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Biomedical subjects

D Vervloet

Publications and source records attributed to D Vervloet.

At least 19 recordsLinked to original sources
PubMed2006

Safety and efficacy of Juniperus ashei sublingual-swallow ultra-rush pollen immunotherapy in cypress rhinoconjunctivitis. A double-blind, placebo-controlled study.

BACKGROUND: The safety and efficacy of high-dose sublingual-swallow immunotherapy (SLIT) has been established in pollen rhinoconjunctivitis. This treatment has now been evaluated using an ultra-rush incremental dose regimen with a Juniperus ashei allergen extract in patients allergic to Cupressus sempervirens and Cupressus arizonica. METHODS: Patients received either placebo or SLIT. Evaluation of safety was based on the frequency of adverse events during the incremental dose period (half a day) and during maintenance therapy (4 months). Evaluation of efficacy was based on symptom and medication scores at the pollen peak. RESULTS: Seventy of the 76 patients included completed the study. There were no drop-outs during the rush procedure. One patient in the active group dropped out during the maintenance therapy due to adverse events: gastric pain and vomiting. There was also 1 drop-out in the placebo group due to pregnancy. Adverse events were infrequent, local and mild. Symptom scores for rhinitis and conjunctivitis were not statistically different between groups, but there was a marked and significant (p < 0.03) decrease of the medication score (about 50%) and nasal steroid consumption (about 75%) in the active treatment group. An increase from baseline of serum IgE and IgG4 J. ashei-specific antibodies was only observed in actively treated patients (p < 0.04 and p < 0.01, respectively). CONCLUSIONS: The tolerability and safety of high-dose ultra-rush SLIT were comparable to those reported in previous SLIT studies. SLIT with J. ashei extract, due to its high Jun a 1 content, significantly reduced nasal steroid consumption in patients allergic to European cypress.

Administration, Sublingual↗
PubMed2006

Do patients with skin allergies have higher levels of anxiety than patients with allergic respiratory diseases? Results of a large-scale cross-sectional study in a French population.

BACKGROUND: Psychological comorbidity is a known aspect of allergic disease. However, there is recent evidence that a large proportion of allergic patients remains undiagnosed and untreated for psychological disease. In addition, the complexities of the anxiety-allergy relationship, i.e. differences for current and past disease, or differences among allergic disease types, are not well understood. OBJECTIVES: To measure the level of anxiety in a large allergic population in France using a standardized measure, the State/Trait Anxiety Inventory (STAI). METHODS: Allergy patients in France (n = 3939) who visited their allergy specialists participated in the study. The patients completed a questionnaire which was then linked to the questionnaire completed by their physician. Only patients with both subject and physician questionnaire were kept in the analyses. Mean STAI scores for the State (S) and Trait (T) scales were obtained for each allergic disease. ANCOVA models testing group differences on the mean scores, using the categories "current disease", "past disease" and "allergic disease ever", were assessed along with relevant confounders. RESULTS: Allergic rhinitis (AR), asthma and atopic dermatitis (AD) were the most prevalent conditions of the 12 allergic diseases assessed in the study. Women had higher mean STAI S/T scores than men and age was also found to be associated with higher S scores; therefore, both age and gender were included as covariates where relevant. A single ANCOVA model for each STAI scale showed a statistical difference among the various allergic diseases. Using the category "current disease" each allergic disease was assessed separately regarding the presence or absence of that disease. Higher, statistically significant mean STAI scores were found for AD and allergic urticaria on the S scale and for AD on the T scale. Similarly, for the category "allergic disease ever", AD and allergic urticaria reached statistical significance on the S scale, while on the T scale only AD was statistically significant. When patients were assessed for anxiety based on their past disease, asthma, AR and sinusitis were significant on the S scale while asthma and nasal polyps were statistically significant on the T scale. When asthma and AD were tested simultaneously, only the latter was significant. CONCLUSIONS: High mean scores for State and Trait anxiety were mostly associated with AD.

Adolescent↗
PubMed2006

Ultra-rush venom immunotherapy induces differential T cell activation and regulatory patterns according to the severity of allergy.

