Fasting serum cholecystokinin immunoreactivity in chronic relapsing pancreatitis.
An increase in fasting cholecystokinin (CCK) levels has been reported in patients with pancreatic insufficiency, but the relationship of these findings to the clinical conditions has not been established. We, therefore, measured fasting serum CCK-like immunoreactivity in 70 patients with chronic relapsing pancreatitis (CRP) (38 non-surgically treated and 32 previously surgically treated) and in 44 healthy subjects. The radioimmunoassay detected three circulating forms of CCK. The mean value of the CCK levels in CRP (260.3 +/- 300.8 pg/ml) was significantly higher than that of the controls (56.6 +/- 61.7 pg/ml) (p less than 0.001), but in 39 (56.7%) of the 70 CRP cases the CCK was in the normal range. A smaller overlap with the controls was observed in the non-surgically than in the surgically treated patients (45 vs. 71.8%). In the 38 non-surgically treated CRP cases no relationship was observed between the CCK levels and each of the following parameters: age, length of history, presence or absence of pancreatic calcification, nutritional and alcoholic habits, and the results of exocrine function tests. The absence of the last-mentioned correlation is somewhat unexpected if the high CCK levels are due to the interruption of a feedback loop for CCK secretion. However, previous pancreatic surgical drainage and/or treatment with pancreatic enzymes, present in almost all these patients, could have an effect on CCK behaviour.