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1.
Allergy ; 79(5): 1089-1122, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38108546

RESUMEN

The accumulation of senescent cells drives inflammaging and increases morbidity of chronic inflammatory lung diseases. Immune responses are built upon dynamic changes in cell metabolism that supply energy and substrates for cell proliferation, differentiation, and activation. Metabolic changes imposed by environmental stress and inflammation on immune cells and tissue microenvironment are thus chiefly involved in the pathophysiology of allergic and other immune-driven diseases. Altered cell metabolism is also a hallmark of cell senescence, a condition characterized by loss of proliferative activity in cells that remain metabolically active. Accelerated senescence can be triggered by acute or chronic stress and inflammatory responses. In contrast, replicative senescence occurs as part of the physiological aging process and has protective roles in cancer surveillance and wound healing. Importantly, cell senescence can also change or hamper response to diverse therapeutic treatments. Understanding the metabolic pathways of senescence in immune and structural cells is therefore critical to detect, prevent, or revert detrimental aspects of senescence-related immunopathology, by developing specific diagnostics and targeted therapies. In this paper, we review the main changes and metabolic alterations occurring in senescent immune cells (macrophages, B cells, T cells). Subsequently, we present the metabolic footprints described in translational studies in patients with chronic asthma and chronic obstructive pulmonary disease (COPD), and review the ongoing preclinical studies and clinical trials of therapeutic approaches aiming at targeting metabolic pathways to antagonize pathological senescence. Because this is a recently emerging field in allergy and clinical immunology, a better understanding of the metabolic profile of the complex landscape of cell senescence is needed. The progress achieved so far is already providing opportunities for new therapies, as well as for strategies aimed at disease prevention and supporting healthy aging.


Asunto(s)
Senescencia Celular , Redes y Vías Metabólicas , Humanos , Senescencia Celular/efectos de los fármacos , Animales , Enfermedad Crónica , Inflamación/metabolismo , Inflamación/inmunología , Enfermedades Pulmonares/etiología , Enfermedades Pulmonares/tratamiento farmacológico , Enfermedades Pulmonares/metabolismo , Enfermedades Pulmonares/inmunología , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Enfermedad Pulmonar Obstructiva Crónica/inmunología , Envejecimiento/inmunología , Envejecimiento/metabolismo
3.
Clin Exp Allergy ; 48(1): 60-65, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28906044

RESUMEN

BACKGROUND: Little is known on the clinical relevance of peanut 2S albumin Ara h 7. OBJECTIVE: To investigate the discriminative ability of Ara h 7 in peanut allergy and assess the role of cross-reactivity between Ara h 2, 6 and Ara h 7 isoforms. METHODS: Sensitization to recombinant peanut storage proteins Ara h 1, 2, 3, 6, and 7 was assessed using a line blot in sera from 40 peanut-tolerant and 40 peanut-allergic patients, based on food challenge outcome. A dose-dependent ELISA inhibition experiment was performed with recombinant Ara h 2, 6 and Ara h 7 isoforms. RESULTS: For Ara h 7.0201, an area under the ROC curve was found of 0.83, comparable to Ara h 2 (AUC 0.81) and Ara h 6 (AUC 0.85). Ara h 7 intensity values strongly correlated with those from Ara h 2 and 6 (rs = 0.81). Of all patients sensitized to 2S albumins Ara h 2, 6, or 7, the majority was co-sensitized to all three (n = 24, 68%), although mono-sensitization to either 2S albumin was also observed in selected patients (Ara h 2: n = 6, 17%; Ara h 6: n = 2, 6%; Ara h 7: n = 2, 6%). Binding to Ara h 7.0101 could be strongly inhibited by Ara h 7.0201, but not the other way around. CONCLUSIONS AND CLINICAL RELEVANCE: Specific IgE against Ara h 7.0201 has a predictive ability for peanut allergy similar to Ara h 2 and 6 and possesses unique IgE epitopes as well as epitopes shared between the other Ara h 7 isoform and Ara h 2 and 6. While co-sensitization to all three 2S albumins is most common, mono-sensitization to either Ara h 2, 6, or 7 occurs in selected patients, leading to a risk of misdiagnosis when testing for a single 2S albumin.


