Oxidative stress status during the acute phase of haemolytic uraemic syndrome.

BACKGROUND: Haemolytic uraemic syndrome (HUS) is characterized by haemolytic anaemia, thrombocytopaenia and acute renal failure. The aim of this study was to investigate the levels of oxidative stress (OS) during the acute phase of HUS. METHODS: This prospective study included 18 patients diagnosed with D + HUS, 6 age-matched healthy controls and 29 children with end-stage renal disease (ESRD) not caused by HUS under regular haemodialysis. Plasma lipid peroxidation and non-enzymatic antioxidant defences were measured as thiobarbituric acid-reactive substances (TBARs) and total reactive antioxidant potential (TRAP), respectively, during hospitalization and in control individuals. RESULTS: TBARs were significantly higher in both oliguric and non-oliguric patients at admission (1.8 ± 0.1; 1.7 ± 0.2 µM) and discharge (1.5 ± 0.1; 1.0 ± 0.1 µM) vs controls (0.5 ± 0.1 µM, P < 0.01) following disease progression. Maximal TBARs values differed significantly between oliguric and non-oliguric groups (4.5 ± 0.9 vs 2.4 ± 0.3 µM, P < 0.01) and were significantly higher (P < 0.05) than those found in ESRD patients (1.63 ± 0.1). TRAP values were significantly higher at admission and when the disease was fully established (measured here as highest TBARs record) vs controls (675 ± 51, 657 ± 60 and 317 ± 30 µM Trolox, P < 0.01), and were similar to control values at discharge (325 ± 33 µM Trolox). CONCLUSIONS: We demonstrate here increased levels of OS during the acute phase of HUS, with peak plasma lipid peroxidation values well above those registered in ESRD individuals, and suggest a connection between OS and the clinical course of HUS.

Antiproteinuric action of amiloride in paediatric patient with corticoresistant nephrotic syndrome.

INTRODUCCION: In nephrotic syndrome, increased podocyturia accompanies pathologic proteinuria. The therapeutic regimen with enalapril, losartan and amiloride could reduce both variables. OBJETIVES: Evaluate the anti-proteinuric effect of 2 non-immunological therapeutic regimens, the quantitative relationship between podocyturia and proteinuria. MATERIAL AND METHODS: We included children aged 4-12 years with corticoresistant nephrotic syndrome, using 2 different schemes: group A, enalapril + losartan, and group B, enalapril + losartan + amiloride. RESULTS: In group A, 17 patients completed the study, the initial mean proteinuria was 39 mg/m2/h and mean proteinuria at the end was 24 mg/m2/h, while in group B 14 patients were treated and the initial average proteinuria was 36 mg/m2/h and the end average proteinuria was 13 mg/m2/h. The paired T test showed significant differences in the decrease in proteinuria, for patients in group B without variation in podocyturia. The 2 factors associated with an increase in proteinuria were podocyturia and the time elapsed from the diagnosis of cortico-resistant nephrotic syndrome to the start of treatment anti-proteinuric. CONCLUSIONS: The use of amiloride decreased proteinuria, without significantly modifying podocyturia; we did not observe a positive relationship between both variables.

[Antiproteinuric action of amiloride in paediatric patient with corticoresistant nephrotic syndrome]. / Acción antiproteinúrica del amiloride en el paciente pediátrico con síndrome nefrótico corticorresistente.

INTRODUCCION: In nephrotic syndrome, increased podocyturia accompanies pathologic proteinuria. The therapeutic regimen with enalapril, losartan and amiloride could reduce both variables. OBJETIVES: Evaluate the anti-proteinuric effect of 2 non-immunological therapeutic regimens, the quantitative relationship between podocyturia and proteinuria. MATERIAL AND METHODS: We included children aged 4 to 12 years with corticoresistant nephrotic syndrome, using 2 different schemes: group A, enalapril+losartan, and group B, enalapril+losartan+amiloride. RESULTS: In group A, 17 patients completed the study, the initial mean proteinuria was 39mg/m2/h and mean proteinuria at the end was 24mg/m2/h, while in group B 14 patients were treated and the initial average proteinuria was 36mg/m2/h and the end average proteinuria was 13mg/m2/h. The paired T test showed significant differences in the decrease in proteinuria, for patients in group B without variation in podocyturia. The 2 factors associated with an increase in proteinuria were podocyturia and the time elapsed from the diagnosis of cortico-resistant nephrotic syndrome to the start of treatment anti-proteinuric. CONCLUSIONS: The use of amiloride decreased proteinuria, without significantly modifying podocyturia; we did not observe a positive relationship between both variables.

Melatonin Decreases Circulating Levels of Galectin-3 and Cytokines, Motor Activity, and Anxiety Following Acute Global Cerebral Ischemia in Male Rats.

