Nonalcoholic steatohepatitis
From Medical-Wiki
Persistently abnormal liver function tests (LFTs) are often a difficult clinical problem. Alcoholism used to be the primary cause of hepatitis and cirrhosis. Hepatitis C has replaced alcoholism in that regard. Hepatitis C may also be mediated such that it does not rapidly proceed to a need for liver transplant. However, both alcoholism and hepatitis C carry a social stigma, and obtaining an accurate history can be difficult.
Complicating these realities is the condition of nonalcoholic steatohepatitis (NASH). This disease closely resembles alcoholic liver disease but occurs in patients who consume little or no alcohol. It is also accompanied by no symptoms. Thus, a circumstance can arise where a patient without symptoms, who does not drink, is accused of being an alcoholic and then submitted to a test involving a needle that is five inches in length being plunged into his or her abdomen to substantiate his or her history.
Common sense and tact must accompany the assessment of NASH.
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Clinical presentation of Nonalcoholic fatty liver disease
Nonalcoholic fatty liver disease (NAFLD) used to be called “fatty liver disease.” It is the replacement of at least 5% of the liver with fat without inflammation and fibrosis of hepatocytes although it may be accompanied by abnormal LFTs.
Primary nonalcoholic fatty liver disease
Primary NAFLD is the result of insulin resistance. It typically occurs in the presence of obesity, type-2 diabetes, and dyslipidemia. Nonalcoholic steatohepatitis is thought to be the most severe form of NAFLD. Approximately one third of Americans have NAFLD, and 2-3% of Americans have nonalcoholic steatohepatitis (NASH). NAFLD is associated with obesity, diabetes, and hypertriglyceridemia.
As America has become increasingly obese, the incidence of both NASH and NAFLD has increased. [1]
Long-term morbidity with nonalcoholic fatty liver disease
A 2006 study has raised concern about the supposed benign nature of NAFLD. It looked at 88 patients diagnosed 14 years earlier with NAFLD. An editorial accompanying the article concluded, "... possibly because of the longer follow-up, the authors were able to show that even patients without cirrhosis developed ESLD [end-stage liver disease], thus refuting the claim that non-cirrhotic NASH is 'benign’ ...treating NASH is a major unmet medical need, and ...strategies for screening patients with risk factors for liver disease, including obesity, diabetes and heart disease, should be developed '" [2]
This would tie what has been called “cryptogenic cirrhosis” into NAFLD and NASH. “... ‘cryptogenic’ cirrhosis share(s) many clinical features of patients with NAFLD suggesting that their cryptogenic cirrhosis is in fact the cirrhotic stage of unrecognized NAFLD.” [3]
Diagnosis of nonalcoholic steatohepatitis
The gold standard relative to diagnosis of NAFLD is liver biopsy. However, because of the risks involved in this procedure, close attention must be paid to risks versus benefit, specifically whether or not it will influence the direction of therapy. [4]
What appears to have further confused a past understanding of NAFLD is that the histologic changes necessary for the diagnosis of NASH are unequally dispersed throughout the liver and may not be noted in liver biopsies. In addition, LFTs normalize spontaneously even though the process of fibrosis continues in an unrelenting fashion. These two factors undoubtedly added to the interpretation that NAFLD was essentially a benign process. [5]
Treatment options limited
At present, there is no specific intervention for NAFLD other than those factors that influence the outcome of metabolic syndrome.
Keywords: Nonalcoholic steatohepatitis, (NASH) nonalcoholic Fatty liver disease, (NAFLD), CRYPTOGENIC CIRRHOSIS