Asunto(s)
Albuminas 2S de Plantas/inmunología , Antígenos de Plantas/inmunología , Epítopos/inmunología , Inmunoglobulina E/inmunología , Hipersensibilidad al Cacahuete/inmunología , Adolescente , Adulto , Anciano , Reacciones Cruzadas , Femenino , Humanos , Masculino , Persona de Mediana Edad
4.
Clin Exp Allergy ; 48(7): 890-897, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29542223

RESUMEN

BACKGROUND: Screening for specific IgE against 2S albumin proteins Ara h 2 and 6 has good positive predictive value in diagnosing peanut allergy. From the third 2S member Ara h 7, 3 isoforms have been identified. Their allergenicity has not been elucidated. OBJECTIVE: This study investigated the allergenicity of Ara h 7 isoforms compared to Ara h 2 and 6. METHODS: Sensitization of 15 DBPCFC-confirmed peanut-allergic patients to recombinant Ara h 2.0201, Ara h 6.01 and isoforms of recombinant Ara h 7 was determined by IgE immunoblotting strips. A basophil activation test (BAT) was performed in 9 patients to determine IgE-cross-linking capacities of the allergens. Sensitivity to the allergens was tested in 5 patients who were sensitized to at least 1 Ara h 7 isoform, by a concentration range in the BAT. 3D prediction models and sequence alignments were used to visualize differences between isoforms and to predict allergenic epitope regions. RESULTS: Sensitization to Ara h 7.0201 was most frequent (80%) and showed to be equally potent as Ara h 2.0201 and 6.01 in inducing basophil degranulation. Sensitization to Ara h 7.0201 together with Ara h 2.0201 and/or 6.01 was observed, indicating the presence of unique epitopes compared to the other 2 isoforms. Differences between the 3 Ara h 7 isoforms were observed in C-terminal cysteine residues, pepsin and trypsin cleavage sites and 3 single amino acid substitutions. CONCLUSION & CLINICAL RELEVANCE: The majority of peanut-allergic patients are sensitized to isoform Ara h 7.0201, which is functionally as active as Ara h 2.0201 and 6.01. Unique epitopes are most likely located in the C-terminus or an allergenic loop region which is a known allergenic epitope region for Ara h 2.0201 and 6.01. Due to its unique epitopes and allergenicity, it is an interesting candidate to improve the diagnostic accuracy for peanut allergy.


Asunto(s)
Albuminas 2S de Plantas/inmunología , Antígenos de Plantas/inmunología , Basófilos/inmunología , Degranulación de la Célula/inmunología , Epítopos/inmunología , Hipersensibilidad al Cacahuete/inmunología , Albuminas 2S de Plantas/química , Adulto , Secuencia de Aminoácidos , Antígenos de Plantas/química , Basófilos/metabolismo , Epítopos/química , Femenino , Humanos , Inmunoglobulina E/inmunología , Masculino , Persona de Mediana Edad , Modelos Moleculares , Hipersensibilidad al Cacahuete/diagnóstico , Conformación Proteica , Isoformas de Proteínas , Relación Estructura-Actividad
5.
Clin Exp Allergy ; 48(6): 679-690, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29575251

RESUMEN

BACKGROUND: Treatment of atopic dermatitis (AD) is focused on topical anti-inflammatory therapy, epidermal barrier repair and trigger avoidance. Multidisciplinary treatment in both moderate maritime and alpine climates can successfully reduce disease activity in children with AD. However, it remains unclear whether abnormalities in B cell and T cell memory normalize and whether this differs between treatment strategies. OBJECTIVE: To determine whether successful treatment in maritime and alpine climates normalizes B- and T lymphocytes in children with moderate to severe AD. METHODS: The study was performed in the context of a trial (DAVOS trial, registered at Current Controlled Trials ISCRTN88136485) in which eighty-eight children with moderate to severe AD were randomized to 6 weeks of treatment in moderate maritime climate (outpatient setting) or in the alpine climate (inpatient setting). Before and directly after treatment, disease activity was determined with SA-EASI and serum TARC, and T cell and B cell subsets were quantified in blood. RESULTS: Both treatment protocols achieved a significant decrease in disease activity, which was accompanied by a reduction in circulating memory Treg, transitional B cell and plasmablast numbers. Alpine climate treatment had a significantly greater effect on disease activity and was accompanied by a reduction in blood eosinophils and increases in memory B cells, CD8+ TemRO, CD4+ Tcm and CCR7+ Th2 subsets. CONCLUSIONS AND CLINICAL RELEVANCE: Clinically successful treatment of AD induces changes in blood B- and T cell subsets reflecting reduced chronic inflammation. In addition, multidisciplinary inpatient treatment in the alpine climate specifically affects memory B cells, CD8+ T cells and Th2 cells. These cell types could represent good markers for treatment efficacy.


