Lipase is produced by the pancreas, liver, intestine, tongue, stomach, and many other cells. Lipase testing is indicated in acute pancreatitis, as well as in the diagnosis of peritonitis, strangulated or infarcted bowel, and pancreatic cyst. [1]
The reference range for lipase is 0-160 U/L or 0-160 U/L (SI units), although values depend on method. [2]
Lipase levels may be increased in the following conditions: [1, 3]
Perforated or penetrating peptic ulcer, particularly involving the pancreas Obstruction of pancreatic duct by stone Drug-induced spasm of sphincter of Oddi (codeine, morphine, methacholine, cholinergics) Gastric malignancy or perforation Acute cholecystitis Intestinal infarction Acute and chronic renal failureOrgan transplantation, particularly associated with a complication (organ rejection, cyclosporine toxicity, cytomegalovirus infection)
Chronic liver diseaseUse of certain drugs: Methodological interference (pancreozymin [contains lipase], deoxycholate, glycocholate, taurocholate [prevents inactivation of enzyme], bilirubin [turbidimetric method])
After endoscopic retrograde cholangiopancreatography (ERCP)Lipase levels are decreased in association with methodological interference (presence of hemoglobin, quinine, heavy metals, calcium ions). [1]
Lipase levels are normal in individuals with mumps and in those with macroamylasemia. Values are lower in neonates.
Methodology: Quantitative enzymatic [3]
Container: Tiger-top tube (serum-separator tube or plasma-separator tube) [3]
Specimen collection method: Routine venipuncture
Processing: Allow the sample to clot completely in the serum tube at room temperature and separate plasma from cells within 2 hours of collection in the laboratory. An adequate sample requires a minimum of 0.2 mL (preferably 2 mL). [3] Ambient temperatures and exposure to room air make the sample unacceptable for analysis. Other unacceptable conditions include specimens collected in EDTA, oxalate/fluoride/citrate tubes with glycerol-lubricated stoppers.
Stability: After separation from cells, frozen one year, refrigerated and ambient one week [3]
Reported: Within 24 hours
Lipase catalyzes hydrolysis of triglycerides to produce fatty acids and glycerol. Lipase is produced by the pancreas, liver, intestine, tongue, stomach, and many other cells.
Because lipase levels remain elevated longer than amylase and its sensitivity in acute alcoholic pancreatitis is increased, serum lipase may be a more reliable test than serum amylase for the initial diagnosis of acute pancreatitis. [4, 5]
Certainly, daily measurements of lipase are of no value in the assessment of the patient's clinical progress or ultimate prognosis. Because of its sensitivity, lipase testing is not very useful in chronic pancreatitis or pancreatic cancer. [4, 5, 6]
Lipase testing is indicated in acute pancreatitis.
It is also used in the diagnosis of peritonitis, strangulated or infarcted bowel, and pancreatic cyst. [1]
Pancreatic inflammation increases enzyme levels.
None of the available tests meet all criteria (establishing the diagnosis accurately, providing early assessment of its severity, identifying the cause) for an ideal laboratory test in the evaluation of a patient with acute pancreatitis. Nevertheless, serum amylase and lipase are considered important tests in the diagnosis of acute pancreatitis.
Easy availability, high sensitivity, and technical simplicity are touted as the advantages of amylase testing, but its greatest disadvantage is its low specificity. Serum lipase is a more reliable diagnostic marker of acute pancreatitis than serum amylase. [6] The major benefit of lipase is in patients with delayed presentation, [7, 8] since its activity remains increased for longer periods (up to 8-14 days), and an increased sensitivity in acute alcoholic pancreatitis. [4, 5] Nonspecific elevations of lipase levels have been reported in almost as many disorders as amylase.
Although lipase is mostly found in the pancreas, serum levels may also increase in association with other intra-abdominal pathologies or renal insufficiency. Most studies have reported specificities above 95%, with sensitivities varying between 55% and 100% at a cutoff activity of 600 IU/L. [5] However, a normal serum lipase level does not exclude acute pancreatitis, particularly recurrent disease, when the clinical features are compatible with the diagnosis.
The level of lipase cannot be used to determine disease severity or to predict outcome. [9] Simultaneous estimation of lipase with amylase does not improve the accuracy. [5]
Pancreatic panniculitis presents with tender, ill-defined, red-brown nodules in the lower limbs that may ulcerate and drain an oily substance. It usually precedes pancreatic disease, particularly pancreatitis and pancreatic carcinoma. Therapy should be directed at the underlying pancreatic disease. [10]