Systemic oxidative and antioxidative status in Chinese patients with asthma.
BACKGROUND
Patients with asthma generate an increased amount of reactive oxygen species from peripheral blood cells. Reactive oxygen species produce many of the pathophysiologic changes associated with asthma and may contribute to its pathogenesis.


OBJECTIVE
We investigated changes in antioxidant enzyme activities and oxidized glutathione (glutathione disulfide; GSSG) levels in erythrocytes from a group of healthy control Chinese subjects (n=135) and patients with asthma (n=106).


METHODS
Baseline pulmonary function was measured for all subjects. Antioxidant status was evaluated by measuring erythrocyte superoxide dismutase, catalase, and glutathione peroxidase activities. Oxidative stress was also measured in terms of GSSG in erythrocytes with a kinetic microassay.


RESULTS
Patients with asthma had significantly increased erythrocyte superoxide dismutase and catalase activities compared with controls (61.10 +/- 1.30 U/g hemoglobin [Hb] vs 55.51 +/- 1.82 U/g Hb [P=.018] and 0.0637 +/- 0.0021 U/g Hb vs 0.0257 +/- 0.0120 U/g Hb [P <.001] for the asthma and control groups, respectively). Conversely, erythrocyte glutathione peroxidase activity decreased (44.21 +/- 1.33 mU/g Hb vs 50.07 +/- 1.39 mU/g Hb for the asthma and control groups, respectively; P=.003). Patients with asthma also had significantly higher GSSG levels in erythrocyte hemolysates compared with controls (167.40 +/- 2.93 micromol/L vs 44.98 +/- 0.44 micromol/L for the asthma and control groups, respectively; P <.001), indicating increased oxidative stress.


CONCLUSIONS
Asthma is accompanied by an alteration in systemic antioxidant status due to possible oxidative stress in this disease.
Department of Medicine, Division of Respiratory and Critical Care Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China. judithmak@hku.hk
Judith C W
JC
Mak
Helen C M
HC
Leung
Siu P
SP
Ho
Barbara K W
BK
Law
Wah K
WK
Lam
Kenneth W T
KW
Tsang
Mary S M
MS
Ip
Moira
M
Chan-Yeung
D000328:Adult; D001249:Asthma / Q000378:metabolism*; D002374:Catalase / Q000097:blood; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D019803:Glutathione Disulfide / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000097:blood
D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D019803:Glutathione Disulfide