Rapid quantitative, specific measurement of pancreatic amylase in serum with use of a monoclonal antibody.

1985 ◽  
Vol 31 (8) ◽  
pp. 1283-1286 ◽  
Author(s):  
T E Mifflin ◽  
D C Benjamin ◽  
D E Bruns

Abstract In this rapid quantitative assay for pancreatic alpha-amylase (EC 3.2.1.1) in serum, we precipitate salivary amylases by 10-min incubation with monoclonal anti-salivary amylase antibody immobilized on particles of polyvinylidene fluoride. We then centrifuge the serum mixture and measure the pancreatic amylase activity remaining in the supernate by a kinetic method. The assay requires 50 microL of serum and the standard curve is linear to at least 1300 U of pancreatic amylase per liter of serum. CVs were 1.3% within-run, 6-8% day-to-day. Apparent analytical recovery of pancreatic amylase activity added to serum was 101% +/- 2%. Addition of purified salivary amylase, 356 U/L, to sera gave a value for apparent pancreatic amylase of less than 4 U/L, or 1% of the added salivary amylase activity. This assay correlated well with an electrophoretic method (slope, 0.97-0.99; intercept, 0.5 to -4 U/L; correlation coefficient, 0.946-0.990; and standard error of the estimate 3-5 U/L). Estimated normal reference intervals with maltotetraose as substrate were: total amylase, 39-118 U/L; pancreatic amylase, 11-50 U/L; and salivary amylase, 18-79 U/L.

1989 ◽  
Vol 35 (1) ◽  
pp. 110-114 ◽  
Author(s):  
T E Mifflin ◽  
M Hamilton ◽  
E Hubbard ◽  
M J Kline ◽  
D E Bruns

Abstract 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.


1988 ◽  
Vol 34 (11) ◽  
pp. 2283-2290 ◽  
Author(s):  
P Mocarelli ◽  
P Brambilla ◽  
L Colombo ◽  
A Marocchi ◽  
C Crespi ◽  
...  

Abstract Urinary excretion of D-glucaric acid (uGA) is an index of type II hepatic microsomal enzyme induction, indirectly revealing possible organic effects of some drugs and environmental pollutants. However, its determination is often cumbersome. We suggest a new, fast microanalytical method for uGA determination in which beta-glucuronidase (BG; EC 3.2.1.31) activity inhibition produced by uGA-derived 1,4-D-glucarolactone is measured. With use of purified BG, the method is suitable for centrifugal analyzers, allowing assay of greater than 100 samples per day. Moreover, the method measures uGA more accurately than other enzymatic methods based on BG inhibition. The within-day CV ranges from 7.9% to 4.6% (uGA 31.55-121.31 mumol/L); the between-day CV ranges from 11.5% to 5.0% (uGA 26.09-124.10 mumol/L). The detection limit is 6.0 mumol/L. The standard curve is linear from 10 to 200 mumol/L. Mean analytical recovery is 100%. Comparison with the method of Simmons et al. (Clin Chim Acta 1974;51:47-51) gave a correlation of r = 0.978, y = 1.40x-2.81. Reference intervals were established in a healthy population sample of 369 people (165 under 14 y), and uGA, expressed in micromoles per gram of creatinine, was higher in women than in girls or in males.


1985 ◽  
Vol 31 (8) ◽  
pp. 1331-1334 ◽  
Author(s):  
M Gerber ◽  
K Naujoks ◽  
H Lenz ◽  
W Gerhardt ◽  
K Wulff

Abstract A monoclonal antibody (66C7) was prepared that specifically binds human salivary amylase (EC 3.2.1.1); it cross reacts with human pancreatic amylase by less than 1%. Two procedures are described for determination of isoamylases in human serum with this antibody: an enzyme immunoassay for determining amylase of salivary origin, and a routine method in which this amylase is immunoprecipitated and the remaining (pancreatic) amylase activity is assayed. Results by the two methods correlate well.


2000 ◽  
Vol 46 (7) ◽  
pp. 928-933 ◽  
Author(s):  
Yoshitaka Morishita ◽  
Yoshitsugu Iinuma ◽  
Nobuo Nakashima ◽  
Keiichi Majima ◽  
Katsuhiko Mizuguchi ◽  
...  

