ABSTRACT
Introducción: En una muestra amplia de niños diagnosticados de malformaciones del tracto urinario y/o infección urinaria, hemos calculado los índices de calidad y eficiencia diagnóstica de cinco marcadores funcionales con la intención de comprobar cuáles son los más sensibles para detectar la existencia de una pérdida de parénquima renal. Pacientes y métodos: Estudio retrospectivo transversal en el que se han evaluado las historias clínicas de 179 pacientes en edad pediátrica (91 varones, 88 mujeres). En 102 de ellos (57%), la gammagrafía demostró pérdida de parénquima. Las lesiones morfológicas más frecuentes fueron las cicatrices renales. A todos se les había practicado, al menos, una prueba de concentración realizada con estímulo de desmopresina. Además, se recogieron los resultados de los cocientes albúmina/creatinina y N-acetilglucosaminidasa (NAG)/creatinina, el filtrado glomerular renal (FGR) y el volumen urinario. Resultados: Distribuidos los pacientes según la normalidad o anormalidad de la gammagrafía, se observaron diferencias estadísticamente significativas entre ambos (..) (AU)
Introduction: We analysed a large sample of children diagnosed with urinary tract malformations and/or infections and calculated diagnostic efficiency and quality indexes for five different functional markers, with the goal of testing which is the most sensitive for detecting a loss of renal parenchyma. Patients and method: Ours was a cross-sectional retrospective study in which the clinical histories of 179 paediatric patients (91 male and 88 female) were evaluated. In 102 of these patients (57%), a scintigraphy revealed loss of parenchyma. The most commonly observed morphological type of damage was renal scarring. All patients had undergone at least one desmopressin urine concentration test. We also analysed albumin/creatinine and N-acetyl-glucosaminidase (NAG)/creatinine ratios, glomerular filtration rate (GFR), and urine volume. Results: By distributing patients according to normal/abnormal scintigraphy, we observed statistically significant differences between the two groups in maximum urine osmolality and GFR. Urine volume was elevated in 31.3% of cases (sensitivity: 37.9%; specificity: 81.8%) and 24% had a defect in renal concentrating ability (sensitivity: 30.4%; specificity: 84.8%). Urinary albumin excretion was high in 12.2% of patients, and 7.2% had a high NAG/creatinine ratio. GFR was low in only 5.7% of patients. These last two markers were the least sensitive but most specific for detecting a loss of renal parenchyma (100%). Conclusions: In our study, the most sensitive functional tests for detecting the loss of renal parenchyma were the two that take into account the ability of the kidney to manage water, i.e. urine volume and maximum urine osmolality. These two tests had specificity >80%. However, the maximum specificity was obtained by the NAG/creatinine ratio and GFR, which were, conversely, the least sensitive tests. A normal GFR does not necessarily show normal renal function (AU)
Subject(s)
Humans , Male , Female , Child , Kidney Function Tests/methods , Renal Insufficiency, Chronic/therapy , Glomerular Filtration Rate , Biomarkers/analysis , Osmolar Concentration , Kidney Cortex/injuriesABSTRACT
INTRODUCTION: We analysed a large sample of children diagnosed with urinary tract malformations and/or infections and calculated diagnostic efficiency and quality indexes for five different functional markers, with the goal of testing which is the most sensitive for detecting a loss of renal parenchyma. PATIENTS AND METHOD: Ours was a cross-sectional retrospective study in which the clinical histories of 179 paediatric patients (91 male and 88 female) were evaluated. In 102 of these patients (57%), a scintigraphy revealed loss of parenchyma. The most commonly observed morphological type of damage was renal scarring. All patients had undergone at least one desmopressin urine concentration test. We also analysed albumin/creatinine and N-acetyl-glucosaminidase (NAG)/creatinine ratios, glomerular filtration rate (GFR), and urine volume. RESULTS: By distributing patients according to normal/abnormal scintigraphy, we observed statistically significant differences between the two groups in maximum urine osmolality and GFR. Urine volume was elevated in 31.3% of cases (sensitivity: 37.9%; specificity: 81.8%) and 24% had a defect in renal concentrating ability (sensitivity: 30.4%; specificity: 84.8%). Urinary albumin excretion was high in 12.2% of patients, and 7.2% had a high NAG/creatinine ratio. GFR was low in only 5.7% of patients. These last two markers were the least sensitive but most specific for detecting a loss of renal parenchyma (100%). CONCLUSIONS: In our study, the most sensitive functional tests for detecting the loss of renal parenchyma were the two that take into account the ability of the kidney to manage water, i.e. urine volume and maximum urine osmolality. These two tests had specificity >80%. However, the maximum specificity was obtained by the NAG/creatinine ratio and GFR, which were, conversely, the least sensitive tests. A normal GFR does not necessarily show normal renal function.
