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Biomedical subjects

B Leynaert

Publications and source records attributed to B Leynaert.

23 records · Page 2Linked to original sources
PubMed1999

Perennial rhinitis: An independent risk factor for asthma in nonatopic subjects: results from the European Community Respiratory Health Survey.

BACKGROUND: Although clinical and experimental studies suggest that upper respiratory tract dysfunction may affect the lower airways, rhinitis is usually not studied as a potential risk factor for asthma. This is because both diseases share key elements of pathogenesis and are usually considered as different manifestations of the same underlying "atopic" state. OBJECTIVE: We sought to assess whether asthma is associated with rhinitis in the absence of immunologic disorders in a population study. METHODS: Data from 34 centers participating in the European Community Respiratory Health Survey were analyzed. Random samples of 20- to 44-year-old subjects were invited to complete a detailed questionnaire and undergo total and specific IgE measurements, skin prick tests to 9 allergens, and bronchoprovocation challenges with methacholine. RESULTS: Subjects with perennial rhinitis (n = 1412) were more likely than control subjects (n = 5198) to have current asthma. After adjustment for sex, age, smoking habit, family history of asthma, geographic area, and season at the time of examination, asthma was strongly associated with rhinitis among atopic subjects (odds ratio [OR] = 8.1; 95% confidence interval [CI] = 5.4-12.1) but also among nonatopic subjects (OR = 11.6; 95% CI = 6.2-21.9). Moreover, the association remained very strong when the analysis was restricted to nonatopic subjects with IgE levels of 80 kIU/L or less (OR = 13.3; 95% CI = 6. 7-26.5). In nonasthmatic subjects bronchial hyperresponsiveness was also more frequent in subjects with rhinitis than in those without rhinitis (OR = 1.7; 95%CI = 1.2-2.6 in nonatopic subjects with IgE levels of </=80 kIU/L). CONCLUSION: The strong association between perennial rhinitis and asthma in nonatopic subjects with normal IgE levels is consistent with the hypothesis that rhinitis is an independent risk factor for asthma.

Adult↗
PubMed1998

Heterosexual transmission of human immunodeficiency virus: variability of infectivity throughout the course of infection. European Study Group on Heterosexual Transmission of HIV.

Although individuals infected with human immunodeficiency virus (HIV) seem to be more infectious in the late stages of HIV infection and possibly also during the seroconversion period, most estimates of per-sexual-contact infectivity have been obtained without allowing for variability over the course of infection. In this analysis, a probabilistic model was fitted to data from a European study carried out between 1987 and 1992 that involved 499 (359 males and 140 females) HIV-infected subjects (index cases) and their regular heterosexual partners. The model used allowed infectivity (the per-sexual-contact HIV transmission probability, mu) to vary through three stages: the first 3 months following infection, the subsequent asymptomatic period, and the advanced stage (HIV-related clinical symptoms or a CD4-positive T lymphocyte count less than 200/mm3). Male-to-female infectivity through penile-anal sex was found to be higher in both the early and advanced stages of infection (mu=0.183) than in the longer intermediate period (mu=0.014) (p < 0.03). Failure to demonstrate significant differences between stages for other types of contact (male-to-female penile-vaginal contacts: mu=0.0007; female-to-male transmission: mu=0.0005) may reflect insufficient power rather than a true lack of variability. Indeed, the results for penile-anal sex suggest that persons who are in the process of seroconverting may be much more infectious than asymptomatic infected persons, whatever the type of contact. Prevention education should stress the risk of HIV transmission from subjects who may be unaware of their infection.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Is bronchial hyperresponsiveness more frequent in women than in men? A population-based study.

To test the hypothesis that a greater proportion of women than men react to methacholine challenge and investigate the possible reasons for any differences observed, we recruited 495 subjects 20 to 44 yr of age (50.9% male) in Paris and 304 subjects (51.3% male) in Montpellier (France), as part of the European Community Respiratory Health Survey. The proportion of responders (PD20 < or = 4 mg methacholine) was 33.7% in women and 11.9% in men (odds ratio = 3.8; 95% confidence interval = 2.4-6.0) in Paris and 43.2% in women and 29.5% in men (odds ratio = 1.8; 95% confidence interval = 1.1-2.9) in Montpellier. These differences could not be explained by asthma, respiratory symptoms, atopy, or lung function parameters. In stepwise logistic regressions including sex, asthma, and asthma-like symptoms, nasal allergies, atopy, baseline FEV1, FEV1%pred, FVC, and FEV1%FVC, the odds-ratios for the effect of female sex on PD20 < or = 4 mg methacholine were 5.2 (3.0-9.0) in Paris and 2.2 (1.2-3.8) in Montpellier. Reacting to low doses of methacholine (PD20 < or = 0.5 mg) was associated with asthma and atopy in both men and women. In contrast, reacting to doses between 0.5 and 4 mg was associated with asthma and atopy only in men and with heavy tobacco consumption only in women. We conclude that the excess of hyperresponsiveness in women is not due to their having smaller lung size or airway caliber than men and may be related to a greater susceptibility to smoking.

Adult↗