BACKGROUND: Global cerebral ischemia (GCI) elicits damages to cerebral structures, learning dysfunction, memory impairments, hyperactivity, and anxiety. Circulating levels of galectin-3 (Gal-3) are associated with patient severity and outcome. AIM: To report circulating levels of Gal-3, and cytokines (TNF-α, IL-6, IL-10) in the initial hours (acute) following GCI in a four-vessel occlusion (4-VO) rat model and the effect of melatonin treatment. METHODS: 4-VO model was used to produce GCI using male Sprague-Dawley rats. Groups were: Sham-Veh, Sham-Mel, Isch-Veh and Isch-Mel. Melatonin was administered 30 min after carotid clamp removal. Gal-3 and cytokines levels were measured at 0, 30 min, 6 h and 24 h after the end of cerebral flow interruption using ELISA kits. Motor activity and anxiety were measured using open-field test. RESULTS: Acute GCI (AGCI) followed by reperfusion decreased serum concentrations of TNF-α and increased IL-6 levels 24 h after ischemia, whereas melatonin reduced significantly the concentrations of these cytokines. In all groups IL-10 was higher 30 min and negligible at other times. Circulating levels of Gal-3 were reduced 30 min after ischemia/reperfusion. In the Isch-Mel group the neuroprotective effect generated a reduction in circulating Gal-3 at 6 and 24 h after AGCI, compared with all the groups. Motor activity was increased due to ischemic reperfusion, but acute melatonin treatment reduced locomotion, similar to the control group. Anxiety was reduced in the melatonin group. CONCLUSIONS: Melatonin treatment following AGCI reduces pro-inflammatory factors, Gal-3, motility, and anxiety, therefore it should be considered as supplementary treatment following ischemic stroke.

Podocyturia in paediatric patients with Fabry disease. / Podocituria en pacientes pediátricos con enfermedad de Fabry.

INTRODUCTION: Fabry disease (FD) is a hereditary disorder caused by a deficiency of α-galactosidase A enzyme activity. The transmission of the disorder is linked to the X chromosome. OBJECTIVES: The objectives of the study were: 1. To quantify the presence of podocytes in paediatric patients with FD and compare them with the value of the measured podocyturia in healthy controls. 2. To determine whether a greater podocyturia is related to the onset of pathological albuminuria in patients with FD. 3. To determine the risk factors associated with pathological albuminuria. METHODS: We performed an analytical, observational study of Fabry and control subjects, which were separated into 2groups in accordance with the absence of the disease (control group) or the presence of the disease (Fabry group). RESULTS: We studied 31 patients, 11 with FD and 20 controls, with a mean age of 11.6 years. The difference between the mean time elapsed from the diagnosis of FD to the measurement of podocyturia (40 months) and the onset of pathological albuminuria (34 months) was not significant (p=0.09). Podocytes were identified by staining for the presence of synaptopodin and the mean quantitative differences between both podocyturias were statistically significant (p=0.001). Albuminuria was physiological in 4 of the patients with FD and the relative risk to develop pathological albuminuria according to podocyturia was 1.1 in the control group and 3.9 in the Fabry group, with a coefficient of correlation between podocyturia and albuminuria in the Fabry group of 0.8354. Finally, the 2 risk factors associated with the development of pathological albuminuria were podocyturia (OR: 14) and being aged over 10 years (OR: 18). We found no significant risk with regard to glomerular filtrate renal (GFR) (OR: 0.5) or gender (OR: 1.3). The mean GFR remained within normal values. CONCLUSION: The detection of podocyturia in paediatric patients with FD could be used as an early marker of renal damage, preceding and proportional to the occurrence of pathological albuminuria.

Long-term evaluation of cytoarchitectonic characteristics of prefrontal cortex pyramidal neurons, following global cerebral ischemia and neuroprotective melatonin treatment, in rats.

Global cerebral ischemia induces alterations of working memory, as evidenced in the eight-arm radial maze, in the absence of significant changes of pyramidal neuron population in the prefrontal cortex. These alterations can be prevented by a neuroprotective melatonin treatment. Thus, the cytoarchitectonic characteristics of the pyramidal neurons located at layers III and V in the prefrontal cortex of rats that had been submitted 120 days earlier to acute global cerebral ischemia (15 min four-vessel occlusion), and melatonin (10 mg/(kgh) for 6h, i.v.) or vehicle administration, starting 30min after the end of cerebral blood flow interruption, were evaluated in order to gain information on the changes of the neural substrate underlying disruption of prefrontocortical functioning. Soma size, rough length and number of bifurcations of basilar and apical dendrites, as well as spine density and proportions of the different types of spines in a 50 microm length segment of a secondary dendrite branching from the apical and the basilar dendrites, of pyramidal neurons of the dorsal medial prefrontal cortex, were evaluated in Golgi material. A significant reduction of soma size, apical and basilar dendrite length, number of dendritic bifurcations, and spine density were observed in pyramidal neurons at layers III and V after cerebral ischemia, while these alterations were prevented by melatonin treatment. These cytoarchitectural differences between groups seem to underlie the observed alterations in spatial working memory of ischemic, vehicle-treated rats in the absence of pyramidal neuron loss, as well as the better display of these functions long after ischemia and melatonin neuroprotection.

