• normal persons
• persons with essentially inactive (though even severe) hepatocellular liver disease (normal does not rule out chronic hepatitis C or any type of cirrhosis)
• acute viral hepatitis essentially never normal

• those nutritionally deficient in pyridoxine (vitamin B6)
• women taking oral contraceptives may get B6 deficit
• renal failure on hemodialysis may get B6 deficit

• NASH, NAFLD (steatosis, steatohepatitis): ALT usually > AST and ALT only rarely higher than 4x upper limit normal³
• liver-cell injury (acute hepatic injury): AST:ALT ratio usually <1.0 because ALT is higher unless systemic and/or mitochondrial poisoning/injury as in alcoholic injury (ratio often >2.0 and Reye's syndrome
  • acute viral hepatitis usually >10x upper limit normal³
  • elevation plus thrombocytopenia...think of:
    • HELLP syndrome of pregnancy
    • TTP
    • borreliosis (e. g. Lyme disease...due to Borrelia burgdorferi).
    • rickettsioses (e. g. Rocky Mountain Spotted Fever...due to Rickettsia rickettsii).
    • anaplasmataceoses (e. g. Human Monocytic Ehrlichiosis)
      • monocyte cytoplasmic "morula" inclusions in cytoplasm (E. chaffeensis)...CBC buffy coat smear.
      • neutrophile inclusions (E. ewingii & A. phagocytophilum)...CBC buffy coat smear.
  • medications: acetaminophen, NSAIDs, antibiotics, ACE inhibitors, inhibitors of hydroxymethylglutaryl-coenzyme A¹
  • normal to barely elevated in sinusoidal & portal-based liver disease (such as idiopathic portal hypertension)
  • autoimmune hepatitis elevations almost always associated with serum globulins elevated at least 2x upper limit of normal³
• >500 U/L with ALP <3x uln (upper limit of normal) is a combination typical of acute widespread liver cell injury¹; and see next list item.
• >10,000 U/L seen in acute ischemic injury due to shock (hypotension) or acute cardiac failure (LDH elevated), acute acetaminophen OD (LDH not elevated, anion gap elevated, and renal damage), and acute HSV hepatitis (LDH not elevated)¹
• 10% of cases of celiac disease^{1, 2, 3, 6}
• hyperthyroidism¹
• hypothyroidism¹
• transient elevations following laparoscopic cholecystectomy¹
• rare instances of stable elevated levels due to circulating serum enzyme-immunoglobulin complexes (macroenzyme) in otherwise-healthy persons¹

References:

1. Burke, MD, "Liver function: test selection and interpretation of results", Clinics In Laboratory Medicine, 22:377-390, 2002.(EBS's office)

2. Bardella MT, Vecchi M, Conte D, et al. Chronic unexplained hypertransaminasemia may be caused by occult celiac disease. Hepatology 1999;29:654-7.

3. Cleveland Clinic CME website

4. Stone JH, et. al., Human Monocytic Ehrlichiosis, JAMA 292(18):2263-2270, 10 Nov. 2004.

5. hepatic lab tests, Practice Guidelines, National Academy of Clinical Biochemistry (NACB), USA.

6. Presutti RJ, et. al. of Mayo Jacksonville, "Celiac Disease", American Family Physician 76(7):1795-1802, 12/15/07.

(posted 26 April 2002; latest addition1 August 2007)