Diagnosis of immediate reactions to amoxicillin: Comparison of basophil activation markers CD63 and CD203c in a prospective study.

BACKGROUND: Amoxicillin (AX) combined or not with clavulanic acid (CLV) is frequently involved in IgE-mediated reactions. Drug provocation test (DPT) is considered as the gold standard for diagnosis, although contraindicated in high-risk patients. Basophil activation test (BAT) can help diagnose immediate reactions to beta-lactams, although controversy exists regarding the best activation marker. We have performed a real-life study in a prospective cohort to analyze the real value of BAT as diagnostic tool and the best activation marker, CD63 and CD203c, for the evaluation of immediate reactions to these drugs. METHODS: We prospectively evaluated patients with a clinical suspicion of immediate reactions after AX or AX-CLV administration during a 6-year period. The allergological work-up was done following the EAACI recommendations. BAT was performed in all patients using CD63 and CD203c as activation markers. RESULTS: In AX-allergic patients, both activation markers, CD63 and CD203c, showed similar SE values (48.6% and 46.7%, respectively); however, specificity was of 81.1% and 94.6%, respectively, with CD203c showing good positive predictive value and like-hood ratio. In CLV-allergic patients, CD203c showed higher SE (50%) than CD63 (42.9%), maintaining the same value of SP (80%). Combining the results of both markers can slightly increase the sensitivity (51.4% for AX and 54.8% for CLV), although decreasing the specificity (79.7% and 73%, respectively). Interestingly, all patients with an anaphylactic shock showed a positive BAT to CLV using CD203c. CONCLUSIONS: BAT using CD203c showed a good confirmatory power, especially for AX allergy. Placing BAT as a first step in the diagnostic procedure can help reduce the need of performing a complete allergological work-up in 46.6% of patients, diminishing the risk of reinducing allergic reactions.

Advances and highlights in T and B cell responses to drug antigens.

The immunological mechanisms involved in drug hypersensitivity reactions (DHRs) are complex, and despite important advances, multiple aspects remain poorly understood. These not fully known aspects are mainly related to the factors that drive towards either a tolerant or a hypersensitivity response and specifically regarding the role of B and T cells. In this review, we focus on recent findings on this knowledge area within the last 2 years. We highlight new evidences of covalent and non-covalent interactions of drug antigen with proteins, as well as the very first characterization of naturally processed flucloxacillin-haptenated human leukocyte antigen (HLA) ligands. Moreover, we have analysed new insights into the identification of risk factors associated with the development of DHRs, such as the role of oxidative metabolism of drugs in the activation of the immune system and the discovery of new associations between DHRs and HLA variants. Finally, evidence of IgG-mediated anaphylaxis in humans and the involvement of specific subpopulations of effector cells associated with different clinical entities are also topics explored in this review. All these recent findings are relevant for the underlying pathology mechanisms and advance the field towards a more precise diagnosis, management and treatment approach for DHRs.

Molecular Mechanisms Involved in the Impairment of Boar Sperm Motility by Peroxynitrite-Induced Nitrosative Stress.

Excessive levels of reactive nitrogen species (RNS) produce nitrosative stress. Among RNS is peroxynitrite, a highly reactive free radical generated when nitric oxide reacts with superoxide anion. Peroxynitrite effects have been mainly studied in somatic cells, and in spermatozoa the majority of studies are focused in humans. The aim of this study is to investigate the in vitro peroxynitrite effect on boar spermatozoa functions and the molecular mechanisms involved. Spermatozoa were exposed to the donor 3-morpholinosydnonimine (SIN-1) in non-capacitating or capacitating medium, motility was evaluated by CASA, functional parameters by flow cytometry and sperm protein phosphorylation by Western blotting. SIN-1 treatment, that significantly increases peroxynitrite levels in boar spermatozoa, potentiates the capacitating-stimulated phosphorylation of cAMP-dependent protein kinase 1 (PKA) substrates and GSK-3α. SIN-1 induced peroxynitrite does not decrease sperm viability, but significantly reduces sperm motility, progressive motility, velocities and motility coefficients. Concomitantly, peroxynitrite does not affect mitochondrial membrane potential, plasma membrane fluidity, or A23187-induced acrosome reaction. However, peroxynitrite significantly increases sperm lipid peroxidation in both media. In conclusion, peroxynitrite compromises boar sperm motility without affecting mitochondrial activity. Although peroxynitrite potentiates the phosphorylation of pathways leading to sperm motility, it also causes oxidative stress that might explain, at least partially, the motility impairment.

Web educativo sobre genética molecular (WEB/genética) / Teaching Web on molecular genetics (WEB/genética)

Concepción de un sitio web educativo que permita a los alumnos del primer año de Medicina acceder a los diferentes contenidos tratados en el tema de Genética Medica correspondiente a la asignatura Biología Celular y Molecular (1er semestre), con los objetivos de lograr en ellos una participación más activa en su aprendizaje, una mejor comprensión y sistematización de los complejos procesos impartidos en este tema y suplir las dificultades bibliográficas existentes para esta especialidad, además de pretender aportar nuevas herramientas para la impartición de la docencia por los profesores y ayudar a estudiantes a aprender practicando, así como practicar con los conceptos. El mismo puede ser utilizado además en los estudios de postgrado de la especialidad de Bioquímica Clínica y otras especialidades de Ciencias Biomédicas o no que sean afines a la disciplina. El sitio está elaborado atendiendo a la forma de diseño docente del tema en la asignatura, es decir a través de conferencias, con vistas a alcanzar los objetivos propuestos; ejercicios interactivos de autoevaluación, un glosario de términos de difícil comprensión al final de cada tema, así como la Bibliografía recomendada, que serán los textos básicos de la asignatura y textos de consulta que incluyen revisiones actualizadas realizadas en Internet. Los alumnos accederán a través del Explorador de Internet a una página de presentación, con la identificación del sitio y vínculos con los temarios correspondientes, así como un vínculo a una selección de tópicos tomados de Internet. También se adiciona un vínculo con el correo electrónico del profesor que imparte la Asignatura, para consultas, dudas o sugerencias(AU)