RESUMO
INTRODUCTION: Severe eosinophilic asthma (SEA) is associated with multiple exacerbations. Fractional exhaled nitric oxide (FeNO), a biomarker of airway T2 inflammation, is known to be correlated with the risk of exacerbations. While the use of FeNO is well established to predict the therapeutic response to dupilumab (anti-IL-4/IL-13), it remains uncertain for biologics targeting the IL-5 pathway. METHODS: We conducted an observational, retrospective, monocentric analysis of adults with SEA who started mepolizumab (anti-IL-5) or benralizumab (anti-IL-5R) between January 1, 2016 and December 31, 2020. RESULTS: Data were collected for 109 patients. All participants reported uncontrolled asthma with a median of 3 annual exacerbations and a median Asthma Control Test score of 12. They all had an initial blood eosinophilia >300/mm3, with a median at 610/mm3 (IQR 420-856). Patients with a baseline FeNO ≥50 ppb reported more exacerbations in the previous year than those with a FeNO <50 ppb (p = 0.02). After initiation of treatment, change in FeNO was not associated with therapeutic response. However, decrease in the annual number of exacerbations was significantly greater in patients with a baseline FeNO ≥50 ppb than in those with a baseline FeNO <50 ppb (-3.3 ± 2.7 vs -0.9 ± 2.4, respectively; p = 0.01). There was no association between baseline FeNO values and subsequent lung function, asthma control or reduction of oral corticosteroids use. CONCLUSION: In this real-world cohort, adults with SEA who had a baseline FeNO ≥50 ppb experienced a greater decrease in exacerbations after 12 months of anti-IL-5 or IL-5R biologics than those with a FeNO <50 ppb.
Assuntos
Asma , Produtos Biológicos , Eosinofilia Pulmonar , Humanos , Adulto , Teste da Fração de Óxido Nítrico Exalado , Produtos Biológicos/uso terapêutico , Estudos Retrospectivos , Óxido Nítrico/metabolismo , Eosinofilia Pulmonar/diagnóstico , Eosinofilia Pulmonar/tratamento farmacológicoRESUMO
BACKGROUND: The mechanisms of the atopic march, characterized by a natural progression from food and cutaneous allergies to rhinitis and asthma, are still unknown. However, as several organs can be involved, chemokines and their receptors might be implicated in this process and may be instrumental factors. OBJECTIVES: We hypothesized that the T-cell gut-homing receptor CCR9 could be implicated in the evolution of allergic diseases. METHODS: We characterized the immune response and the role of CCR9 in a murine model combining food allergy to wheat gliadin and a model of acute airways inflammation in response to house dust mite. RESULTS: Compared with solely asthmatic-like mice, we demonstrated that the aggravation of pulmonary symptoms in consecutive food and respiratory allergies, characterized by an increase in pulmonary resistance and a higher Th17/Treg ratio, was abrogated in CCR9 knockout mice. Moreover, transfer of food-allergic CD4+ T cells from wild-type but not from CCR9-/- aggravated airways inflammation demonstrating that CCR9 is involved in food allergy-enhanced allergic airway inflammation to unrelated allergens. CONCLUSION: Taken together, our results demonstrated a crucial role of the T-cell homing receptor CCR9 in this model and validated its potential for use in the development of therapeutic strategies for allergic diseases.
Assuntos
Alérgenos/imunologia , Hipersensibilidade Alimentar/imunologia , Alimentos/efeitos adversos , Linfócitos/imunologia , Linfócitos/metabolismo , Receptores CCR/metabolismo , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/metabolismo , Adulto , Animais , Biomarcadores , Citocinas/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Feminino , Hipersensibilidade Alimentar/patologia , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Knockout , Pyroglyphidae/imunologia , Hipersensibilidade Respiratória/patologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Células Th17/imunologia , Células Th17/metabolismo , Adulto JovemRESUMO
Chronic lung allograft dysfunction (CLAD) is the major limitation of long-term survival after lung transplantation. CLAD manifests as bronchiolitis obliterans syndrome (BOS) or restrictive allograft syndrome (RAS). Alloimmune reactions and epithelial-to-mesenchymal transition have been suggested in BOS. However, little is known regarding the role of allogenicity in epithelial cell differentiation. Primary human bronchial epithelial cells (BECs) were treated with activated T cells in the presence or absence of transforming growth factor (TGF)-ß. The expression of epithelial and mesenchymal markers was investigated. The secretion of inflammatory cytokines and matrix metalloproteinase (MMP)-9 was measured in culture supernatants and in plasma from lung transplant recipients (LTRs): 49 stable, 29 with BOS, and 16 with RAS. We demonstrated that C-C motif chemokine 2 secreted by T cells supports TGF-ß-induced MMP-9 production by BECs after binding to C-C chemokine receptor type 2. Longitudinal investigation in LTRs revealed a rise in plasma MMP-9 before CLAD onset. Multivariate analysis showed that plasma MMP-9 was independently associated with BOS (odds ratio [OR] = 6.19, p = 0.002) or RAS (OR = 3.9, p = 0.024) and predicted the occurrence of CLAD 12 months before the functional diagnosis. Thus, immune cells support airway remodeling through the production of MMP-9. Plasma MMP-9 is a potential predictive biomarker of CLAD.
Assuntos
Biomarcadores/sangue , Células Epiteliais/imunologia , Rejeição de Enxerto/diagnóstico , Pneumopatias/complicações , Transplante de Pulmão/efeitos adversos , Metaloproteinase 9 da Matriz/sangue , Receptores CCR2/metabolismo , Linfócitos T/imunologia , Adulto , Aloenxertos , Brônquios/imunologia , Brônquios/metabolismo , Brônquios/patologia , Doença Crônica , Citocinas/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Seguimentos , Rejeição de Enxerto/sangue , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/imunologia , Humanos , Estudos Longitudinais , Pneumopatias/cirurgia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Prognóstico , Fatores de Risco , Linfócitos T/metabolismo , Fator de Crescimento Transformador beta/metabolismoRESUMO
BACKGROUND: Airway epithelial cells (AEC) act as the first line of defence in case of lung infections. They constitute a physical barrier against pathogens and they participate in the initiation of the immune response. Yet, the modalities of pathogen recognition by AEC and the consequences on the epithelial barrier remain poorly documented. METHOD: We investigated the response of primary human AEC to viral (polyinosinic-polycytidylic acid, poly(I:C)) and bacterial (lipopolysaccharide, LPS) stimulations in combination with the lung remodeling factor Transforming Growth Factor-ß (TGF-ß). RESULTS: We showed a strong production of pro-inflammatory cytokines (Interleukin (IL)-6, Tumor Necrosis Factor α, TNFα) or chemokines (CCL2, CCL3, CCL4, CXCL10, CXCL11) by AEC stimulated with poly(I:C). Cytokine and chemokine production, except CXCL10, was Toll Like Receptor (TLR)-3 dependent and although they express TLR4, we found no cytokine production after LPS stimulation. Poly(I:C), but not LPS, synergised with TGF-ß for the production of matrix metalloproteinase-9 (MMP-9) and fibronectin. Mechanistic analyses suggest the secretion of Wnt ligands by AEC along with a degradation of the cellular junctions after poly(I:C) exposure, leading to the release of ß-catenin from the cell membrane and stimulation of the Wnt/ß-catenin pathway. CONCLUSION: Our results highlight the cross talk between TGF-ß and TLR signaling in bronchial epithelium and its impact on the remodeling process.
Assuntos
Metaloproteinase 9 da Matriz/biossíntese , Mucosa Respiratória/metabolismo , Receptor 3 Toll-Like/biossíntese , Via de Sinalização Wnt/fisiologia , beta Catenina/metabolismo , Células Cultivadas , Quimiocinas/metabolismo , Citocinas/metabolismo , Humanos , Lipopolissacarídeos/farmacologia , Receptor Cross-Talk/efeitos dos fármacos , Receptor Cross-Talk/fisiologia , Mucosa Respiratória/efeitos dos fármacos , Fator de Crescimento Transformador beta/farmacologia , Via de Sinalização Wnt/efeitos dos fármacosRESUMO
Under homeostatic conditions, as well as in various diseases, leukocyte migration is a crucial issue for the immune system that is mainly organized through the activation of bone marrow-derived cells in various tissues. Immune cell trafficking is orchestrated by a family of small proteins called chemokines. Leukocytes express cell-surface receptors that bind to chemokines and trigger transendothelial migration. Most allergic diseases, such as asthma, rhinitis, food allergies, and atopic dermatitis, are generally classified by the tissue rather than the type of inflammation, making the chemokine/chemokine receptor system a key point of the immune response. Moreover, because small antagonists can easily block such receptors, various molecules have been developed to suppress the recruitment of immune cells during allergic reactions, representing potential new drugs for allergies. We review the chemokines and chemokine receptors that are important in asthma, food allergies, and atopic dermatitis and their respectively developed antagonists.
