Different airway responsiveness profiles in atopic asthma, nonatopic asthma, and Sjögren's syndrome. BHR Study Group. Bronchial hyperresponsiveness.
BACKGROUND
Different mechanisms may underlie bronchial hyperresponsiveness (BHR) in different diseases. The aim of this study was to investigate the bronchial responsiveness profile produced by three different challenge tests, methacholine, a direct stimulus, and two indirect stimuli, adenosine 5'-monophosphate (AMP) and cold air, in subjects with asthma and patients with Sjögren's syndrome.


METHODS
The study population comprised 40 adult patients with asthma, 18 subjects with Sjögren's syndrome, and 20 controls. Blood samples were collected before each challenge for measurements of serum eosinophil peroxidase (S-EPO) and eosinophil cationic protein (S-ECP). The investigated subjects recorded peak expiratory flow and kept a symptom diary.


RESULTS
Atopic subjects with asthma were significantly more hyperresponsive to AMP than nonatopic subjects with asthma (P=0.01) and subjects with Sjögren's syndrome (P=0.02). No difference was seen between atopic and nonatopic subjects with asthma in the case of challenges with methacholine or cold air. In atopic subjects with asthma, a significant correlation was found between challenges with methacholine and AMP (r=0.91, P=0.0001) and methacholine and cold air (r=0.83, P=0.004), but, in nonatopic subjects with asthma, no significant correlation was seen between methacholine and AMP or cold air challenges. In atopic subjects with asthma, the dose-response slope for AMP was correlated to S-EPO (r= -0.56; P = 0.01) and S-ECP (r= -0.51, P = 0.02), while no correlation between BHR and inflammation markers was found in the two other patient groups.


CONCLUSIONS
The results of this study suggest that patients with asthma and subjects with Sjögren's syndrome display different bronchial responsiveness profiles for different challenge agents. Atopic subjects with asthma are more hyperresponsive to AMP than nonatopic subjects and patients with Sjögren's syndrome. More than one challenge may be required to detect different aspects of bronchial responsiveness.
Lúdvíksdóttir
D
D
Department of Respiratory Medicine and Allergology, Asthma Research Centre, Akademiska sjukhuset, Uppsala University, Sweden.
Janson
C
C
Björnsson
E
E
Stålenheim
G
G
Boman
G
G
Hedenström
H
H
Venge
P
P
Gudbjörnsson
B
B
Valtysdóttir
S
S
D000249:Adenosine Monophosphate; D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000276:immunology / Q000503:physiopathology*; D001798:Blood Proteins / Q000378:metabolism; D016535:Bronchial Hyperreactivity / Q000276:immunology / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D003080:Cold Temperature; D004305:Dose-Response Relationship, Drug; D047091:Eosinophil Granule Proteins; D047209:Eosinophil Peroxidase; D004804:Eosinophils / Q000201:enzymology; D005260:Female; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate; D010544:Peroxidases / Q000378:metabolism; D012260:Ribonucleases; D012859:Sjogren's Syndrome / Q000276:immunology / Q000503:physiopathology*
D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D016210:Methacholine Chloride; D000249:Adenosine Monophosphate; D047209:Eosinophil Peroxidase; D010544:Peroxidases; D012260:Ribonucleases