Asunto(s)
Linfocitos B/inmunología , Clima , Dermatitis Atópica/etiología , Dermatitis Atópica/terapia , Memoria Inmunológica , Linfocitos T Colaboradores-Inductores/inmunología , Adolescente , Linfocitos B/metabolismo , Biomarcadores , Niño , Dermatitis Atópica/diagnóstico , Femenino , Humanos , Inmunoglobulina A/inmunología , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Recuento de Linfocitos , Masculino , Índice de Severidad de la Enfermedad , Suiza , Linfocitos T Colaboradores-Inductores/metabolismo , Resultado del Tratamiento
6.
Allergy ; 73(4): 765-798, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-28940458

RESUMEN

Allergic rhinoconjunctivitis (AR) is an allergic disorder of the nose and eyes affecting about a fifth of the general population. Symptoms of AR can be controlled with allergen avoidance measures and pharmacotherapy. However, many patients continue to have ongoing symptoms and an impaired quality of life; pharmacotherapy may also induce some side-effects. Allergen immunotherapy (AIT) represents the only currently available treatment that targets the underlying pathophysiology, and it may have a disease-modifying effect. Either the subcutaneous (SCIT) or sublingual (SLIT) routes may be used. This Guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on AIT for AR and is part of the EAACI presidential project "EAACI Guidelines on Allergen Immunotherapy." It aims to provide evidence-based clinical recommendations and has been informed by a formal systematic review and meta-analysis. Its generation has followed the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach. The process included involvement of the full range of stakeholders. In general, broad evidence for the clinical efficacy of AIT for AR exists but a product-specific evaluation of evidence is recommended. In general, SCIT and SLIT are recommended for both seasonal and perennial AR for its short-term benefit. The strongest evidence for long-term benefit is documented for grass AIT (especially for the grass tablets) where long-term benefit is seen. To achieve long-term efficacy, it is recommended that a minimum of 3 years of therapy is used. Many gaps in the evidence base exist, particularly around long-term benefit and use in children.


Asunto(s)
Conjuntivitis Alérgica/prevención & control , Desensibilización Inmunológica/métodos , Desensibilización Inmunológica/normas , Rinitis Alérgica/prevención & control , Humanos
7.
Allergy ; 73(4): 799-815, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29205393

RESUMEN

Food allergy can result in considerable morbidity, impairment of quality of life, and healthcare expenditure. There is therefore interest in novel strategies for its treatment, particularly food allergen immunotherapy (FA-AIT) through the oral (OIT), sublingual (SLIT), or epicutaneous (EPIT) routes. This Guideline, prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Task Force on Allergen Immunotherapy for IgE-mediated Food Allergy, aims to provide evidence-based recommendations for active treatment of IgE-mediated food allergy with FA-AIT. Immunotherapy relies on the delivery of gradually increasing doses of specific allergen to increase the threshold of reaction while on therapy (also known as desensitization) and ultimately to achieve post-discontinuation effectiveness (also known as tolerance or sustained unresponsiveness). Oral FA-AIT has most frequently been assessed: here, the allergen is either immediately swallowed (OIT) or held under the tongue for a period of time (SLIT). Overall, trials have found substantial benefit for patients undergoing either OIT or SLIT with respect to efficacy during treatment, particularly for cow's milk, hen's egg, and peanut allergies. A benefit post-discontinuation is also suggested, but not confirmed. Adverse events during FA-AIT have been frequently reported, but few subjects discontinue FA-AIT as a result of these. Taking into account the current evidence, FA-AIT should only be performed in research centers or in clinical centers with an extensive experience in FA-AIT. Patients and their families should be provided with information about the use of FA-AIT for IgE-mediated food allergy to allow them to make an informed decision about the therapy.


Asunto(s)
Desensibilización Inmunológica/métodos , Desensibilización Inmunológica/normas , Hipersensibilidad a los Alimentos/prevención & control , Animales , Humanos , Inmunoglobulina E/inmunología
8.
Allergy ; 72(8): 1156-1173, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28152201

RESUMEN

BACKGROUND: Allergen immunotherapy (AIT) is an effective treatment for allergic rhinoconjunctivitis (AR) with or without asthma. It is important to note that due to the complex interaction between patient, allergy triggers, symptomatology and vaccines used for AIT, some patients do not respond optimally to the treatment. Furthermore, there are no validated or generally accepted candidate biomarkers that are predictive of the clinical response to AIT. Clinical management of patients receiving AIT and efficacy in randomised controlled trials for drug development could be enhanced by predictive biomarkers. METHOD: The EAACI taskforce reviewed all candidate biomarkers used in clinical trials of AR patients with/without asthma in a literature review. Biomarkers were grouped into seven domains: (i) IgE (total IgE, specific IgE and sIgE/Total IgE ratio), (ii) IgG-subclasses (sIgG1, sIgG4 including SIgE/IgG4 ratio), (iii) Serum inhibitory activity for IgE (IgE-FAB and IgE-BF), (iv) Basophil activation, (v) Cytokines and Chemokines, (vi) Cellular markers (T regulatory cells, B regulatory cells and dendritic cells) and (vii) In vivo biomarkers (including provocation tests?). RESULTS: All biomarkers were reviewed in the light of their potential advantages as well as their respective drawbacks. Unmet needs and specific recommendations on all seven domains were addressed. CONCLUSIONS: It is recommended to explore the use of allergen-specific IgG4 as a biomarker for compliance. sIgE/tIgE and IgE-FAB are considered as potential surrogate candidate biomarkers. Cytokine/chemokines and cellular reponses provided insight into the mechanisms of AIT. More studies for confirmation and interpretation of the possible association with the clinical response to AIT are needed.