Assuntos
Hipersensibilidade/imunologia , Hipersensibilidade/metabolismo , Receptores de Quimiocinas/metabolismo , Animais , Antiasmáticos/farmacologia , Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Asma/genética , Asma/imunologia , Asma/metabolismo , Quimiocinas/genética , Quimiocinas/metabolismo , Dermatite Atópica/tratamento farmacológico , Dermatite Atópica/genética , Dermatite Atópica/imunologia , Dermatite Atópica/metabolismo , Hipersensibilidade Alimentar/tratamento farmacológico , Hipersensibilidade Alimentar/genética , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/metabolismo , Humanos , Hipersensibilidade/tratamento farmacológico , Hipersensibilidade/genética , Sistema Imunitário/citologia , Sistema Imunitário/efeitos dos fármacos , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Receptores de Quimiocinas/antagonistas & inibidoresRESUMO
BACKGROUND: Food allergies affect 4-8% of children and are constantly on the rise, thus making allergies a timely issue. Most importantly, prevention strategies are nonexistent, and current therapeutic strategies have limited efficacy and need to be improved. One alternative to prevent or reduce allergies, particularly during infancy, could consist of modulating maternal immunity and microbiota using nondigestible food ingredients, such as prebiotics. For this purpose, we studied the preventive effects of prebiotics in Balb/c mothers during pregnancy and breastfeeding on food allergy development in offspring mice. METHODS: After weaning, the offspring from mothers that were exposed to GOS/inulin mixture or fed a control diet were intraperitoneally sensitized to wheat proteins to induce a systemic allergic response and orally exposed to the same allergen. Immunological, physiological, and microbial parameters were analyzed. RESULTS: GOS/inulin mixture diet modified the microbiota of mothers and their offspring. Offspring from mothers that received GOS/inulin prebiotics were protected against food allergies and displayed lower clinical scores, specifically of IgE and histamine levels, compared to offspring from mothers fed a control diet. Moreover, GOS/inulin supplementation for the mother resulted in stronger intestinal permeability in the offspring. Enhancement of the regulatory response to allergic inflammation and changes in the Th2/Th1 balance toward a dampened Th2 response were observed in mice from GOS/inulin mixture-exposed mothers. CONCLUSION: The treatment of pregnant and lactating mice with nondigestible GOS/inulin prebiotics promotes a long-term protective effect against food allergies in the offspring.
Assuntos
Hipersensibilidade Alimentar/prevenção & controle , Tolerância Imunológica , Inulina , Exposição Materna , Oligossacarídeos , Efeitos Tardios da Exposição Pré-Natal , Animais , Suplementos Nutricionais , Modelos Animais de Doenças , Feminino , Hipersensibilidade Alimentar/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Inulina/administração & dosagem , Lactação , Camundongos , Microbiota , Oligossacarídeos/administração & dosagem , Permeabilidade , Gravidez , Células Th2/imunologia , Células Th2/metabolismoRESUMO
BACKGROUND: We performed post hoc analyses to evaluate the effect of humanized monoclonal antibody mepolizumab in patients with severe eosinophilic asthma previously treated with omalizumab. METHODS: Data were collected from two randomized double-blind, placebo-controlled studies: MENSA (NCT01691521: 32-week treatment phase) and SIRIUS (NCT01691508: 24-week treatment phase). Active treatment was 75 mg intravenous mepolizumab (MENSA) or 100 mg subcutaneous mepolizumab (MENSA, SIRIUS). Patients had evidence of eosinophilic inflammation ≥150 cells/µl (at screening) or ≥300 cells/µl (during the previous year). Primary outcomes were the rate of exacerbations (MENSA) and the percentage reduction in oral corticosteroid (OCS) dose (SIRIUS). Other outcomes included lung function (forced expiratory volume in 1 s and morning peak expiratory flow), Asthma Control Questionnaire (ACQ-5), St George's Respiratory Questionnaire (SGRQ) scores, and safety. RESULTS: Overall, 576 patients were included from MENSA and 135 from SIRIUS, with 13% and 33% previously receiving omalizumab, respectively. In MENSA, mepolizumab reduced the rate of exacerbations by 57% (prior omalizumab) and 47% (no prior omalizumab) vs placebo. In SIRIUS, reductions in OCS use were comparable regardless of prior omalizumab use. Despite reducing chronic OCS use, mepolizumab also resulted in similar reductions in exacerbation rate relative to placebo in both subgroups. Asthma control and quality of life improved with mepolizumab vs placebo in both studies independent of prior omalizumab use, as shown by ACQ-5 and SGRQ scores. Adverse events were also comparable irrespective of prior omalizumab use. CONCLUSIONS: These post hoc analyses indicate that patients with severe eosinophilic asthma respond positively to mepolizumab regardless of prior use of omalizumab.
Assuntos
Antiasmáticos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Asma/diagnóstico , Asma/tratamento farmacológico , Eosinofilia/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Omalizumab/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Testes de Função Respiratória , Retratamento , Índice de Gravidade de Doença , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Exposure to respiratory allergens triggers airway hyperresponsiveness and inflammation characterized by the expansion of TH 2 cells and the production of allergen specific IgE. Allergic asthma is characterized by an alteration in immune regulatory mechanisms leading to an imbalance between pro- and anti-inflammatory components of the immune system. AIMS: Recently B cells have been described as central regulators of exacerbated inflammation, notably in the case of autoimmunity. However, to what extent these cells can regulate airway inflammation and asthma remains to be elucidated. MATERIALS & METHODS: We took advantage of a allergic asthma model in mice induced by percutaneous sensitization and respiratory challenge with an extract of house dust mite. RESULTS: In this study, we showed that the induction of allergic asthma alters the homeostasis of IL-10(+) Bregs and favors the production of inflammatory cytokines by B cells. Deeper transcriptomic and phenotypic analysis of Bregs revealed that they were enriched in a CD9(+) B cell subset. In asthmatic mice the adoptive transfer of CD9(+) B cells normalized airway inflammation and lung function by inhibiting TH 2- and TH 17-driven inflammation in an IL-10-dependent manner, restoring a favorable immunological balance in lung tissues. Indeed we further showed that injection of CD9(+) Bregs controls the expansion of lung effector T cells allowing the establishment of a favorable regulatory T cells/effector T cells ratio in lungs. CONCLUSION: This finding strengthens the potential for Breg-targeted therapies in allergic asthma.
Assuntos
Linfócitos B Reguladores/imunologia , Pyroglyphidae/imunologia , Hipersensibilidade Respiratória/imunologia , Transferência Adotiva , Alérgenos/imunologia , Animais , Antígenos de Superfície/genética , Antígenos de Superfície/metabolismo , Linfócitos B Reguladores/metabolismo , Biomarcadores , Citocinas/metabolismo , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Homeostase/genética , Homeostase/imunologia , Humanos , Imunoglobulina E/imunologia , Interleucina-10/deficiência , Interleucina-10/genética , Camundongos , Camundongos Knockout , Hipersensibilidade Respiratória/genética , Hipersensibilidade Respiratória/metabolismo , Hipersensibilidade Respiratória/terapia , Tetraspanina 29/metabolismo , Células Th2/imunologia , Células Th2/metabolismo , TranscriptomaRESUMO
B cells are essentially described for their capacity to produce antibodies ensuring anti-infectious immunity or deleterious responses in the case of autoimmunity or allergy. However, abundant data described their ability to restrain inflammation by diverse mechanisms. In allergy, some regulatory B-cell subsets producing IL-10 have been recently described as potent suppressive cells able to restrain inflammatory responses both in vitro and in vivo by regulatory T-cell differentiation or directly inhibiting T-cell-mediated inflammation. A specific deficit in regulatory B cells participates to more severe allergic inflammation. Induction of allergen tolerance through specific immunotherapy induces a specific expansion of these cells supporting their role in establishment of allergen tolerance. However, the regulatory functions carried out by B cells are not exclusively IL-10 dependent. Indeed, other regulatory mechanisms mediated by B cells are (i) the production of TGF-ß, (ii) the promotion of T-cell apoptosis by Fas-Fas ligand or granzyme-B pathways, and (iii) their capacity to produce inhibitory IgG4 and sialylated IgG able to mediate anti-inflammatory mechanisms. This points to Bregs as interesting targets for the development of new therapies to induce allergen tolerance. In this review, we highlight advances in the study of regulatory mechanisms mediated by B cells and outline what is known about their phenotype as well as their suppressive role in allergy from studies in both mice and humans.
