Serum ribonuclease levels in patients with cystic fibrosis.

Cystic fibrosis is an autosomal recessive disease, usually fatal before the third 
decade, characterized by chronic obstructive lung disease, elevated sweat electrolyte concentrations, 
and pancreatic insufficiency. The present investigation was carried out to determine 
if P-type serum RNase activity was reduced in CF patients 3 
to 24 years of age. No difference in serum RNase activity 
was found among the groups of 17 normals, 21 CF patients, 
and 5 CF heterozygotes. It appears that observations of decreased RNase 
activity in the serum of young children with pancreatic insufficiency cannot 
be extended to older children, at least without withholding pancreatic supplements. 