Melatonin and ischemia-reperfusion injury of the brain.

This review summarizes the reports that have documented the neuroprotective effects of melatonin against ischemia/reperfusion brain injury. The studies were carried out on several species, using models of acute focal or global cerebral ischemia under different treatment schedules. The neuroprotective actions of melatonin were observed during critical evolving periods for cell processes of immediate or delayed neuronal death and brain injury, early after the ischemia/reperfusion episode. Late neural phenomena accounting either for brain damage or neuronal repair, plasticity and functional recovery taking place after ischemia/reperfusion have been rarely examined for the protective actions of melatonin. Special attention has been paid to the advantageous characteristics of melatonin as a neuroprotective drug: bioavailability into brain cells and cellular organelles targeted by morpho-functional derangement; effectiveness in exerting several neuroprotective actions, which can be amplified and prolonged by its metabolites, through direct and indirect antioxidant activity; prevention and reversal of mitochondrial malfunction, reducing inflammation, derangement of cytoskeleton organization, and pro-apoptotic cell signaling; lack of interference with thrombolytic and neuroprotective actions of other drugs; and an adequate safety profile. Thus, the immediate results of melatonin actions in reducing infarct volume, necrotic and apoptotic neuronal death, neurologic deficits, and in increasing the number of surviving neurons, may improve brain tissue preservation. The potential use of melatonin as a neuroprotective drug in clinical trials aimed to improve the outcome of patients suffering acute focal or global cerebral ischemia should be seriously considered.

Long-term study of dendritic spines from hippocampal CA1 pyramidal cells, after neuroprotective melatonin treatment following global cerebral ischemia in rats.

Melatonin reduces pyramidal neuronal death in the hippocampus and prevents the impairment of place learning and memory in the Morris water maze, otherwise occurring following global cerebral ischemia. The cytoarchitectonic characteristics of the hippocampal CA1 remaining pyramidal neurons in brains of rats submitted 120 days earlier to acute global cerebral ischemia (15-min four vessel occlusion, and melatonin 10mg/(kg h 6h), i.v. or vehicle administration) were compared to those of intact control rats in order to gain information concerning the neural substrate underlying preservation of hippocampal functioning. Hippocampi were processed according to a modification of the Golgi method. Dendritic bifurcations from pyramidal neurons in both the oriens-alveus and the striatum radiatum; as well as spine density and proportions of thin, stubby, mushroom-shaped, wide, ramified, and double spines in a 50 microm length segment of an oblique dendrite branching from the apical dendrite of the hippocampal CA1 remaining pyramidal neurons were evaluated. No impregnated CA1 pyramidal neurons were found in the ischemic-vehicle-treated rats. CA1 pyramidal neurons from ischemic-melatonin-treated rats showed stick-like and less ramified dendrites than those seen in intact control neurons. In addition, lesser density of spines, lower proportional density of thin spines, and higher proportional density of mushroom spines were counted in ischemic-melatonin-treated animals than those in the sinuously branched dendrites of the intact control group. These cytoarchitectural arrangements seem to be compatible with place learning and memory functions long after ischemia and melatonin neuroprotection.

Differential expression of function-related antigens on blood monocytes in children with hemolytic uremic syndrome.

Monocytes (Mo) mediate central functions in inflammation and immunity. Different subpopulations of Mo with distinct phenotype and functional properties have been described. Here, we investigate the phenotype and function of peripheral Mo from children with hemolytic uremic syndrome (HUS). For this purpose, blood samples from patients in the acute period of HUS (HUS AP) were obtained on admission before dialysis and/or transfusion. The Mo phenotypic characterization was performed on whole blood by flow cytometry, and markers associated to biological functions were selected: CD14 accounting for lipopolysaccharide (LPS) responsiveness, CD11b for adhesion, Fc receptor for immunoglobulin G type I (FcgammaRI)/CD64 for phagocytosis and cytotoxicity, and human leukocyte antigen (HLA)-DR for antigen presentation. Some of these functions were also determined. Moreover, the percentage of CD14+ CD16+ Mo was evaluated. We found that the entire HUS AP Mo population exhibited reduced CD14, CD64, and CD11b expression and decreased LPS-induced tumor necrosis factor production and Fcgamma-dependent cytotoxicity. HUS AP showed an increased percentage of CD14+ CD16+ Mo with higher CD16 and lower CD14 levels compared with the same subset from healthy children. Moreover, the CD14++ CD16- Mo subpopulation of HUS AP had a decreased HLA-DR expression, which correlated with severity. In conclusion, the Mo population from HUS AP patients presents phenotypic and functional alterations. The contribution to the pathogenesis and the possible scenarios that led to these changes are discussed.

[Comparative study of the conventional scheme and prolonged treatment with steroids on primary steroid-sensitive nephrotic syndrome in children]. / Estudio comparativo entre el esquema convencional y el tratamiento prolongado con esteroides en el síndrome nefrótico cortico-sensible primario en Pediatría.

BACKGROUND: In the steroid-sensitive nephrotic syndrome (SSNS) the prolonged treatment with steroids could decrease the frequency of relapses. We conducted a comparative study of prolonged steroid scheme and the usual treatment of primary SSNS to assess: the number of patients with relapses, mean time to treatment initiation, to remission and to first relapse, total number of relapses, total cumulative dose of steroids, and the steroid toxicity. METHODS: Patients were divided into two groups: group A (27 patients) received 16-ß-methylprednisolone for 12 weeks, reducing the steroid until week 24. Group B (29 patients) received 16-ß-methylprednisolone for 12 weeks and placebo until week 24. RESULTS: Cumulative incidence rate of relapse (person/years) for group A was of 36/100 and 66/100 for group B (p=0.04). Average elapsed time to first relapse was of 114 days for group A and of 75 days to for group B (p=0.01). The difference in time for initial response to treatment and up to achieve remission between both groups was not significant. Total cumulative relapses were 9 for group A and 17 for group B (p=0.04). Total patients with relapses were 3 for group A and 7 for group B (p=0.17). Cumulative average dose per patient was 5,243mg/m2 for group A and 4,306mg/m2 for group B (p=0.3), and serum cortisol was 14µg/dl for group A and 16µg/dl for group B (p=0.4). There were no steroid toxicity differences between groups. CONCLUSIONS: The duration of the treatment had an impact on the number of relapses without increasing steroid toxicity.

Post-ischemic administration of progesterone in rats exerts neuroprotective effects on the hippocampus.

Progesterone is neuroprotective in models of focal or global ischemia when treatment starts either before the insult or at the onset of reperfusion. In these cases the steroid may act during the occurrence of the early pathophysiological events triggered by ischemia or reperfusion. As opposed to this condition, the aim of the present study was to assess the effect of delayed, post-injury administration of progesterone on the preservation of pyramidal neurons of the hippocampus of rats 21 days after been exposed to global ischemia by the four vessel occlusion model. Progesterone (8 mg/kg, i.v.) or its vehicle, were administered at 20 min, 2, 6, and 24h after the end of ischemia. At histological examination, brains of the ischemic vehicle-treated rats showed a severe reduction of the population of pyramidal neurons in the CA1 and CA2 subfields (12% and 29% remaining neurons, respectively), and a less severe neuronal loss in the CA3 and CA4 subfields of the hippocampus (68% and 63% remaining neurons, respectively), as compared to rats exposed to sham procedures. They also showed a two-fold enlargement of the lateral ventricles and 33% shrinkage of the cerebral cortex as compared to the sham group. Progesterone treatment resulted in a significant preservation of pyramidal neurons in CA1 and CA2 (40% and 62% remaining neurons), with no ventricular dilation and only a mild (12%) cortical shrinkage. Results suggest that progesterone is able to interfere with some late pathophysiological mechanisms leading both to selective neuronal damage in the hippocampal CA1 and CA2 subfields, and to shrinkage of the cerebral cortex.

Exome sequencing identifies a novel homozygous mutation in the phosphate transporter SLC34A1 in hypophosphatemia and nephrocalcinosis.

CONTEXT: Two Argentinean siblings (a boy and a girl) from a nonconsanguineous family presented with hypercalcemia, hypercalciuria, hypophosphatemia, low parathyroid hormone (PTH), and nephrocalcinosis. OBJECTIVE: The goal of this study was to identify genetic causes of the clinical findings in the two siblings. DESIGN: Whole exome sequencing was performed to identify disease-causing mutations in the youngest sibling, and a candidate variant was screened in other family members by Sanger sequencing. In vitro experiments were conducted to determine the effects of the mutation that was identified. PATIENTS AND OTHER PARTICIPANTS: Affected siblings (2 y.o. female and 10 y.o male) and their parents were included in the study. Informed consent was obtained for genetic studies. RESULTS: A novel homozygous mutation in the gene encoding the renal sodium-dependent phosphate transporter SLC34A1 was identified in both siblings (c.1484G>A, p.Arg495His). In vitro studies showed that the p.Arg495His mutation resulted in decreased phosphate uptake when compared to wild-type SLC34A1. CONCLUSIONS: The homozygous G>A transition that results in the substitution of histidine for arginine at position 495 of the renal sodium-dependent phosphate transporter, SLC34A1, is involved in disease pathogenesis in these patients. Our report of the second family with two mutated SLC34A1 alleles expands the known phenotype of this rare condition.