Assuntos
Linfócitos B Reguladores/imunologia , Hipersensibilidade/imunologia , Animais , Linfócitos B Reguladores/metabolismo , Humanos , Hipersensibilidade/metabolismo , Imunomodulação , Inflamação/imunologia , Inflamação/metabolismo , Interleucina-10/biossínteseRESUMO
INTRODUCTION: Despite evidence of the benefits of the written asthma action plans (WAP) in asthma control, they remain poorly applied. The aim of our study was to assess the practices of French-speaking pulmonologists and paediatricians in their use of WAP for asthma control and to analyse the contents of several WAPs routinely consulted in treatment of asthma patients. METHODS: Members of three French medical societies (SPLF, G2A, SP2A) were requested to share their WAPs for asthma patients and to participate in an online survey about the possible influence of these documents on their practices. RESULTS: Most (95%) of the 41 WAPs taken into consideration were symptom-based and 34% included peak expiratory flow measurement. All of these action plans were in full compliance with current guidelines. Among the 110 survey respondents, while 65% systematically provided a WAP to their asthma patients, only 30% often or always supplemented the written document with therapeutic education sessions. In almost every case, it was the doctor who presented the WAP to the patient, generally devoting to less than 10minutes to explanation of what they were handing out. CONCLUSIONS: In France, WAPs are generally presented to the patient by the physician, which probably limits the time devoted to explanation of their contents. Furthermore, WAPs are rarely reinforced with therapeutic education. The current study suggests ways of improving the utilization of WAPs in asthma care and treatment.
Assuntos
Asma , Pneumologistas , Humanos , Asma/terapia , Asma/tratamento farmacológico , Cooperação do Paciente , Autocuidado , França/epidemiologiaRESUMO
Asthma exacerbations and severe asthma are linked with high morbidity, significant mortality and high treatment costs. Recurrent asthma exacerbations cause a decline in lung function and, in childhood, are linked to development of persistent asthma. This position paper, from the European Academy of Allergy and Clinical Immunology, highlights the shortcomings of current treatment guidelines for patients suffering from frequent asthma exacerbations and those with difficult-to-treat asthma and severe treatment-resistant asthma. It reviews current evidence that supports a call for increased awareness of (i) the seriousness of asthma exacerbations and (ii) the need for novel treatment strategies in specific forms of severe treatment-resistant asthma. There is strong evidence linking asthma exacerbations with viral airway infection and underlying deficiencies in innate immunity and evidence of a synergism between viral infection and allergic mechanisms in increasing risk of exacerbations. Nonadherence to prescribed medication has been identified as a common clinical problem amongst adults and children with difficult-to-control asthma. Appropriate diagnosis, assessment of adherence and other potentially modifiable factors (such as passive or active smoking, ongoing allergen exposure, psychosocial factors) have to be a priority in clinical assessment of all patients with difficult-to-control asthma. Further studies with improved designs and new diagnostic tools are needed to properly characterize (i) the pathophysiology and risk of asthma exacerbations, and (ii) the clinical and pathophysiological heterogeneity of severe asthma.
Assuntos
Asma/diagnóstico , Asma/terapia , Animais , Asma/prevenção & controle , Progressão da Doença , Humanos , Guias de Prática Clínica como Assunto , Índice de Gravidade de DoençaRESUMO
In 2010 over 200 articles were published in Clinical and Experimental Allergy including editorials, reviews, opinion articles, letters, book reviews and of course at the heart of the journal, papers containing original data which have moved the field of allergy forward on a number of fronts. For the third year running the editors felt it would be of value to summarize the key messages contained in these papers as a snapshot of where the cutting edge of research into allergic disease is leading. We have broadly followed the sections of the journal, although this year the mechanistic articles are grouped together and the studies involving experimental models of disease are discussed throughout the paper. In the field of asthma and rhinitis phenotypes and biomarkers continue to a major pre-occupation of our authors. There is continued interest in mechanisms of inflammation and disordered lung function with the mouse model of asthma continuing to offer new insights. There is also a steady flow of papers investigating new therapies, including those derived from plants and herbs, although many are mechanistic with too few high quality clinical trials. The mechanisms involved in allergic disease are well covered with many strong papers using clinical material to ask relevant questions. Pro-pre and snybiotics continue to be of major interest to our authors and this remains a controversial and complicated field. The discipline of epidemiology has retained its interest in risk factors for the development of allergic disease with a view to refining and debating the reasons for the allergy epidemic. There is continued interest in the relationship between helminthic disease and allergy with a new twist in 2010 involving studies using infection with helminths as a potential treatment. The genetics of allergic disease continues to be very productive, although the field has moved on from only investigating single nucleotide polymorphisms of candidate genes to Genome Wide Association Studies and an increasing and welcome emphasis on gene-environment interactions. In the field of clinical allergy there is steady flow of papers describing patterns of drug allergy with renewed interest in reactions to contrast media, but food allergy is the major area of interest in this section of the journal. Lastly in the field of allergens there is a growing interest in the role of component resolved diagnosis in improving the diagnosis and management of allergic disease. Another excellent year, full of fascinating and high quality work, which the journal has been proud to bring to the allergy community.
