Evaluation of bone metabolism in children with cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) bone disease (CFBD) has attracted considerable recent interest from researchers, although several aspects of CFBD pathophysiology remain poorly understood. The objective of this research was to investigate CFBD in children with CF and its relation to clinical and bone metabolism markers. METHODS: In a prospective observational study of 68 patients with CF and 63 healthy controls, we studied bone turnover biomarkers and bone mineral density (BMD). The biomarkers included osteocalcin, total-alkaline phosphatase, bone-alkaline phosphatase, N-terminal propeptide of type-1-procollagen, osteoprotegerin (OPG), interleukine-6, tumor necrosis factor alpha (TNF-α), type-1-collagen cross-linked C-telopeptide (CTX), parathormone (PTH), 25-vitamin D, 1,25-vitamin D, calcium and phosphorus. BMD was examined in lumbar spine, comparing two healthy Spanish populations. Two regression analyses were applied to any significant associations to evaluate predictors of BMD and of CF, expressed as odds ratios (OR) with 95% confidence intervals. RESULTS: After adjusting for age, sex, and height Z-score, gains in BMD LS in children and adolescents (6-16 years) with CF were not less than in healthy reference population. Patients with CF showed significant associations with different bone turnover biomarkers. Age, gender, body mass index, PTH, CTX and OPG were significant predictors of BMD (R2 = 0.866, p < 0,001). Moreover, we found that PTH (OR = 1.070; 95% CI 1.019-1.123), and TNFα (OR = 2.173; 95% CI 1.514-3.118) were significantly linked to CF, and calcium (OR = 0.115; 95% CI 0.025-0.524), 1,25-vitamin D (OR = 0.979; 95% CI 0.962 0.996) and OPG (OR = 0.189; 95% CI 0.073-0.489) were significant reduced. CONCLUSION: A normal bone mineral density along with altered remodeling was found in CF patients with a normal nutritional status and without acute lung disease.

Estudio comparativo de los niveles de procalcitonina en el plasma y las muestras de sangre seca mediante electroquimioluminiscencia (ECLIA) / A comparative study of procalcitonin levels in plasma and dried blood specimens using electrochemiluminescence (ECLIA)

Introducción. Los procesos febriles constituyen uno de los motivos de consulta más frecuentes en las urgencias pediátricas, siendo las infecciones bacterianas una de las principales causas responsables de los mismos. Su diagnóstico es un reto a superar pues representan una importante causa de morbimortalidad. Entre los biomarcadores séricos utilizados, es la procalcitonina la que aparece en el suero con anterioridad a otros biomarcadores inflamatorios agudos tales como el número de leucocitos en circulación periférica y la proteína C reactiva. Material y métodos. Se utilizaron muestras de 135 pacientes pediátricos recogidas mediante punción en el dedo o talón. Las determinaciones se realizaron respectivamente en plasma y sangre seca recogida sobre papel (DBS), en la misma muestra de cada uno de ellos. Resultados. El estudio estadístico comparativo realizado entre los resultados obtenidos en ambos tipos de muestras, nos indica la existencia de una correlación estadísticamente significativa entre muestras analizadas por ambas metodologías. El test U de Mann-Whitney aplicado asimismo, manifiesta la no existencia de diferencias estadísticamente significativas entre los resultados. Conclusiones. Las muestras DBS tienen una gran utilidad para la cuantificación de los niveles de procalcitonina en la población pediátrica donde, con frecuencia, la extracción de sangre venosa presenta dificultades. La obtención de este tipo de muestra por simple punción en el talón o yema del dedo evita este problema, contribuyendo al diagnóstico rápido de los procesos infecciosos. No obstante, podría mejorarse la sensibilidad del método realizando determinaciones seriadas en aquellas muestras con valores iniciales bajos (menores de 0,650 ng/mL) (AU)

Introduction. Fever processes constitute one of the main reasons for pediatric emergency department visits, being bacterial infections one of the principal causes of this process. Its diagnosis represents a challenge to overcome, due to the high morbidity and mortality rates related to these infections. Among analyzed serum biomarkers, procalcitonin shows an earlier appearance in serum than others inflammatory biomarkers such as peripheral blood leukocytes number and C-reactive protein. Materials and methods. Blood samples were collected by finger or heel puncture from 135 pediatric patients. Procalcitonin was measured in plasma and in dried blood specimen (DBS) for each blood sample. Results. The comparative statistical analysis has revealed a significant correlation between the two procalcitonin assays. The Mann-Whitney U test has demonstrated that there was no difference on the procalcitonin results obtained by both techniques. Conclusions. DBS represent a useful tool for quantifying procalcitonin levels in pediatric population, where venous blood collection is usually difficult. The extraction of this type of blood sample, by finger or heel puncture, avoids this problem, contributing to a rapid diagnosis of this kind of infectious processes. However, method sensitivity could be improved by performing serial measurements in samples with low basal levels (lower than 0.650 ng/mL) (AU)