African Americans More Likely to Have Normal ALT, Less Fibrosis

While research has shown that African Americans respond less well to interferon-based treatment for hepatitis C, this disadvantage may be partially offset by the fact that this group appears less likely to develop severe fibrosis or cirrhosis.

In a study presented at the recent Digestive Disease Week conference in Los Angeles, researchers aimed to assess the spectrum of liver histopathology among African American patients with various levels of alanine aminotransferase (ALT), and to determine whether the relationship between ALT level and fibrosis is different in African Americans and Caucasians. This is important because information about the relative likelihood of treatment success and of fibrosis progression can influence decisions about disease management.

The study included 581 consecutive U.S. veterans (375 African Americans and 206 Caucasians) with chronic hepatitis C undergoing liver biopsy. All patients also underwent liver imaging and received biochemical and serological tests. The researchers used electronic medical records to determine ALT levels going back as long as 23 years. At the time of biopsy, patients were classified as having persistently normal ALT, currently high ALT, or currently normal ALT but intermittently high ALT in the past. Fibrosis was graded on a scale of 0-6 according to the Ishak staging system.

Results

Approximately half the patients with a normal ALT at the time of biopsy were found to have had elevated ALT on at least one previous test. African American patients with currently high ALT and intermittently high ALT in the past had similar fibrosis scores (2.75 vs 3.1 respectively). These patients also had a similar prevalence of advanced fibrosis (48% and 54%, respectively) and cirrhosis (14% and 19%, respectively). African American individuals with persistently normal ALT had significantly lower fibrosis scores (1.22; P < 0.01), and their cirrhosis prevalence was just 0.8%. The proportion of patients with persistently normal ALT was greater among African Americans than among Caucasians (32% vs 22%; P < 0.05). Among the groups with persistently normal, currently high, and intermittently high ALT, no racial differences were observed with respect to mean fibrosis score or prevalence of advanced fibrosis or cirrhosis.

Conclusion

The researchers concluded that African American hepatitis C patients are more likely than Caucasians to have persistently normal ALT, and that the prevalence of cirrhosis among both African Americans and Caucasians with well-documented persistently normal ALT is negligible.

Thus, they suggested that if long-term follow-up is available for patients with persistently normal ALT, liver biopsy -- with its attendant risk, discomfort, and cost -- may be unnecessary and antiviral therapy may be deferred. "This conservative approach to the persistently normal ALT patient is preferable especially in African Americans with HCV genotype 1 and high viral titer, in whom probability of sustained virological response to interferon and ribavirin is low," they said.

This recommendation should be adopted cautiously, however, since studies have shown that [some patients with persistently normal ALT nevertheless go on to develop advanced fibrosis, cirrhosis, and liver cancer; more research is needed in African Americans and other previously underrepresented groups -- including patients with HIV/HCV coinfection, who appear to progress more rapidly to advanced liver disease.

6/13/06

References
AA Mihas, ML Shiffman, HR Lippman, and others. Low prevalence of advanced fibrosis in African Americans with chronic hepatitis C and persistently normal serum ALT: The case for conservative management. Abstract 550. Digestive Disease Week 2006. May 20-25, 2006. Los Angeles, CA.