BACKGROUND: Venom immunotherapy (VIT) induces immune tolerance to hymenoptera venom antigens in allergic patients and is therefore a helpful model for studying modulation of allergic immune response. The objectives were to assess the early effects of ultra-rush VIT on T lymphocyte activation and regulatory profile induction, in all subjects combined and according to the four severity grades of the Mueller classification. MATERIALS AND METHODS: Blood samples from 30 vespid-allergic patients were taken before and after the first day of treatment, and before day 15 and day 45 booster injections. IFN-gamma and IL-4 levels were assayed by ELISA, in whole-blood supernatants. IFN-gamma and IL-13-producing T cells, but also natural CD4+CD25+high regulatory T cells and acquired regulatory T cell proportions were assessed by flow cytometry. Results were analysed in the whole population and compared between patients with I-II or III-IV allergic reactions. RESULTS: During VIT, IFN-gamma increased in whole blood when IL-4 decreased. Among T cells, the percentage of CD3+IFN-gamma+ cells increased while IL-13-producing T cells decreased. Proportions of CD4+CD25+high cells and IL-10-producing T cells increased with VIT. In I-II subjects, IFN-gamma increased gradually, whereas it remained at low levels in III-IV patients. By contrast, IL-4 decrease was more pronounced in III-IV patients. Increase in CD4+CD25+high T cells occurred early in I-II patients but was delayed in III-IV patients. IL-10-producing T cells increased gradually in both groups but were in a lower proportion in III-IV patients. CONCLUSION: A T helper type 2 (Th2)-to-Th1 switch occurs during ultra-rush VIT, in parallel with natural and acquired regulatory T cell increase. These events occur earlier and at a higher level in less severe subjects, suggesting that VIT tolerance induction is easier to achieve in these patients.

Adult↗
PubMed2006

Variation of T-cell activation in allergic subjects during natural pollen exposure.

BACKGROUND: Allergic inflammation is characterized by a Th2 activation. However, little is known about dynamics of T-cell cytokine production during natural allergen exposure. The aim of this study was to assess the Th1/Th2 balance in cypress allergic patients compared with controls, and variations of this balance over the pollen season. METHODS: Twenty cypress allergic patients and 10 controls were studied, distributed during two consecutive pollen seasons. Cytokine production was assessed by flow cytometry and ELISA. The variation of cytokine production during the pollen season was analyzed among patients in four occasions, and the preseason values were compared with controls. IL-13 and IFN-gamma-containing T cells were assessed among whole blood cells and PBMC. In addition the effect of specific stimulation by Juniperus ashei pollen extract was studied. RESULTS: Compared with controls, IL-13-producing T cells were increased in allergics in any case. By contrast, compared with controls, allergic IFN-gamma-producing T cells were decreased in whole blood, but not in PBMC, and were increased after specific stimulation. During the season, an increase in IFN-gamma- and a decrease in IL-13-producing T cells occurred in patients, whatever the culture conditions. CONCLUSION: These results show that the allergic T-cell activation is not limited to a Th2 profile: allergen-stimulated T cells are able to produce IFN-gamma at baseline, and the Th1/Th2 ratio increases during the pollen season.

Adult↗
PubMed2006

Diesel exhaust particles enhance T-cell activation in severe asthmatics.

Prevalence of asthma is increasing in westernized countries. Epidemiological studies showed the impact of traffic pollution on the triggering of asthma symptoms and exacerbations, and this effect is mainly attributed to the polycyclic aromatic hydrocarbon core of diesel exhaust particles (DEP). However, although DEP induce IgE synthesis, little is known of their role on T-cell activation, the main cells orchestrating asthma inflammation. We assessed the effect of DEP on T-cell activation in severe uncontrolled asthmatics during (n = 13) and outside (n = 19) exacerbations. Results were compared with data obtained in healthy controls (n = 14). Peripheral blood mononuclear cells were cultured in the presence of low-dose DEP. T-cell activation markers, CD69 and CD25, interleukin-4 (IL-4) and interferon (IFN)-gamma production and T-cell proliferation were assessed by flow cytometry. DEP exposure increased the proportion of CD3+CD69+ T cells in all subjects. The proportion of CD25+ T cells increased under DEP stimulation in the exacerbation group only. IFN-gamma- and IL-4-producing T cells increased in both asthmatic groups, especially during exacerbations, but not in controls. This effect was more pronounced for IL-4. In response to DEP stimulation, T-cell proliferation increased in higher proportion in asthmatics compared with controls. These results show that DEP activate T cells in asthmatics only, with a higher effect during exacerbations. This is in keeping with epidemiological data which demonstrated that DEP trigger respiratory symptoms in asthmatics but not in controls. The higher effect of DEP in exacerbated asthmatics suggests that uncontrolled asthma is a risk factor for aggravation under exposure to traffic pollutants.

