Predictive value of allergy and pulmonary function tests for the diagnosis of asthma in elite athletes.

BACKGROUND: Asthma is frequently found in athletes, often associated with rhinitis and allergy. AIM: To study the predictive value of allergy and pulmonary function tests for the diagnosis of asthma in athletes. SUBJECTS AND METHODS: Ninety-eight national preOlympic athletes underwent an accurate medical examination including a validated questionnaire for asthma and rhinitis, spirometric recordings and skin prick testing with a panel of the most frequent inhalant allergens. Bronchodilator and/or exercise challenge were also performed in asthmatic subjects. RESULTS: Clinical asthma was present in 20.4% of athletes, rhinitis in 35.3% (in 21.4% of cases alone and in 13.9% associated with asthma). Positive prick tests were recorded in 44.4% of athletes (in 60.5% of asthmatics, in 95.2% of rhinitics and in 21.0% of nonasthmatic - nonrhinitic subjects). Mean spirometric values and distribution of abnormal values were not different among asthmatics, rhinitics and nonasthmatics - nonrhinitic patients. Skin-tests positivity was not related to the abnormal spirometric data found in individual cases. Provocation tests with bronchodilators or exercise did not appear sensitive enough to diagnose mild forms of asthma in subjects with normal basal spirometric values. CONCLUSIONS: Allergy testing and spirometry should be performed routinely in athletes because of the high prevalence of allergy, rhinitis and asthma in this population. However, the predictive value of these tests and of the bronchial provocation tests performed in this study seems too low to document mild or subclinical asthma in athletes.

Human lung fibroblast response to NGF, IL-1beta, and dexamethsone.

It has been shown that lung mast cells, eosinophils, and fibroblasts are receptive to the action of nerve growth factor (NGF) and that NGF is released in to the bloodstream of subjects affected by allergic inflammatory response. The role of NGF in lung inflammatory disorders is unclear because there is evidence suggesting that NGF can be involved in both proinflammatory and anti-inflammatory responses. Lung fibroblasts play a marked role in inflammation. In this study we investigated the effect of NGF, interleukin 1beta (II-1beta), and dexamethasone (DEX) on human lung fibroblasts in vitro. We found that II-1beta, but not NGF, promotes fibroblasts' survival and that NGF stimulates trkA receptor expression, down regulates TFG-alpha, and has no effect on TNF-beta immunoreactivity. Moreover, DEX exerts different effects on NGF release by fibroblasts pre-exposed to II-1gamma. Our findings suggest that the NGF released by lung fibroblast during inflammation is not associated with the increase of proinflammatory factors such as TNF-alpha and II-1beta.

Nerve growth factor and asthma.

An increasing body of evidence shows that nerve growth factor (NGF) exerts biological activity not only on the central and peripheral nervous system, but also on the immune system thereby influencing allergic diseases and asthma. (1) NGF circulating levels are increased in patients with allergic diseases and asthma, and are related to the severity of the inflammatory process and disease. In vernal keratoconjunctivitis, NGF plasma levels correlate with the number of mast cells infiltrating the conjunctiva, and NGF mRNA is increased in nasal mucosal scrapings of patients with allergic rhinitis who have high levels of NGF in serum and nasal fluids; NGF is further increased in nasal fluids after specific allergen challenge. (2) NGF is produced and released by several modulatory and effector cells of allergic inflammation and asthma, for example T-helper 2 lymphocytes, mast cells and eosinophils. (3) NGF receptors are expressed on the conjunctival epithelium of patients with allergic conjunctivitis and the number of NGF-receptor positive cells is increased in the conjunctiva of these patients. Indeed, local administration of NGF induces fibroblast activation and healing processes of human corneal ulcers, which suggests that NGF plays a role in tissue remodelling processes occurring in asthma. (4) NGF increases airway hyperreactivity to histamine in an animal model of asthma, while anti-NGF treatment reduces airway hyperreactivity induced by ovalbumin topical challenge in the sensitized mouse.