- Red top, tiger top, green top(heparin) tube
- 5 mL venous blood
Care of specimen
- Maintain at room temperature
Amylase is a digestive enzyme that functions primarily in the digestion of complex carbohydrates. It is primarily formed by the pancreas and salivary glands, but is also present in other tissues including:
- Fallopian tube
- Lungs
- Thyroid
- Tonsils
- Various malignant neoplasms
The pancreatic and the salivary isoenzymes are the ones most commonly detected by the assay.
Serum amylase assays have the following clinical utility:
- Aid in the diagnosis of acute pancreatitis
- Aid in the diagnosis of macroamylasemia
- Aid in the diagnosis of pancreatic duct obstruction
- Detect injury to the pancreas due to blunt trauma or surgery
- Exclude acute pancreatitis as a cause of acute abdominal pain
Additional information:
- In early acute pancreatitis, serum amylase levels start increasing 6-24 hours after onset. It often decreases after 3-7 days due to increased renal amylase excretion (Lipase will be useful in these situations).
- When normal amylase combines with high molecular weight protein immunoglobulin, macroamylase is formed which is characterized by high serum amylase
- Pancreatic amylase is tightly bound to the mucosa of the small intestine. Small bowel injury is often associated with elevated serum amylase.
- Patients with elevated serum amylase, in the absence of signs of pancreatic diseases, should undergo screening for celiac disease.
- When routine monitoring is being performed, the patient should abstain from alcohol for at least 24 hours before the test (alcohol consumption may result in elevations).
- For at least 2 hours before the test, no food or fluids, except water, should be taken.
Overview:
- In neonates, usually no amylase activity is detected.
- At about 2 months of age, measurable amylase activity is detected. It increases gradually and reaches adult values by age of 1 year.
Consult your laboratory for their normal ranges as these may vary somewhat from the ones listed below.
| Conv. units (U/L) | SI units (µKat/L) |
|---|---|
| 20-110 | 0.33-1.85 |
High serum amylase concentration is called hyperamylasemia. It may occur in the following conditions:
- Increase in pancreatic amylase
- Pancreatic diseases
- Acute Pancreatitis
- Biliary Tract Disease
- Choledocholithiasis
- Chronic Pancreatitis
- Early Cystic Fibrosis
- Pancreatic Ascites
- Pancreatic Abscess
- Pancreatic Cancer
- Pancreatic Trauma
- Post ERCP
- Pseudocyst
- Gut diseases
- Appendicitis
- Celiac Disease
- Gastric Resection
- Intestinal Obstruction
- Mesenteric Infarct
- Perforated Bowel
- Peritonitis
- Other
- Abdominal Aortic aneurysm
- Burns
- Cerebral Trauma
- Hyperparathyroidism
- Postoperative State
- Increase in salivary amylase
- Salivary diseases
- Salivary gland calculi
- Salivary gland inflammation (e.g. Parotitis)
- Salivary gland radiation
- Salivary gland surgery
- Salivary gland trauma
- Female Genital tract
- Ectopic Pregnancy (Ruptured)
- Fallopian Cysts
- Ovarian Cysts
- Salpingitis
- Tubo-ovarian Abscess
- Malignancies
- Ectopic production (especially esophagus, lungs and ovary)
- Other
- Anorexia Nervosa
- Bulimia
- Nonketotic Acidosis
- Pneumonia
- Increase in both salivary and pancreatic isoenzymes
- Liver diseases
- Cirrhosis
- Hepatitis
- Renal Failure
- Increase in either salivary or pancreatic isoenzyme
- Alcoholism
- Others
- Ketoacidosis
- Extracorporeal Circulation
- Increase in macroamylase
- Macroamylasemia (high serum amylase but low urine amylase)
Drugs that increase the serum amylase levels include:
- Asparaginase
- Aspirin
- Azathioprine
- Captopril
- Cholinergic agents
- Cimetidine
- Clofibrate
- Corticosteroids
- Diuretics (Loop & Thiazide)
- Estrogens
- Ethacrynic acid
- Ibuprofen
- Indomethacin
- Methyldopa
- Nitrofurantoin
- Opiates
- Oral contraceptives
- Pentamidine
- Pentazocine
- Sulfonamides
- Tetracycline
- Valproic acid
- Zalcitabine
Normal or high serum amylase levels may be seen in:
- Relapsing or chronic pancreatitis
- Alcoholism
- Pregnancy
Low levels of serum amylase may be seen in the following conditions
- Cystic fibrosis (advanced)
- Eclampsia
- Hepatic disease or Cirrhosis
- Hypertriglyceridemia (may be falsely low)
- Pancreatic cancer
- Pancreatectomy
- Pancreatic insufficiency
- Renal disease
Drugs that decrease the serum amylase levels include:
- Anabolic steroids
- Citrates
- Fluorides
- Oxalates
- Carroccio A et al. Unexplained elevated serum pancreatic enzymes: a reason to suspect celiac disease.Clin Gastroenterol Hepatol 2006 Apr;4(4):455-9.
- Deprettere AJR et al. Disappearance of Macroamylasemia in a Celiac Patient After Treatment With a Gluten-Free Diet. Journal of Pediatric Gastroenterology and Nutrition. September 2001;33(3):346-8.
- Laboratory Corporation of America® Amylase, Serum. [Homepage on the internet] ©2003[cited 2006 August 2] Available from http://www.labcorp.com/datasets/labcorp/html/chapter/mono/pr000900.htm
- Labtestsonline[Homepage on internet] ©2001-2006 [updated 2002 Nov 26;cited 2006 July 1] Available from http://labtestsonline.org/understanding/analytes/amylase/test.html
- MedlinePlus[Homepage on internet]c2005 [updated 2005 Feb 14;cited 2006 July 1] Available from http://www.nlm.nih.gov/medlineplus/ency/article/003464.htm
- Voudris K et al. Serum total amylase, pancreatic amylase and lipase activities in epileptic children treated with sodium valproate monotherapy. Brain Dev. 2006 May 24; [Epub ahead of print]