alpha-Amylase and isoamylase levels in renal transplant recipients compared to uremic patients.

Hyperamylasemia is a common finding in chronic renal failure (CRF) patients. The present study was designed to evaluate the frequency, the type, and the hyperamylasemia levels in renal transplant recipients (RTR) compared to patients with renal failure with or without replacement of renal function. One hundred and forty-one subjects [42 with varying degree of renal insufficiency (group A), 74 on hemodialysis (group B), and 25 RTR (group C)] and 47 normal individuals were studied. Total serum alpha-amylase (Ta) as well as pancreatic (Pa) and salivary (Sa) types of serum isoamylases were elevated in all groups when compared to the levels found in normal subjects. A remarkable proportion of patients belonging to groups A and B had Ta as well as Pa levels over three times the upper normal limits. On the contrary, no RTR had such increased levels of both Ta and isoamylases. A statistically significant correlation was found between Ta, Pa, and Sa and serum creatinine in RTR. However, no statistically significant correlation was found between urine amylases and serum creatinine or between urine and serum levels in all amylases in this group. In conclusion, serum amylase levels are increased in RTR. However, no subject in this group had amylase and isoamylase values more than three times the upper normal limits, which was a common finding in the other groups of patients.

The value of alpha-amylase and isoamylase determination in chronic renal failure patients.

Hyperamylasemia is a common finding in chronic renal failure (CRF) patients. It has been suggested that the diagnosis of acute pancreatitis in these patients is confirmed when serum amylase activities are greater than three times the upper normal limits. In order to evaluate the frequency, the type, and the hyperamylasemia levels in patients with various degree of chronic renal failure, the total serum amylase (Ta), the pancreatic (Pa) and salivary (Sa) types of serum isoamylases, as well as the urine isoamylases (Tu, Pu, Su, respectively) have been determined by the Phadebas method. Moreover, the levels of serum electrolytes and triglycerides were determined in order to study any relationship between serum electrolytes as well as triglycerides and alpha-amylase activities. We studied 102 patients of whom 33 (group A) had CRF with serum creatinine levels 8.5 +/- 3.1 mg/dL (mean +/- SD), 59 (group B) were receiving chronic hemodialysis, and 10 (group C) were on continuous ambulatory peritoneal dialysis as well as 47 normal individuals. None of the subjects studied had any clinical manifestation of acute pancreatitis. Our results showed that the Ta, Pa and Sa levels of groups A, B, and C were significantly elevated compared to normal subjects. Eighteen patients had Pa activities greater than three times the upper normal limits. In the present study, no relationship between serum electrolytes as well as triglycerides and alpha-amylases was found. In conclusion, hyperamylasemia was a much more common finding in CRF patients than previously reported in the literature.(ABSTRACT TRUNCATED AT 250 WORDS)

Total amylase and pancreatic isoamylase in serum and urine: considerations from data on biological variation.

The analytical, within-subject and between-subject components of variation were estimated for amylase activity and pancreatic isoamylase activity in serum measured using newer analytical methods. Desirable analytical imprecisions based on within-subject variation were CV less than or equal to 4.4% and CV less than or equal to 7.0%, respectively. Conventional population-based reference intervals were not useful because of marked individuality; clinical decision-making points should be derived from the desired sensitivity and specificity. Serial results must change more than about 30% and 40% respectively before significance (P less than or equal to 0.05) can be claimed. Similar data on total amylase and pancreatic isoamylase activities in random and first morning urines showed that the use of conventional reference intervals was appropriate. Very large changes (greater than 100%) were required before a difference in serial results was significant. Calculation of the urine amylase/creatinine ratio appeared to confer no advantage. Derivation of the ratio of pancreatic isoamylase to total amylase activity in serum or urine was unlikely to provide additional information of value in either diagnosis or monitoring.

Failure of inhibitor assay to determine isoamylase distribution.

