombinant human growth hormone (rhGH). Phosphorylation activity at both the cytoplasmic and nuclear level was expressed as the ratio phosphorylated (p)/total (t) abundance of the product (p/t) at 30 and 60 min. Fifteen healthy children were recruited as the control group. Values were expressed in arbitrary units (AU) and normalized for comparison. Significance was defined as p < 0.05. RESULTS: Thirty minutes after rhGH stimulus, the cytoplasmic (p/t) JAK2 ratio was significantly lower in patients than in controls [median and interquartile range (IQR): 7.4 (4.56) vs. 20.5 (50.06) AU]. At 60 min after rhGH stimulation, median JAK2 phosphorylation activity was still significantly lower in the patients [7.14 (IQR 3.8) vs. 10.2 (IQR 29.8) AU; p < 0.05]. The increase in the cytoplasmic (p/t) STAT5b/ß-actin ratio was lower at both measurement points in the patients compared to the controls, without reaching statistical significance between groups. Median IGFBP3 mRNA abundance was significantly decreased in fibroblasts from uremic patients 24 h after rhGH stimulation compared to the healthy controls [1.27 (IQR 0.83) vs. 2.37 (IQR 0.80) AU]. Median ALS and IGF-1 mRNA expression changed in response to rhGH stimuli at 24 and 48 h. CONCLUSION: In this study, children with CKD undergoing PD therapy showed an impaired phosphorylation of JAK2/STAT5b signaling in fibroblasts after GH stimulation, as well as impaired IGFBP3 mRNA abundance. Both impairments may be partially responsible for the observed resistance to the growth-promoting actions of GH in chronic kidney failure.

The mini-PET in pediatric peritoneal dialysis: a useful tool to predict volume overload?

BACKGROUND: Cardiovascular disease (CVD) in patients on chronic peritoneal dialysis (PD) is a major cause of death and is closely linked to hypertension and volume overload. The mini-Pet has been proposed as a useful tool to evaluate free-water transport (FWT) and characterize ultrafiltration across the peritoneum. Knowledge regarding FWT could be of great value to predict volume overload in PD patients. Our objective in this study was to characterize FWT through the peritoneum in children on PD. METHODS: We studied clinically stable patients with >2 months on PD. Exclusion criteria were a peritonitis episode up to 2 months prior to entrance into the study and active nephrotic syndrome. A 1-h mini-peritoneal equilibration test (mini-PET) was performed with 3.86 % glucose. Calculations (see text for full definitions) were: Dip Na (Na dial min60 - Na dial min1), Dip D/PNa (D/PNa60 - D/PNa1), total Na removal (NaR = total Na dial60 - Na dial1), ultrafiltration small pores [(UFSP = NaR × 1,000)/Nap], and FWT (UF-UFSP). Peritoneal equilibration test (PET), left ventricular mass index (LVMI, g/m(2)), daily UF, and residual renal function were evaluated. Pearson's correlation coefficient was used to establish correlation between variables. RESULTS: Sixteen patients were included, with a mean age of 11.8 ± 3.8 years. Free water transport normalized to body surface area (BSA) (FWTn) was 133.9 ± 85.7 ml/m(2); creatinine dialysate-to-plasma (D/P) and glucose dialysate at X dwell time-to-0 dwell time (Dx/D0) ratios were 0.38 ± 0.1 and 0.65 ± 0.09, respectively. LVMI was 46.6 ± 14.8 g/m(2); 2-h creatinine D/P and glucose Dx/D0 showed no correlation with FWTn, UF, and LVMI. FWTn showed a significant inverse correlation with LVMI (r 0.58, p 0.02). CONCLUSIONS: This study characterized FWT in PD children through the mini-PET. Left ventricular hypertrophy showed a high prevalence in this group, and a significant correlation between LVMI and FWT was found. FWT could be a useful tool to evaluate UF in PD children.

Ovarian function in adolescents with McCune-Albright syndrome.