Adult↗
PubMed2005

[Economic burden of COPD: the SCOPE study].

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is a major health problem. Few data about COPD economic burden are available. METHODS: SCOPE was an observational economical retrospective and prospective study conducted in France in 2001, by 114 general practitioners (GPs) and 57 lung specialists. The aim was to describe the burden of COPD patients and to estimate the annual cost according to severity stages. Health resource utilization was collected by questionnaires over a 12-month period for 285 patients. RESULTS: It was a cost-of-illness analysis. COPD patients followed by a lung specialist were more severe than patients followed by a GP and had a higher level of medical resource consumption. The COPD disease and its complications explained 66% of the total cost. The main cost drivers were inpatient care (35%, or 1509,9 euros/year/patient) and prescription medications (31%, or 1340,6 euros/year/patient). The direct total cost varied according to COPD severity on account of inpatient care and respiratory assistance. DISCUSSION: This study confirmed the economic burden of COPD in France. Actions allowed to slow down the disease's evolution and to anticipate the exacerbation could reduce the cost.

Aged↗
PubMed2005

[T regulatory lymphocytes, atopy and asthma: a new concept in three dimensions].

BACKGROUND: Allergic inflammation is considered to be the result of a pattern of Th2 lymphocyte activation. However this inflammation, relevant for atopy and infiltration of affected tissues by eosinophils, is insufficient by itself to explain the clinical features of asthma. Several studies have demonstrated that Th2 type inflammation was also associated in asthma with a Th1 response, with production of gamma interferon. It has recently been shown that the regulatory T lymphocytes (Treg) which produce IL-10 and/or TGF-beta and induce tolerance are defective in allergic patients. In addition, these lymphocytes increase during specific immunotherapy. Their decrease could explain the Th2 activation found in atopic patients. PERSPECTIVE: We review the potential importance of Treg cells in atopy and also asthma, and propose a concept whereby the allergic inflammatory response would not be due to a Th1/Th2 imbalance, but rather to a Treg deficiency progressively rising from normal to atopic, from atopy to asthma and from asthma to acute exacerbations. CONCLUSION: Three dimensions of inflammation need therefore to be taken into account: Th1, Th2 and Treg.

Animals↗
PubMed2005

Genome screen in the French EGEA study: detection of linked regions shared or not shared by allergic rhinitis and asthma.

In the sample of 295 French EGEA families with at least one asthmatic subject, a genome screen was conducted to identify potential linkage regions specific either to allergic rhinitis (AR) or to asthma as well as those shared by the two diseases. Two binary rhinitis phenotypes based on (1) diagnosis (ARbin1) and (2) symptoms (ARbin2) and a categorical ordered trait (ARcat) were considered. Asthma phenotype was based on answers to a standardized questionnaire plus the presence of bronchial hyper-responsiveness. Linkage analyses were conducted using the maximum likelihood binomial (MLB) method. These analyses provided potential evidence for linkage to three regions in the whole sample: 1p31 for the phenotype defined by ARbin2 plus asthma (P=0.00016), 2q32 for ARbin2 (P=0.00016) and 3p24-p14 for ARcat (P=0.001). Two other regions were detected in the subset of 185 families with at most one asthmatic sib: 9p22 and 9q22-q34 for ARbin1 (P=0.001 and 0.0007, respectively). No region showed evidence for linkage to asthma without being also linked to AR. While 1p31 may contain a genetic determinant common to asthma and AR, 2q32, 3p24-p14, 9p22 and 9q22-q34 are more likely to harbor genetic factors specific to AR.

