Chemical markers of mucous and serum glycoproteins and their relation to viscosity in mucoid and purulent sputum from various hypersecretory diseases.

Mucus and serum are always present in sputum. The concentrations of their 
markers were measured in mucoid and purulent sputum from patients with 
chronic bronchitis, asthma, cystic fibrosis, or bronchiectasis. Differences in the concentrations 
of both mucous and serum glycoproteins were greater among different macroscopic 
types of sputum than among diseases for the same macroscopic type. 
Comparison between diseases showed that sputum from patients with asthma had 
the widest variation in concentrations of markers of mucous glycoprotein and 
dry macromolecular weight. When the astham group was further analyzed, it 
became apparent that patients with extrinsic asthma without chronic bronchitis represented 
a homogeneous group, whereas those with intrinsic asthma, with or without 
chronic bronchitis, were responsible for the wide variation. The concentrations of 
markers of mucous and serum glycoproteins in a sputum sample were 
correlated with the apparent viscosity of the sputum to establish the 
relative contribution of the glycoproteins to the viscosity of sputum. In 
mucoid sputum, the mucous glycoprotein was most important in determining the 
viscosity, whereas when in infected sputum, both mucous and serum components 
contributed to the viscosity. 