From the Guidelines
Standard laboratory tests used to evaluate Alcohol Use Disorder (AUD) include liver function tests (AST, ALT, GGT), complete blood count (CBC), carbohydrate-deficient transferrin (CDT), ethyl glucuronide (EtG), ethyl sulfate (EtS), phosphatidylethanol (PEth), and blood alcohol concentration (BAC). These tests are essential in assessing the severity of AUD and monitoring treatment progress, as they provide complementary information about recent and chronic alcohol consumption patterns 1. Liver function tests, particularly AST and ALT, indicate liver damage, while GGT is highly sensitive to alcohol consumption and can remain elevated for 2-3 weeks after drinking cessation. CBC may reveal macrocytic anemia due to alcohol's impact on folate metabolism. CDT is a specific marker that remains elevated for 2-4 weeks after heavy drinking. EtG and EtS can be detected in urine for up to 80 hours after alcohol consumption, making them useful for monitoring abstinence. PEth is a highly specific biomarker detectable in blood for up to 3-4 weeks after drinking. It is crucial to interpret these tests together rather than in isolation, as they provide a comprehensive understanding of AUD severity and treatment progress 1. Additionally, quantification of alcohol use, consideration of local standard drink definition, and assessment of drinking patterns, including daily intake and binge drinking, are essential in evaluating AUD 1. The use of alcohol biomarkers, such as PEth, EtG, and EtS, can also aid in the diagnosis and monitoring of AUD 1. The AUDIT questionnaire is a valuable tool in screening for AUD, with scores ranging from 8 to 14 suggesting hazardous or harmful alcohol consumption and a score of 15 or more indicating the likelihood of alcohol dependence 1. Overall, a comprehensive evaluation of AUD should include a combination of laboratory tests, clinical assessment, and screening tools to provide an accurate diagnosis and guide treatment.
From the Research
Standard Laboratory Tests for Evaluating AUD
The following laboratory tests are used to evaluate Alcohol Use Disorder (AUD):
- Liver function tests, including:
- Serum Bilirubin
- Total Proteins
- Aspartate Amino Transferase (AST)
- Alanine Amino Transferase (ALT)
- Alkaline Phosphatase (ALP)
- Gamma Glutamyl Transferase (GGT)
- Mean Corpuscular Volume (MCV)
- Blood glucose levels
- Carbohydrate Deficient Transferrin (CDT) 2, 3, 4
- Disialo-carbohydrate-deficient transferrin (%dCDT) 5
Sensitivity and Specificity of Laboratory Tests
The sensitivity and specificity of these tests vary:
- %CDT has a high sensitivity and specificity (84% and 92% respectively) for diagnosing alcohol abuse 2
- GGT has a lower sensitivity and specificity (64% and 72% respectively) compared to %CDT 2
- MCV has a low sensitivity and specificity (48% and 52% respectively) for diagnosing alcohol abuse 2
- %dCDT has a higher sensitivity than GGT and breath test for detecting heavy drinking, but is not adequately sensitive to detect heavy drinking (missing 34-59% of the cases) 5
Additional Tests
Other tests that may be useful in evaluating AUD include: