What laboratory tests should be ordered for individuals with a history of alcoholism?

Laboratory Testing for Individuals with Alcoholism

For patients with alcoholism, obtain liver function tests (AST, ALT, GGT, alkaline phosphatase, bilirubin, albumin, prothrombin time), complete blood count with MCV, comprehensive metabolic panel including electrolytes and creatinine, and consider screening for viral hepatitis (HCV, HBV, HIV) in at-risk individuals. 1, 2

Essential Liver Function Tests

Aminotransferases and Enzyme Patterns

• AST and ALT levels should be measured, with an AST/ALT ratio >1.5-2.0 being highly suggestive of alcoholic liver disease, particularly when AST is elevated but rarely exceeds 300 IU/ml 1, 2, 3
• Gamma-glutamyl transpeptidase (GGT) is the most widely used marker, detecting 34-85% of problem drinkers, though its lack of specificity limits general screening utility 1, 4
• Alkaline phosphatase should be measured; a GGT/alkaline phosphatase ratio >1.4 has 78% specificity for alcoholic liver injury 4
• The combination of elevated GGT with AST provides better diagnostic accuracy than either marker alone 1, 5

Hepatic Synthetic Function

• Albumin, bilirubin, and prothrombin time/INR assess hepatic synthetic capacity and help identify advanced liver disease 1, 6
• Hypoalbuminemia and hyperbilirubinemia correlate with alcohol intake severity 3
• Albumin/globulin ratio is significantly decreased in alcoholic liver disease 3

Hematologic Testing

Complete Blood Count

• Mean corpuscular volume (MCV) is commonly elevated in chronic alcohol use and should be measured 1, 2, 5
• Platelet count may be decreased, indicating advanced liver disease or direct alcohol toxicity 1, 6
• Hemoglobin and RBC count assess for anemia from multiple potential causes in alcoholics 6, 3
• Neutrophilia may be present, particularly in alcoholic hepatitis 1

Metabolic and Electrolyte Assessment

• Comprehensive metabolic panel including glucose, electrolytes (sodium, potassium, chloride, bicarbonate), blood urea nitrogen, and creatinine 1, 6
• Magnesium and phosphate levels, as disturbances are common in alcoholic patients 6
• Uric acid may be elevated 6, 3

Screening for Viral Coinfections

• Anti-HCV testing is essential, as hepatitis C and alcohol have a synergistic relationship resulting in more advanced liver disease than either alone 1
• HBsAg and anti-HBc for hepatitis B screening, particularly in endemic populations 1
• Anti-HIV testing in at-risk individuals, as 6-13% of HIV-infected persons are coinfected with HBV, and coinfection affects liver disease progression 1
• Anti-HDV in persons from countries where hepatitis D is common or those with injection drug use history 1

Additional Considerations

Fibrosis Assessment

• Non-invasive fibrosis markers should be used to screen for advanced liver disease 1
• Liver biopsy via transjugular route may be needed when diagnostic uncertainty exists or precise staging is required 1

Monitoring Abstinence

• Ethyl glucuronide (EtG) in urine or hair can accurately monitor abstinence 1
• GGT levels recover slowly following alcohol cessation and can be monitored every 2-4 weeks initially 7

Hepatocellular Carcinoma Screening

• Alpha-fetoprotein (AFP) at baseline and ultrasound in high-risk patients 1

Common Pitfalls to Avoid

• Do not rely on GGT alone due to poor specificity; it can be elevated by enzyme-inducing drugs, obesity, and non-alcoholic conditions 1, 5, 4
• Normal transaminases do not exclude alcoholic liver disease, particularly early steatosis 2
• Patients commonly underreport alcohol consumption; use structured questionnaires like AUDIT alongside laboratory testing 1
• AST/ALT ratio <1.0 suggests acute liver injury from other causes, while >1.0 is characteristic of alcoholic hepatitis 3