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Serum immuno reactive trypsin and pancreatic isoamylase in older patients with cystic fibrosis

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We measured serum trypsin by radio-immunoassay and differential serum amylases using an inhibitor technique, in 24 patients with cystic fibrosis (C.F.), 20 of whom had symptomatic steatorrhea, and 24 normal controls. Both mean serum trypsin and pancreatic isoamylase were significontly lower in the 20 C.F. patients with symptomatic steatorrhea than in the controls (p<0.001), indicating pancreatic insufficiency. Both techniques showed good, though not complete, separation of these 2 groups. The remaining 4 C.F. patients who did not have symptomatic steatorrhea had mean serum trypsin and pancreatic isoamylase values which were significantly higher than those of the controls (p<0.05 and p<0.01, respectively). In these 4 patients this may indicate that the chronic pancreatitis of C.F. may be preceded by a state of active degeneration. Significant correlation between serum trypsin and pancreatic isoamylase levels was found in both the controls and the C.F. patients, particularly in the subgroup with symptomatic steatorrhea (r=+0.92, p<0.001). Measurement of serum immunoreactive trypsin, being simple and non-invasive, may prove useful in screening for pancreatic insufficiency and in helping to diagnose those C.F. patients with repeatedly equivocal sweat tests.

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Tobin, M.J., Duffy, M.J., Duffy, G. et al. Serum immuno reactive trypsin and pancreatic isoamylase in older patients with cystic fibrosis. I.J.M.S. 150, 325 (1981).

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  • Cystic Fibrosis
  • Acute Pancreatitis
  • Chronic Pancreatitis
  • Pancreatic Insufficiency
  • Serum Trypsin