Asunto(s)
Asma/diagnóstico , Asma/terapia , Conjuntivitis Alérgica/diagnóstico , Conjuntivitis Alérgica/terapia , Desensibilización Inmunológica , Rinitis Alérgica/diagnóstico , Rinitis Alérgica/terapia , Alérgenos/inmunología , Asma/inmunología , Basófilos/inmunología , Basófilos/metabolismo , Biomarcadores , Conjuntivitis Alérgica/inmunología , Citocinas/metabolismo , Desensibilización Inmunológica/métodos , Humanos , Inmunoglobulina E/inmunología , Inmunoglobulina G/inmunología , Subgrupos Linfocitarios/inmunología , Subgrupos Linfocitarios/metabolismo , Pronóstico , Rinitis Alérgica/inmunología , Resultado del Tratamiento
9.
Allergy ; 72(8): 1133-1147, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28058751

RESUMEN

BACKGROUND: The European Academy of Allergy and Clinical Immunology (EAACI) is developing Guidelines for Allergen Immunotherapy (AIT) for IgE-mediated Food Allergy. To inform the development of clinical recommendations, we sought to critically assess evidence on the effectiveness, safety and cost-effectiveness of AIT in the management of food allergy. METHODS: We undertook a systematic review and meta-analysis that involved searching nine international electronic databases for randomized controlled trials (RCTs) and nonrandomized studies (NRS). Eligible studies were independently assessed by two reviewers against predefined eligibility criteria. The quality of studies was assessed using the Cochrane Risk of Bias tool for RCTs and the Cochrane ACROBAT-NRS tool for quasi-RCTs. Random-effects meta-analyses were undertaken, with planned subgroup and sensitivity analyses. RESULTS: We identified 1814 potentially relevant papers from which we selected 31 eligible studies, comprising of 25 RCTs and six NRS, studying a total of 1259 patients. Twenty-five trials evaluated oral immunotherapy (OIT), five studies investigated sublingual immunotherapy, and one study evaluated epicutaneous immunotherapy. The majority of these studies were in children. Twenty-seven studies assessed desensitization, and eight studies investigated sustained unresponsiveness postdiscontinuation of AIT. Meta-analyses demonstrated a substantial benefit in terms of desensitization (risk ratio (RR) = 0.16, 95% CI 0.10, 0.26) and suggested, but did not confirm sustained unresponsiveness (RR = 0.29, 95% CI 0.08, 1.13). Only one study reported on disease-specific quality of life (QoL), which reported no comparative results between OIT and control group. Meta-analyses revealed that the risk of experiencing a systemic adverse reaction was higher in those receiving AIT, with a more marked increase in the risk of local adverse reactions. Sensitivity analysis excluding those studies judged to be at high risk of bias demonstrated the robustness of summary estimates of effectiveness and safety of AIT for food allergy. None of the studies reported data on health economic analyses. CONCLUSIONS: AIT may be effective in raising the threshold of reactivity to a range of foods in children with IgE-mediated food allergy whilst receiving (i.e. desensitization) and post-discontinuation of AIT. It is, however, associated with a modest increased risk in serious systemic adverse reactions and a substantial increase in minor local adverse reactions. More data are needed in relation to adults, long term effects, the impact on QoL and the cost-effectiveness of AIT.


