Carboxypeptidase B-like activity and C3 in cystic fibrosis.

Assays of carboxypeptidase B-like activity and C3 in serum from patients with cystic fibrosis and appropriate control subjects failed to demonstrate a deficiency of carboxypeptidase B-like activity or a consistent increase in C3, as was suggested by Conover and associates. Differences between men and women with cystic fibrosis were apparent, in that women with cystic fibrosis had higher concentrations of both serum carboxypeptidase B-like activity and C3 than either men with cystic fibrosis or control subjects.