Alcoholic liver disease overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: M. Khurram Afzal, MD [2]
Overview
Alcohol has existed as early as the Neolithic period, there are many warnings against excessive alcohol consumption in greek literature as well. Alcoholic liver disease is one of the most common preventable causes of death in Western countries. The main cause of alcoholic liver disease is excessive alcohol consumption over a long period of time. The disease spectrum ranges from alcoholic steatosis to alcoholic hepatitis and alcoholic cirrhosis. The most feared complications are hepatic failure and hepatocellular carcinoma. Since the most important cause is alcohol abuse, physicians must have a low threshold to screen patients for abuse, as many alcohol dependent patients will not discuss the problem or may not see it as a problem. Alcoholic steatosis is mostly asymptomatic, and patients may present either with alcoholic hepatitis or fulminant hepatic failure or carcinoma. The cornerstone of therapy for alcoholic liver disease is abstinence, abstinence can reverse alcoholic steatosis, hepatitis as well as fibrosis in some cases.
Historical Perspective
Alcohol has existed as the most abused substance for many centuries. In 1960 alcohol was recognized as a hepatotoxin.
Classification
Alcoholic liver disease may be classified according to histology and symptoms into different subtypes: reversible and irreversible.
Pathophysiology
The pathogenesis of alcoholic liver disease is complex and still remains unclear, the metabolites of the oxidative metabolism in the liver; acetaldehyde and reactive oxygen species are thought to be involved in the toxic effects of ethanol on the liver.
Causes
The primary cause of alcoholic liver disease is excessive consumption of alcohol over a long period of time.
Differentiating Alcoholic Liver Disease from other Diseases
Alcoholic liver disease should be differentiated from other diseases that produce similar symptoms, and other types of liver diseases. It should also be differentiated from diseases of the gallbladder. Conditions that may present in a similar manner to alcoholic liver disease are; cholecystitis, cholelithiasis, drug toxicity, non-alcoholic fatty liver disease, and other forms of hepatitis (eg. viral, autoimmune).
Epidemiology and Demographics
The incidence of alcoholic liver disease is very high among alcoholics, and those who consume excessive amounts of alcohol. It does still depend on the amount and type of alcohol consumed. The mortality rate is high in those who present with alcoholic hepatitis and those individuals whose disease has progressed to cirrhosis. The average age of presentation is between 40 and 50 years. The disease tends to progress faster in individuals of hispanic ethnicity and women are at greater risk of developing alcoholic liver disease than men.
Risk Factors
The most potent risk factor in the development of alcoholic liver disease is alcohol consumption. Other risk factors include female gender, hispanic ethnicity, and genetic factors.
Screening
All patients who present with elevated liver enzymes, signs of liver disease or increased frequency of accidental trauma should be screened for alcohol abuse. Most individuals who consume heavy amounts of alcohol tend to deny it, hence there must be a strong suspicion under these circumstances. Physicians must have a low threshold to screen for alcohol abuse.
Natural History, Complications and Prognosis
Alcoholic liver disease progresses through three stages (steatosis, alcoholic hepatitis, and cirrhosis) with the continued use of alcohol. Serious complications begin to occur with the development of alcoholic hepatitis, when portal hypertension, coagulopathies, and intractable jaundice. Complications of cirrhosis include hepatic encephalopathy and hepatocellular carcinoma. Prognosis varies dependent on level of progression of illness, and whether treatment is given. Prognosis can be measured using laboratory values, and three prognostic scores: the MELD score, the Glasgow Alcoholic Hepatitis Score, and the ABIC score.
Diagnosis
Diagnostic study of choice
The diagnostic study of choice in developing countries for the diagnosis of cirrhosis in alcoholic liver disease is liver biopsy. In developed countries the diagnostic study of choice for cirrhosis is now the FibroScan or transient elastography.
History and Symptoms
History should focus on the history of alcohol use by the patient, and the history of symptoms that may have developed.
