The components of basal membrane (BM) were investigated in bronchi of 15 hu
mans with allergic airways diseases, Including asthma, by immunohistochemis
try Three patterns of type IV collagen, laminin and fibronectin distributio
n were observed in BM The pattern characteristic for main part of asthmatic
s displayed absence or interrupted staining for type IV collagen and lamini
n with notable Increase of fibronectin in BM The patterns do not depend on
age of patients, duration and type of allergic airways disease.