Infección por Strongyloides stercoralis en pacientes trasplantados renales / No disponible

Presentamos dos casos de infección por Strongyloides stercoralis (S. stercoralis) en pacientes trasplantados renales en nuestro centro. Se describen las características de su presentación clínica, el tratamiento y la resolución del mismo (AU)

We present two cases of Strongyloides stercoral is infection in renal transplant recipients in our centre. We describe clinical presentation characteristics ,treatment and resolution (AU)

Analysis of variability in determining intact parathyroid hormone (iPTH) according to the method used to process the sample

Background: The measurement of i-PTH circulating is not easy due to its analytical variablity. Variability that appears in the process that goes from the sample collection to the final result determination. There are several important aspects that can influence within the pre-test variability: type of sample (serum o plasma),temperature, time elapses from blood extraction to freezing and from freezing to i-PTH quantification. Blood coming from centres far from our laboratory do not always meet the required processing conditions. Our aim was to study the stability of i-PTH with varying conditions of temperature and time until freezing in patients with chronic kidney disease (CKD). Method: We have analyzed294 blood samples of 49 patients with chronic kidney disease (18 transplantated patients (36.7%) and 31 patients in haemodyalisis (63.3%)). The blood samples were collected using tubes treated with ethylenediamino tetraacetic acid(EDTA); these samples were subjected to different conditions of temperature and time before they were frozen, constituting 6 groups: blood centrifuged and plasma immediately frozen (group A or reference group);blood maintained 1 hour at room temperature and (..) (AU)

Background: The measurement of i-PTH circulating is not easy due to its analytical variablity. Variability that appears in the process that goes from the sample collection to the final result determination. There are several important aspects that can influence within the pre-test variability: type of sample (serum o plasma), temperature, time elapses from blood extraction to freezing and from freezing to i-PTH quantification. Blood coming from centres far from our laboratory do not always meet the required processing conditions. Our aim was to study the stability of i-PTH with varying conditions of temperature and time until freezing in patients with chronic kidney disease (CKD). Method: We have analyzed 294 blood samples of 49 patients with chronic kidney disease (18 transplantated patients (36.7%) and 31 patients in haemodyalisis (63.3%)). The blood samples were collected using tubes treated with ethylenediaminotetraacetic acid (EDTA); these samples were subjected to different conditions of temperature and time before they were frozen, constituting 6 groups: blood centrifuged and plasma immediately frozen (group A or reference group); blood maintained 1 hour at room temperature and plasma stored at 2-8 ºC during 0, 8 and 24 hours (groups B,C,D); blood maintained 3 hours at room temperature and plasma stored at 2-8 ºC during 0 and 8 hours (groups E,F). The intact PTH (i-PTH) was measured using the immunoradiometric assay (IRMA Total Intact Scantibodies assay). We have analyzed the differences between the PTH-i mean values in the referenced groud and the others. We have applied the tests of homogeneity variance and normality and we have perform a comparation by pairs with the t-test including the Bonferroni correction. Results: The mean value of intact- PTH in the referente Group was 202.5±199.72 pg/ml. The means values of intact-PTH in the other groups were 196 ± 203.23 pg/ml, 202.8 ± 200.2 pg/ml, 200.06 ± 194.87 pg/ml, 204.08 ± 204.073 pg/ml, 197.94 ± 182.31 pg/ml. The results were practically identical for each group. We did not find important differences with respect to the reference group (p = 0.87, p = 0,99, p = 0,95, p = 0,96, p = 0,90 when comparing with groups 2a, 2b, 2c, 3a y 3b). Conclusions: The use of EDTA maintain the PTH stability during a longer period without the necessity of freezing the samples immediately. These results can help to state strategies to management the samples in patients with ERC (AU)

Introducción: Las alteraciones del metabolismo óseo-mineral presentan una alta prevalencia en los pacientes con enfermedad renal crónica (ERC), siendo mayor conforme avanza el estadio de enfermedad. El diagnóstico de dichas alteraciones se basa fundamentalmente en la determinación de niveles de hormona paratiroide (PTH-i). Sin embargo, la determinación de esta hormona no es sencilla y está sometida a gran variabilidad. Los métodos para procesar las muestras de PTH-i no están estandarizados, hecho que podría ser una fuente importante de variabilidad preanalítica. Objetivo: Analizar la variabilidad en los resultados de la determinación de la PTH-i comparando distintas formas de procesar la misma muestra de plasma tratado conácido etilendiaminotetraacético (EDTA) en pacientes con ERC. Material y métodos: Se han analizado 294 muestras, correspondientes a 49 pacientes con ERC, 18 procedentes de la Consulta de Trasplante Renal (36,7%) y 31 del programa de Hemodiálisis Crónica de nuestro Centro (63,3%). Se ha procesado la misma muestra de cada uno de nuestros pacientes de seis maneras distintas, comparando las medias entre el grupo de referencia o gold standard y los otros grupos a estudio. Las muestras se procesaron con diferentes condiciones de temperatura y tiempo antes de ser congeladas, constituyendo seis grupos: centrifugación y congelación inmediata (grupo 1, de referencia); muestra a temperatura ambiente una hora, centrifugación y mantenimiento en nevera (2-8 ºC) durante 0, 8 o 24 horas (grupos 2 A, 2B y 2C, respectivamente); mantenimiento de sangre a temperatura ambiente 3 horas, mantenimiento en nevera (2-8 ºC) durante 0 y 8 horas (grupos 3A y 3B). La PTH-i se ha determinado mediante Inmunoradiometria (IRMA Total Intact Scantibodies assay). Se ha realizado el test de homogeneidad de varianzas y normalidad, y depués comparaciones por pares con el t-test con la corrección de Bonferroni. Resultados: La PTH-intacta media en el grupo de referencia fue 202,5 ± 199,72 pg/ml. Las medias de PTH-intacta en distintos grupos analizados fueron 196 ± 203,23 pg/ml, 202,8 ± 200,2 pg/ml, 200,06 ± 194,87 pg/ml, 204,08 ± 204,073 pg/ml, 197,94 ± 182,31 pg/ml. Los resultados fueron prácticamente superponibles, no encontrando diferencias significativas respecto al grupo de referencia (p = 0,87, p = 0,99, p = 0,95, p = 0,96, p = 0,90 al comparar con grupos 2A, 2B, 2C, 3A y 3B, respectivamente). Conclusiones: La utilización de EDTA como conservante en el procesamiento de las muestras analíticas para la determinación sanguínea de PTH-i permite un mayor tiempo de procesamiento de la misma, sin la exigencia de su congelación inmediata, mostrando una mínima variabilidad en los resultados obtenidos según diferentes formas de procesamiento. Estos resultados pueden ayudar a establecer estrategias logísticas para el procesamiento de muestras sanguíneas en los pacientes con ERC (AU)