From the Guidelines
Elevated Alanine Transaminase (ALT) in a teenage woman is most likely caused by hepatocyte injury, which can be due to various factors such as nonalcoholic fatty liver disease (NAFLD), viral hepatitis, medication effects, autoimmune hepatitis, or alcohol consumption, as indicated by the most recent study 1.
Causes of Elevated ALT
The causes of elevated ALT can be categorized into several groups, including:
- Hepatocellular injury, which can be caused by viral hepatitis, medication effects, or autoimmune hepatitis
- Nonalcoholic fatty liver disease (NAFLD), which is a spectrum of fat deposition and hepatic inflammation followed by fibrosis due to metabolic insults
- Alcohol-induced liver disease, which is caused by excess alcohol consumption
- Other rare causes, such as alpha1-antitrypsin deficiency, Wilson disease, and hemochromatosis
Normal ALT Values
Normal ALT values typically range from 7-55 U/L for females, though reference ranges may vary slightly between laboratories, as stated in the study 1.
Evaluation of Elevated ALT
If a true elevation in ALT were present, further evaluation would be needed to determine the underlying cause, including a thorough medical history, physical examination, and additional laboratory tests, such as hepatitis panel, autoimmune hepatitis panel, and imaging studies, as suggested by the study 1.
Importance of ALT in Liver Disease
ALT is an enzyme primarily found in liver cells, and when these cells are damaged, ALT is released into the bloodstream, causing elevated levels, as explained in the study 1.
Screening for NAFLD
The study 1 suggests that using ALT as a screening tool for NAFLD, a threshold of 30-40 IU/L can achieve a sensitivity of 50% and specificity of 90%, meaning that half of those with NAFLD can be detected, while 1 out of 10 would have a false positive screening result.
From the FDA Drug Label
WARNINGS Liver warning: This product contains acetaminophen. Severe Liver damage may occur if you take • more than 6 caplets in 24 hours, which is the maximum daily amount • with other drugs containing acetaminophen • 3 or more alcoholic drinks everyday while using this product
The FDA drug label suggests that elevated Alanine Transaminase (ALT), indicating liver damage, may be caused by:
- Taking more than the recommended dose of acetaminophen
- Taking acetaminophen with other drugs containing acetaminophen
- Consuming 3 or more alcoholic drinks everyday while using acetaminophen 2
From the Research
Causes of Elevated Alanine Transaminase (ALT) Levels
Elevated ALT levels in a teenage woman can be caused by various factors, including:
- Nonalcoholic fatty liver disease (NAFLD) or metabolic dysfunction-associated steatotic liver disease (MASLD) 3, 4, 5
- Alcoholic liver disease 3, 4, 5
- Drug-induced liver injury 3, 4, 5
- Viral hepatitis (hepatitis B and C) 3, 4, 5, 6
- Hereditary hemochromatosis 3, 4, 5, 6
- Alpha-1 antitrypsin deficiency 3, 4, 5, 6
- Autoimmune hepatitis 3, 4, 5, 6
- Wilson disease 3, 4, 5, 6
- Extrahepatic conditions such as thyroid disorders, celiac disease, hemolysis, and muscle disorders 3, 4, 5, 7
Evaluation of Elevated ALT Levels
The evaluation of elevated ALT levels should include:
- Initial laboratory testing such as complete blood count, blood glucose, lipid profile, hepatitis B surface antigen, hepatitis C antibody, serum albumin, iron, total iron-binding capacity, and ferritin 3, 4, 5
- Assessment for metabolic syndrome and insulin resistance 3
- Nonalcoholic fatty liver disease fibrosis score and the alcoholic liver disease/nonalcoholic fatty liver disease index 3
- FIB-4 Index Score or NAFLD Fibrosis Score to predict fibrosis risk 4
- Hepatic ultrasonography and further testing for uncommon causes if initial testing is unremarkable 3, 5
- Referral to a hepatologist if necessary 4, 5