Pancreatic amylase measured in serum by use of a monoclonal antibody immunochemically immobilized to a solid phase.
We studied a method for measuring the pancreatic isoenzyme of amylase (EC 3.2.1.1) by use of a mouse monoclonal antibody against human salivary-type amylase (Clin Chem 1985;31:1283) coupled indirectly to particles of polyvinylidene fluoride via polyclonal goat anti-mouse immunoglobulin. These particles, in 200 microL of a suspension, could remove salivary amylase (activity 2200 U/L) from an equal volume of serum in 5 min. Measurement of amylase activity in the supernatant fluids from treated sera thus provided an assay of pancreatic amylase. Precision studies at three activity concentrations yielded within-run CVs of 1.6% to 1.7% (n = 25) and total CVs of 2.2% to 5.1% (20 days). Salivary amylase added to each of 10 sera was completely (99.8%, SD 1.6%) removed. The new method (y) showed the following regression statistics when compared with an electrophoretic method (x): slope = 0.989 (SD 0.019), intercept = -0.220% (SD 1.48%), SEE 4.0%, n = 51. Similar respective regression values were found for urine samples: slope = 0.934 (SD 0.053), intercept = 2.3 U/L (SD 3.2), SEE 8.4 U/L, n = 26. The following respective values were found when the new method (y) was compared with the previously described immunoprecipitation assay (x): slope = 1.02 (SD 0.02), intercept = 2.2% (SD 1.4%), SEE 3.3%, n = 23 sera. Reference intervals for pancreatic amylase activity in serum were established for three different substrates: maltotetraose, maltopentaose, and p-nitrophenylheptaoside.
Mifflin
T E
TE
Department of Pathology, University of Virginia Health Sciences Center, Charlottesville 22908.
Hamilton
M
M
Hubbard
E
E
Kline
M J
MJ
Bruns
D E
DE
D000208:Acute Disease; D000681:Amylases / Q000097:blood*; D000911:Antibodies, Monoclonal; D004587:Electrophoresis, Agar Gel; D006801:Humans; D007118:Immunoassay; D007527:Isoenzymes / Q000097:blood*; D010179:Pancreas / Q000201:enzymology*; D010195:Pancreatitis / Q000201:enzymology; D011786:Quality Control; D012016:Reference Values; D012463:Saliva / Q000201:enzymology
D000911:Antibodies, Monoclonal; D007527:Isoenzymes; D000681:Amylases