[Improvement in the specificity of the PABA test (PFT) by combined PABA peptide/D-xylose administration and serum kinetic measurement?].

To obtain higher specificity of peptide-PABA-test, an indirect pancreatic functions test, 150 mg N-BT-PABA together with 25 g D-Xylose in 300 ml tea were administered to a group of 68 persons. Maximal concentration of PABA and D-Xylose were investigated serum by time-concentration-curves 0, 60, 90, 120 and 150 min after test meal. Serum-PABA was found pathologically low in 18 of 20 patients with proofed chronic pancreatitis. In 16 of 17 patients with chronic pancreatitis serum-D-Xylose was normal. In a group of 39 patients, in which a pancreatic disease was excluded, PABA-serum-test showed no false-pathological results. In 7 patients with small-bowel diseases and pathological D-Xylose-test, PABA-serum-test was false-pathologically in 6/7 cases. By serum-PABA-time-concentration-curves there was a significant discrimination between patients with chronic pancreatitis and controls at 60, 90, 120 and 150 min (p less than 0.01), but early and late peak concentration of PABA was often found in the two groups. If the PABA-concentration was estimated only 120 min after test meal, diminished test-specificity was found. Peak-PABA-serum-concentration was significantly correlated with lipase output (p less than 0.001) and trypsin output (p = 0.01) at secretin-caerulein test, but PABA was only at low enzyme outputs pathological, showing a moderate sensitivity of test.