DIE DIAGNOSTISCHE WERTIGKEIT DES AMINOSAUREN-ABSORPTIONSTESTS BEIM NACHWEIS EINER EXOKRINEN PANKREASFUNKTIONSSTORUNG

The amino acid consumption test (AACT) during exogenous stimulation with secretin and CCK was proposed as a sensitive and highly specific test for detection of exocrine pancreatic insufficiency. To further investigate the diagnostic value of this test we measured the AACT in comparison with the pancreolauryl serum test (PLT) in patients with chronic pancreatitis and in patients with gastrointestinal diseases but without pancreatic disease. A total of 48 patients, 23 patients with chronic pancreatitis (CP) and 25 patients with gastrointestinal diseases, were included in the study. Diagnosis of chronic pancreatitis was established by standardized morphological criteria in ultrasound, ERCP, CT, and was confirmed by surgery in 11 cases. The PLT was abnormal in 83% of patients with chronic pancreatitis and normal in 92% of the control subjects (diagnostic accuracy 88%). Basal amino acid concentration was comparable in patients with chronic pancreatitis and in control subjects (300 ± 12 < = > 325 ± 16 μmol/l). The peak decrease of amino acids occurred after 30 min during combined stimulation with secretin and ceruletide and was not different between the two groups (CP: 11.2 ± 1.7%, controls: 13.9 ± 1.9% below basal values). With a 12% decrease of amino acids as cutoff, sensitivity was 74% and specificity 52% (diagnostic accuracy 63%). Integrated amino acid decrease did not show any significant differences between CP and controls (CP: 228 ± 63% min, controls: 397 ± 80% min). Determination of the individual amino acids serine, valine, histidine, and isoleucine could also not discriminate between patients with chronic pancreatitis and other gastrointestinal diseases. The amino acid decrease showed a big overlap between the two groups and did not allow to discriminate between patients with chronic pancreatitis and patients without pancreatic disease. Referring to the observed low specificity the ACCT cannot be recommended as a reliable test for diagnosis of exocrine pancreatic function impairment in chronic pancreatitis.