Abstract Background: Many different methods have been used to assay amylase activity, using nitrophenylated oligosaccharides as substrate; however, the hydrolysis steps in these methods are complex. Methods: We developed a new continuously monitoring assay for amylase activity in biological fluids, using 2-chloro-4-nitrophenyl-4-O-β-d-galactopyranosylmaltoside (GalG2CNP) as the substrate; this assay was used with anti-human salivary amylase monoclonal antibodies for specific determination of the pancreatic isoenzyme. Amylase converted GalG2CNP into β-d-galactopyranosylmaltose and 2-chloro-4-nitrophenol, which was measured at 405 nm. Results: GalG2CNP was cleaved between 2-chloro-4-nitrophenol and β-d-galactopyranosylmaltose and did not undergo transfer reactions. The within-assay CVs (n = 20) for total amylase (T-AMY) and pancreatic amylase (P-AMY) were 0.6–1.6% and 0.5–2.5%, respectively; and day-to-day CVs (n = 10) for T-AMY and P-AMY were 0.8–3.7% and 0.6–4.1%, respectively. T-AMY and P-AMY activities in serum or urine obtained by the proposed method correlated well with those determined by the 2-chloro-4-nitrophenyl 4-O-β-d-galactopyranosyl-β-maltotetraoside method or the modified IFCC method. Conclusions: This novel assay for T-AMY and P-AMY measures both activities stoichiometrically, directly, and easily, and may be suitable for routine procedures.


1989 ◽  
Vol 35 (4) ◽  
pp. 662-664 ◽  
Author(s):  
E Svens ◽  
K Käpyaho ◽  
P Tanner ◽  
T H Weber

Abstract In this immunocatalytic assay for alpha-amylase (EC 3.2.1.1) of pancreatic origin, a highly specific monoclonal antibody coupled to plastic beads is used to extract pancreatic amylase from samples, leaving salivary amylase in solution. The catalytic activity of the bound pancreatic amylase is then determined with blocked p-nitrophenyl maltoheptaoside as substrate. The method shows no cross-reactivity with salivary amylase, analytical recovery is 89-109% for pancreatic amylase, and interassay imprecision is 7.1-7.7%. We used the method to determine pancreatic amylase in serum and urine from healthy controls and different patient groups. The reference intervals for 34 supposedly healthy controls were: serum, 10-48 U/L (mean 27 U/L); urine, less than 20-435 U/L (mean 104 U/L). Results by the present assay correlated well with a salivary amylase inhibition assay (Boehringer Mannheim). We conclude that the described immunocatalytic assay is clinically useful for detecting increased activities of pancreatic amylase in serum and urine.


1986 ◽  
Vol 32 (2) ◽  
pp. 296-300 ◽  
Author(s):  
R O Wolf ◽  
V S Hubbard ◽  
B K Gillard ◽  
A Kingman

Abstract We evaluated three methods for serum amylase (EC 3.2.1.1) isoenzymes to determine whether they are interchangeable and to test their ability to discriminate between cystic fibrosis patients with and without pancreatic insufficiency. One method involved salivary amylase inhibitor (O), and two were polyacrylamide gel electrophoresis separations differing in method of detection--either direct zymogram (G) or gel slicing followed by activity estimates per slice (W). Results for percentage pancreatic amylase differed significantly. Reproducibility for percentage pancreatic amylase was high, moderate, and low (r = 0.95, 0.53, and 0.02) for methods G, O, and W, respectively; moderate (r = 0.60) among the three methods; and moderate between pairs. Therefore, this result for a subject must be considered relative to the method used in its determination. The clinical diagnosis of pancreatic insufficiency was verified by 77.8%, 83.3%, and 94.4% correct classification rates for methods O, W, and G, respectively. Evidently, method G is the most efficient and may be the method of choice for measuring serum amylase isoenzymes in cystic fibrosis.


