[Study of renal function and compensatory changes in children with single kidney]. / Determinación de función renal y cambios compensadores en niños con riñón único.

INTRODUCTION: It has always been thought that a reduction of renal tissue in childhood sometimes causes some irreversible injury in the remnant kidney as the years go by. The aim of this paper is to look over the presence of these changes and identify the risk of nephropaty throughout several parameters. MATERIAL AND METHODS: We reviewed 38 children, 23 males and 15 females, aged between 1 and 15 years, who had lost unilateral renal mass because of congenital or adquired diseases. We made two groups of patients on the basis of having born without any unilateral renal function -group I- or having lost unilateral renal function after the second year of life. We measured: Somatometry, arterial pressure, glomerular filtration, microalbuminuria, renal volume and gammagraphic studies were also made. We also considered the presence of contralateral anomalies. RESULTS: Body weight and height were within normal percentiles. Arterial pressure increased in 5 patients. Seric creatinine was normal, creatinine clearance (Ccr) was higher than normal in all patients of both groups, and urinary excretion of protein was normal. Renal volume of remnant kidney was similar in both groups, and no relation with renal function level was found, but it increased through the years. Isotopic studies showed ectatic drainage in all urinary systems. Contralateral anomalies were seen in 7 patients, and they consisted in hydronephrosis and vesico-ureteral reflux. CONCLUSIONS: Hypertension was not related to the cause of renal absence nor the pathology of remnant kidney. Ccr was higher than normal, showing an hyperfiltration status, not confirmed by the values of isotopic filtrate. Renal volume reached by the single kidney was affected by the time after the renal loss, and apparently has been slowed down in cases with contralateral anomalies.

Determinación de función renal y cambios compensadores en niños con riñón único / Study of renal function and compensatory changes in children with single kidney

Introducción. Se ha considerado siempre que la reducción de la masa renal durante la infancia, causa una serie de cambios funcionales que eventualmente pueden conducir a un daño irreversible en el riñón remanente con el paso de los años. Objetivos. La evidencia de estas lesiones en múltiples publicaciones nos movió a revisar a un grupo de 38 pacientes monorrenos en la edad infantil y a intentar determinar el riesgo de aparición de las mismas a través de parámetros como la función renal, la tensión arterial, la presencia de proteinuria y el volumen renal. Material y métodos. Se estudiaron 38 pacientes, 23 de ellos varones y 15 mujeres, de edades entre 1 y 13 años, que habían sufrido pérdida de masa renal por causas congénitas o adquiridas. Se separaron en dos grupos de enfermos: Grupo I: Ausencia congénita unilateral de riñón funcionante (25 casos). Grupo II: Nefrectomizados por pérdida de un riñón(con función previa normal) después del segundo año de vida (13 casos). Se midió la somatometría, la tensión arterial (TA), el filtrado glomerular (FG), la proteinuria, el volumen renal (VR) y se consideró la presencia de anomalías contralaterales (AC). Resultados. El peso y la talla se encontró en percentiles normales. La TA se encontró elevada en 5 pacientes. La creatinina sérica sólo estaba elevada en 1 paciente con severa afectación del riñón remanente, el aclaramiento de creatinina (Ccr) resultó elevado de forma generalizada y se observó microalbuminuria en 2 pacientes. El volumen renal fue similar en ambos grupos. El estudio isotópico evidenció ectasia sin obstrucción en el 80% de todos los casos y el FG según el método de Inoue (corregido para niños) resultó en ambos grupos dentro de valores normales. Conclusiones. No encontramos diferencias significativas en la función renal entre los dos grupos de pacientes ni tampoco indicios de nefropatía por hiperfiltración. El Ccr evidenció una situación de hiperfiltrado en todos los casos. El filtrado glomerular calculado por estudio isotópico no confirmó estasituación. El volumen renal no se observó relacionado con la edad a la que se produjo la pérdida renal, y sí con el tiempo transcurrido postpérdida. La existencia de anomalías en el riñón contralateral influye en el grado de hipertrofia que desarrolla (AU)