Assuntos
Hipersensibilidade/imunologia , Alérgenos/imunologia , Alergia e Imunologia/tendências , Animais , Asma/diagnóstico , Asma/tratamento farmacológico , Asma/imunologia , Humanos , Hipersensibilidade/diagnóstico , Hipersensibilidade/epidemiologia , Hipersensibilidade/terapia , Publicações Periódicas como Assunto , Pesquisa , Rinite/diagnóstico , Rinite/tratamento farmacológico , Rinite/imunologiaRESUMO
BACKGROUND: More perioperative cefazolin use has resulted in an increased risk of cefazolin-associated reactions. OBJECTIVE: The aim of this article is to study immediate reactions to cefazolin and attempt to determine possible allergic cross-reactivity with other ß-lactams using data from the Drug Allergy and Hypersensitivity Database (DAHD). METHODS: All 25 cefazolin-associated reactions in the DAHD were reviewed. The cases identified were then investigated according to the European Network for Drug Allergy (ENDA) recommendations by skin testing and challenges. RESULTS: A total of 10 individuals with proven IgE-mediated cefazolin hypersensitivity were identified between January 1999 and July 2009. All the index reactions were compatible with an acute IgE-mediated process, six with anaphylaxis, two with systemic allergic reactions without hypotension, and two with urticaria/angioedema. Cefazolin skin tests were positive in seven individuals and cefazolin challenges were positive in three more individuals. In the eight cefazolin allergic patients who had challenges with other ß-lactams, there was no positive reaction noted. CONCLUSION AND CLINICAL RELEVANCE: In this cohort of patients with IgE-mediated reactions to cefazolin, a majority tolerated amoxicillin and several patients tolerated other cephalosporins. This implies that the R1 side-chain may play an essential role in IgE-mediated reactions to cefazolin. No clear rule to predict cross-reactivity with other ß-lactams could be determined. More research on IgE-mediated hypersensitivity to cefazolin and other cephalosporins is needed.
Assuntos
Antibacterianos/imunologia , Cefazolina/imunologia , Hipersensibilidade a Drogas/imunologia , Hipersensibilidade Imediata/imunologia , Adolescente , Adulto , Idoso , Antibacterianos/química , Cefazolina/química , Criança , Reações Cruzadas/imunologia , Bases de Dados Factuais , Hipersensibilidade a Drogas/diagnóstico , Feminino , Humanos , Hipersensibilidade Imediata/diagnóstico , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Testes Cutâneos , Adulto JovemRESUMO
BACKGROUND: Asthma guidelines recommend that patients receive inhaler technique training, with rechecks at each visit. However, suboptimal inhaler technique is common. METHODS: This prospective observational study evaluated patient training in use of the Autohaler, a breath-actuated metered-dose inhaler. Physicians enrolled the first four consecutive, eligible adult patients receiving inhaled corticosteroid therapy for asthma. Patients demonstrated their inhaler technique after seeing a demonstration of proper technique and again after physicians gave verbal instruction addressing individual difficulties in technique. Their first and last attempts were evaluated using a 12-item checklist comprising 7 consecutive steps for correct inhaler use and 5 potential errors in device handling or inhalation manoeuvre. RESULTS: A total of 1723 physicians (91% general practitioners) enrolled 6512 patients (mean age 43 years, 52% male). On their first attempt, 2561/6387 (40.1%) of patients were able to complete all procedural steps correctly and without error. A poor inhalation manoeuvre was the most common cause of failure in technique. After education, 91.4% of patients were able to complete all procedural steps correctly and without error. Training session median length was 4 minutes (range 0-45 minutes). CONCLUSIONS: Practical training, coupled with demonstration of inhaler use and observation of technique by a physician, can help patients to improve their inhaler technique and appears feasible in every day practice. Further work is needed to evaluate whether patients maintain good inhaler technique and whether physicians continue the training sessions in everyday practice.
