Reflux nephropathy and scarring nephropathy: So close and yet so different.

OBJECTIVES: Reflux nephropathy is a radiologic condition commonly used to express the existence of renal morphological lesions in patients who have or had vesicoureteral reflux (VUR). This morphological concept is used based on the image data collected, without conducting basic complementary renal function studies. The present study was designed to demonstrate that patients with active VUR present different functional renal alterations from those shown by patients with disappeared VUR. METHODS: Longitudinal descriptive retrospective analysis including 89 children (46M, 43F) with VUR diagnosis through a standard voiding cystourethrogram (VCUG). The basic renal function tests collected were the maximum urinary osmolality (UOsm) and the urinary albumin/creatinine and NAG/creatinine ratios. The data collected corresponded to two moments, when VUR was diagnosed and when it had already disappeared. RESULTS: Quantitative differences were verified in the three functional parameters when comparing those corresponding to both moments of the study. In the qualitative analysis, in relation to the intensity of the VUR, differences were observed in UOsm at diagnosis and in the albumin/creatinine ratio once the VUR had cured. At this last moment, a significant increase in the albumin/creatinine ratio was observed in patients with loss of renal parenchyma in relation to those without residual morphological lesions. CONCLUSIONS: Concentrating ability defect is the most frequent finding in children with active reflux (true reflux nephropathy), whereas the most frequent functional disturbance found, once VUR has cured, is an increase in urinary albumin excretion, related to parenchymal damage. The term dysplastic-scarring nephropathy, could be more appropriate for patients with residual morphological lesions and impaired renal function, once VUR is cured.

Nefropatía de reflujo y nefropatía cicatricial. Dos entidades tan cercanas pero funcionalmente tan distintas / Reflux nephropathy and scarring nephropathy: So close and yet so different

Objetivo: La nefropatía de reflujo es el término radiológico que se utilizó para expresar la existencia de lesiones morfológicas renales en pacientes con reflujo vesicoureteral (RVU). Este concepto morfológico se acuñó a partir de los datos de imagen recogidos, aunque sin realizar estudios complementarios básicos de función renal. Este estudio se diseñó para demostrar que las pruebas de función renal básicas muestran resultados distintos en presencia de RVU activo y una vez desaparecido. Pacientes y métodos: Estudio descriptivo retrospectivo longitudinal en el que se incluyeron 89niños (46V, 43M) con RVU diagnosticado mediante cistouretrografía miccional seriada. Las pruebas básicas de función renal recogidas fueron la osmolalidad urinaria máxima (UOsm) y los cocientes urinarios albúmina/creatinina y NAG/creatinina. Los datos acopiados correspondían a dos momentos: al diagnosticarse el RVU y cuando ya se había curado. Resultados: Se comprobaron diferencias cuantitativas en los tres parámetros funcionales al comparar los correspondientes a ambos momentos del estudio. En el análisis cualitativo, en relación con la intensidad del RVU, se apreciaron diferencias en UOsm al diagnóstico y en el cociente albúmina/creatinina una vez desaparecido el RVU. En este último momento se observó un aumento significativo en el cociente albúmina/creatinina en los pacientes con pérdida de parénquima renal en relación con aquellos sin lesiones morfológicas residuales. (AU)

Objectives: Reflux nephropathy is a radiologic condition commonly used to express the existence of renal morphological lesions in patients who have or had vesicoureteral reflux (VUR). This morphological concept is used based on the image data collected, without conducting basic complementary renal function studies. The present study was designed to demonstrate that patients with active VUR present different functional renal alterations from those shown by patients with disappeared VUR. Patients and methods: Longitudinal descriptive retrospective analysis including 89 children (46M, 43F) with VUR diagnosis through a standard voiding cystourethrogram (VCUG). The basic renal function tests collected were the maximum urinary osmolality (UOsm) and the urinary albumin/creatinine and NAG/creatinine ratios. The data collected corresponded to two moments, when VUR was diagnosed and when it had already disappeared. Results: Quantitative differences were verified in the three functional parameters when comparing those corresponding to both moments of the study. In the qualitative analysis, in relation to the intensity of the VUR, differences were observed in UOsm at diagnosis and in the albumin/creatinine ratio once the VUR had cured. At this last moment, a significant increase in the albumin/creatinine ratio was observed in patients with loss of renal parenchyma in relation to those without residual morphological lesions. (AU)

[Reflux nephropathy and scarring nephropathy: So close and yet so different]. / Nefropatía de reflujo y nefropatía cicatricial. Dos entidades tan cercanas pero funcionalmente tan distintas.

