Interaction of immobilized anti-salivary amylase antibody with human macroamylases: implications for use in a pancreatic amylase assay to distinguish macroamylasemia from acute pancreatitis.

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.

Author(s):  
Chiyo Fujita ◽  
Chihiro Kasai ◽  
Hiromi Kosuge ◽  
Kenji Ogata ◽  
Ichiyo Oshima ◽  
...  

A monoclonal antibody (E-21) was obtained that specifically binds to human pancreatic amylase and shows negligible cross-reaction with human salivary amylase. Using this antibody a radioimmunoassay was developed for pancreatic amylase in human serum. The assay was shown to be sensitive (detectable up to 7 mg/L), reproducible, and specific for pancreatic amylase. In normal subjects, the mean concentration of serum pancreatic amylase determined by this method was 36·3 mg/L with a 95% confidence range of 16·5 to 79·2 mg/L. A good correlation was observed between the concentrations of immunoreactive pancreatic amylase (IR-PA) and enzymatic activities in 20 serum samples ( r = 0·97). The concentration of serum IR-PA was below the detectable limit in pancreatectomised patients, and was greatly increased in patients with acute pancreatitis; the latter was accompanied by parallel changes in total enzymic activity. In patients with mumps, the serum IR-PA level was within the normal range whereas the total enzymic activity was elevated.


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.


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.


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.


1986 ◽  
Vol 32 (8) ◽  
pp. 1539-1541 ◽  
Author(s):  
D A Lacher ◽  
M B Harize

Abstract A rapid procedure for determining salivary- and pancreatic-type amylase (EC 3.2.1.1) in serum by incorporating a wheat germ inhibitor (from Triticum aestivum) was developed for the Du Pont aca IV analyzer. Under optimal assay conditions, activities of salivary and pancreatic amylase were inhibited by 93% and 19%, respectively. The 95% central reference interval for the percentage of inhibition of serum amylase was 38-84%. Patients with acute pancreatitis showed less than 26% inhibition of amylase after addition of the wheat germ extract, reflecting the prevalence of pancreatic-type amylase in this disorder.


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.


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.


1992 ◽  
Vol 38 (9) ◽  
pp. 1725-1729
Author(s):  
J L Rosenblum ◽  
G L Hortin ◽  
C H Smith ◽  
G E Pashos ◽  
M Landt

Abstract Hyperamylasemia caused by macroamylases can lead to the overdiagnosis of acute pancreatitis. We examined whether interference from macroamylase is less in assays that use high-molecular-mass (high-M(r)) substrates rather than oligosaccharide substrates. We hypothesized that high-M(r) substrates would be sterically excluded from macroamylasemic complexes and thus would be hydrolyzed less efficiently. Eighteen macroamylasemic samples were assayed by using red-dyed amylopectin or blue-dyed starch as polysaccharide substrates or by using maltoheptaose or maltotetraose as oligosaccharide substrates. The oligosaccharide substrates gave comparable results (y = 0.81x + 83), but we observed consistently lower activities for amylopectin than for maltotetraose (y = 0.32x + 38). We observed no bias among methods when nonmacroamylasemic specimens were analyzed. The mechanism of this difference was examined by adding antihuman pancreatic amylase antibodies to hyperamylasemic serum samples from patients without macroamylasemia and to purified human pancreatic or salivary isoamylases. In each case, polyclonal and monoclonal antibodies lowered amylase activity more in assays with complex polysaccharides than in those with oligosaccharides. The use of high-M(r) substrates diminishes interference, and detection of suspected macroamylasemia may be possible through comparing activities determined from automated methods that use different substrates.


1988 ◽  
Vol 34 (3) ◽  
pp. 589-591 ◽  
Author(s):  
J F Wetzels ◽  
J C Hafkenscheid ◽  
M Hessels ◽  
A J Hoitsma ◽  
R A Koene

Abstract To study the charge-selective properties of the glomerular filter in renal disease, we measured the fractional clearance, relative to creatinine clearance (ECC), of the amylase isoenzymes pancreatic amylase and salivary amylase, which have identical size but different charge. In 63 healthy subjects the mean (and SD) fractional excretion of pancreatic amylase, 4.07% (1.24%), was fourfold that of salivary amylase: 1.02% (0.54%). For 29 patients with renal disease and proteinuria, the mean fractional excretion of pancreatic amylase was significantly lower, 3.31% (1.94%), and that of salivary amylase significantly higher, 2.06% (1.41%), than in controls. In these patients, fractional excretions of both these isoenzymes were negatively correlated with urinary excretion of beta 2-microglobulin and ECC. Evidently, differences in clearances of pancreatic and salivary amylase are a consequence of differences in charge-related glomerular filtration. The relative increase of salivary amylase clearance in patients with renal disease and proteinuria is most probably caused by a loss of the charge-selective properties of the glomerular basement membrane.


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.


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