CHROMOGRANIN-A AND PANCREASTATIN-LIKE IMMUNOREACTIVITY IN SERUM OF GASTRINOMA PATIENTS

Gastrin and pancreastatin-like immunoreactivity were determined by rad ioimmunoassay methods and chromogranin A was determined by enzyme-link ed immunoassay in sera from 18 patients with gastrinomas (Zollinger-El lison syndrome) and in 20 age and sex matched controls. Gastrin serum levels in the gastrinoma patients were in the range 26-80 000 pmol/l, and in the controls 5-31 pmol/l. Chromogranin A serum levels in the ga strinoma group were in the range 6-2 700 ng/ml (mean +/- SEM: 400 +/- 147 ng/ml). The mean value of chromogranin A was significantly higher than in the control group (8 +/- 2 ng/ml, p = 0.008). The serum levels of pancreastatin-like immunoreactivity in the gastrinoma patients wer e in the range 23-1 994 pg/ml (597 +/- 123 pg/ml). The mean value of p ancreastatin-like immunoreactivity in the gastrinoma group was signifi cantly higher than in the control group (104 +/- 25 pg/ml, p = 0.0002) . The levels of chromogranin A and pancreastatin-like immunoreactivity were significantly higher in patients with verified metastatic diseas e (p = 0.04, p = 0.01 respectively). There was a significantly positiv e correlation between levels of gastrin and pancreastatin-like immunor eactivity r = 0.7, p = 0.002), while no correlation was found between gastrin and chromogranin A levels or between levels of chromogranin A and pancreastatin-like immunoreactivity. The study demonstrates an ele vation of both chromogranin A and pancreastatin-like immunoreactivity in serum of gastrinoma patients. The lack of correlation between gastr in and chromogranin A, however, gives an indication that the gastrinom a cells are not the main source of serum chromogranin A elevation.