Treatment of idiopathic hypercalciuria and its impact on associated diseases.

UNLABELLED: Idiopathic hypercalciuria may be associated with urinary tract infection, hematuria, nephrolithiasis and osteopenia. In order to describe the occurrence of these concurrent conditions related to the variation in urinary calcium and hypercalciuria response to sequential therapy, with a normal protein and low sodium diet, potassium citrate and hydrochlorothiazide; 46 patients older than 4 years, with no urinary tract diseases, sphincter control and normal blood creatinine values were followed-up during 43 months. Hypercalciuria was seen to be associated with kidney stones (EAR 47%; RR 3.3), hematuria (EAR 71%; RR 2.5), urinary tract infections (EAR 57%; RR 3), and osteopenia (EAR 33%; RR 3). A normal value of urinary calcium was achieved with sequential therapy in 43 patients, but during follow-up 32 patients discontinued treatment and hypercalciuria recurred in 44% of them, in association with hematuria and urinary tract infection. CONCLUSIONS: Sequential therapy reduced hypercalciuria and the incidence of associated diseases.

Guías de Vacunación en Huéspedes Especiales / Guidelines for the Vaccination of Special Hosts

Los niños con alteración de su sistema inmunológico son más vulnerables ante las infecciones que el resto de la población. Una de las formas de protegerlos de infecciones graves es a través de la vacunación, deben ser correctamente evaluados al planear los esquemas a fin de establecer los riesgos vs. los beneficios que implican inmunizarlos. El rol del médico pediatra y del médico especialista trabajando en equipo es fundamental, para que puedan beneficiarse con vacunas y esquemas especiales que requieran por su patología de base. Una protección óptima de estos pacientes incluye además la adecuada inmunización de los convivientes y del equipo médico tratante. La inmunización de los huéspedes especiales es una situación clínica compleja que requiere un análisis exhaustivo personalizado en cada caso, debido a las diferentes características de estos pacientes con enfermedades crónicas y/o inmunosuprimidos, los diversos grupos y muchos tipos de terapias inmunosupresoras que se están desarrollando y utilizando en un número cada vez mayor. Es fundamental el trabajo en equipo del médico especialista y el pediatra de cabecera para lograr el mejor control de las enfermedades inmunoprevenibles en estos pacientes de tan alta complejidad

Children with weakened immune systems are more vulnerable to infections than the rest of the population. One of the ways to protect them against serious infections is vaccination; they must be correctly evaluated when planning schedules in order to define the risks versus the benefits involved by their immunization. The role of pediatricians and medical specialists working as a team is fundamental, so that patients can benefit from vaccines and special schedules that they may require due to their underlying pathologies. Optimal protection of these patients also includes the adequate immunization of household members and their treating medical teams. The immunization of special hosts is a complex clinical situation that requires an exhaustive personalized case-by-case analysis, due to the different characteristics of these patients who have chronic diseases and / or are immunosuppressed, the various groups and many types of immunosuppressive therapies that are being developed and increasingly used. The teamwork of specialists and family pediatricians is essential to achieve the best control of immuno-preventable diseases in these highly complex patients

Use of sirolimus in patients with primary steroid-resistant nephrotic syndrome.

Persistent nephrotic syndrome that does not respond to treatment may cause progression to kidney failure. We designed a therapeutic protocol with sirolimus for this group of patients. We conducted a prospective, interventional, time series, cohort study lasting 20 months. Thirteen patients were enrolled, with a mean age of 10 years (range: 8-18 years old) with steroid-resistant primary nephrotic syndrome and a histological diagnosis of focal and segmental glomerulosclerosis. We administered sirolimus 3.6mg/m2/day. The duration of this regimen was 12 months in responsive patients. The protocol's efficacy was assessed according to reduction of proteinuria (3 response levels: total, partial, or no response). Severity of histological renal damage and mean time from clinical diagnosis to protocol initiation were also assessed. Nine of 13 patients responded to the treatment with sirolimus, and mean progression time and the severity of histological renal damage influenced response to therapy. We believe that sirolimus is a valid treatment option in patients with steroid-resistant nephrotic syndrome, even though this regimen probably requires an earlier treatment.