Assuntos
Asma/tratamento farmacológico , Nebulizadores e Vaporizadores , Educação de Pacientes como Assunto , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Observação , Estudos ProspectivosRESUMO
After stimulation of the T cell receptor (TCR), the tyrosine residues 292 and 315 in interdomain B of the protein tyrosine kinase ZAP-70 become phosphorylated and plausibly function as docking sites for Cbl and Vav1, respectively. The two latter proteins have been suggested to serve as substrates for ZAP-70 and to fine-tune its function. To address the role of these residues in T cell development and in the function of primary T cells, we have generated mice that express ZAP-70 molecules with Tyr to Phe substitution at position 292 (Y292F) or 315 (Y315F). When analyzed in a sensitized TCR transgenic background, the ZAP-70 Y315F mutation reduced the rate of positive selection and delayed the occurrence of negative selection. Furthermore, this mutation unexpectedly affected the constitutive levels of the CD3-zeta p21 phosphoisoform. Conversely, the ZAP-70 Y292F mutation upregulated proximal events in TCR signaling and allowed more T cells to produce interleukin 2 and interferon gamma in response to a given dose of antigen. The observation that ZAP-70 Y292F T cells have a slower rate of ligand-induced TCR downmodulation suggests that Y292 is likely involved in regulating the duration activated TCR reside at the cell surface. Furthermore, we showed that Y292 and Y315 are dispensable for the TCR-induced tyrosine phosphorylation of Cbl and Vav1, respectively. Therefore, other molecules present in the TCR signaling cassette act as additional adaptors for Cbl and Vav1. The present in vivo analyses extend previous data based on transformed T cell lines and suggest that residue Y292 plays a role in attenuation of TCR signaling, whereas residue Y315 enhances ZAP-70 function.
Assuntos
Mutação Puntual , Proteínas Tirosina Quinases/genética , Linfócitos T/citologia , Linfócitos T/imunologia , Tirosina/genética , Animais , Sequência de Bases , Primers do DNA , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação , Proteínas Tirosina Quinases/química , Receptores de Antígenos de Linfócitos T/imunologia , Timo/imunologia , Proteína-Tirosina Quinase ZAP-70RESUMO
BACKGROUND: Effects of mast cell-released histamine on smooth muscle and endothelial cells are considered as responsible of immediate symptoms of anaphylaxis. However, little is known about histamine effects on Th2 lymphocytes, which orchestrate the allergic reaction upstream of mast cells. OBJECTIVE: We addressed this question in house dust mite (HDM) allergics, according to the presence of rhinitis or asthma and allergen stimulation. METHODS: Peripheral blood mononuclear cell from 15 rhinitic and 14 asthmatic HDM-allergic subjects and 16 controls were cultured with Der p 1 or histamine. The effect of Der p 1 on histamine receptor (H1R and H2R) expression was studied. T-cell cytokine production was studied upon Der p 1 or histamine stimulation. The role of H1R in histamine effects was assessed with levocetirizine. RESULTS: H1R and H2R are overexpressed on T cells from asthmatic but not from rhinitic subjects. Der p 1 increases H1R expression on CD4(+) cells from both allergic groups, and decreases it in controls, on CD4(+) and CD8(+) subsets. Der p 1 decreases T-cell H2R expression in asthmatics. Allergen increases IL-4 and IL-13 in both allergic groups. Histamine increases Th2 cytokines in rhinitics only, and levocetirizine abolishes this effect. In asthmatics and controls, histamine decreases T-cell cytokines through a non-H1R dependent pathway. CONCLUSION: In rhinitis but not in asthma, histamine is able to increase allergic inflammation by increasing Th2 cytokine production in a positive feedback dependent on H1R. This result could explain in part why H1R antagonists, are very efficient in rhinitis, but not in asthma.
Assuntos
Asma/imunologia , Histamina/imunologia , Ativação Linfocitária , Receptores Histamínicos H1/metabolismo , Rinite Alérgica Perene/imunologia , Células Th2/imunologia , Adulto , Alérgenos/imunologia , Antígenos de Dermatophagoides/imunologia , Proteínas de Artrópodes , Células Cultivadas , Cisteína Endopeptidases , Citocinas/biossíntese , Feminino , Histamina/farmacologia , Humanos , Masculino , Rinite Alérgica Perene/etiologia , Células Th2/efeitos dos fármacosRESUMO
Asthma symptoms are the main reason for healthcare utilization and are a fundamental parameter for the evaluation of asthma control. Currently, asthma is defined as a chronic inflammatory disease. A French expert group studied the association between inflammation and asthma symptoms by carrying out a critical review of the international literature. Uncontrolled asthmatics have an increased number of polynuclear eosinophils in the induced sputum and an increased production of exhaled NO. Control by anti-inflammatory treatment is accompanied by a reduction in bronchial eosinophilia and exhaled NO. Asthma symptoms are the result of complex mechanisms and many factors modify their perception. Experimental data suggest that there is a relationship between the perception of symptoms and eosinophilic inflammation and that inhaled corticoid therapy improves this perception. Although they are still not applicable in routine practice, follow-up strategies based on the evaluation of inflammation are thought to be more effective in reducing exacerbations than those usually recommended based on symptoms and sequential analysis of respiratory function. Inhaled corticosteroid therapy is the reference disease-modifying therapy for persistent asthma. Recent studies demonstrated that adjustment of anti-inflammatory treatment based on symptoms is an effective strategy to prevent exacerbations and reduce the total number of doses of inhaled corticosteroids.
