Abstract
An analysis of the plasma proteins in the sol phase of sputum was carried out using quantitative cross immunoelectrophoresis. The average concentrations of nine plasma proteins were estimated in the sol phase of sputum specimens from 30 patients with chronic bronchitis and the values were compared with the concentrations of these proteins in saliva and serum specimens from the same group of patients. The results showed that alpha1 antichymotrypsin and IgA concentrations were higher in the sol phase of sputum than would be expected if their presence were due entirely to passive transudation.