Superior response to pegylated interferon and ribavirin in Asians with chronic hepatitis C

Purpose: Reported sustained virological response (SVR) rates in Asians with chronic hepatitis C (CHC) exceed those of other ethnic groups, but differences in body weight across races potentially confound this observed superior response. Our aim was to determine whether Asian race independently predicts SVR within a multicultural clinic setting.

Methods: Patients with genotype 1, 2 and 3 CHC prescribed peginterferon and weight-based ribavirin were included in this retrospective study. Logistic regression was performed to identify factors associated with SVR.

Results: Three-hundred ninety-two patients (BMI 26.9 ± 5.0 kg/m(2), genotype 1 66%, viral load 5.9 ± 0.66 log(10) IU/ml, advanced fibrosis 53%) were included in this study. Caucasians comprised 81%, South Asians 9% and Asians (Non-South) 10%. SVR was achieved by 54% overall, but was highest amongst Asians (Non-South) (79%) compared with South Asians (56%, P = 0.04) and Caucasians (50%, P < 0.001) despite a predominance of genotype 3 infection amongst the South Asians. Asians (Non-South) had the highest SVR rate even amongst those infected with genotype 1 (75%) and those with advanced fibrosis (77%). Independent of viral genotype, Asian (Non-South) race was a strong predictor of SVR (OR 5.10 vs. Caucasians, 95% CI 1.72-17.71, OR 7.84 vs. South Asians, 95% CI 1.62-37.84), as were treatment naïve status (OR 3.85, 95% CI 1.76-8.89), non-diabetic status (OR 3.70, 95% CI 1.30-11.11), non-obesity (OR 2.13, 95% CI 1.06-4.35), peginterferon α2a (2.08 vs. α2b, 95% CI 1.16-3.85), steatosis <10% (OR 2.0, 95% CI 1.05-3.85) and ribavirin exposure (mg/kg/day) (OR 1.13, 95% CI 1.01-1.28).

Conclusion: Asian (Non-South) race is a strong independent predictor of SVR.