Variantes genéticas y actividad enzimática de la citidin desaminasa: relación con la toxicidad a la capecitabina y recomendación de ajuste de las dosis / Genetic variants and enzyme activity in citidin deaminase: Relationship with capecitabine toxicity and recommendation for dose adjustment

Objetivo: la capecitabina es un fármaco antineoplásico utilizado en el tratamiento del cáncer de mama y de colon que puede dar lugar a una toxicidad grave, llegando a ser mortal en algunos pacientes. La variabilidad interindividual de esta toxicidad es debida en gran medida a las variaciones genéticas en los genes diana y las enzimas de metabolismo de este fármaco, como la timidilato sintasa y la dihidropirimidina deshidrogenasa. La enzima citidin desaminasa (CDA), imprescindible en la activación de la capecitabina, también presenta diversas variantes asociadas con un mayor riesgo de toxicidad al tratamiento, aunque su papel como biomarcador aún no está claramente definido. Por ello, nuestro objetivo principal es estudiar la asociación entre la presencia de las variantes genéticas en el gen CDA, su actividad enzimática y el desarrollo de la toxicidad grave en los pacientes tratados con capecitabina, cuya dosis inicial se haya ajustado con base en el perfil genético del gen de la dihidropirimidina deshidrogenasa (DPYD). Método: estudio de cohortes observacional multicéntrico prospectivo, centrado en el análisis de la asociación genotipo-fenotipo de la enzima CDA. Tras la fase experimental, se desarrollará un algoritmo que permita determinar el ajuste necesario de las dosis para disminuir el riesgo de toxicidad del tratamiento en función del genotipo CDA, elaborando una guía clínica para la dosificación de la capecitabina en función de las variantes genéticas en DPYD y CDA. Con base en esta guía, se creará una herramienta bioinformática que genere el informe farmacoterapéutico de manera automática, facilitando la implementación del consejo farmacogenético en la práctica clínica. Esta herramienta proporcionará un gran respaldo en la toma de decisiones farmacoterapéuticas basadas en el perfil genético del paciente, incorporando la medicina de precisión en la rutina clínica. ... (AU)

Objective: Capecitabine, an antineoplastic drug used in the treatment of breast and colon cancer, can cause severe, even fatal toxicity in some patients. The interindividual variability of this toxicity is largely due to genetic variations in target genes and enzymes of metabolism of this drug, such as thymidylate synthase and dihydropyrimidine dehydrogenase. The enzyme cytidine deaminase (CDA), involved in the activation of capecitabine, also has several variants associated with an increased risk of toxicity to treatment, although its role as a biomarker is not yet clearly defined.Therefore, our main objective is to study the association between the presence of genetic variants in CDA gen, CDA enzymatic activity and the development of severe toxicity in patients treated with capecitabine whose initial dose was adjusted based on the genetic profile of the dihydropyrimidine dehydrogenase gen (DPYD). Method: Prospective multicenter observational cohort study, focused on the analysis of the genotype-phenotype association of the CDA enzyme.After the experimental phase, an algorithm will be developed to determine the dose adjustment needed to reduce the risk of treatment toxicity according to CDA genotype, developing a clinical guide for capecitabine dosing according to genetic variants in DPYD and CDA. Based on this guide, a Bioinformatics Tool will be created to generate the pharmacotherapeutic report automatically, facilitating the implementation of pharmacogenetic advice in clinical practice. This tool will be a great support in making pharmacotherapeutic decisions based on the patient's genetic profile, incorporating precision medicine into clinical routine. Once the usefulness of this tool has been validated, it will be offered free of charge to facilitate the implementation of pharmacogenetics in hospital centers and equitably benefit all patients on capecitabine treatment. (AU)

[Translated article] Genetic variants and enzyme activity in citidin deaminase: Relationship with capecitabine toxicity and recommendation for dose adjustment.

OBJECTIVE: Capecitabine, an antineoplastic drug used in the treatment of breast and colon cancer, can cause severe, even fatal toxicity in some patients. The interindividual variability of this toxicity is largely due to genetic variations in target genes and enzymes of metabolism of this drug, such as Thymidylate Synthase (TS) and Dihydropyrimidine Dehydrogenase (DPD). The enzyme Cytidine Deaminase (CDA), involved in the activation of capecitabine, also has several variants associated with an increased risk of toxicity to treatment, although its role as a biomarker is not yet clearly defined. Therefore, our main objective is to study the association between the presence of genetic variants in CDA gen, CDA enzymatic activity and the development of severe toxicity in patients treated with capecitabine whose initial dose was adjusted based on the genetic profile of the DPD gen (DPYD). METHOD: Prospective multicenter observational cohort study, focused on the analysis of the genotype-phenotype association of the CDA enzyme. After the experimental phase, an algorithm will be developed to determine the dose adjustment needed to reduce the risk of treatment toxicity according to CDA genotype, developing a Clinical Guide for capecitabine dosing according to genetic variants in DPYD and CDA. Based on this guide, a Bioinformatics Tool will be created to generate the pharmacotherapeutic report automatically, facilitating the implementation of pharmacogenetic advice in clinical practice. This tool will be a great support in making pharmacotherapeutic decisions based on the patient's genetic profile, incorporating precision medicine into clinical routine. Once the usefulness of this tool has been validated, it will be offered free of charge to facilitate the implementation of pharmacogenetics in hospital centers and equitably benefit all patients on capecitabine treatment.

