Enzyme studies. pp. 285-90.

It has been reported that saliva and serum of patients contain macromolecular 
"factors" which are presumably cationic and inhibit transport of electrolytes, induce 
dyskinesis or degranulate sensitized polymorphonuclear leukocytes and contain polypeptide moieties. The 
difference between levels of trypsin-like activity of mixed saliva of patients 
with cystic fibrosis and controls has been confirmed. A number of 
studies have been carried out in order to determine if a 
deficiency of proteolytic activity might account for the presence of cystic 
fibrosis serum factors. It was presumed that the observed partial deficiency 
of arginine esterase activity might well represent the total deficiency of 
one of several arginine esterases assayed under the experimental conditions. Although 
it was postulated that the deficiency of arginine esterase activity is 
related to the elevation of the levels of polypeptide or protein 
"factors", the hydrolysis of peptide bands by activated plasma could not 
be demonstrated, probably due to the limitations of the methods employed. 
The deficiency of plasma arginine esterase in cystic fibrosis has been 
questioned and confirmed in another laboratory. 