Influence of long-term cigarette smoking on immunoglobulin E-mediated allergy, pulmonary function, and high-resolution computed tomography lung densitometry in elderly patients with asthma.
BACKGROUND
Smoking is the most important cause of chronic obstructive pulmonary disease (COPD). However, the influence of cigarette smoking on the pathogenesis of asthma in the elderly remains controversial. This study attempted to clarify the influence of cigarette smoking on elderly asthmatics.


METHODS
Forty-eight asthmatics over 70 years old (25 ex-smokers and 23 never-smokers) and 20 patients with COPD over 70 years old (all ex-smokers) were studied to determine the influence of cigarette smoking on IgE-mediated allergy (total IgE, IgE antibodies against inhalant allergens, bronchial hyper-responsiveness (BHR), generation of leukotriene (LT) B4 and C4), pulmonary function, and the relative area of lung showing attenuation values less than -950 Hounsfield units (RA950) on high-resolution computed tomography scans.


RESULTS
The incidence of positive IgE antibodies against inhalant allergens, BHR, and the generation of leukotriene B4 (LTB4) by leucocytes were significantly increased in patients with a history of smoking compared with those without. Residual volume (%RV) was significantly increased, and diffusing capacity for carbon monoxide was significantly decreased in ex-smokers with asthma and COPD compared with never-smokers with asthma. Inspiratory RA950 and ratio of expiratory RA950 to inspiratory RA950 were significantly larger in asthmatics with a smoking history than in those without, and in COPD patients than in asthmatics.


CONCLUSIONS
Cigarette smoking enhances the production of IgE antibodies, BHR, and generation of LTB4 by leucocytes in elderly asthmatics. Increased hyper-inflation or emphysematous changes of the lungs expressed by increased RA950, closely related to %RV, was more frequently observed in ex-smokers compared with never-smokers.
Mitsunobu
F
F
Department of Medicine, Misasa Medical Center Second Department of Internal Medicine, Okayama University Medical School, Yamada, Misasa, Tottori, Japan. fumin@cc.okayama-u.ac.jp
Ashida
K
K
Hosaki
Y
Y
Tsugeno
H
H
Okamoto
M
M
Nishida
N
N
Nagata
T
T
Tanizaki
Y
Y
Tanimoto
M
M
D000368:Aged; D001249:Asthma / Q000276:immunology* / Q000378:metabolism / Q000503:physiopathology; D016535:Bronchial Hyperreactivity; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D007962:Leukocytes / Q000276:immunology; D007975:Leukotriene B4 / Q000097:blood; D017997:Leukotriene C4 / Q000097:blood; D008297:Male; D011653:Pulmonary Diffusing Capacity; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D012129:Respiratory Function Tests; D012907:Smoking / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed
D007975:Leukotriene B4; D017997:Leukotriene C4; D007073:Immunoglobulin E