Isoamylase distribution in the urine of normal individuals and patients admitted to the hospital with hyperamylasemia was determined by a wheat inhibitor mmethod and compared to results obtained by cellulose-acetate electrophoresis. We report two cases where the inhibitor ethod failed to give accurate results in urine, as well as serum, when compared to both electrophoresis and column chromatography. The discrepant results were due to the unexpected inhibition of P isoamylase.

Measurement of amylase isoenzymes in human sera and urine using a DEAE-cellulose mini-column method.

A DEAE-cellulose mini-column method has been developed which allows for the separation and quantitation in human sera and urine of pancreatic and salivary type isoamylases. Determination of the isoamylases was found to be of value in differentiation of hyperamylasemias due to disorders of the pancreas and parotid gland.

Value of pancreatic-type isoamylase assay as an index of pancreatic insufficiency.

The study here reported was undertaken to assess the value of assay of the specific isoamylase form arising from the pancreas (P-type) as an index of pancreatic exocrine insufficiency. Measurements were made of serum total amylase activity, serum P-type isoamylase activity, and the amount of P-type isoamylase relative to creatinine (Upam/Ucr) in the urine in a series of patients with clinically suspected chronic pancreatitis and pancreatic insufficiency as determined from the pancreatic secretory response to secretin stimulation. Abnormally low values for P-type isoamylase in the serum and urine of these patients were infrequent. Conversely, values within the normal ranges for serum P-type isoamylase and Upam/Ucr were common. It is concluded that while subnormal values for P-type isoamylase in the serum and urine may be viewed as supportive evidence for pancreatic insufficiency, failure to find such values does not exclude this condition.

Urinary isoamylases in juvenile diabetics.

An anomalous ratio of salivary to pancreatic amylase activities has been observed in urine from juvenile diabetics. Decreased pancreatic amylase activity in urine from these subjects appears to be a characteristic trait.

Pancreatitis-like isoamylase pattern in normal persons.

On the assumption that a rise in the pancreatic type isoamylases may not necessarily indicate underlying pancreatitis, genetic studies of human serum and urinary amylase isoenzymes have been performed with the use of electrophoresis. Although the preponderant increase in the two principal pancreatic isoamylases Amylase-1 and 2 has been accepted to be a specific index of pancreatic involvement, 1.68% of normal persons had Amylase-2 with an elevated amylase activity (named "Dominant Amylase-2") up to the same levels as the major isoenzymes. Results of pancreozymin-secretin test and other laboratory findings of these persons with Dominant Amylase-2 were all within normal ranges. Pedigree studies confirmed an autosomal dominant mode of inheritance for this variant. The important of serial determination and pedigree investigations has been shown to distinguish normal persons having Dominant Amylase-2 from patients with pancreatitis without elevated amylase activity. The existence of an inherited trait of pancreatitis-like isoamylase pattern in healthy individuals must be born in mind before coming to a conclusion when amylase isoenzymes are used for clinical medicine, though preponderance of the pancreatic type isoenzymes in serum and urine has been revealed to be a characteristic finding in pancreatitis. Knowledge of amylase genetic polymorphism provides a scientific basis for amylase isoenzyme interpretation.

The characteristics of amylase activity and the isoamylase pattern in serum and urine of infants and children.

Determination of amylase activity and isoamylase patterns were performed in serum and urine of normal newborns, infants and children of different ages. In the serum of newborn infants measurable amounts of amylase were present. The activity increased with the age and reached the normal adult level by approximately 8 months of age. Isoamylase analysis revealed that the low level of serum amylase in infants was mainly due to deficiency of the pancreatic-type isoamylase. The absence of the pancreatic isoamylase in newborns and young infants is a physiological and developmental phenomenon. Great caution is therefore necessary when amylase isoenzymes are used in the diagnosis of abnormal pancreatic function and such results have always to be interpreted in relation to the age of the child.

Assay of amylase and isoamylase activities in serum and urine. Modifications in methods and range of normal values.

