BACKGROUND AND AIMS: Studies of HBV/HCV dual infection are limited. Most are small, conducted outside the U.S., and compare dual infection with HCV monoinfection. The goal of this study was to characterize HBV/HCV dual infection in a large multiethnic, matched, case-control study of dual infected and HBV-monoinfected patients at two U.S. centers.
METHODS: Using ICD-9 electronic query and chart review, we identified 115 HBV/HCV dual infection patients with serial HBV DNA, HCV RNA, and ALT levels. As a control, 115 monoinfected HBV patients were chosen randomly and matched to cases by age±10 years, gender, Asian vs. non-Asian ethnicity, and study site.
RESULTS: Both groups had similar gender, ethnic, and age distributions: 68% male, 83% Asian, and age 52±14 years. Median follow-up was 33-38 months. More monoinfected patients received HBV antiviral therapy than dual infected patients (43% vs. 24%, P= 0.002). No significant difference was detected between the proportion of monoinfected vs. dual infected patients with ALT above 40 U/L at presentation or during follow-up. Dual infection patients exhibited very little HBV/HCV codominance at baseline and throughout follow up: patients had either HBV viremia with low or absent HCV RNA or detectable HCV RNA with low or absent HBV DNA. Asian ethnicity was predictive of HBV dominance after adjusting for gender, age, and baseline ALT elevation (OR = 7.35, P= 0.01).
CONCLUSION: HBV/HCV dual infected and HBV monoinfected patients generally had similar clinical characteristics. Asian ethnicity is a major independent predictor of HBV-dominant disease, and HCV dominance with undetectable HBV DNA is more common in non-Asians. Larger studies are needed to further characterize the natural history of HBV/HCV dual infection in Asians and non-Asians.