Asunto(s)
Alérgenos/inmunología , Desensibilización Inmunológica , Hipersensibilidad a los Alimentos/inmunología , Hipersensibilidad a los Alimentos/terapia , Alimentos/efectos adversos , Inmunoglobulina E/inmunología , Alérgenos/administración & dosificación , Animales , Desensibilización Inmunológica/métodos , Humanos , Oportunidad Relativa , Calidad de Vida , Inmunoterapia Sublingual , Resultado del Tratamiento
10.
Allergy ; 72(11): 1597-1631, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28493631

RESUMEN

BACKGROUND: The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing Guidelines on Allergen Immunotherapy (AIT) for Allergic Rhinoconjunctivitis. To inform the development of clinical recommendations, we undertook a systematic review to assess the effectiveness, cost-effectiveness, and safety of AIT in the management of allergic rhinoconjunctivitis. METHODS: We searched nine international biomedical databases for published, in-progress, and unpublished evidence. Studies were independently screened by two reviewers against predefined eligibility criteria and critically appraised using established instruments. Our primary outcomes of interest were symptom, medication, and combined symptom and medication scores. Secondary outcomes of interest included cost-effectiveness and safety. Data were descriptively summarized and then quantitatively synthesized using random-effects meta-analyses. RESULTS: We identified 5960 studies of which 160 studies satisfied our eligibility criteria. There was a substantial body of evidence demonstrating significant reductions in standardized mean differences (SMD) of symptom (SMD -0.53, 95% CI -0.63, -0.42), medication (SMD -0.37, 95% CI -0.49, -0.26), and combined symptom and medication (SMD -0.49, 95% CI -0.69, -0.30) scores while on treatment that were robust to prespecified sensitivity analyses. There was in comparison a more modest body of evidence on effectiveness post-discontinuation of AIT, suggesting a benefit in relation to symptom scores. CONCLUSIONS: AIT is effective in improving symptom, medication, and combined symptom and medication scores in patients with allergic rhinoconjunctivitis while on treatment, and there is some evidence suggesting that these benefits are maintained in relation to symptom scores after discontinuation of therapy.


Asunto(s)
Conjuntivitis Alérgica/terapia , Desensibilización Inmunológica/métodos , Rinitis Alérgica Estacional/terapia , Alérgenos/inmunología , Bases de Datos Factuales , Humanos
11.
Allergy ; 71(11): 1540-1551, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27224838

RESUMEN

IgE sensitization tests, such as skin prick testing and serum-specific IgE, have been used to diagnose IgE-mediated clinical allergy for many years. Their prime drawback is that they detect sensitization which is only loosely related to clinical allergy. Many patients therefore require provocation tests to make a definitive diagnosis; these are often expensive and potentially associated with severe reactions. The likelihood of clinical allergy can be semi-quantified from an IgE sensitization test results. This relationship varies though according to the patients' age, ethnicity, nature of the putative allergic reaction and coexisting clinical diseases such as eczema. The likelihood of clinical allergy can be more precisely estimated from an IgE sensitization test result, by taking into account the patient's presenting features (pretest probability). The presence of each of these patient-specific factors may mean that a patient is more or less likely to have clinical allergy with a given test result (post-test probability). We present two approaches to include pretest probabilities in the interpretation of results. These approaches are currently limited by a lack of data to allow us to derive pretest probabilities for diverse setting, regions and allergens. Also, cofactors, such as exercise, may be necessary for exposure to an allergen to result in an allergic reaction in specific IgE-positive patients. The diagnosis of IgE-mediated allergy is now being aided by the introduction of allergen component testing which may identify clinically relevant sensitization. Other approaches are in development with basophil activation testing being closest to clinical application.


Asunto(s)
Pruebas Diagnósticas de Rutina/normas , Hipersensibilidad/diagnóstico , Hipersensibilidad/inmunología , Inmunoglobulina E/inmunología , Alérgenos/inmunología , Pruebas Diagnósticas de Rutina/métodos , Humanos , Inmunización , Inmunoglobulina E/sangre , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Pronóstico , Reproducibilidad de los Resultados , Factores de Riesgo
12.
Pediatr Allergy Immunol ; 27 Suppl 23: 1-250, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-27288833

RESUMEN

The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients.


Asunto(s)
Alérgenos/inmunología , Hipersensibilidad Inmediata/diagnóstico , Inmunoglobulina E/metabolismo , Biomarcadores/metabolismo , Humanos , Hipersensibilidad Inmediata/inmunología , Hipersensibilidad Inmediata/metabolismo , Hipersensibilidad Inmediata/terapia , Pruebas Inmunológicas/métodos , Medicina de Precisión/métodos
13.
J Anim Breed Genet ; 133(3): 180-6, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26676611