Introduction. It has always been thought that a reduction of renal tissue in childhood sometimes causes some irreversible injury in the remnant kidney as the years go by. The aim of this paper is to look over the presence of these changes and identify the risk of nephropaty throughout several parameters. Material and methods. We reviewed 38 children, 23 males and 15 females, aged between 1 and 15 years, who had lost unilateral renal mass because of congenital or adquired diseases. We made two groups of patients on the basis of having born without any unilateral renal function –group I– or having lost unilateral renal function after the second year of life. We measured: Somatometry, arterial pressure, glomerular filtration, microalbuminuria, renal volume and gammagraphic studies were also made. We also considered the presence of contralateral anomalies. Results. Body weight and height were within normal percentiles. Arterial pressure increased in 5 patients. Seric creatinine was normal, creatinine clearance (Ccr) was higher than normal in all patients of both groups, and urinary excretion of protein was normal. Renal volume of remnant kidney was similar in both groups, and no relation with renal function level was found, but it increased through the years. Isotopic studies showed ectatic drainage in all urinary systems. Contralateral anomalies were seen in 7 patients, and they consisted in hydronephrosis and vesico-ureteral reflux. Conclusions. Hypertension was not related to the cause of renal absence nor the pathology of remnant kidney. Ccr was higher than normal, showing an hyperfiltration status, not confirmed by the values of isotopic filtrate. Renal volume reached by the single kidney was affected by the time after the renal loss, and apparently has been slowed down in cases with contralateral anomalies Introduction. It has always been thought that a reduction of renal tissue in childhood sometimes causes some irreversible injury in the remnant kidney as the years go by. The aim of this paper is to look over the presence of these changes and identify the risk of nephropaty throughout several parameters. Material and methods. We reviewed 38 children, 23 males and 15 females, aged between 1 and 15 years, who had lost unilateral renal mass because of congenital or adquired diseases. We made two groups of patients on the basis of having born without any unilateral renal function –group I– or having lost unilateral renal function after the second year of life. We measured: Somatometry, arterial pressure, glomerular filtration, microalbuminuria, renal volume and gammagraphic studies were also made. We also considered the presence of contralateral anomalies. Results. Body weight and height were within normal percentiles. Arterial pressure increased in 5 patients. Seric creatinine was normal, creatinine clearance (Ccr) was higher than normal in all patients of both groups, and urinary excretion of protein was normal. Renal volume of remnant kidney was similar in both groups, and no relation with renal function level was found, but it increased through the years. Isotopic studies showed ectatic drainage in all urinary systems. Contralateral anomalies were seen in 7 patients, and they consisted in hydronephrosis and vesico-ureteral reflux. Conclusions. Hypertension was not related to the cause of renal absence nor the pathology of remnant kidney. Ccr was higher than normal, showing an hyperfiltration status, not confirmed by the values of isotopic filtrate. Renal volume reached by the single kidney was affected by the time after the renal loss, and apparently has been slowed down in cases with contralateral anomalies (AU)

[Acute lobar nephronia. Report of 3 new cases]. / Nefronía lobar aguda. Aportación de tres nuevos casos.

We present three patients, aged 4, 6 and 8 years old, with a diagnosis of urinary tract infection. In all patients, initial ultrasonographic studies revealed a single area of acute lobar nephronia (ALN). The patients underwent renal scintigraphy with dimercaptosuccinic acid-99mTc (DMSA Tc 99m), which showed multiple foci with below normal uptake in both kidneys of two patients, consistent with bilateral multifocal bacterial nephritis. Although this entity has been reported together with ALN in adults, very few pediatric cases have been reported. We emphasize the diagnostic value of ultrasonography and renal scintigraphy.

Hipomagnesemia familiar con hipercalciuria y nefrocalcinosis / Familial hypermagnesemia with hypercalciuria and nephrocalcinosis

La hipomagnesemia familiar con hipercalciuria y nefrocalcinosis es un síndrome poco frecuente que pertenece a un grupo de tubulopatías de naturaleza heterogénea, cuya característica común es la pérdida urinaria de magnesio. Se presenta el caso de un niño de 9 años de edad con sintomatología de poliuria, polidipsia y enuresis. Existía nefrocalcinosis ecográfica y radiológica. Se encontró hipomagnesemia, normopotasemia, hipermagnesiuria, hipercalciuria, acidosis tubular distal incompleta, hipocitraturia e insuficiencia renal leve. El tratamiento con sales de magnesio, hidroclorotiacida, citrato potásico y bicarbonato sódico no ha conseguido normalizar ni la magnesiuria ni la calciuria. La función renal y la nefrocalcinosis permanecen estables tras 3 años de control. Se trata de un nuevo caso de este raro síndrome producido por un defecto congénito de la resorción tubular de magnesio, y su evolución clínica y analítica tras 3 años de seguimiento (AU)

[Technetium-99m-dimercaptosuccinic acid (DMSA) scintigraphy in the first febrile urinary tract infection in children]. / Gammagrafía con tecnecio-99m-ácido dimercaptosuccínico en el estudio de la primera infección urinaria febril del niño.

OBJECTIVE: The objective of this study was to evaluate the findings of 99mTc-DMSA renal scintigraphy in children with their first acute febrile urinary tract infection in relation with several clinical-biological parameters and other imaging studies and a long-term follow up. MATERIAL AND METHODS: 103 children between 1 month and 10 years old with their first acute febrile urinary tract infection were studied by means of clinical and laboratory assessment, renal ultrasonography and 99mTc DMSA renal scintigraphy in the acute illness period. Patients were divided into two groups, those under 2 years old (n = 63) and those over 2 years old (n = 40). RESULTS: Cortical scintigraphy showed renal changes in 56 patients (54,5%). Children over 2 years of age had a higher incidence of renal lesions than younger children (39,7% vs. 77,5%). Ultrasonography measuring renal volume showed a simple concordance with scintigraphy in 64% of the patients. Reflux was demonstrated in 23 patients (22,3%) without differences between patients with normal or abnormal cortical scintigraphy. After having studied the factors that were associated independently to the pathological results in the scintigraphy through a logistical multivariant regression, it was observed that the child's age, the elevation of the PCR and the alterations of the renal volume were significant according to statistics and also associated to a larger amount of pathological DMSA scintigraphy. CONCLUSIONS: DMSA scintigraphy associated with other diagnostic methods can improve the sensitivity and specificity to establish renal damage stage. During the follow-up the acute lesions disappeared or improved in all cases and the chronic lesions have not been modificated.

Gammagrafía con tecnecio-99m-ácido dimercaptosuccínico en el estudio de la primera infección urinaria febril del niño / Technetium-99m-dimercaptosuccinic acid (DMSA) scintigraphy in febrile first-time urinary tract infection in children

Objetivo: Evaluar los hallazgos de la gammagrafía renal (DMSA) en niños con una primera infección del tracto urinario (ITU) febril en relación con diversos parámetros clínico-biológicos y otros estudios de imagen y seguimiento a largo plazo. Material y métodos: En un grupo de 103 pacientes (con edades comprendidas entre un mes y 10 años) con una primera ITU febril, se han evaluado parámetros clínicos, analíticos y pruebas de imagen en la fase aguda de la enfermedad. Los pacientes se dividieron en dos grupos de edad, menores (n = 63) y mayores de 2 años (n = 40). Resultados: La gammagrafía fue patológica en el 54,5 por ciento del grupo total, en el 39,7 por ciento en menores de 2 años y en el 79,5 por ciento de los mayores de 2 años. En la ecografía con medición del volumen renal se detectó una concordancia simple con la gammagrafía en el 64 por ciento de los casos. La cistografía objetivó un reflujo en el 22,3 por ciento de los pacientes, sin encontrar diferencias estadísticamente significativas entre los que presentaron un DMSA normal o patológico. Al estudiar los factores que se asociaron de forma independiente a un resultado patológico en el DMSA mediante un análisis multivariante de regresión logística, se observó que la edad del niño, la elevación de la proteína C reactiva (PCR) y la alteración del volumen renal resultaron asociarse de forma estadísticamente significativa a una mayor presencia de DMSA patológico. Conclusiones: El DMSA combinado con otras pruebas diagnósticas puede mejorar la sensibilidad y especificidad para establecer el grado de afectación renal. Durante el seguimiento, las lesiones agudas desaparecen o mejoran en todos los casos y las crónicas no se modifican (AU)