Assuntos
Asma/imunologia , Asma/fisiopatologia , Inflamação/imunologia , Inflamação/fisiopatologia , Antiasmáticos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Asma/tratamento farmacológico , Humanos , Inflamação/tratamento farmacológico , Testes de Função RespiratóriaRESUMO
BACKGROUND: Masitinib is a tyrosine kinase inhibitor targeting stem cell factor receptor (c-kit) and platelet-derived growth factor (PDGF) receptor, which are expressed on several cell types including mast cells and bronchial structural cells, respectively. We hypothesized that c-kit and PDGF receptor inhibition may decrease bronchial inflammation and interfere with airway remodeling, which are crucial features of severe asthma. OBJECTIVES: The primary endpoint was the percent change from baseline in oral corticosteroids after 16 weeks of treatment. Change in asthma control (asthma control questionnaire), exacerbation rate, pulmonary function tests, rescue medication requirement and safety were secondary endpoints. METHODS: A 16-week randomized, dose-ranging (3, 4.5, and 6 mg/kg/day), placebo-controlled study was undertaken in 44 patients with severe corticosteroid-dependent asthma who remained poorly controlled despite optimal asthma management. RESULTS: At 16 weeks of treatment, a comparable reduction in oral corticosteroids was achieved with masitinib and placebo (median reduction of -78% and -57% in the masitinib and placebo arms, respectively). Despite this similar reduction, the Asthma Control Questionnaire score was significantly better in the masitinib arm as compared to placebo with a reduction by 0.99 unit at week 16 (P < 0.001) vs 0.43 unit in the placebo arm. Masitinib therapy was associated with more transient skin rash and edema. CONCLUSIONS: Masitinib, a c-kit and PDGF-receptor tyrosine kinase inhibitor, may represent an innovative avenue of treatment in corticosteroid-dependent asthma. These preliminary results warrant further long-term clinical studies in severe asthma
Assuntos
Antiasmáticos/administração & dosagem , Asma/tratamento farmacológico , Inibidores de Proteínas Quinases/administração & dosagem , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Administração Oral , Adolescente , Adulto , Idoso , Antiasmáticos/efeitos adversos , Benzamidas , Edema/etiologia , Exantema/etiologia , Feminino , França , Humanos , Hidroxicorticosteroides/administração & dosagem , Masculino , Adesão à Medicação , Pessoa de Meia-Idade , Piperidinas , Inibidores de Proteínas Quinases/efeitos adversos , Proteínas Proto-Oncogênicas c-kit/metabolismo , Piridinas , Tiazóis/administração & dosagem , Tiazóis/efeitos adversos , Resultado do TratamentoRESUMO
BACKGROUND: Reading impairment is the major learning disability in children. While research on illiteracy has mainly been conducted from a sociological perspective, research on dyslexia has typically been studied from a cognitive-linguistic perspective. Studies that jointly investigate sociological, behavioral and cognitive factors in predicting reading outcome are rare and limited to English-speaking populations. The goal of the present study was to screen second grade children with reading impairment in French urban elementary schools and to pin down the factors that explain the various facets of reading failure and success. METHODS: A total of 1062 children from 20 different schools in the city of Paris participated in the study. Different aspects of reading were assessed individually for children with a suspected impairment in reading acquisition. Subsequently, 131 poor readers and 50 typically developing readers were matched for sex, age, and school. For these children, medical, cognitive, behavioral and individual socioeconomic data were obtained. Group differences were examined and multiple regression analyses were conducted to examine how much variance in reading was explained by the various variables. RESULTS: The prevalence of poor reading skills in grade 2 was highly influenced by neighborhood socioeconomic status (SES) (ranging from 3.3% in high SES to 20.5% in low SES areas). Among the SES variables, employment of the father was a significant predictor of poor reading. Among the cognitive variables, phonological awareness and rapid naming were the most significant factors, much more than verbal or nonverbal intelligence. Among the behavioral variables, attention was an important factor but not externalized symptoms. Multiple regression analyses showed that reading outcome was best predicted by phonological awareness skills and attention deficits. CONCLUSION: The majority of children with reading disability come from low SES areas. As in the English literature, the most robust predictor for reading impairment is phonological awareness, even when SES is taken into account. In addition, attention deficits seemed to aggravate reading impairments for children with weak phonological awareness skills. Successful early prevention should focus on reinforcing phonological awareness, recoding and attention skills.