Plasma hydrolases in cystic fibrosis [letter].

Dr Hosli and Esther Vogt reported that the alpha-mannosidase and acid phosphatase 
activities of cystic fibrosis plasma assayed at pH 5.4 are abnormally 
thermolabile at 41 degrees and 36.5 degrees C, respectively, and that 
the levels of residual activity after heat inactivation clearly distinguish between 
CF patients, CF carriers, and normal subjects. We have repeated these 
experiments under identical conditions and found no differences between the three 
groups. 