1988 ◽  
Vol 34 (9) ◽  
pp. 1794-1798 ◽  
Author(s):  
C M Preissner ◽  
G G Klee ◽  
C J Krco

Abstract In this sequential assay, the thyroglobulin in serum binds to polystyrene beads coated with two mouse monoclonal antibodies. These beads then react with a rabbit polyclonal antibody, biotinylated sheep anti-rabbit IgG, streptavidin-horseradish peroxidase, and a peroxidase substrate to yield a colored product that is measured spectrophotometrically at 492 nm. The range of the standard curve is 1.6 to 100 micrograms/L. The detection limit of the assay is 1.2 micrograms/L. The interassay coefficient of variation is 14.0% at 6.2 micrograms/L, 5.7% at 32.7 micrograms/L; the intra-assay CVs range from 7.8% to 14.8%. The reference intervals are 2.7 to 42.1 micrograms/L for euthyroid persons and less than or equal to 5 micrograms/L for athyreotic patients not on thyroxin replacement therapy. Some autoantibodies to thyroglobulin cause thyroglobulin values to be falsely low. The concentration of autoantibodies is not correlated with the analytical recovery of human thyroglobulin. The coefficient of correlation between the measurement of thyroglobulin by this assay and by an immunoradiometric assay was 0.969 for 186 autoantibody-negative samples, 0.963 for 37 autoantibody-positive samples.


1989 ◽  
Vol 35 (8) ◽  
pp. 1651-1654
Author(s):  
T E Mifflin ◽  
R W Forsman ◽  
D E Bruns

Abstract We examined the ability of an immobilized antibody to salivary amylase (Clin Chem 1985;33:1283-8) to react with amylase in macroamylasemic sera. The antibody removed 50% (SD 23%) of the total amylase activity from 39 macroamylase sera, a percentage indistinguishable (P greater than 0.75) from the percentage removed from concurrently analyzed sera from healthy volunteers (49%, SD 11%). Electrophoretic analysis of 23 macroamylasemic sera revealed that the antibody removed only part of the macroamylase band(s) in 71% of the cases. We conclude that the mean isoenzyme composition of the macroamylase complexes is essentially identical to the mean isoenzyme distribution in normal sera (i.e., about half salivary and half pancreatic amylase). Further, the immobilized antibody can be used to distinguish most patients with macroamylasemia from those with acute pancreatitis, because sera from the latter contain an increased proportion (greater than 80%) of pancreatic amylase.


1988 ◽  
Vol 34 (12) ◽  
pp. 2552-2555 ◽  
Author(s):  
M Zaninotto ◽  
R Bertorelle ◽  
S Secchiero ◽  
M Plebani ◽  
A Burlina

Abstract To evaluate a new method for measuring pancreatic amylase in serum, in which the salivary isoenzyme is inhibited with a specific monoclonal antibody, we determined the activity of pancreatic and salivary amylase in sera from 103 healthy subjects and from 114 hospitalized patients having a wide range of total amylase activities. CVs for the proposed method ranged from 0.8% to 5.1% (within day) and from 2.3% to 6.6% (day to day). Results correlated well with those obtained by the wheat-germ inhibition method (r = 0.998) and by electrophoresis on cellulose acetate. Analytical-recovery studies confirmed the good specificity of the monoclonal antibody for salivary amylase (97%) and its low cross-reactivity (0.6%) toward pancreatic amylase. The assay procedure presents a wide range of linearity (141-1817 U/L) and can easily be adapted to an automated kinetic system. We found the proposed method suitable for routine determinations of pancreatic amylase.


1972 ◽  
Vol 18 (12) ◽  
pp. 1493-1497 ◽  
Author(s):  
L Fridhandler ◽  
J Edward Berk ◽  
M Ueda

Abstract We describe a sensitive quantitative procedure for separating isoamylases in human serum, urine, and tissue homogenates. Two components have been discerned with chromatographic characteristics resembling those of pancreatic and salivary amylases, respectively. Several lines of evidence—derived from studies in normal subjects, pancreatectomized patients, and patients with acute pancreatitis—indicate that the pancreas is probably the source of the component in serum and urine that exhibits characteristics of pancreatic amylase. The source of the component resembling salivary amylase has not yet been fully defined. Isoamylase analysis of extracts of fallopian tube and liver revealed two amylase components with chromatographic properties similar to pancreatic and salivary amylases, respectively.


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