- Red top, tiger top, green top or gold top tube
- 5mL venous blood
Alanine aminotransferase (ALT) is an enzyme found in the liver and in smaller quantities in other tissues including kidneys, heart and muscles. When liver cells are damaged, ALT is released and blood levels increase.
ALT may be done to assess liver function in the following conditions:
- Known or possible infection with hepatitis viruses, Epstein Barr Virus or Cytomegalovirus
- Family history of liver disease
- Intake of hepatotoxic drugs
- Evaluation in alcoholism
- Monitoring therapy in patients with liver disease
- Evaluating patients with symptoms suggestive of liver disease such as
- Jaundice
- Dark urine
- Nausea
- Vomiting
- Abdominal swelling
- Unusual gain in weightz
- Abdominal pain
Additional information:
- In normal males, the levels are significantly higher than in normal females
- Independently related to the body mass index of the person
- More sensitive for detecting hepatocellular damage than cholestasis
- ALT values are compared to levels of other liver enzymes like alkaline phosphatase and aspartate aminotransferase to determine the type of liver disease present
- ALT test is more specific than the aspartate aminotransferase (AST) in detecting hepatocellular injury
- In viral hepatitis, the ALT is usually more elevated than the AST (the reverse is typical in alcoholic hepatitis)
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) | |
|---|---|---|
| <1 yr | 6-45 | 0.10-0.77 |
| >1 yr Male | 10-50 | 0.17-0.85 |
| >1 yr Female | 7-35 | 0.12-0.59 |
Note: Obesity often increases ALT levels.
Very high levels of ALT may occur in the following conditions:
- Acute liver damage (e.g. acute viral hepatitis)
- Hepatotoxic drugs
- Lead poisoning
- Necrosis of a large tumor
- Shock
Mild to moderately high ALT levels may be seen in the following conditions:
- Alcohol abuse
- Cytomegalovirus infection
- Hepatotoxic drugs (e.g. statins)
- Hepatitis (Chronic)
- Infectious mononucleosis
- Rapid growth in young children
Slight increases in ALT levels may be seen in the following conditions:
- Burns; Severe
- Cirrhosis
- Exercise; Vigorous
- Hepatocellular carcinoma
- Injections; Intramuscular
- Kidney damage
- Myocardial infarction
- Pancreatic injury
- Polymyositis
- Thyroid disease
- Sometimes, in those with normal livers
Chronically elevated ALT levels maybe seen in the following conditions:
-1 antitrypsin deficiency- Celiac sprue
- Hemochromatosis
- Wilson's disease
Drugs and substances that may cause an increase in ALT levels include:
- Drugs that cause cholestasis
- Amitriptyline
- Anabolic steroids
- Androgens
- Atorvastatin
- Benzodiazepines
- Carbamazepine
- Chlorothiazide
- Chlorpropamide
- Dapsone
- Digitalis
- Erythromycin
- Estrogen
- Ethionamide
- Glipizide
- Gold salts
- Imipramine
- Isoniazid
- Lovastatin
- Mercaptopurine
- Nitrofurans
- Oral contraceptives
- Penicillins
- Phenothiazines
- Phenytoin
- Pravastatin
- Progesterone
- Propoxyphene
- Simvastatin
- Sulfonamides
- Tamoxifen
- Tolbutamide
- Drugs and substances that cause hepatocellular damage
- Acetaminophen (toxic)
- Acetylsalicylic acid
- Allopurinol
- Amiodarone
- Anabolic steroids
- Anticonvulsants
- Asparaginase
- Aspirin
- Azithromycin
- Benzodiazepines
- Bromocriptine
- Captopril
- Cephalosporins
- Chloramphenicol
- Ciprofloxacin
- Clindamycin
- Clofibrate
- Cocaine
- Danazol
- Enflurane
- Ethambutol
- Ethionamide
- Fenofibrate
- Fluconazole
- Fluoroquinolones
- Foscarnet
- Gentamicin
- Glues
- Heparin
- Herbs and homeopathic therapies like
- Chaparral
- Chinese Herbs
- Gentian
- Germander
- Shark cartilage
- Indomethacin
- Interferon
- Interleukin-2
- Ketoconazole
- Levamisole
- Levodopa
- Lincomycin
- Low-molecular weight heparin
- Methyldopa
- Monoamine oxidase inhibitors
- Naproxen
- Nifedipine
- Nitrofurans
- NMDA
- Non-steroidal anti-inflammatory drugs
- Oral contraceptives
- Phencyclidine
- Phenytoin
- Probenecid
- Procainamide
- Quinine
- Ranitidine
- Retinol
- Ritodrine
- Solvents
- Sulfonylureas
- Tetracycline
- Tobramycin
- Verapamil
Low ALT levels maybe seen in:
- Pyridoxine (vitamin B6) deficiency
Drugs that may decrease the ALT levels include
- Cyclosporine
- Interferon
- Lab Tests Online ®. ALT: At a glance. [Homepage on the Internet]. c2006. Updated March 2006. Last Accessed July 7, 2006. Available on http://www.labtestsonline.org/understanding/analytes/alt/glance.html
- Laboratory Corporation of America®. Alanine Aminotransferase. [Homepage on the Internet]. c2003. Updated November 2004. Last Accessed July 7, 2006. Available on http://www.labcorp.com/datasets/labcorp/html/chapter/mono/pr008000.htm
- Larsson A and Tryding N. Is It Necessary to Order Aspartate Aminotransferase with Alanine Aminotransferase in Clinical Practice? Clin Chem 2001; 47:1133-1135.
- MedlinePlus® Medical Encyclopedia. ALT. [Homepage on the Internet]. c2005. Updated February 2005. Last Accessed July 7, 2006. Available on http://www.nlm.nih.gov/medlineplus/ency/article/003473.htm
- NIH Consensus Development Conference Reports and State of the Science Statements: Infectious Disease Testing for Blood Transfusions. To What Extent Does the Alanine Aminotransferase Test Contribute to Transfusion Safety; Should Its Use as in Current Practice Continue or Should Its Use Be Modified?[Homepage on the Internet]. Updated June 2006. Last Accessed July 7, 2006. Available on http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat4.section.14504
- Prati D et al. Updated Definitions of Healthy Ranges for Serum Alanine Aminotransferase Levels. Annals, 2002;137(1):1-10.
- Riberio RM, Layden-Almer J, Powers KA et al. Dynamics of alanine aminotransferase during hepatitis C virus treatment. Hepatology 2003 Aug;38(2):509-17.