Comparison of hepatitis B virus genotypes B and C among chronically hepatitis B virus-infected patients who received nucleos(t)ide analogs: A multicenter retrospective study

Aim: Hepatitis B virus genotype B (HBV/B) has been reported to have less risk of liver cirrhosis and hepatocellular carcinoma (HCC), but long-term observation has rarely been reported. We aimed to clarify the characteristics of HBV/B in nucleos(t)ide analog-treated patients in an area where HBV/B is more prevalent than in other areas of Japan.

Methods: A total of 498 chronically HBV-infected patients treated with nucleos(t)ide analog (lamivudine, entecavir, tenofovir disoproxil fumarate, or tenofovir alafenamide fumarate) for >6 months (mean 70.6 months) were included from nine hospitals in northeast Japan. The frequencies of hepatitis B surface antigen loss and HCC occurrence were analyzed.

Results: Among 427 patients whose genotype could be determined, 34.0% and 64.4% were infected with HBV/B and genotype C (HBV/C), respectively. The age of patients with HBV/B was significantly older than those with HBV/C (57.7 vs. 48.1). The cumulative rate of hepatitis B surface antigen loss was significantly higher in HBV/B than in HBV/C (3.6% vs. 0.7% at 10 years). Among 480 patients without HCC history, HCC occurrence was found in 40 patients (13.4% at 10 years). There was no cumulative rate difference of HCC occurrence among the genotypes, but after propensity score matching for age/sex, it was significantly lower in HBV/B than in HBV/C (5.3% vs. 18.5% at 10 years).

Conclusions: Although a lower rate of HCC occurrence in HBV/B was shown by an age/sex-matched analysis than that in HBV/C, patients with HBV/B were significantly older and had a comparative risk of HCC occurrence in nucleos(t)ide analog-treated patients.