Reference Range
The reference range for lipase is 0-160 U/L or 0-160 U/L (SI units), although values depend on the method used. [1]
Interpretation
Lipase levels may increase in the following conditions: [2, 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, prostigmin, methacholine, cholinergics) [4]
-
Pancreatic malignancy such as acinar cell carcinoma of pancreas [4]
-
Gastric malignancy or perforation
-
Intestinal infarction
-
Acute and chronic renal failure
-
Organ transplantation, particularly associated with a complication (organ rejection, cyclosporine toxicity, cytomegalovirus infection)
-
Lymphoma
-
Chronic liver disease
-
Use of certain drugs - Methodological interference (pancreozymin [contains lipase], deoxycholate, glycocholate, taurocholate [prevents inactivation of enzyme], bilirubin [turbidimetric method]). After administration of the dipeptidyl peptidase-4 inhibitors, sitagliptin and saxagliptin, for treating type 2 diabetes. [4]
Other conditions associated with elevated serum lipase levels include:
- Diminished physiological clearance due to renal impairment as seen in [4]
• Formation of macrolipases (enlarged lipase molecules) that can increase serum lipase levels due to poor renal filtration and may signal certain autoimmune or lymphoproliferative diseases. They may be associated with celiac disease, Crohn's disease, liver cirrhosis, Multiple Myeloma, Systemic Lupus Erythematosus, and hypergammaglobulinemia. [4]
2. Intra-abdominal pathologies such as [4]
• Malignancies: Hepatocellular Carcinoma, bowel cancer with liver metastases
• Nonpathological pancreatic hyperenzymemia (absence of identifiable pancreatic disease despite elevated pancreatic enzymes)
• Intra-abdominal hemorrhage caused by ruptured abdominal aorta aneurysm, ruptured ectopic pregnancy, or ruptured ovarian cyst. [4]
• Hepatobiliary causes: Biliary atresia, cholangitis, and liver necrosis [4]
3. Critical Illnesses: Multi-trauma patients without head injury [4]
4. Infections: Chronic hepatitis C virus, human immunodeficiency virus. [4] Emerging scientific evidence has linked severe acute respiratory syndrome coronavirus-2 infection to elevated serum lipase, likely due to pancreatic involvement, multiorgan dysfunction or both [5]
5. Inflammation or neoplasm of the salivary gland [1]
Lipase levels are decreased in association with methodological interference (presence of hemoglobin, quinine, heavy metals, calcium ions). [2] An earlier study had shown that serum lipase levels decrease with progressive worsening of chronic pancreatitis, possibly due to a decline in the secretory capacity of pancreas. [6]
Lipase levels are normal in individuals with mumps and in those with macroamylasemia. They are lower in neonates.
Collection and Panels
Methodology: Quantitative enzymatic [3]
Container: Tiger top tube (serum-separator tube or plasma-separator tube) [3]
Specimen collection method: Routine venipuncture; fasting is required [1]
Processing: Allow the sample to clot completely in the serum tube at room temperature and separate plasma from cells within 2 h 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 ethylenediaminetetraacetic acid, oxalate/fluoride/citrate tubes with glycerol-lubricated stoppers.
Stability: After separation from cells, frozen 1 year, refrigerated and ambient 1 week [3]
Reported: Within 24 h
Background
Description
Lipase catalyzes the hydrolysis of triglycerides to produce fatty acids and glycerol. Lipase is produced by the pancreatic acinar cells, liver, intestine, tongue, esophagus, stomach, colon, heart, lung, leukocytes, and many other cells. [4]
Because lipase levels remain elevated longer than amylase and its sensitivity in acute alcoholic pancreatitis is high, serum lipase may be a more reliable test than serum amylase for the initial diagnosis of acute pancreatitis. [7, 8] 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. [7, 8, 9]
Indications/Applications
-
Lipase testing is indicated in acute pancreatitis.
Considerations
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. [9] Acute pancreatitis is diagnosed when serum lipase levels are at least three times greater than the upper limit of normal. [4] The major benefit of lipase is in patients with delayed presentation [10, 11] as its activity remains increased for longer periods up to 8-14 days, while the amylase remains elevated for up to 5 days, and an increased sensitivity in acute alcoholic pancreatitis. [12, 7, 8] Serum lipase levels are independent of hypertriglyceridemia, whereas in case of serum amylase, hypertriglyceridemia competitively interferes with the assay [12] . Nonspecific elevations of lipase levels have been reported in almost as many disorders as amylase. In adults, urinary enzymes have less clinical significance than serum enzymes; however, they may be helpful in diagnosing acute pancreatitis in children. [12]
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. [8] However, a normal serum lipase level does not exclude acute pancreatitis, particularly recurrent disease, when the clinical features are compatible with the diagnosis.
Lipase levels cannot be used to determine disease severity or to predict outcomes. [13] Simultaneous estimation of lipase with amylase does not improve the accuracy. [8]
Pancreatic panniculitis presents with tender, ill-defined, red-brown nodules in the lower limbs that may ulcerate and drain an oily substance. It can precede the common symptoms of pancreatic disease, particularly pancreatitis and pancreatic carcinoma. Therapy should be directed at the underlying pancreatic disease. [14]