Estudio comparativo entre el esquema convencional y el tratamiento prolongado con esteroides en el síndrome nefrótico cortico-sensible primario en Pediatría / Comparative study of the conventional scheme and prolonged treatment with steroids on primary steroid-sensitive nephrotic syndrome in children

Resumen: Introducción: En el síndrome nefrótico cortico-sensible (SNCS), la corticoterapia prolongada podría reducir la frecuencia de recaídas. El objetivo de este trabajo fue la comparación de un esquema corticoide prolongado frente al tratamiento habitual del SNCS primario, evaluando los siguientes parámetros: el número de pacientes con recaídas, el número total de recaídas, el tiempo medio transcurrido al iniciar el tratamiento, hasta la remisión y hasta la primera recaída, la dosis acumulada de corticosteroides y la toxicidad esteroide. Métodos: La población se dividió en dos grupos: el grupo A (27 pacientes) recibió 16-β-metilprednisona durante 12 semanas, reduciendo la dosis hasta la semana 24; y el grupo B (29 pacientes) recibió 16-β-metilprednisona durante 12 semanas, y placebo hasta la semana 24. Resultados: La tasa de incidencia acumulada de recaídas (persona/año) fue en el grupo A 36/100, y en el grupo B 66/100 (p = 0.04). El tiempo medio transcurrido (días) hasta la primera recaída fue de 114 en el grupo A y 75 en el grupo B (p = 0.01). Las diferencias de tiempo transcurrido al iniciar tratamiento y hasta la remisión entre ambos grupos no fueron significativas. El total acumulado de recaídas fue de 9 en el grupo A y 17 en el grupo B (p = 0.04), y el total de pacientes con recaídas fue de 3 (grupo A) y 7 (grupo B) (p = 0.17). La dosis media acumulada (mg/m2) por paciente fue de 5,243 en el grupo A y de 4,306 en el grupo B (p = 0.3), y el cortisol sérico (μg/dl) final fue de 14 en el grupo A y 16 en el grupo B (p = 0.4). La toxicidad esteroide fue similar entre ambos grupos. Conclusiones: La duración del tratamiento disminuyó el número de recaídas, sin incrementar la toxicidad esteroide.

Abstract: Background: In the steroid-sensitive nephrotic syndrome (SSNS) the prolonged treatment with steroids could decrease the frequency of relapses. We conducted a comparative study of prolonged steroid scheme and the usual treatment of primary SSNS to assess: the number of patients with relapses, mean time to treatment initiation, to remission and to first relapse, total number of relapses, total cumulative dose of steroids, and the steroid toxicity. Methods: Patients were divided into two groups: group A (27 patients) received 16-β-methylprednisolone for 12 weeks, reducing the steroid until week 24. Group B (29 patients) received 16-β-methylprednisolone for 12 weeks and placebo until week 24. Results: Cumulative incidence rate of relapse (person/years) for group A was of 36/100 and 66/100 for group B (p = 0.04). Average elapsed time to first relapse was of 114 days for group A and of 75 days to for group B (p = 0.01). The difference in time for initial response to treatment and up to achieve remission between both groups was not significant. Total cumulative relapses were 9 for group A and 17 for group B (p = 0.04). Total patients with relapses were 3 for group A and 7 for group B (p = 0.17). Cumulative average dose per patient was 5,243 mg/m2 for group A and 4,306 mg/m2 for group B (p = 0.3), and serum cortisol was 14 μg/dl for group A and 16 μg/dl for group B (p = 0.4). There were no steroid toxicity differences between groups. Conclusions: The duration of the treatment had an impact on the number of relapses without increasing steroid toxicity.

[Comparative measurement of urine specific gravity: reagent strips, refractometry and hydrometry]. / Medición comparativa de la densidad urinaria: tira reactiva, refractómetro y densímetro.

INTRODUCTION: The urine specific gravity is commonly used in clinical practice to measure the renal concentration/dilution ability. Measurement can be performed by three methods: hydrometry, refractometry and reagent strips. AIM: To assess the accuracy of different methods to measure urine specific gravity. METHODS: We analyzed 156 consecutive urine samples of pediatric patients during April and May 2007. Urine specific gravity was measured by hydrometry (UD), refractometry (RE) and reagent strips (TR), simultaneously. Urine osmolarity was considered as the gold standard and was measured by freezing point depression. Correlation between different methods was calculated by simple linear regression. RESULTS: A positive and acceptable correlation was found with osmolarity for the RE as for the UD (r= 0.81 and r= 0.86, respectively). The reagent strips presented low correlation (r= 0.46). Also, we found good correlation between measurements obtained by UD and RE (r= 0.89). Measurements obtained by TR, however, had bad correlation when compared to UD (r= 0.46). Higher values of specific gravity were observed when measured with RE with respect to UD. CONCLUSIONS: Reagent strips are not reliable for measuring urine specific gravity and should not be used as an usual test. However, hydrometry and refractometry are acceptable alternatives for measuring urine specific gravity, as long as the same method is used for follow-up.