OBJECTIVE: To evaluate ovarian function, especially ovulation rate, in adolescents with McCune-Albright syndrome (MAS) and a history of peripheral precocious puberty. DESIGN: Prospective cross-sectional study. SETTING: Academic center. PATIENT(S): A total of eight adolescents with MAS were compared with 15 healthy adolescents matched by age, Tanner stage and body mass index. INTERVENTION(S): We determined basal gonadotropins, sex steroids, sex hormone binding globulin, anti-Müllerian hormone, glucose and insulin. A leuprolide acetate test was performed to measure luteinizing hormone (LH) and follicle stimulating hormone (FSH) (at 0 and 3 h), and 17B-estradiol, testosterone and 17-OH-progesterone (at 0 and 24 h). Salivary progesterone levels were used to assess ovulation during the 13th, 18th, 23rd and 28th days of each menstrual cycle for three to five consecutive cycles, and one pelvic ultrasound was performed during the follicular phase. MAIN OUTCOME MEASURE(S): Ovulation rate in adolescents with MAS. RESULT(S): The proportion of ovulatory cycles was 52.6% in controls compared with 35.7% in patients with MAS. CONCLUSION(S): The adolescent girls with MAS appear to have a lower ovulatory rate compared with controls.

[Association between Fok I vitamin D receptor (VDR) gene polymorphism and plasmatic concentrations of transforming growth factor-beta1 and interferon gamma in type 1 diabetes mellitus]. / Asociación del polimorfismo Fok I del gen del receptor de vitamina D (VDR) con concentraciones plasmáticas del factor transformador de crecimiento beta1 e interferón gamma en la diabetes mellitus tipo 1.

BACKGROUND AND OBJECTIVE: In order to assess whether Fok I vitamin D receptor gene (VDR) polymorphism is involved in the genetic susceptibility of type 1 diabetes, a case-control study was conducted and VDR genotypes were related to serum concentrations of 25(OH) vitamin D and cytokines transforming growth factor beta1 (TGF-beta1) and interferon gamma (INF-gamma). PATIENTS AND METHOD: 151 incident cases of type 1 diabetes and 182 non related healthy controls from Santiago were studied for VDR polymorphisms in peripheral blood DNA. Exon 2 (Fok I) segments were amplified by polimerase chain reaction and analyzed by means of restriction fragment length polymorphism to determine each corresponding genotype. Differences for allele, genotype and serological markers as 25(OH) vitamin D, TGF-beta1 and INF-gamma levels distribution between patients and controls were analyzed. RESULTS: Fok I polymorphism distribution analysis showed no differences between patients and controls. Among diabetics, higher levels of TGF-beta1 (median, 282.6 pg/ml; range, 131.8-3,031.4) were observed compared with healthy children (median, 232.2 pg/ml; range, 135.7-506.5) (p < 0.0038). Similar results were observed for INF-gamma concentrations (median, 121.1 pg/ml, and range, 5.3-228.8, in cases, and median, 89.6 pg/ml, and range, 10.9-117.2 in controls) (p < 0.0004). The diabetic carriers of the ff genotype showed low levels of 25(OH) vitamin D compared with the carriers of the F allele: mean (standard deviation), 23.1 (5.9) versus 27.9 (10.3) ng/ml (p < 0.03). A similar result was observed for TGF-beta1 concentrations in diabetic carriers of ff genotype and patients carriers of the F allele (298.5 versus 276.6; p < 0.05). CONCLUSIONS: Fok I polymorphism of VDR could have a marginal role in the immunologic disturbance in type 1 diabetes.

Asociación del polimorfismo Fok I del gen del receptor de vitamina D (VDR) con concentraciones plasmáticas del factor transformador de crecimiento Beta1 e interferón gamma en la diabetes mellitus tipo 1 / Association between Fok I vitamin D receptor (VDR) gene polymorphism and plasmatic concentrations of transforming growth factor-Beta1 and interferon gamma in type 1 diabetes mellitus

