Pancreatic Amylase
Method: EPS-G7 Method
Liquid reagent, R1:R2=3:1
CLINICAL SIGNIFICANCE
Alpha-amylases are hydrolases that act on the alpha-1,4 glucosidic bond of starch. There are two isoenzymes of α-amylase in the human body, namely Salivary Amylase (SAMY) and Pancreatic Amylase (PAMY). Among them, PAMY is secreted by the pancreas and discharged into the digestive tract in an active state. It can be filtered by the glomerulus and detected in the urine.
Clinically, amylase is the most widely used diagnostic index for pancreatitis, but its sensitivity and specificity are not high. PAMY is organ-specific and is considered more suitable for the diagnosis and monitoring of acute pancreatitis and acute attacks of chronic pancreatitis [1]. In most cases of acute pancreatitis, the total activity of AMY and PAMY in blood and urine are elevated, and SAMY is normal. In some cases, the activity of PAMY accounts for 79% to ** of the total activity of AMY. In addition, in acute pancreatitis, the increase in PAMY is higher than that of AMY. The total activity lasts for a long time, and PAMY often increases significantly after the latter returns to normal. After comparison, some scholars believe that in acute pancreatitis, the specificity of lipase, trypsin and PAMY is the highest in the determination of PAMY [2]. There are also reports in the literature that the ratio of pancreatic amylase/total amylase>64% is a sensitive and reliable biochemical indicator for the diagnosis of acute pancreatitis [3].
SENSITIVITY
When the sample concentration is 180.0U/L, the absorbance change should in range of 0.0200-0.2000.
LINEARITY
In the range of [5.00,1500.00] U/L,the linearity correlation coefficient r≥0.99; in the range of [5.00,100.00] U/L, the absolute deviation should ≤±15U/L; in the range of (100.00,1500.00]mg/dL, the relative deviation should ≤±15%.
PRECISION
a)Repeatability(N=20)
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|
Mean(U/L) |
CV（%） |
|
Level1 |
39.38 |
0.85 |
|
Level 2 |
223.91 |
0.36 |
b)Intermediate precision(N=80)
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|
Mean(U/L) |
CV（%） |
|
Level1 |
37.8 |
0.87 |
|
Level 2 |
227.4 |
0.67 |
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INTERFERENCES
When samples concentration is up to 33U/L, the effect of bilirubin ≤50mg/dL, hemoglobin ≤ 500 mg/dL, ascorbic acid ≤ 100 mg/dL, Intralipid ≤ 1000mg/dL, is less than 10%.