Lipase and amylase tests in acute pancreatitis

The article is written by Dr. BS Vu Hoang Huy - Emergency Doctor - Emergency Department - Vinmec Times City International General Hospital.

Lipase and amylase tests both help diagnose diseases related to the pancreas. Lipase is an enzyme produced by the pancreas and in humans it is produced only in the pancreas. Amylases are a group of enzymes produced mainly in the pancreas and salivary glands, with a small part produced in the liver, lining of the small intestine, fallopian tubes, and ovaries.

The main function of amylase is to break down starch into smaller polysaccharides at 1 to 4 alpha internal bonds during digestion. The main sources of amylase in humans are the pancreas and salivary glands, but it can be found in other tissues in small amounts.

Acute pancreatitis or exacerbation of chronic pancreatitis. In acute pancreatitis, blood amylase activity is often increased to 4-6 times the reference value and is often elevated in parallel with lipase levels. Pancreatic duct obstruction and pancreatic cancer. Elevated levels of amylase in peritoneal fluid can occur in acute pancreatitis but can also occur in other abdominal disorders, such as bowel obstruction or decreased blood flow to the intestines (infarction), small bowel perforation or perforated peptic ulcer. Amylase is also elevated in chronic pancreatitis often associated with alcoholism, trauma, and pancreatic duct obstruction. Drug-induced acute pancreatitis Acute alcohol poisoning. Diseases of the biliary tract: common bile duct stones, acute cholecystitis, biliary obstruction... End stage renal failure. Salivary gland disease: Acute or chronic inflammation of the salivary glands, blocked salivary ducts, mumps.

Decreased blood amylase levels in a person with symptoms of pancreatitis may indicate permanent damage to the amylase-producing cells of the pancreas, pancreatic cancer Severe liver damage: Toxic hepatitis, cirrhosis, pregnancy poisoning, severe burns. Severe thyrotoxicosis. Serum amylase increases within 6 to 12 hours after the onset of acute pancreatitis. Amylase has a short half-life of about 10 hours and should return to normal within 3-5 days.

Lipase is mainly synthesized and stored as granules in pancreatic cells. There are several lipases in the human body, including pancreatic, lipoprotein, intestinal, stomach, and liver lipases. The activity of all lipases was inhibited by bile acids. The activity of pancreatic lipase depends on the presence of another enzyme.
The main function of pancreatic lipase is to hydrolyze triglycerides into glycerol and free fatty acids. Like amylase, lipase is a relatively small molecule that can be filtered by the kidneys. Unlike amylase, lipase can be reabsorbed in the renal tubules, increasing its half-life (6.9 to 13.7 hours).

Serum lipase has a sensitivity of 82-100% for acute pancreatitis. Serum lipase rises within 4 to 8 hours of the onset of symptoms, peaks at 24 hours, and returns to normal within 8-14 days.

Patients with acute alcoholic pancreatitis may have normal amylase and elevated serum lipase. Normal amylase is significantly associated with previous episodes of acute pancreatitis, indicating that the pancreatic parenchyma is no longer able to produce adequate amounts of the enzyme.

Pancreatic tissue in chronic pancreatitis showed a significant decrease in both amylase and lipase activity, with amylase activity showing a greater reduction than lipase (91% vs 26%).

In patients with hypertriglyceridemia causing acute pancreatitis, the serum amylase level may be normal. An oddly low serum amylase level due to circulating inhibitors of serum amylase interferes with the test, but it can be corrected if the laboratory perceives the plasma to be milky and performs the following tests. serial dilution.

The preferred test indicates blood Lipase over blood amylase in acute pancreatitis. The choice depends on the test facility conditions. Serum lipase has a sensitivity of 82-100% for acute pancreatitis, serum amylase has a sensitivity of 67-83% and a specificity of 85-98%. Lipase elevations occur earlier and last longer than amylase elevations and are therefore particularly useful in patients presenting >24 hours after onset of pain Patients with acute pancreatitis often have elevated amylase and/or lipase levels. triple. However, patients with acute pancreatitis, acute hypertriglyceridemia, and acute alcoholic pancreatitis may have elevations in serum lipase only, which is also more sensitive than amylase in patients with acute pancreatitis secondary to acute pancreatitis. alcohol and hypertriglyceridemia. Amylase is not elevated in approximately 20% of patients with alcoholic pancreatitis and in 50% of patients with hypertriglyceridemia. Vinmec International General Hospital is one of the hospitals that not only ensures professional quality with a team of leading doctors, modern equipment and technology, but also stands out for its examination and consulting services. and comprehensive, professional medical treatment; civilized, polite, safe and sterile medical examination and treatment space. Customers when choosing to perform tests and treat diseases here can be completely assured of the accuracy and high efficiency in the treatment process.