Polypeptide marker and disease patterns found while mapping proteins in ascitis

Abstract

To assess the protein composition of ascitis, 28 samples of ascitic fluid were obtained from patients admitted to Geneva University Hospital. The samples were analysed randomly and blindly by high-resolution two-dimensional polyacrylamide gel electrophoresis. The final visual evaluation was compared with the discharged summary and diagnosis. The protein pattern of ascitis was, as expected, very similar to normal or diseased plasma, with the exception of two spots which were present in ascitic fluids but not in the 200 plasma samples analyzed in parallel. After microsequencing, they proved to be β-fibrinogen fragments. Several diseases showed distinct patterns, especially acute pancreatitis. A group of intense spots with an apparent molecular mass between those of α 1-antitrypsin and β-haptoglobin were found in all ascitic fluid from pancreatitis cases (six patients). These spots had isoelectric points similar to those of α 1-antitrypsin and β-haptoglobin and microsequencing revealed that they were three different fragments of α 1-antitrypsin.