Physical Examination
There are certain stigmata associated with alcoholic liver disease that one should look for on physical examination. These include; jaundice, gynecomastia, spider angiomata, bruising, hepatosplenomegaly, ascites, testicular atrophy, asterixis, and palmar erythema. A thorough neurologic and mental status exam should also be done to assess for signs of hepatic encephalopathy, or other neurologic deficits that may be caused by chronic alcohol use.
Laboratory Findings
It is important to take a complete history and find out about the patient's alcohol use and current signs and symptoms for alcoholic liver disease. As laboratory tests do not give the definitive diagnosis of alcoholic liver disease. It is also important to rule out other causes of liver disease such as, chronic viral hepatitis which could co-exist, autoimmune hepatitis, hemochromatosis and drug related hepatotoxicity. Initial assessment must include a complete blood count, hepatic panel (ALT, AST, bilirubin, GGT, alkaline phosphatase), INR and PT.
Electrocardiogram
An ECG may be helpful in the diagnosis of alcoholic liver disease. Findings on an ECG suggestive of cirrhosis include prolonged QTc interval.
X Ray
There are no x-ray findings associated with alcoholic liver disease. However, a chest x-ray may be helpful in the diagnosis of complications of cirrhosis, which include hydrothorax and pneumonia.
CT Scan
Abdominal CT scan may be helpful in the diagnosis of alcoholic liver disease. Findings on CT scan suggestive of hepatic steatosis and cirrhosis may be seen.
MRI
An abdominal MRI may be helpful in the diagnosis of alcoholic liver disease. Findings on MRI can not confirm the cause of the liver disease but they are suggestive of underlying liver disease. An MRI can be expensive as an initial choice of diagnostic study and does not yield any advantages when compared to an ultrasound in the setting of alcoholic steatosis.
Echocardiography/Ultrasound
Echocardiography/ultrasound may be helpful in the diagnosis of alcoholic liver disease.Since ultrasound is a non invasive technique it is used for initial evaluation of the liver. Findings on an ultrasound are suggestive of underlying liver disease but they can not confirm the etiology. However ultrasound can be used to exclude other causes of abnormal liver tests in patients who abuse alcohol; infiltrative disease, neoplastic disease, obstructive biliary pathology, cirrhosis or screen for hepatocellular carcinoma. Echocardiography can be used to detect hepatic cardiomyopathy and the severity of volume overload in cirrhotic patients.
Other Imaging Findings
There have been recent advances towards newer imaging modalities to help detect and quantify hepatic fibrosis and cirrhosis. These investigations are comparable to the gold standard that is liver biopsy to confirm the diagnosis of liver cirrhosis.
Other Diagnostic Studies
Liver biopsy is used to confirm the diagnosis when alcoholic hepatitis is suspected, and to help in guiding medical treatment. Microscopic findings on biopsy that indicate alcoholic hepatitis are: polymorphonuclear infiltration of cells, hepatic necrosis, ballooning hepatocytes, Mallory bodies within cells, and perivenular and perisinusoidal fibrosis.
Treatment
Medical Therapy
The most important part of treatment is to stop using alcohol completely. If liver cirrhosis has not yet occurred, the liver can heal if you stop drinking alcohol. An alcohol rehabilitation program or counseling may be necessary to break the alcohol addiction. Vitamins, especially B-complex and folic acid, can help reverse malnutrition. If cirrhosis develops, there is a need to manage the complications of cirrhosis. It may need a liver transplant.
Surgery
The most important part of treatment is to stop using alcohol completely. If liver cirrhosis has not yet occurred, the liver can heal if you stop drinking alcohol. An alcohol rehabilitation program or counseling may be necessary to break the alcohol addiction. Vitamins, especially B-complex and folic acid, can help reverse malnutrition.
Primary Prevention
Effective measures for the primary prevention of alcoholic liver disease include screening and counseling for alcohol abuse disorder. Physicians must have a low threshold for screening as many patients would not be comfortable about discussing their alcohol dependence.
Secondary Prevention
Effective measures for the secondary prevention of alcoholic liver disease include abstinence. Abstinence can be achieved through drug therapies in an inpatient as well as an out patient setting.