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May 1982

Aged AmylaseA Valuable Test for Detecting and Tracking Pancreatic Pseudocysts

Author Affiliations

From the Department of Surgery, Wayne State University School of Medicine, Detroit.

Arch Surg. 1982;117(5):707-711. doi:10.1001/archsurg.1982.01380290153027

• Amylase-rich fluid that incubates ("ages") within a pancreatic pseudocyst undergoes a change that can be detected by isoenzyme analysis of amylase from the serum. This aging is a result of deamination of the asparagine and glutamine residues on the amylase molecule. Eighteen of 20 patients with surgically proved pseudocysts had greater than 15% aged (deaminated) amylase in their serum. Levels of aged amylase returned to normal following treatment of their pseudocysts. Twenty of 23 patients with acute pancreatitis had levels of aged amylase below 15% (P <.05). A criterion of 15% aged amylase resulted in 87% specificity, and 91% sensitivity for the diagnosis of pseudocysts. Because this test is noninvasive and easy to perform, it should become the ideal screen for patients at risk of development of pseudocysts. Endoscopic retrograde pancreatography, ultrasonography, and abdominal computed tomographic scanning should be reserved for confirmation of the diagnosis when the result of isoenzyme analysis is positive.

(Arch Surg 1982;117:707-711)

Seghal LR, Kraft AR:  Isoamylase pattern diagnostic of pancreatic pseudocyst . Lancet 1977;2:149.
Warshaw A, Lee KH:  Aging changes of pancreatic isoamylases and the appearance of 'old amylase' in the serum of patients with pancreatic pseudocysts . Gastroenterology 1980;79:1246-1251.
Keller PJ, Kauffman DL, Allan BJ, et al:  Further studies on the structural differences between the isoenzymes of human parotid α-amylase . Biochemistry 1971;10:4867.Article
Lorentz K, Flatter B:  Studies on isoamylase formation in biological fluids . Enzyme 1979;24:163-168.
Karn RC, Rosenblum BB, Ward JC, et al:  Genetic posttranslational mechanisms determining human amylase isoenzyme heterogeneity , in Market CL (ed): Isoenzyme IV: Genetics and Evolution . New York, Academic Press Inc, 1975, pp 745-761.
Legaz ME, Kenney MA:  Electrophoretic amylase fractionation as an aid in diagnosis of pancreatic disease . Clin Chem 1976;22:57-62.
Sankaran S, Walt AJ:  The natural and unnatural history of pancreatic pseudocysts . Br J Surg 1975;62:37-44.Article
Kamaryt J, Loxova R:  Amylase heterogeneity with some genetic and clinical aspects . Hum Genet 1965;1:579.Article
Robinson AB, McKerrow JH, Cary P:  Controlled deamination of peptides and proteins: An experimental hazard and a possible biological timer . Proc Natl Acad Sci USA 1970;66:753-757.Article
Duane WC, Frerilis R, Levitt MD:  Distribution, turnover and mechanism of renal excretion of amylase in the baboon . J Clin Invest 1971;50:156.Article