Certain modifications are described in assay methods previously reported from this laboratory for total amylase and isoamylase activities. These modifications provided more consistent results and achieve superior separation of pancreatic and salivary type (P- and S-type) isoamylases. The estimated range of values in the serum and urine of normal subjects using the modified assay procedures is presented for total amylase as well as for P- and S-type isoamylases.

Mechanism of increased renal clearance of amylase/creatinine in acute pancreatitis.

We investigated three possible causes of the increased ratio of amylase/creatinine clearance observed in acute pancreatitis. The presence of rapidly cleared isoamylase was excluded by studies of serum and urine, which demonstrated no anomalous isoamylases. In pancreatitis, the ratios (+/-1 S.E.M.) of both pancreatic isoamylase (9.2+/-0.6 per cent) and salivary isoamylase (8.6+/-1.6 per cent) were significantly (P less than 0.01) elevated over respective control values (2.4+/-0.2 and 1.8+/-0.2 per cent). Increased glomerular permeability to amylase was excluded by the demonstration of normal renal clearance of dextrans. We tested tubular reabsorption of protein by measuring the renal clearance of beta2-microglobulin, which is relatively freely filtered at the glomerulus and then avidly reabsorbed by the normal tubule. During acute pancreatitis the ratio of the renal clearance of beta2-microglobulin to that of creatinine was 1.22+/-0.52 per cent, an 80-fold increase over normal (0.015+/-0.002 per cent), with a rapid return toward normal during convalescence. Presumably, this reversible renal tubular defect also reduces amylase reabsorption and accounts for the elevated renal clearance of amylase/creatinine observed in acute pancreatitis.

Nonpancreatic-type hyperamylasemia associated with pancreatic cancer.

Isoamylase analysis of the serum and urine of a patient with anaplastic spindel cell carcinoma of the pancreas revealed that virtually all of the serum amylase and almost all of the urine amylase behaved chromatographically as the salivary (S) type. Both the serum and urine amylases were bound by a substance derived from a macroamylase complex which had been shown to bind only salivary amylase and to lack any affinity for pancreatitis (P) type amylase. The ratio of amylase to creatinine clearance was markedly increased (12.5%) without evidence of acute pancreatitis at autopsy and despite the presence of only a minute amount of P-type isoamylase in the serum.

Isoamylases in blood, urine, and tissue homogenates from some experimental mammals.

The isoamylase patterns of the serum, urine, and various tissue extracts of some mammalian species were studied with the aid of agarose gel electrophoresis followed by incubation with a starch-dye polymer. In the dog and cat mainly one fraction of amylase, derived from the pancreatic gland, was found in the serum and in the urine. In the rabbit, identical isoamylases were produced by the salivary and pancreatic glands and possibly also by the duodenum; they were detectable in serum and were excreted in the urine in partly changed form. In the rat, the salivary isoamylase was clearly differentiated from the pancreatic isoamylases in serum and urine. Skeletal muscle also produced a starch-degrading enzyme, but no conclusive evidence of hepatic amylase production was found. In the mouse, the salivary and pancreatic isoamylases of serum and urine were clearly separated. Evidence of amylase production was found in the liver and duodenum. These amylases belonged to the pancreatic group of isoamylases. In the guinea-pig, the salivary and pancreatic isoamylases differed from one another in their electrophoretic migration rates; in the serum and urine only salivary isoamylases were detectable. In the Golden Syrian hamster, the salivary glands, the pancreatic glands, and the small intestine-fallopian tube differed from each other in respect of the groups of isoamylases they produced. The pancreatic isoamylase was never seen in the serum or the urine.

Amylase iso-enzymes in primates of the families Lemuridae, Cebidae, Cercopithecidae, Hylobatidae and Pongidae.

This paper presents the first data in the alpha-amylase iso-enzymes in primates of the families: Lemuridae, Cebidae, Cercopithecidae, Hylobatidae and Pongidae. By means of agar-gel electrophoresis of urine samples from 33 individuals belonging to ten species of the above mentioned families a total of 14 different variants of amylase heterogeneity were found.