RESUMEN

Independent of whether prediction is based on pedigree or genomic information, the focus of animal breeders has been on additive genetic effects or 'breeding values'. However, when predicting phenotypes rather than breeding values of an animal, models that account for both additive and dominance effects might be more accurate. Our aim with this study was to compare the accuracy of predicting phenotypes using a model that accounts for only additive effects (MA) and a model that accounts for both additive and dominance effects simultaneously (MAD). Lifetime daily gain (DG) was evaluated in three pig populations (1424 Pietrain, 2023 Landrace, and 2157 Large White). Animals were genotyped using the Illumina SNP60K Beadchip and assigned to either a training data set to estimate the genetic parameters and SNP effects, or to a validation data set to assess the prediction accuracy. Models MA and MAD applied random regression on SNP genotypes and were implemented in the program Bayz. The additive heritability of DG across the three populations and the two models was very similar at approximately 0.26. The proportion of phenotypic variance explained by dominance effects ranged from 0.04 (Large White) to 0.11 (Pietrain), indicating that importance of dominance might be breed-specific. Prediction accuracies were higher when predicting phenotypes using total genetic values (sum of breeding values and dominance deviations) from the MAD model compared to using breeding values from both MA and MAD models. The highest increase in accuracy (from 0.195 to 0.222) was observed in the Pietrain, and the lowest in Large White (from 0.354 to 0.359). Predicting phenotypes using total genetic values instead of breeding values in purebred data improved prediction accuracy and reduced the bias of genomic predictions. Additional benefit of the method is expected when applied to predict crossbred phenotypes, where dominance levels are expected to be higher.


Asunto(s)
Modelos Genéticos , Sus scrofa/crecimiento & desarrollo , Sus scrofa/genética , Animales , Cruzamiento , Genes Dominantes , Linaje , Fenotipo , Polimorfismo de Nucleótido Simple , Sus scrofa/clasificación
14.
J Anim Breed Genet ; 133(3): 187-96, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27174095

RESUMEN

We studied the effect of including GWAS results on the accuracy of single- and multipopulation genomic predictions. Phenotypes (backfat thickness) and genotypes of animals from two sire lines (SL1, n = 1146 and SL3, n = 1264) were used in the analyses. First, GWAS were conducted for each line and for a combined data set (both lines together) to estimate the genetic variance explained by each SNP. These estimates were used to build matrices of weights (D), which was incorporated into a GBLUP method. Single population evaluated with traditional GBLUP had accuracies of 0.30 for SL1 and 0.31 for SL3. When weights were employed in GBLUP, the accuracies for both lines increased (0.32 for SL1 and 0.34 for SL3). When a multipopulation reference set was used in GBLUP, the accuracies were higher (0.36 for SL1 and 0.32 for SL3) than in single-population prediction. In addition, putting together the multipopulation reference set and the weights from the combined GWAS provided even higher accuracies (0.37 for SL1, and 0.34 for SL3). The use of multipopulation predictions and weights estimated from a combined GWAS increased the accuracy of genomic predictions.


Asunto(s)
Peso Corporal , Estudio de Asociación del Genoma Completo , Sus scrofa/genética , Tejido Adiposo , Animales , Polimorfismo de Nucleótido Simple , Sus scrofa/clasificación , Sus scrofa/fisiología
15.
BMC Genomics ; 16: 1049, 2015 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-26652161

RESUMEN

BACKGROUND: In many traits, not only individual trait levels are under genetic control, but also the variation around that level. In other words, genotypes do not only differ in mean, but also in (residual) variation around the genotypic mean. New statistical methods facilitate gaining knowledge on the genetic architecture of complex traits such as phenotypic variability. Here we study litter size (total number born) and its variation in a Large White pig population using a Double Hierarchical Generalized Linear model, and perform a genome-wide association study using a Bayesian method. RESULTS: In total, 10 significant single nucleotide polymorphisms (SNPs) were detected for total number born (TNB) and 9 SNPs for variability of TNB (varTNB). Those SNPs explained 0.83 % of genetic variance in TNB and 1.44 % in varTNB. The most significant SNP for TNB was detected on Sus scrofa chromosome (SSC) 11. A possible candidate gene for TNB is ENOX1, which is involved in cell growth and survival. On SSC7, two possible candidate genes for varTNB are located. The first gene is coding a swine heat shock protein 90 (HSPCB = Hsp90), which is a well-studied gene stabilizing morphological traits in Drosophila and Arabidopsis. The second gene is VEGFA, which is activated in angiogenesis and vasculogenesis in the fetus. Furthermore, the genetic correlation between additive genetic effects on TNB and on its variation was 0.49. This indicates that the current selection to increase TNB will also increase the varTNB. CONCLUSIONS: To the best of our knowledge, this is the first study reporting SNPs associated with variation of a trait in pigs. Detected genomic regions associated with varTNB can be used in genomic selection to decrease varTNB, which is highly desirable to avoid very small or very large litters in pigs. However, the percentage of variance explained by those regions was small. The SNPs detected in this study can be used as indication for regions in the Sus scrofa genome involved in maintaining low variability of litter size, but further studies are needed to identify the causative loci.


