Hydrolases acting on glycosidic bonds: chromatographic and electrophoretic separations

Multiple myeloma associated with sialyl salivary-type amylase

BACKGROUND

There have been several reports describing a notable hyperamylasaemia in patients with multiple myeloma. Such amylase-producing myelomas have been mainly described in the context of concomitant salivary-type hyperamylasaemia, with sialyl salivary-type amylase identified in a portion of those cases. We investigated the incidence of the production of sialyl salivary-type amylase in serum of multiple myeloma patients.

METHODS

Eleven patients (6 male and 5 female) who had been diagnosed as having multiple myeloma were enrolled in this study. Sialyl salivary-type amylase was detected by isoamylase electrophoresis and HPLC analysis, and identified by detecting either abnormal neuraminidase-sensitive band through isoamylase electrophoresis or abnormal extra-elution peak of amylase by means of HPLC analysis.

RESULTS

Sialyl salivary-type amylase was detected in 7 out of 11 (63.6%) patients. Median total amylase activity was 154 U/l (range 109-43020). Isoamylase electrophoretic patterns of patients' serum were normal in 5 patients (71.4%) out of 7 patients and salivary-dominant in 2 (50.0%) out of 4 patients.

CONCLUSIONS

We consider that there is no significant relationship between total serum amylase level and amylase isoenzyme pattern in the incidence of production of sialyl salivary-type amylase with multiple myeloma.

Potential diagnostic value of pancreatic isoamylases for pancreaticobiliary maljunction with mild biliary dilatation in patients and a porcine model

PURPOSE

The aim of this study was to evaluate the diagnostic value of serum pancreatic isoamylases for pancreaticobiliary maljunction (PBM) with mild biliary dilatation.

METHODS

Serum and bile from 8 children with PBM and mild biliary dilatation (6 to 11 mm in diameter) and 4 young pigs with an anastomosis constructed between an isolated pancreas-duodenal segment and the gallbladder were studied for pancreatic isoamylases. Using an electrophoretic technique, the assay of pancreatic isoamylases was expressed by peak appearance rate (PAR). Serum from 20 healthy children served as normal controls.

RESULTS

In the serum of the patients, preoperatively there were 5 pancreatic peaks with PAR as follows: P1, 100%; P2, 100%; P3, 100%; P4, 100%; and P5, 66.7%. These abnormal pancreatic isoamylases disappeared 2 weeks after operative treatment. In normal controls, there were only P1 (PAR, 40%) and P2 (PAR, 100%). Mild cylindrical dilatation (6 to 8 mm in diameter) of the common bile duct developed in the porcine PBM model. There were P1 (PAR, 100%) and P2 (PAR, 100%) in the porcine serum preoperatively. Thirty days and 60 days after establishing the model, there appeared in the serum 6 pancreatic peaks with PAR as follows: P1, 100%; P2, 100%; P3, 75%; P4, 100%; P5, 100%, and P6; 75%. The bile patterns of pancreatic isoenzymes in the patients and pigs were similar to those in serum.

CONCLUSIONS

Abnormal pancreatic isoamylases are characteristically present in the serum from both children and a porcine model of PBM and mild biliary dilatation. Assay for these abnormalities is promising to recognize this subset of patients in whom diagnosis remains a challenge.