Fundamento y objetivo: Analizar el polimorfismo Fok I del gen del receptor de vitamina D (VDR) y su relación con la susceptibilidad a desarrollar diabetes tipo 1. Se realizó un estudio de casos y controles y se relacionaron los genotipos del VDR con las concentraciones circulantes de 25(OH)-vitamina D y las concentraciones séricas de factor transformador de crecimiento ß1 (TGF-ß1) e interferón gamma (INF-*). Pacientes y método: Se analizaron 151 casos de diabetes tipo 1 y 182 controles sanos no relacionados. Se amplificó el exón 2 del gen VDR mediante reacción en cadena de la polimerasa. Los genotipos se obtuvieron mediante análisis de fragmentos de restricción. La concentración de 25(OH) vitamina D se determinó por radioinmunoanálisis y las de las citocinas TGF-ß1 e INF-*, por enzimoinmunoanálisis. Resultados: La distribución del polimorfismo Fok I no mostró diferencias entre casos y controles. El grupo de niños diabéticos mostró valores más altos de TGF-ß1 (mediana, 282,6 pg/ml; intervalos, 131,8-3.031,4) que los niños controles (mediana, 232,2 pg/ml; intervalos, 135,7-506,5) (p < 0,0038). También se observaron valores aumentados de INF-* (mediana, 121,1 pg/ml; intervalos, 5,3-228,8) en los casos comparados con los controles (mediana, 89,6 pg/ ml; intervalos, 10,9-117,2) (p < 0,0004). Los pacientes diabéticos portadores del genotipo ff mostraron concentraciones de 25(OH) vitamina D menores que los portadores del alelo F: media (desviación estándar) de 23,1 (5,9) frente a 27,9 (10,3) ng/ml (p < 0,03). De forma similar, los diabéticos portadores del genotipo ff mostraron valores aumentados de TGF-ß1 al compararlos con los genotipos portadores del alelo F (298,5 frente a 276,6 pg/ml; p < 0,05). Conclusiones: El polimorfismo Fok I del VDR podría tener un papel marginal en la alteración inmunológica que se desarrolla en la diabetes tipo 1 a través de una posible modulación de la vitamina D

Background and objective: In order to assess whether Fok I vitamin D receptor gene (VDR) polymorphism is involved in the genetic susceptibility of type 1 diabetes, a case-control study was conducted and VDR genotypes were related to serum concentrations of 25(OH) vitamin D and cytokines transforming growth factor ß1 (TGF-ß1) and interferon gamma (INF-*). Patients and method: 151 incident cases of type 1 diabetes and 182 non related healthy controls from Santiago were studied for VDR polymorphisms in peripheral blood DNA. Exon 2 (Fok I) segments were amplified by polimerase chain reaction and analyzed by means of restriction fragment length polymorphism to determine each corresponding genotype. Differences for allele, genotype and serological markers as 25(OH) vitamin D, TGF-ß1 and INF-* levels distribution between patients and controls were analyzed. Results: Fok I polymorphism distribution analysis showed no differences between patients and controls. Among diabetics, higher levels of TGF-ß1 (median, 282.6 pg/ml; range, 131.8-3,031.4) were observed compared with healthy children (median, 232.2 pg/ml; range, 135.7-506.5) (p < 0.0038). Similar results were observed for INF-* concentrations (median, 121.1 pg/ml, and range, 5.3-228.8, in cases, and median, 89.6 pg/ml, and range, 10.9-117.2 in controls) (p < 0.0004). The diabetic carriers of the ff genotype showed low levels of 25(OH) vitamin D compared with the carriers of the F allele: mean (standard deviation), 23.1 (5.9) versus 27.9 (10.3) ng/ml (p < 0.03). A similar result was observed for TGF-ß1 concentrations in diabetic carriers of ff genotype and patients carriers of the F allele (298.5 versus 276.6; p < 0.05). Conclusions: Fok I polymorphism of VDR could have a marginal role in the immunologic disturbance in type 1 diabetes

[Type 1 diabetes mellitus incidence in Santiago, Chile. Analysis by counties in the period 2000-2004]. / Incidencia de diabetes mellitus tipo 1 en Santiago de Chile: análisis por comunas de la Región Metropolitana en el período 2000-2004.

BACKGROUND: There are great geographical differences in the incidence of type I diabetes mellitus. AIM: To determine the incidence rate of type 1 diabetes mellitus (DM1) in the Metropolitan Region of Santiago, Chile from January 1, 2000 to December 31, 2004 and to observe the distribution of cases in the different counties of Santiago. MATERIAL AND METHODS: All the cases diagnosed with DM1 in the Metropolitan Region who fulfilled the following requirements were included in the study: age of onset <15 years, insulin treatment from onset, permanent residency in the area, and a diagnosis made between January, 2000 and December, 2004. RESULTS: The incidence of DM1 was 6.58/100,000 inhabitants/year, and showed a significant increase from 2001 to 2004 (5.44 and 8.33 inhabitants/year, respectively, p <0.04). The incidence of DM1 also increased significantly in children younger than 4 years old. The incidence by counties exhibited large differences, ranging from 1.5 to 26.6/100,000 inhabitants. Counties with higher income, urbanization and low aborigine component showed a high incidence rate of type 1 diabetes. CONCLUSIONS: In the Metropolitan Region of Santiago, an increase of the incidence of DM1 has occurred in the period 2000-2004, especially in children younger than 4 years old. Large differences among counties were observed.

