Mast cell numbers in airway smooth muscle and PC20AMP in asthma and COPD.
BACKGROUND
Most patients with asthma and many patients with COPD show bronchial hyperresponsiveness to adenosine (BHR(AMP)). BHR(AMP) may be caused by release of mast cell histamine, which induces smooth muscle contraction.


OBJECTIVE
To evaluate whether mast cell numbers in airway smooth muscle are increased in patients with asthma and COPD compared to their age-matched controls, and whether mast cell numbers are correlated with BHR(AMP).


METHODS
Twenty-two non-smoking subjects with asthma (age 31yr, FEV(1): 89% pred, PC(20)AMP: 2.7mg/ml), 18 ex-smoking subjects with COPD (age 62yr, FEV(1): 58% pred, PC(20)AMP: 52.4mg/ml).


METHODS
Snap-frozen bronchial biopsies were immunostained with anti-mast cell tryptase and anti-desmin antibodies. Mast cell number was expressed as the number of tryptase positive cells per area of smooth muscle.


RESULTS
There were no significant differences in mast cell number between patients with asthma, COPD, and their respective age-matched healthy controls. Furthermore, there was no significant correlation between mast cell number and FEV(1) or PC(20)AMP in any of the groups. Surprisingly, the mast cell number was negatively correlated with reversibility to salbutamol in COPD patients (rho -0.47, P<0.05).


CONCLUSIONS
Mast cell numbers in central airway smooth muscle apparently do not contribute importantly to bronchial hyperresponsiveness to adenosine.
Liesker
J J W
JJ
Department of Pulmonology, University Medical Center Groningen, University of Groningen, the Netherlands.
Ten Hacken
N H T
NH
Rutgers
S R
SR
Zeinstra-Smith
M
M
Postma
D S
DS
Timens
W
W
D000241:Adenosine; D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000473:pathology* / Q000503:physiopathology; D001706:Biopsy; D001980:Bronchi / Q000473:pathology; D016535:Bronchial Hyperreactivity / Q000473:pathology; D001985:Bronchial Provocation Tests / Q000379:methods; D001999:Bronchoscopy; D002452:Cell Count; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000473:pathology*; D008875:Middle Aged; D009130:Muscle, Smooth / Q000473:pathology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000473:pathology* / Q000503:physiopathology; D012189:Retrospective Studies; D053802:Tryptases / Q000378:metabolism
D053802:Tryptases; D000241:Adenosine