Quality indicators for extra-analytical processes in clinical laboratory: ten years’ experience / Indicadores de calidad para los procesos extra-analíticos en el laboratorio clínico: 10 años de experiencia

Introduction. The selection and definition of quality indicators is essential for proper control of processes. This is not always easy, particularly with extra-analytical indicators, due to the complexity and degree of comparison of processes between laboratories, and the fact that data collection is not always automated. For this reason, the indicators and specifications need to be dynamic and re-designed in accordance with changes in the system. The aim of this paper is to describe the methodology used in the selection and definition of quality indicators, and their specifications for extra-analytical processes in public laboratories in Catalonia. Material and methods. During the study period (2004-2013), the members of the working group reported the mean annual value for each indicator, and the overall yearly mean of all participants was calculated. These results were compared and analyzed during periodic meetings, with regards to the pre-established specifications of the different laboratories. Results. Quality indicators and their specifications are presented. The evaluation of the validity of each quality indicator was made taking into account aspects including usefulness of the indicator in process monitoring, a clear definition, and a precise and reliable quantification. This methodology has made it possible to contrast the validity of the indicators or to reconsider the specification. Conclusions. The last 10 years’ experience of the Catalonian Health Institute Working Group on Quality Indicators in designing indicators and establishing quality specifications has proved very useful for improving the monitoring of processes in clinical laboratories included in the group (AU)

Introducción. La selección y definición de los indicadores de la calidad es imprescindible para controlar adecuadamente un proceso. Ello no siempre es fácil, sobre todo en el caso de los indicadores extraanalíticos, dada la complejidad y grado de comparabilidad de los procesos entre laboratorios y la necesaria recogida de datos que en muchas ocasiones no está automatizada. Asimismo, los indicadores y especificaciones deben ser dinámicos y rediseñarse en función de los cambios del sistema. El objetivo de este trabajo es describir la metodología utilizada en la selección y definición de indicadores de calidad y especificaciones para los procesos extraanalíticos en los laboratorios públicos de Cataluña. Material y métodos. Durante el período de estudio (2004-2013), los miembros del grupo han informado del valor medio anual para cada indicador, y se ha calculado la media anual de todos los participantes para cada uno de ellos. Estos resultados se han comparado y analizado a través de reuniones periódicas, con respecto a las especificaciones preestablecidas de los diferentes laboratorios. Resultados. Se presentan los indicadores de calidad y sus especificaciones. La evaluación de la validez de cada indicador de calidad se llevó a cabo teniendo en cuenta los aspectos incluyendo la utilidad del indicador en la supervisión de procesos, una definición clara y una cuantificación precisa y fiable. Esta metodología ha permitido contrastar la validez de los indicadores o reconsiderar la especificación. Conclusiones. Los últimos 10 años de experiencia del Grupo de Trabajo del Instituto Catalán de la Salud de Indicadores de Calidad en el diseño de indicadores y en establecer especificaciones de calidad ha demostrado ser muy útil para mejorar el seguimiento de los procesos en los laboratorios clínicos integrados en el grupo (AU)

Increased serum IgG and IgA in overweight children relate to a less favourable metabolic phenotype.

BACKGROUND: The adaptive immune system has emerged as an unexpected modulator of insulin resistance. B lymphocytes accumulate in adipose tissue and produce pathogenic antibodies that cause insulin resistance. OBJECTIVE: We studied whether circulating immunoglobulins (IgG, IgA and IgM) were related to metabolic risk markers in pre-pubertal children with and without overweight. DESIGN AND METHODS: Subjects were 270 asymptomatic pre-pubertal Caucasian children (145 lean, 125 overweight) recruited in a primary care setting. Assessments included serum IgG, IgA and IgM concentrations (nephelometry), insulin resistance (HOMA-IR) and fasting lipids (triacylglycerol and high-density lipoprotein [HDL]-cholesterol). RESULTS: Overweight children had higher IgG and IgA serum levels than lean children (P ≤ 0.01). Increasing serum IgG and IgA, but not IgM, were associated with a less favourable metabolic phenotype, consisting of higher HOMA-IR and triacylglycerol and lower HDL-cholesterol, particularly in obese children, in whom serum IgG and IgA were both independently associated with HOMA-IR (ß = 0.308, P = 0.017, r2 = 9.5% and ß = 0.361, P = 0.005, r2 = 13.0%, respectively) and triacylglycerol (ß = 0.343, P = 0.006, r2 = 11.1% and ß = 0.354, P = 0.003, r2 = 12.2%, respectively). CONCLUSIONS: Increased circulating IgG and IgA in overweight children are associated with a less favourable metabolic phenotype, particularly in obese children. These results suggest a relationship between adaptive immunity and insulin resistance in childhood obesity.

Soluble fatty acid synthase relates to bone biomarkers in prepubertal children.

SUMMARY: Circulating soluble fatty acid synthase (FASN, a key enzyme in de novo biosynthesis of fatty acids, expressed in both adipocytes and osteoblasts) is clinically related to a less favorable bone profile in healthy prepubertal children. Soluble FASN may participate in the reciprocal regulation between fat and bone metabolism. INTRODUCTION: Fatty acid synthase (FASN), a key enzyme in de novo biosynthesis of fatty acids, is expressed in adipocytes and osteoblasts. We hypothesized that FASN may participate in the crosstalk between fat and bone. To this aim, we studied the relation between circulating soluble FASN (an extracellular FASN that reflects previously intracellular enzymatic activity) and adipose tissue and bone biomarkers in prepubertal children. METHODS: Circulating soluble FASN, total and high molecular weight (HMW) adiponectin, bone biomarkers [osteocalcin (OC), uncarboxylated osteocalcin (ucOC), C-terminal cross-linked telopeptide of type I collagen (CTX), bone-specific alkaline phosphatase (BSAP)], and a profile of energy metabolism [body fat, insulin resistance and secretion (HOMA), serum lipids] were assessed in 84 asymptomatic prepubertal children (44 girls, 40 boys, age 6.8 ± 0.1 year). Serum 25-OH Vitamin D (Vit D) was additionally measured. RESULTS: Circulating soluble FASN increased with increasing HMW adiponectin (r = 0.29, p = 0.01) and decreasing serum Vit D (r = -0.21, p < 0.05), and was related to a less favorable bone profile, showing negative associations with bone-derived metabolic parameters [total OC (r = -0.33, p = 0.002) and ucOC (r = -0.37, p < 0.0001)] and a positive association with the CTX-to-BSAP ratio (r = 0.31, p < 0.01). These correlations were not explained by age, gender, body fat, insulin resistance or secretion or serum lipids; however, they were predominant in those subjects with Vit D levels below the population median. CONCLUSIONS: Circulating soluble FASN relates to both adipose tissue and bone biomarkers in prepubertal children, with associations that are dependent on Vit D concentrations. These findings suggest that FASN may participate in the crosstalk between fat and bone metabolism.