Ovarian function during puberty in girls with type 1 diabetes mellitus: response to leuprolide.

CONTEXT: An increased prevalence of polycystic ovary syndrome (PCOS) has been reported in adult women with type 1 diabetes mellitus (DM1). We investigated whether these hormonal abnormalities begin during puberty by evaluating the ovarian steroidogenic response to leuprolide acetate. METHODS: We studied 56 adolescent girls with DM1 (aged 12.3 +/- 0.2 yr) and 64 healthy girls (C) (aged 11.9 +/- 0.2 yr) up to 2 yr post menarche, matched by age, body mass index, and pubertal development. We evaluated anthropometrical data and Ferriman-Gallway score and performed a leuprolide test (500 microg sc) to study ovarian function. Ovarian volume was determined by transabdominal ultrasonography. RESULTS: We found five DM1 but no C girls with abnormally located terminal hair (Fisher's exact, P < 0.05). Free androgen index increased throughout puberty in girls with DM1 (ANOVA, P < 0.0001), which was associated with a decrease in SHBG levels in girls with DM1 (ANOVA, P < 0.0001). Stimulated 17OH progesterone (17OHProg) increased throughout puberty only in girls with DM1 (ANOVA, P < 0.01). Girls with DM1 at Tanner stage 5 had higher stimulated LH to FSH ratio, testosterone, and 17OHProg levels than girls at Tanner stage 4. In contrast, in C girls the stimulated testosterone, 17OHProg, and LH to FSH ratio were similar at Tanner stages 4 and 5. Ovarian volumes and uterine length were larger in girls with DM1 (analysis of covariance, P < 0.05). CONCLUSIONS: These data suggest that patients with DM1 have differences in ovarian steroidogenic response to leuprolide, compared with C girls during puberty. Future studies in young women should clarify whether these findings are related to the pathogenesis of hyperandrogenism later in life.

Ponderal gain, waist-to-hip ratio, and pubertal development in girls with type-1 diabetes mellitus.

OBJECTIVES: We assessed pubertal development, height, weight, and waist-to-hip ratio (WHR), an index of central adiposity during puberty, in girls with type-1 diabetes mellitus (T1DM), compared to a contemporary control group. METHODS: Pubertal development, weight, height and WHR were studied in 100 pubertal girls with T1DM, and were compared to a control group of 576 normal girls (C), recruited from schools with a similar socioeconomic level and ethnicity. The age of onset of various pubertal stages was estimated by using probit analysis. RESULTS: Breast Tanner stage 2 (BT2) began at 8.89 +/- 0.11 and 9.10 +/- 0.28 yr in C and T1DM, respectively. A delay of 6 months was observed in T1DM for BT3 and BT4 (p < 0.05). Menarche occurred 6 months later in girls with T1DM (p = 0.03). WHR decreased during puberty in C (p < 0.001), but not in T1DM. In girls with T1DM, the body mass index standard deviation score (BMI-SDS) increased throughout puberty (p < 0.001), but it was stable in C. In T1DM girls, BMI-SDS, but not hemoglobin A1c levels (HbA1c), was a significant determinant of pubertal development. Final height was similar in T1DM and C. CONCLUSIONS: Pubertal development in girls with T1DM occurred earlier than described in historical cohorts, but a later onset of menarche and final stages of breast development were observed. The increase in BMI-SDS and the stability of WHR in girls with T1DM during puberty suggest that this period may be critical for determining later weight gain and body composition in adult women with this condition.

Síndrome de Donohue (leprechaunismo) / Donohue's syndrome

Se presenta el caso de una niña de 5 meses, con un fenotipo compatible con síndrome de Donohue; confirmándose el diagnóstico en la anatomía patológica por la presencia de transformación quística de los corpúsculos de Hassall en el timo, abundante pigmento de fierro en el hígado e hiperplasia de los islotes de Langerhans y aumento de células Beta en el páncreas. Se revisa la literatura y se discuten los posibles mecanismos patogénicos involucrados