Evaluación del metabolismo fosfo-cálcico en el síndrome nefrófico córtico-sensible primario en pediatría / Evaluation of bone and mineral metabolism in primary corticosteroid-sensitive pediatric nephrotic syndrome

Introducción: el tratamiento esteroide del síndrome nefrótico cortico sensible (SNCS) puede causar alteraciones del metabolismo mineral, prevenibles con calcio y vitamina D. Se llevó a cabo un estudio de cohortes de tipo retrospectivo longitudinal a lo largo de 36 meses. Objetivos: 1) evaluar la relación entre la Dosis Acumulativa de corticoides (DAC) con la concentración sérica de 25-OH Vitamina D y con el Contenido Mineral Ëseo (CMO); 2) evaluar la relación entre la DAC y el CMO en la Densitometría Mineral Ësea (DMO). Material y métodos: Incluimos a pacientes entre 2 años y 12 años con síndrome nefrótico primario cortico-sensible (SNCS) (primer episodio o síndrome nefrótico recaedor o síndrome nefrótico cortico-dependiente), normotensos, eutróficos y con FG>90ml/min/1.73m2, los cuales se separaron en 3 grupos: GRUPO A: 3 o 6 años (puntaje Z y CMO), edad ósea, PTHi. Resultados: Evaluamos a 29 pacientes, con una edad media de 4,4 años. La DMO se realizó en 11 pacientes y no hubo diferencias significativas entre los grupos (p=0,08). Tampoco hubo diferencias significativas entre la media de la edad cronológica y la edad ósea media media (p 0,3). La prueba T para evaluar la dosis de 25-OH colecalciferol al aumentar la dosis de Ergocalciferol fue significativa (T:32.4 Q: <0.001). Hubo una correlación significativa entre los tres grupos: entre la dosis de Vitamina D y el dosaje sérico de Vitamina D de 0,9; entre el DAC y la dosis de 25 OH colecalciferol de 0,62 y entre el DAC y el CMO de 0.44. Por último, el aumento promedio en los tres grupos de dosis de vitamina D fue de 1833UI. Conclusiones: Observamos una relación entre la DAC e hipovitaminosis D, corregible al aumentar la dosis de Vitamina D.

Introduction: steroid treatment for corticosteroid-sensitive nephrotic syndrome (CSNS) could cause bone and mineral metabolism alterations, preventable with calcium and Vitamin D. Objectives: We carried out a preliminary retrospective study along 36 months with the following objectives. 1) To evaluate the relationship between Cumulative Corticosteroid Doses (CCD) and 25-0 Vitamin D serum concentration and with Bone Mineral Content (BMC); 2) To evaluate the relationship between CCD and Bone Mineral Densitomety (BMD). Methods: We included patients between 2 and 12 years of age with corticosteroid sensitive primary nephrotic syndrome (CSNS) (first episode, relapsing nephrotic syndrome, corticosteroid dependent nephrotic syndrome) normotensive, eutrophic and FG>:90ml/min/1.73 m2, who were divided into three groups: GROUP A: =3 or 4 relapses/year, GROUP C: CSNS, we measured: a) Quarterly: calcemia, phosphatemia, alkaline phosphatase; b) half-yearly: 25-OH cholecalcipherol levels, CCD; c) annually BMD in children >6 years (score Z and BMC), bone age, PTHi. Results: We evaluated 29 patients, average age: 4.4 years. The BMD was performed on 11 patients and there were no significant differences among the groups (p=0.08). No significant differences were seen between chronologic age and average bone age (p=0.3). Change in 25-OH cholecalcipherol levels due to the increase of ergocalcipherol dose was significant (T:32.4 Q:<0.001). There were significant correlation in the three groups, between Vitamin D dose and Vitamin D serum levels (Pearson correlation R=0.9), between CCD and 25 OH cholecalcipherol dose: (Pearson correlation R=0.62) and between CCD and BMC (Pearson correlation R=0.44). Finally, in these three groups the average increase of vitamin D was: 1833IU. Conclusions: We found a relationship between CCD and hypovitaminosis D, which could be corrected increasing Vitamin D dose.

Podocituria en pacientes pediátricos con enfermedad de Fabry / Podocyturia in paediatric patients with Fabry disease

Introducción: La enfermedad de Fabry (EF) es un trastorno hereditario causado por una deficiencia de la actividad de la enzima alfa-galactosidasa A, cuya transmisión está relacionada con el cromosoma X. Objetivos: Los objetivos del estudio fueron: 1. Cuantificar la presencia de podocitos en pacientes pediátricos con EF y compararla con el valor de la podocituria medida en controles sanos. 2. Determinar en pacientes con EF si una mayor podocituria está relacionada con la albuminuria patológica. 3. Determinar los factores de riesgo asociados con la albuminuria patológica. Métodos: Implementamos un estudio analítico observacional de casos y controles, separados en 2 grupos de acuerdo con la ausencia de enfermedad (grupo control) o con la presencia de enfermedad (grupo Fabry). Resultados: Estudiamos a 31 pacientes, 11 con EF y 20 controles, con una media de edad de 11,6 años. La diferencia entre el tiempo medio transcurrido desde el diagnóstico de EF hasta la medición de la podocituria (40 meses) y la aparición de la albuminuria patológica (34 meses) no fue significativa (p: 0,09). Los podocitos se identificaron mediante tinción para sinaptopodina y las diferencias medias cuantitativas entre ambas podociturias fueron estadísticamente significativas (p: 0,001). La albuminuria fue fisiológica en 4 de las pacientes Fabry y el riesgo relativo para desarrollar albuminuria patológica de acuerdo con la podocituria fue en el grupo control 1,1 y en el grupo Fabry 3,9, con un coeficiente de correlación entre la podocituria y la albuminuria en el grupo Fabry de 0,8354. Finalmente los 2 factores de riesgo asociados al desarrollo de albuminuria patológica fueron la podocituria (OR 14) y la edad mayor a 10 años (OR 18). No encontramos riesgo significativo ni en el filtrado glomerular (FG) (OR 0,5), ni en el género (OR 1,3). El FG medio se mantuvo dentro de valores normales. Conclusión: La detección de podocituria en pacientes pediátricos con EF podría utilizarse como un marcador temprano de daño renal previo y relacionado con la albuminuria patológica

Introduction: Fabry disease (FD) is a hereditary disorder caused by a deficiency of α-galactosidase A enzyme activity. The transmission of the disorder is linked to the X chromosome. Objectives: The objectives of the study were: 1. To quantify the presence of podocytes in paediatric patients with FD and compare them with the value of the measured podocyturia in healthy controls. 2. To determine whether a greater podocyturia is related to the onset of pathological albuminuria in patients with FD. 3. To determine the risk factors associated with pathological albuminuria. Methods: We performed an analytical, observational study of Fabry and control subjects, which were separated into 2groups in accordance with the absence of the disease (control group) or the presence of the disease (Fabry group). Results: We studied 31 patients, 11 with FD and 20 controls, with a mean age of 11.6 years. The difference between the mean time elapsed from the diagnosis of FD to the measurement of podocyturia (40 months) and the onset of pathological albuminuria (34 months) was not significant (p = 0.09). Podocytes were identified by staining for the presence of synaptopodin and the mean quantitative differences between both podocyturias were statistically significant (p = 0.001). Albuminuria was physiological in 4 of the patients with FD and the relative risk to develop pathological albuminuria according to podocyturia was 1.1 in the control group and 3.9 in the Fabry group, with a coefficient of correlation between podocyturia and albuminuria in the Fabry group of 0.8354. Finally, the 2 risk factors associated with the development of pathological albuminuria were podocyturia (OR: 14) and being aged over 10 years (OR: 18). We found no significant risk with regard to glomerular filtrate renal (GFR) (OR: 0.5) or gender (OR: 1.3). The mean GFR remained within normal values. Conclusion: The detection of podocyturia in paediatric patients with FD could be used as an early marker of renal damage, preceding and proportional to the occurrence of pathological albuminuria

[Efficacy of Enalapril in patients with single kidney and with or without normoprotein diet]. / Eficacia del Enalapril en pacientes monorrenos con dieta normoproteica y sin ella.

INTRODUCTION: The patient with a solitary kidney and free protein intake can present pathological microalbuminuria. OBJECTIVE: To evaluate the efficacy of Enalapril in patients with single kidney and with or without normoprotein diet. MATERIALS AND METHODS: We studied 49 patients, mean age 11 years, eutrophics, with normal renal function and with approved medical consent. The exclusion criteria were: uropathies, arterial hypertension, malignant diseases, orthostatic proteinuria and previous treatments with nephrotoxics drugs. Patients were classified in two groups: Group A: with normoprotein diet (0.8 to 1.2 g/kg/day). Group B: with free protein intake. The patients with abnormal microalbuminuria received Enalapril (doses between 0.1-0.3 mg/kg/ day). RESULTS: Group A: 21 patients, 2 with abnormal microalbuminuria. Mean increase of the renal size 14% (SD 8), risk of presenting pathological microalbuminuria: 9%. Group B: 28 patients, 11 with pathological microalbuminuria. Mean increase of the renal size: 33.8% (SD 6.1), risk of presenting abnormal microalbuminuria: 40%. RR: 4.125 (CI 1-16) (p: 0.01). NND: 3. Mean range of microalbuminuria pre- Enalapril 50 microg/min and post-Enalapril 11 microg/ min. Mean doses of Enalapril: 0.2 mg/kg/day. Correlation coefficient between increase of renal size and microalbuminuria range: 0.75 and between increase renal size and protein intake: 0.72. Mean time to reach abnormal microalbuminuria: 81 months (DS 7). CONCLUSION: Enalapril together with the normoprotein diet in patient with single kidney reduces the risk of developing abnormal microalbuminuria.