To determine the clinical value of tumour markers in the diagnosis of malignancy-related ascites (not including hepatocellular carcinoma), serum and ascitic fluid levels of carcinoembryonic antigen, cancer antigen 125, carbohydrate antigen 19-9, tissue polypeptide antigen and serum-ascites albumin gradient were determined in 66 patients with cirrhotic ascites, 28 patients with hepatocellular carcinoma and ascites, and 29 patients with malignancy-related ascites. Three tumour markers and serum-ascites albumin gradient showed significant difference between patients with malignancy-related ascites and those without: serum carcinoembryonic antigen (26.4 +/- 31.5 vs 4.8 +/- 4.6 ng/mL, P < 0.01), ascitic fluid carcinoembryonic antigen (118.4 +/- 196.5 vs 2.0 +/- 1.4 ng/mL, P < 0.01), ascitic fluid carbohydrate antigen 19-9 (12,933 +/- 25,496 vs 23 +/- 67 U/mL, P < 0.01) and serum-ascites albumin gradient (1.1 +/- 0.4 vs 2.0 +/- 0.4 g/dL, P < 0.01). At the best cut-off levels chosen from near 95% of the data in those without malignancy-related ascites, the sensitivity, specificity and accuracy to diagnose malignancy-related ascites were, respectively, 65.5%, 93.6%, 87.0% using serum carcinoembryonic antigen > or = 10 ng/mL; 69.0%, 94.7%, 88.6% using ascitic fluid carcinoembryonic antigen > or = 5 ng/mL; 65.5%, 93.6%, 87.0% using ascitic fluid carbohydrate antigen 19-9 > or = 50 U/mL; 62.1%, 98.9%, 90.2% using serum-ascites albumin gradient < 1.1 g/dL. Although serum-ascites albumin gradient offered the best diagnostic accuracy and specificity, its sensitivity was not good enough. Our study indicates that serum-ascites albumin gradient and tumour markers are not sensitive parameters in the diagnosis of malignancy-related ascites.

Procarboxypeptidase B (human pancreas-specific protein) has been reported to be a good serum marker for the diagnosis of acute pancreatitis. The current study was conducted in order to evaluate the frequency and degree of elevated serum levels of procarboxypeptidase B in chronic renal failure and their correlations with serum levels of amylase, lipase and renal function tests. Blood samples were taken from 84 asymptomatic patients with chronic renal failure, including 34 patients with periodical haemodialysis and 50 patients without haemodialysis. Serum levels of procarboxypeptidase B, amylase, lipase, creatinine and blood urea nitrogen were measured. Serum levels of procarboxypeptidase B in 84 patients were 63.4 +/- 5.5 micrograms/L significantly greater than the figure of 29.6 +/- 1.6 micrograms/L in healthy adults in our previous report (P < 0.0001). There was a significant difference in serum levels of PCPB between patients with and without haemodialysis (78.0 +/- 9.4 vs 53.6 +/- 6.3 micrograms/L; P < 0.01). The frequencies of elevated serum levels of procarboxypeptidase B, amylase and lipase greater than upper normal limits were 27.4, 35.7 and 26.2%, respectively. The frequencies of elevated PCPB in patients with and without haemodialysis were 38.2 and 20%, respectively. Only one patient had a serum procarboxypeptidase B level greater than three-fold the upper normal limit. A significant correlation was found between procarboxypeptidase B and lipase (r = 0.785; P < 0.0001). No significant correlation was noted between procarboxypeptidase B vs amylase or renal function tests. In conclusion, in patients with chronic renal failure, the elevation of serum procarboxypeptidase B is as common as the elevations of other pancreatic enzymes.