Genetic variants and enzyme activity in citidin deaminase: Relationship with capecitabine toxicity and recommendation for dose adjustment. / Variantes genéticas y actividad enzimática de la citidin desaminasa: relación con la toxicidad a la capecitabina y recomendación de ajuste de las dosis.

OBJECTIVE: Capecitabine, an antineoplastic drug used in the treatment of breast and colon cancer, can cause severe, even fatal toxicity in some patients. The interindividual variability of this toxicity is largely due to genetic variations in target genes and enzymes of metabolism of this drug, such as thymidylate synthase and dihydropyrimidine dehydrogenase. The enzyme cytidine deaminase (CDA), involved in the activation of capecitabine, also has several variants associated with an increased risk of toxicity to treatment, although its role as a biomarker is not yet clearly defined. Therefore, our main objective is to study the association between the presence of genetic variants in CDA gen, CDA enzymatic activity and the development of severe toxicity in patients treated with capecitabine whose initial dose was adjusted based on the genetic profile of the dihydropyrimidine dehydrogenase gen (DPYD). METHOD: Prospective multicenter observational cohort study, focused on the analysis of the genotype-phenotype association of the CDA enzyme. After the experimental phase, an algorithm will be developed to determine the dose adjustment needed to reduce the risk of treatment toxicity according to CDA genotype, developing a clinical guide for capecitabine dosing according to genetic variants in DPYD and CDA. Based on this guide, a Bioinformatics Tool will be created to generate the pharmacotherapeutic report automatically, facilitating the implementation of pharmacogenetic advice in clinical practice. This tool will be a great support in making pharmacotherapeutic decisions based on the patient's genetic profile, incorporating precision medicine into clinical routine. Once the usefulness of this tool has been validated, it will be offered free of charge to facilitate the implementation of pharmacogenetics in hospital centers and equitably benefit all patients on capecitabine treatment.

Development, and Internal, and External Validation of a Scoring System to Predict 30-Day Mortality after Having a Traffic Accident Traveling by Private Car or Van: An Analysis of 164,790 Subjects and 79,664 Accidents.

Predictive factors for fatal traffic accidents have been determined, but not addressed collectively through a predictive model to help determine the probability of mortality and thereby ascertain key points for intervening and decreasing that probability. Data on all road traffic accidents with victims involving a private car or van occurring in Spain in 2015 (164,790 subjects and 79,664 accidents) were analyzed, evaluating 30-day mortality following the accident. As candidate predictors of mortality, variables associated with the accident (weekend, time, number of vehicles, road, brightness, and weather) associated with the vehicle (type and age of vehicle, and other types of vehicles in the accident) and associated with individuals (gender, age, seat belt, and position in the vehicle) were examined. The sample was divided into two groups. In one group, a logistic regression model adapted to a points system was constructed and internally validated, and in the other group the model was externally validated. The points system obtained good discrimination and calibration in both the internal and the external validation. Consequently, a simple tool is available to determine the risk of mortality following a traffic accident, which could be validated in other countries.

Utilización de marcadores genéticos de la CYP2E1 en la valoración de riesgos de exposición laboral a estireno mediante control biológico / Use of genetic markers for CYPE1 in the assessment of risks through occupational exposure to styrene using biologic controls

Hemos estudiado la utilidad del genotipado y fenotipado de la enzima CYP2E1 para la evaluación del riesgo de exposición laboral a estireno, correlacionando los datos obtenidos con los indicadores biológicos habituales en programas de Salud Laboral (ácidos mandélico y fenilglioxílico, principales metabolitos urinarios del estireno). Se examinaron 49 trabajadores con exposición conocida a estireno y un grupo control, determinándose mARN de CYP2E1 en sangre y polimorfismos de la enzima en muestras de mucosa oral. Nuestros resultados muestran que el efecto combinado del fenotipo de CYP2E1 y del genotipo de los alelos CYP2E1*5B y CYP2E1*6 puede explicar en parte la variabilidad en la excreción urinaria de metabolitos del estireno. La técnica de obtención de material biológico a partir de la mucosa oral puede ser de interés en el ámbito laboral (AU)

We have studied the usefulness of geno and phenotyping of the enzyme CYP2E1 for the assessment of risk through occupational exposure to styrene and correlated the results achieved with the habitual biologic markers in Occupational Health programmes (mandelic and phenylglyoxylic acids, the main urinary metabolites of styrene). The study group comprised 49 workers with known exposure to styrene and a control group; CYP2E1 mRNA in blood and enzyme polymorphisms in samples of the oral mucosa were assessed. Our results show that the combined affects of CYP2E1 phenotype and of the CYP2E1*5B and CYP2E1*6 allele genotype may in part explain the variability in the urinary excretion of styrene metabolites. The sampling technique for biologic material from the oral mucosa may be useful in the occupational environment (AU)