Asthma↗
PubMed2005

Dog factor differences in Can f 1 allergen production.

BACKGROUND: The clinical importance of dog allergy is well known, but it is unknown if all types of dogs represent the same risk for allergic patients. The purpose of this work was to evaluate among 288 healthy dogs if the levels of Can f 1 on fur vary between breeds (German Shepherd, Pyrenean Shepherd, Poodle, Cocker spaniel, Spaniel, Griffon, Labrador retriever and Yorkshire terrier), gender, hormonal status, hair length, and according to the presence of seborrhea. METHODS: Each dog was shaved in a limited area and Can f 1 concentrations were measured in mug/g fur by ELISA. The results (geometric mean values and 95% confidence intervals) were analyzed using analysis of variance and with nonparametric tests. RESULTS: A wide variability in Can f 1 levels was found between dog breeds, from Labradors [1.99 (0.03-129.91)] to Yorkshires [16.72 (3.67-76.16)] and Poodles [17.04 (2.79-103.94)] but only the Labrador levels were significantly different from each other breed. Males produced more Can f 1 than females, 11.75 (1.27-108.40) vs 8.89 (0.91-86.39). No difference was found according to hair length or hormonal status. The seborrheic status highly (P = 0.0019) influenced the presence of Can f 1 on hair: 16.66 (1.59-173.96) vs 9.40 (1.03-85.70). CONCLUSION: Breeds (Labrador retriever), sex and seborrhea seem to influence the levels of Can f 1 on fur.

Allergens↗
PubMed2005

Twenty five year mortality and air pollution: results from the French PAARC survey.

AIMS AND METHODS: Long term effects of air pollution on mortality were studied in 14,284 adults who resided in 24 areas from seven French cities when enrolled in the PAARC survey (air pollution and chronic respiratory diseases) in 1974. Daily measurements of sulphur dioxide, total suspended particles, black smoke, nitrogen dioxide, and nitric oxide were made in 24 areas for three years (1974-76). Cox proportional hazards models controlling for individual confounders (smoking, educational level, body mass index, occupational exposure) were applied, and frailty models used to take into account spatial correlation. Indicators of air pollution were the mean concentration. RESULTS: Models were run before and after exclusion of six area monitors influenced by local traffic (NO/NO2 >3 in ppb). After exclusion of these areas, analyses showed that adjusted risk ratios (95% CI) for TSP, BS, NO2, and NO for non-accidental mortality were 1.05 (1.02 to 1.08), 1.07 (1.03 to 1.10), 1.14 (1.03 to 1.25), and 1.11 (1.05 to 1.17) for 10 microg/m3 respectively. Consistent patterns for lung cancer and cardiopulmonary causes were observed. CONCLUSIONS: Urban air pollution assessed in the 1970s was associated with increased mortality over 25 years in France.

Adult↗
PubMed2004

[2000 classification of idiopathic interstitial lung diseases].

OBJECTIVES: Diagnosis of interstitial lung diseases was recently improved by the use of diagnostic tools, such as high-resolution Computed Tomography, and by new insights in their pathogenesis and histology. This led the American Thoracic Society and the European Respiratory Society to propose a new classification of these diseases, in the aim to facilitate early diagnosis and specific care. CURRENT KNOWLEDGE AND KEY POINTS: Standard radiography gives the first suspicion of chronic diffuse infiltrative lung disease, and anamnesis and physical examination are essential steps of etiological diagnosis. High-Resolution computed tomography confirms the diagnosis of diffuse infiltrative lung disease. Longitudinal lung function tests are essential to assess the consequences of the lung disease. Lung biopsies are often, but not systematically, a useful tool. The 2000 classification consists of seven entities of idiopathic interstitial diseases which are defined on clinical, radiological and pathological criteria: idiopathic pulmonary fibrosis, non-specific interstitial pneumonia, cryptogenic organizing pneumonia, acute interstitial pneumonia, respiratory bronchiolitis associated interstitial lung disease, desquamative interstitial pneumonia and lymphoid interstitial pneumonia. The most frequent is Idiopathic Pulmonary Fibrosis, which has a poor prognosis. FUTURE PROSPECT AND PROJECTS: This new classification results from a multidisciplinary confrontation with chest physicians, radiologists and pathologists. A better characterization of anatomoclinical entities should lead to a better pronostic evaluation, more informative comparisons of published studies, and therefore to rational therapeutic approach.

