From the Guidelines
The alcoholic liver enzyme pattern is characterized by an AST:ALT ratio greater than 2:1, with AST levels moderately elevated (2-6 times normal) and ALT levels mildly increased or normal, accompanied by markedly elevated gamma-glutamyl transferase (GGT) levels, as reported in the EASL clinical practice guidelines for the management of alcohol-related liver disease 1. This pattern is highly suggestive of alcoholic liver disease and differs from other liver conditions where ALT is usually higher than AST. The characteristic enzyme pattern occurs because alcohol metabolism depletes mitochondrial NAD+, reducing ALT activity while AST has both mitochondrial and cytosolic forms. Some key features of the alcoholic liver enzyme pattern include:
- Elevated AST levels, often 2-6 times normal
- Mildly increased or normal ALT levels
- Markedly elevated GGT levels
- Elevated alkaline phosphatase in some cases
- Hyperbilirubinemia in advanced disease
- Macrocytic anemia due to folate deficiency The EASL guidelines highlight the importance of considering the pattern of alcohol consumption, including binge drinking, which can accelerate the progression to advanced ALD, as well as host-related factors such as female gender, ethnicity, and obesity, which can influence the risk of developing ALD 1. It is essential to note that the enzyme pattern may vary depending on the stage and severity of the disease, and other liver conditions, such as viral hepatitis or medication-induced liver injury, should be ruled out through further testing and evaluation.
From the Research
Alcoholic Liver Enzyme Pattern
- The liver enzyme pattern in alcoholic liver disease is characterized by elevated levels of certain enzymes, including gamma-glutamyltransferase (GGT), aspartate aminotransferase (ASAT), and alanine aminotransferase (ALAT) 2.
- An ASAT/ALAT ratio greater than 1.5 can be considered highly suggestive of an alcoholic etiology of liver injury 2.
- The ratio of GGT to alkaline phosphatase can also be used to discriminate between alcoholic and nonalcoholic liver disease, with a ratio exceeding 1.4 indicating a high specificity for alcoholic liver injury 2.
- The determination of the mitochondrial isoenzyme of ASAT can also improve the diagnostic value of ASAT determination, with a ratio of mitochondrial isoenzyme to total over 4 being highly suggestive of alcohol-related liver injury 2.
Enzyme Levels and Alcohol Consumption
- The quantity of regular alcohol use is roughly linearly related to GGT and ALT activities 3.
- Binge drinking can result in higher GGT and ALT activities, even in those with low-risk overall consumption 3.
- The pattern of drinking, including binge drinking, should be considered in clinical recommendations for drinking reduction 3.
Diagnosis and Treatment
- Alcohol-associated liver disease is a major cause of liver-related mortality and the leading indication for liver transplant 4.
- The diagnosis of alcoholic liver disease is based on a combination of clinical, laboratory, and imaging findings, including liver enzyme levels 4.
- Treatment of alcoholic liver disease includes abstinence from alcohol, corticosteroid therapy, and liver transplantation in select cases 4.