Alcohol-Related Liver Disease Diagnostics

Laboratory Tests and Ancillaries

Lab Tests  

With regards to liver function tests (LFTs), there is a noted elevation of the ALT and ALT, with AST>ALT usually 2 times the upper limit of normal. An AST:ALT ratio of >1.5 gives a likely diagnosis of ALD. If the ratio is ≥3, this is strongly suggestive of ALD. Alkaline phosphatase and gamma-glutamyl transpeptidase (GGT) (>100 U/mL) are both usually elevated; the latter is a marker for the detection of previous alcohol consumption. Elevated AST and GGT levels indicate recent excessive alcohol use. It is also noted that total bilirubin is >3 mg/dL and the albumin <3 g/L. Lastly, prothrombin time (PT) may be prolonged; this may be used in determining prognosis of patients with alcoholic hepatitis.  

Alcohol biomarkers include urine ethyl sulfate, urine and hair ethyl glucuronide, and phosphatidylethanol (PEth). These are direct markers for alcohol consumption which aid in the diagnosis and support recovery. Measurement of urine or hair ethyl glucuronide can accurately monitor abstinence.  

Different metabolic alterations may be present such as hyperglycemia, hypertriglyceridemia, hyperuricemia, and even electrolyte abnormalities. Hematologic abnormalities may also be present. For example, macrocytic anemia may be seen in as much as 75% of cases. Thrombocytopenia may also be present which may only be transitory; persistence may be due to progression to cirrhosis. Leukocytosis may also be present which is a leukemoid reaction in the absence of infection.  

The Child-Pugh classification is a scoring system that may be utilized that uses various lab tests such as albumin level, PT, international normalized (INR), bilirubin level, presence of ascites and encephalopathy severity to determine evidence of hepatic dysfunction.

Liver Biopsy  

It must be noted that that liver biopsy is rarely needed to establish the diagnosis of ALD. However, it may be used to clarify atypical cases or uncertain diagnosis, determine if any concomitant disease is present, establish stage and severity of the disease and define the prognosis, and to aid in therapeutic decision making.  

Infectious Disease Work-up  

Infectious disease work-up may also be done including blood tests, sputum cultures, urinalysis and urine culture, ascitic fluid cell counts and culture, and hepatitis serology. 

Imaging

Transient elastography measures liver stiffness in the evaluation of liver fibrosis of ALD. Other imaging studies like ultrasound, computed tomography (CT) scan, or magnetic resonance imaging (MRI) cannot document alcohol as the etiology of the liver disease but can help in ruling out other causes of abnormal test results such as biliary obstruction, infiltrative and neoplastic liver diseases.  

Steatosis can be identified on ultrasonography, CT, and MRI with ultrasound having the lowest sensitivity and specificity, while MRI is more accurate in quantifying fat.

Alcohol-Related Liver Disease_Diagnostics