Acute Disease↗
PubMed2004

[Bronchial obstruction by an aberrant left pulmonary artery misdiagnosed as asthma in a 7 year old child].

INTRODUCTION: Wheezing is common symptom in infants and is usually due to asthma. However an alternative diagnosis should be sought if there is no reversibility to B2-agonist. CASE REPORT: This case report describes a 7 years old child who had been treated for poorly controlled asthma for several years. The absence of B2-agonist reversibility, indirect signs of thoracic straining on spirometry and evidence of right heart decompensation raised doubts about the diagnosis. CT angiography demonstrated a pulmonary artery malformation. Formal pulmonary angiography confirmed the diagnosis of pulmonary artery sling. This malformation had been causing intermittent bronchial compression and the symptoms resolved after surgical intervention. CONCLUSION: Wheezing symptoms over two Years in a child, misdiagnosed as asthma, is an unusual presentation of this pulmonary vascular anomaly.

Adrenergic beta-Agonists↗
PubMed2004

Increased prevalence of asthma and allied diseases among active adolescent tobacco smokers after controlling for passive smoking exposure. A cause for concern?

BACKGROUND: Whereas effects on allergic and respiratory health have been established for passive tobacco smoking, contradictory results still exist for active tobacco smoking. OBJECTIVE: Whether adolescents with asthma and allied diseases have higher rates of active smoking compared with adolescents without asthma was assessed after controlling for environmental tobacco smoking exposure. METHODS: A population-based sample of 14,578 adolescents was enrolled in an epidemiological survey on allergies in France. RESULTS: After controlling for age, sex, geographic region, familial allergy and passive smoking, current (in the past year) wheezing (12.4%), current asthma (5.6%), lifetime asthma (12.3%), current rhinoconjunctivitis (13.9%), lifetime hayfever (14.4%) and current eczema (9.3%) but not lifetime eczema (22.5%) were all significantly related to active smoking (>1 cigarette/day) (9.3%). A higher risk of current wheezing, current and lifetime asthma or current eczema was seen in smokers exposed to passive smoking compared with smokers not exposed to it using a polychotomous logistic regression model, in which the different modalities of exposure to active and passive smoking constituted the response variable. Passive smoking was significantly associated only with current diseases. Active smoking was also highly related to both severe asthma (OR=4.02; 95% confidence interval: 1.37, 11.79) and severe rhinoconjunctivitis (OR=2.95; 1.58, 5.49). The highest rate of adolescents suffering from the co-morbidity of lifetime asthma and hayfever (3.6%) was also seen in active smokers compared with passive and non-smokers (5.5% vs. 3.6% and 3.1%, respectively; P=0.001). CONCLUSIONS: Being asthmatic or allergic does not seem to act as a deterrent towards starting active smoking or continuing to smoke in adolescence. Results suggest the need for considering individual allergic status in programming health educational activities aimed at reducing smoking among adolescents.

Adolescent↗
PubMed2003

Study of cytokine gene expression in small cell samples: use in induced sputum.

Sputum examination is being increasingly used as a non-invasive method for the study of airway inflammation. However, the technical applications of sputum are still limited because of the small number of cells recovered. In attempt to extend applications of sputum examinations, we developed and standardised, the reverse transcriptase-polymerase chain reaction (RT-PCR), a sensitive and specific technique of detection of mRNA, in induced sputum samples. Total RNA were extracted from samples containing as few as 50 to 80,000 cells, using a phenol-chloroform extraction method. RT-PCR was successfully tested on beta-actin, interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and tumour necrosis factor-beta (TGF-beta) genes. This protocol provides a simple technique to extract total RNA from a few number of induced sputum cells. It permits the semi-quantitatively study of cytokine gene expression in airways with simple means.

Actins↗