Asunto(s)
Estudio de Asociación del Genoma Completo/veterinaria , Tamaño de la Camada , Polimorfismo de Nucleótido Simple , Sus scrofa/genética , Animales , Teorema de Bayes , Cromosomas de los Mamíferos/genética , Sitios Genéticos , Estudio de Asociación del Genoma Completo/métodos , Proteínas HSP90 de Choque Térmico/genética , Modelos Lineales , Porcinos , Factor A de Crecimiento Endotelial Vascular/genética
16.
Clin Exp Allergy ; 45(4): 788-96, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25665021

RESUMEN

BACKGROUND: Mast cells are mainly present in strategic locations, where they may have a role in defence against parasites and bacteria. These pathogens can be recognized by mast cells via Toll-like receptors (TLR). Allergic symptoms are often increased in the presence of pathogens at the site of allergen exposure, but it is unknown which cytokines can mediate such an effect. OBJECTIVE: To study whether an interaction between IgE- and TLR-mediated activation of human mast cells can contribute to exacerbated inflammatory responses. METHODS: Peripheral blood-derived mast cells were stimulated with TLR ligands, in the presence or absence of anti-IgE triggering, after which degranulation was measured using flow cytometry and cytokine production was evaluated by multiplex assays, and ELISA. For evaluation of allergen-specific responses, mast cells were sensitized with serum of allergic individuals or controls, after which they were stimulated using allergens in combination with TLR ligands. RESULTS: Simultaneous triggering of mast cells via IgE and TLR ligands greatly enhanced cytokine production but not IgE-induced degranulation. Different TLR ligands specifically enhanced the differential production of cytokines in conjunction with FcεRI triggering. Importantly, only TLR-4 and TLR-6 were able to induce robust production of IL-13, an important molecule in allergic reactions. CONCLUSIONS & CLINICAL RELEVANCE: These results indicate that the simultaneous presence of pathogen- or danger-associated signals and FcεRI triggering via specific IgE can significantly modify mast cell-mediated allergic reactions via synergistic production of cytokines and inflammatory mediators and provide an explanation of augmented allergic symptoms during infection.


Asunto(s)
Citocinas/biosíntesis , Mastocitos/inmunología , Mastocitos/metabolismo , Receptores de IgE/metabolismo , Receptores Toll-Like/metabolismo , Alérgenos/inmunología , Animales , Especificidad de Anticuerpos/inmunología , Células Cultivadas , Humanos , Inmunoglobulina E/inmunología , Ligandos
17.
Clin Exp Allergy ; 45(4): 720-30, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25226880

RESUMEN

The diagnostic accuracy of skin prick test (SPT) and specific IgE (sIgE) to peanut extract in diagnosing peanut allergy is suboptimal. Recent studies have evaluated sIgE to peanut components as a possible new diagnostic tool. The aim of our review was to systematically search the literature to assess the diagnostic value of sIgE to peanut components in diagnosing peanut allergy. A literature search was performed in PubMed, Embase and the Cochrane Library. Results were subsequently screened for in- and exclusion criteria. The quality of eligible studies was assessed using a standardized quality assessment tool (QUADAS-2). Data on sensitivity, specificity, and positive and negative likelihood ratios were extracted or calculated for a descriptive analysis. Twenty-two studies were eligible, of which 21 studies in paediatric populations. Most studies reported on sIgE to peanut extract (15) and sIgE to Ara h 2 (12), followed by SPT (9) and sIgE to Ara h 1 (7). All studies were at risk of bias or caused applicability concerns on at least one item of the quality assessment tool. The best combination of diagnostic accuracy measures of all diagnostic tests was found for sIgE to Ara h 2. This finding was independent of geographical location. Compared to SPT and sIgE to peanut extract, sIgE to Ara h 2 was mainly superior in diagnosing peanut allergy in case of a positive test result. Worst diagnostic accuracy measures were found in general for sIgE to Ara h 8 and sIgE to Ara h 9. sIgE to Ara h 2 showed the best diagnostic accuracy of all diagnostic tests to diagnose peanut allergy. Compared to the currently used SPT and sIgE to peanut extract, sIgE to Ara h 2 was superior in diagnosing peanut allergy and should therefore replace these tests in daily clinical practice, especially in children.


Asunto(s)
Especificidad de Anticuerpos/inmunología , Antígenos de Plantas/inmunología , Arachis/efectos adversos , Inmunoglobulina E/inmunología , Hipersensibilidad al Cacahuete/diagnóstico , Hipersensibilidad al Cacahuete/inmunología , Alérgenos/inmunología , Humanos , Inmunoglobulina E/sangre , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Pruebas Cutáneas
18.
Allergy ; 70(7): 727-54, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25819018

RESUMEN

Biologic agents (also termed biologicals or biologics) are therapeutics that are synthesized by living organisms and directed against a specific determinant, for example, a cytokine or receptor. In inflammatory and autoimmune diseases, biologicals have revolutionized the treatment of several immune-mediated disorders. Biologicals have also been tested in allergic disorders. These include agents targeting IgE; T helper 2 (Th2)-type and Th2-promoting cytokines, including interleukin-4 (IL-4), IL-5, IL-9, IL-13, IL-31, and thymic stromal lymphopoietin (TSLP); pro-inflammatory cytokines, such as IL-1ß, IL-12, IL-17A, IL-17F, IL-23, and tumor necrosis factor (TNF); chemokine receptor CCR4; and lymphocyte surface and adhesion molecules, including CD2, CD11a, CD20, CD25, CD52, and OX40 ligand. In this task force paper of the Interest Group on Biologicals of the European Academy of Allergy and Clinical Immunology, we review biologicals that are currently available or tested for the use in various allergic and urticarial pathologies, by providing an overview on their state of development, area of use, adverse events, and future research directions.


Asunto(s)
Antialérgicos/uso terapéutico , Factores Biológicos/uso terapéutico , Hipersensibilidad/tratamiento farmacológico , Hipersensibilidad/inmunología , Antialérgicos/farmacología , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Antígenos/inmunología , Antígenos/metabolismo , Factores Biológicos/farmacología , Ensayos Clínicos como Asunto , Humanos , Hipersensibilidad/diagnóstico , Resultado del Tratamiento
19.
Allergy ; 70(11): 1393-405, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26198455

RESUMEN

The basophil activation test (BAT) has become a pervasive test for allergic response through the development of flow cytometry, discovery of activation markers such as CD63 and unique markers identifying basophil granulocytes. Basophil activation test measures basophil response to allergen cross-linking IgE on between 150 and 2000 basophil granulocytes in <0.1 ml fresh blood. Dichotomous activation is assessed as the fraction of reacting basophils. In addition to clinical history, skin prick test, and specific IgE determination, BAT can be a part of the diagnostic evaluation of patients with food-, insect venom-, and drug allergy and chronic urticaria. It may be helpful in determining the clinically relevant allergen. Basophil sensitivity may be used to monitor patients on allergen immunotherapy, anti-IgE treatment or in the natural resolution of allergy. Basophil activation test may use fewer resources and be more reproducible than challenge testing. As it is less stressful for the patient and avoids severe allergic reactions, BAT ought to precede challenge testing. An important next step is to standardize BAT and make it available in diagnostic laboratories. The nature of basophil activation as an ex vivo challenge makes it a multifaceted and promising tool for the allergist. In this EAACI task force position paper, we provide an overview of the practical and technical details as well as the clinical utility of BAT in diagnosis and management of allergic diseases.


Asunto(s)
Prueba de Desgranulación de los Basófilos , Basófilos/inmunología , Hipersensibilidad/diagnóstico , Hipersensibilidad/inmunología , Algoritmos , Alérgenos/inmunología , Basófilos/metabolismo , Biomarcadores , Citometría de Flujo , Humanos , Tetraspanina 30/metabolismo
20.
Reprod Domest Anim ; 50 Suppl 2: 103-9, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26174927

RESUMEN

Diluting semen from high fertile breeding boars, and by that inseminating many sows, is the core business for artificial insemination (AI) companies worldwide. Knowledge about fertility results is the reason by which an AI company can lower the concentration of a dose. Efficient use of AI boars with high genetic merit by decreasing the number of sperm cells per insemination dose is important to maximize dissemination of the genetic progress made in the breeding nucleus. However, a potential decrease in fertility performance in the field should be weighed against the added value of improved genetics and, in general, is not tolerated in commercial production. This overview provides some important aspects that influence the impact of low-dose AI on fertility: (i) the importance of monitoring field fertility, (ii) the need for accurate and precise semen assessment, (iii) the parameters that are taken into account, (iv) the application of information from genetic and genomic selection and (v) the optimization when using different AI techniques. Efficient semen production, processing and insemination in combination with increasing use of genetic and genomic applications result in maximum impact of genetic trend.


Asunto(s)
Inseminación Artificial/genética , Inseminación Artificial/veterinaria , Semen/fisiología , Recuento de Espermatozoides , Porcinos , Animales , Cruzamiento , Computadores , Daño del ADN , Femenino , Fertilidad/genética , Inseminación Artificial/métodos , Masculino , Embarazo , Carácter Cuantitativo Heredable , Análisis de Semen/métodos , Análisis de Semen/veterinaria , Motilidad Espermática , Espermatozoides/química
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