Evaluation of emphysema in patients with asthma using high-resolution CT.
BACKGROUND
Bronchial asthma is a clinical syndrome characterized by reversibility of airway obstruction. However, many asthmatics have evidence of residual airway obstruction. It has become evident that the repair of the chronic inflammatory process can lead to various irreversible changes. It is generally accepted that the most common cause for the change is cigarette smoking but it is controversial whether asthma progresses to emphysema. High resolution computed tomography (HRCT) is more sensitive and more accurate than chest plain films in determining the type and extent of emphysema. This study was carried out to determine whether asthma can be a cause of emphysema without the effect of cigarette smoking and to evaluate clinical characteristics in asthmatics with emphysema.


METHODS
We studied 58 asthmatic patients with reversible airway obstruction and evaluated the presence of emphysema using HRCT and pulmonary function test. According to HRCT findings, they were divided into 2 groups: Asthmatics with emphysema and the ones without emphysema.


RESULTS
Of the 58 patients, 7 were revealed to have emphysema. (1) 6 asthmatics with emphysema were smokers, but one patient was a nonsmoker. (2) Highly significant differences between asthmatics with and without emphysema were found in cigarette smoking (p < 0.01) and smoking consumption (p < 0.01). (3) There were no significant differences in the duration of asthma, age or sex between patients with and without emphysema. (4) There were no significant differences in FEV1(%), FEV1/FVC (%), diffusing capacity for carbon monoxide (DLco) (%) and DLco/alveolar volume between patients with and without emphysema (5) Differences between asthma patients without emphysema and those with emphysema were found to be significant in bronchial wall thickness (p < 0.05) and in total Ig E levels (p = 0.07).


CONCLUSIONS
These results indicate that smoking is a main factor in causing emphysema in asthmatics.
Hong
Ki Young
KY
Departments of Internal Medicine and Radiology, Soonchunhyang University College of Medicine, Seoul, Korea.
Lee
June Hyuk
JH
Park
Sung Woo
SW
Joo
Jae Hak
JH
Kim
Do Jin
DJ
Moon
Sung Heuk
SH
Uh
Soo Taek
ST
Kim
Yong Hoon
YH
Park
Choon Sik
CS
Park
Jae Seung
JS
D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D012129:Respiratory Function Tests / Q000706:statistics & numerical data; D012907:Smoking / Q000009:adverse effects; D014057:Tomography, X-Ray Computed / Q000379:methods