By Liz Highleyman

It is well known that race/ethnicity influences response to interferon-based combination therapy for chronic hepatitis C virus (HCV) infection. Numerous studies have shown that people of African descent -- and possibly Hispanics/Latinos, though data less inconsistent -- do not respond as well as Caucasians; some research has found that Asians may respond better than any other group.

Philip Vutien from Stanford University Medical Center and colleagues compared sustained virological response (SVR) rates among Asian-American and Caucasian patients accurately classified as having HCV genotype 1 or genotypes 2/3 using viral core sequencing.

In some prior studies, Asian patients with genotype 6 -- which responds better to interferon -- were inaccurately classified as having genotype 1 using the less sensitive INNO-LiPA assay, leading to falsely high reported genotype 1 response rates. HCV genotype 6 is predominant in Southeast Asia but rare in the U.S. and Europe.

The researchers analyzed data from a cohort of 269 treatment-naive chronic hepatitis C patients with genotypes 1 or 2/3 treated with pegylated interferon plus ribavirin between 2001 and November 2007 at 4 community-based gastroenterology clinics in Northern California; 157 were Caucasian and 112 were of Asian descent.