Therapy may not be necessary for asymptomatic autoimmune hepatitis
Aug 15, 2005 - 9:07:38 PM
It is not uncommon for patients with autoimmune hepatitis (AIH), a disease in which the patient's own immune system attacks the liver, to have no symptoms. Such cases are being diagnosed more frequently due to the increased practice of administering routine liver enzyme and antibody tests. Whether or not to treat asymptomatic AIH remains unclear--therapy with immunosuppressants could potentially slow progress of the disease but involves side effects that are sometimes toxic.
In order to determine if immunosuppressive therapy is indicated when no symptoms are present, researchers led by Jordan J. Feld, M.D. of the Departments of Medicine and Pathology at the University Health Network of the University of Toronto, compared the natural course of asymptomatic AIH with symptomatic AIH.
The study included 124 patients diagnosed with AIH at the Toronto Western Hospital Liver Clinic between 1970 and 2002 31 of whom were asymptomatic. Researchers reviewed the patients' clinical records to document the presence or absence of symptoms. Patients were considered asymptomatic if they were free of all symptoms, even non-specific ones such as fatigue or abdominal pain. Immunosuppressive therapy was recommended for all symptomatic patients, while asymptomatic patients were not treated, unless treatment had already been initiated. Patients who developed symptoms during the study period were started on immunosuppressive therapy. If they remained in remission for two years with no relapse the therapy was discontinued, but it was restarted if the disease recurred off treatment.
The results of the study indicated that asymptomatic patients had lower liver enzyme and IgG antibody levels, as well as lower scores on the hepatic activity index (HAI), which measures liver inflammation, but otherwise did not differ from patients with symptoms. Half of the asymptomatic patients ended up receiving treatment either because it was already started by their physicians or because they eventually developed symptoms. "Our data suggest that it may be safe to follow asymptomatic patients with a strategy to institute immunosuppressive treatment if symptoms develop over time," the authors state, although they note that patients with no symptoms were less likely to respond to treatment than those that had symptoms.
Notably, the current study also showed that patients who had cirrhosis when diagnosed had a worse outcome than those that did not, with a higher incidence of complications or death. Treatment is normally initiated in asymptomatic patients because it is thought to prevent the development of cirrhosis, but whether this is the case remains unclear. Other studies have been inconclusive in this area and based on the current study the authors conclude: "Most [asymptomatic] patients will not develop symptoms during follow-up and they appear to do well without immunosuppressive therapy at least for as long as they remain asymptomatic."
Although the authors note that the results should be considered with caution due to the limited number of patients who underwent liver biopsy, they conclude that severe OSA, independent of being overweight, is a risk factor for liver disease. In addition, they postulate that OSA may contribute to insulin resistance and fatty liver disease, since insulin responsiveness improves after treating OSA. They suggest that the striking relationship between the severity of sleep apnea and liver damage indicates that OSA may play a role in how fatty liver disease develops.
In conclusion, the authors state, OSA is a risk factor for abnormal liver enzymes independently from BMI, and should be investigated in patients without other cause of liver disease. They conclude: Further studies are needed to assess the prevalence of OSA in patients with NASH [nonalcoholic steatohepatitis, or fatty liver disease with inflammation] and to evaluate whether treatment of OSA may improve liver injury.
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