OBJECTIVES: Reflux nephropathy is a radiologic condition commonly used to express the existence of renal morphological lesions in patients who have or had vesicoureteral reflux (VUR). This morphological concept is used based on the image data collected, without conducting basic complementary renal function studies. The present study was designed to demonstrate that patients with active VUR present different functional renal alterations from those shown by patients with disappeared VUR. PATIENTS AND METHODS: Longitudinal descriptive retrospective analysis including 89 children (46M, 43F) with VUR diagnosis through a standard voiding cystourethrogram (VCUG). The basic renal function tests collected were the maximum urinary osmolality (UOsm) and the urinary albumin/creatinine and NAG/creatinine ratios. The data collected corresponded to two moments, when VUR was diagnosed and when it had already disappeared. RESULTS: Quantitative differences were verified in the three functional parameters when comparing those corresponding to both moments of the study. In the qualitative analysis, in relation to the intensity of the VUR, differences were observed in UOsm at diagnosis and in the albumin/creatinine ratio once the VUR had cured. At this last moment, a significant increase in the albumin/creatinine ratio was observed in patients with loss of renal parenchyma in relation to those without residual morphological lesions. CONCLUSIONS: Concentrating ability defect is the most frequent finding in children with active reflux (true reflux nephropathy), whereas the most frequent functional disturbance found, once VUR has cured, is an increase in urinary albumin excretion, related to parenchymal damage. The term dysplastic-scarring nephropathy, could be more appropriate for patients with residual morphological lesions and impaired renal function, once VUR is cured.

Estudio de las enzimas lisosomales N-acetil-a-D-glucosaminidasa y arilsulfatasa A en adultos cubanos / Assay of lysosomal N-acetyl-a-D-glucosaminidase and arylsulfatase A activities in Cuban adults

El objetivo de este estudio fue determinar, en una muestra de individuos cubanos, un rango preliminar de valores normales de actividad específica de N-acetil- a-D-glucosaminidasa y arilsulfatasa A, enzimas deficientes en la mucopolisacaridosis tipo III B y la leucodistrofia metacromática, respectivamente. Se realizó una investigación de corte transversal, en muestras de sangre de 38 individuos adultos. Se realizó la extracción de los leucocitos y se determinó la actividad específica de las enzimas por métodos espectrofotométricos. Todos los participantes fueron caracterizados desde el punto de vista clínico como sanos para ambas enfermedades. Se obtuvieron valores medios de actividad específica de N-acetil-a-D-glucosaminidasa y arilsulfatasa A de 1,52±0,30 y 121,37±20,14 nmol/mg/h, respectivamente. No se encontraron diferencias significativas en relación a las características étnicas para ninguna de las dos enzimas (p<0,05). Este constituye el primer estudio cubano en el cual se publican rangos de actividad específica para estas enzimas en individuos cuya condición de sanos y no relacionados familiarmente con la enfermedad ha sido clínicamente demostrada. El análisis de un mayor número de muestras permitirá establecer los puntos de corte que dotarán al diagnóstico bioquímico de estas enfermedades de una mayor confiabilidad.

The aim of this study was to determine, in a sample of Cuban individuals, a preliminary range of normal values of N-acetyl-a-D-glucosaminidase and arylsulfatase A activity, enzymes that are deficient in mucopolysaccharidosis type III B and metachromatic leukodystrophy, respectively. A cross-sectional research was conducted. Blood samples were obtained out of 38 adult individuals. The leucocytes were extracted and the specific enzymatic activity was assayed by spectrophotometric methods. All participants were characterized from the clinical point of view as healthy for both diseases. Average values of N-acetyl-a-D-glucosaminidase and arylsulfatase A specific activities of 1.52 ± 0.30 and 121.37 ± 20.14 nmol/mg/h, respectively were obtained. There were no significant differences related to ethnicity for any of the two enzymes (p <0.05). This is the first Cuban study in which ranges of activity for these enzymes have been reported in healthy individuals whose healthy and non-familiarly related with the disease status have been clinically demonstrated. The analysis of more samples will establish the cutoff points that will increase the reliability of the biochemical diagnosis of these diseases.