BACKGROUND: Eosinophils play a central role in asthma, but the interplay of the effects of smoking, eosinophils and asthma remains unclear. OBJECTIVE: The primary objective of our study was to investigate the extent to which smoking modifies the effect of asthma on circulating eosinophils, CD4+ and CD8+ T cell counts. METHODS: Data were collected semiannually between 1987 and 1994 from HIV-negative participants in the Multicenter AIDS Cohort Study. Asthma was defined by a questionnaire at baseline as a self-report of diagnosed asthma. A total of 1420 blood samples from 197 asthmatics and 15 822 from 1997 non-asthmatics were collected. RESULTS: Eosinophil levels were higher in asthmatics (28% of asthmatics had eosinophils >/=4% and 16% of non-asthmatics) regardless of smoking history, but smoking modified the association between eosinophils and asthma. Namely, the odds ratios for eosinophils being >/=4% in asthmatics to non-asthmatics decreased from 2.7 (95% CI: 2.0, 3.6) in never, to 2.1 (1.4, 3.1) in former, and to 1.5 (0.9, 2.3) in current smokers. Cross-sectional and longitudinal analyses coherently showed that smoking increased eosinophils in non-asthmatics, but the converse was true for asthmatics. In contrast, no differences in peripheral blood T cell counts between asthmatics and non-asthmatics were observed. CONCLUSION: Under the established link between increased eosinophils and asthma, these data indicate that smoking modified this relationship. This finding suggests that smoking plays a different immunological role in asthmatics and non-asthmatics.
BACKGROUND: Eosinophils play a central role in asthma, but the interplay of the effects of smoking, eosinophils and asthma remains unclear. OBJECTIVE: The primary objective of our study was to investigate the extent to which smoking modifies the effect of asthma on circulating eosinophils, CD4+ and CD8+ T cell counts. METHODS: Data were collected semiannually between 1987 and 1994 from HIV-negative participants in the Multicenter AIDS Cohort Study. Asthma was defined by a questionnaire at baseline as a self-report of diagnosed asthma. A total of 1420 blood samples from 197 asthmatics and 15 822 from 1997 non-asthmatics were collected. RESULTS: Eosinophil levels were higher in asthmatics (28% of asthmatics had eosinophils >/=4% and 16% of non-asthmatics) regardless of smoking history, but smoking modified the association between eosinophils and asthma. Namely, the odds ratios for eosinophils being >/=4% in asthmatics to non-asthmatics decreased from 2.7 (95% CI: 2.0, 3.6) in never, to 2.1 (1.4, 3.1) in former, and to 1.5 (0.9, 2.3) in current smokers. Cross-sectional and longitudinal analyses coherently showed that smoking increased eosinophils in non-asthmatics, but the converse was true for asthmatics. In contrast, no differences in peripheral blood T cell counts between asthmatics and non-asthmatics were observed. CONCLUSION: Under the established link between increased eosinophils and asthma, these data indicate that smoking modified this relationship. This finding suggests that smoking plays a different immunological role in asthmatics and non-asthmatics.
Authors: T Sjåheim; T S Halstensen; M B Lund; Ø Bjørtuft; P A Drabløs; D Malterud; J Kongerud Journal: Occup Environ Med Date: 2004-09 Impact factor: 4.402
Authors: Ida Mogensen; Tiago Jacinto; Kjell Alving; João A Fonseca; Christer Janson; Andrei Malinovschi Journal: PLoS One Date: 2020-12-03 Impact factor: 3.240
Authors: Bradley E Chipps; Nizar Jarjour; William J Calhoun; Ahmar Iqbal; Tmirah Haselkorn; Ming Yang; Jochen Brumm; Jonathan Corren; Cecile T J Holweg; Mona Bafadhel Journal: Ann Am Thorac Soc Date: 2021-12