Hepatitis B Virus Genotypes Associated with Treatment Response and Disease Progression
By
Liz Highleyman It
is well known that different hepatitis
C virus (HCV) genotypes are associated with better or worse response to interferon-based
therapy. There is an increasing body of evidence showing that genotype
is important in treatment response and outcomes of hepatitis
B virus (HBV) infection as well. Response
to thymosin alpha-1 In
the December 2006 Journal of Viral Hepatitis, researchers from Taiwan reported
on a study assessing the relationship between HBV genotype and response to treatment
with thymosin alpha-1. The authors retrospectively examined HBV genotypes and
pre-core and core promoter mutations in patients treated with thymosin alpha-1,
and analyzed the relationship between genotype and complete response (defined
as ALT normalization plus sero-clearance of HBeAg and HBV DNA). The
study included 98 chronic hepatitis B patients randomly assigned to 3 arms: 
Group T6 (n = 32) received a 26-week course of thymosin alpha-1 1.6 mg 2 times
weekly.
Group T12 (n = 34) received the same regimen for 52 weeks.
Group T0 (n = 32) served as controls and was followed for 18 months without treatment.
Results
Stepwise logistic regression analysis showed that genotype (OR 3.747; P = 0.039),
pre-core mutation (OR 6.285; P = 0.003), and thymosin alpha-1 treatment (OR 12.045;
P = 0.004) were independently associated with complete response.
Complete response to thymosin alpha-1 occurred more often in patients with HBV
genotype B compared to patients with genotype C (52% vs 24%; P = 0.036), and in
patients with pre-core mutation (64% vs 19%; P = 0.002).
In
conclusion, the authors wrote, "genotype, presence of pre-core mutation and
thymosin alpha-1 therapy were independent predictors to complete response. Genotype
B, compared to genotype C, is associated with a higher response rate to thymosin
alpha-1 therapy." Hepatocellular
carcinoma In
a related study reported in the January 1, 2007 Journal of Infectious Diseases,
researchers with the Alaska Native Tribal Health Consortium in Anchorage, Alaska,
examined the development of hepatocellular carcinoma
(HCC) in patients with chronic hepatitis B, and its association with HBV genotypes
and presence of specific mutations. From
a cohort of Alaska Native people with chronic HBV infection, the researchers obtained
genotypes for 47 patients with HCC and 1129 individuals without HCC; they also
tested participants for mutations in the HBV basal core promoter and pre-core
regions. Results
Genotype F was found in 68% of patients with HCC, compared to 18% of individuals
without HCC (P < 0.001).
For patients with genotype F, the median age at HCC diagnosis was lower than for
patients with other genotypes (22.5 vs 60 years, respectively; P = 0.002).
Overall, there were no significant differences in the number of basal core promoter
or pre-core region mutations between patients with and without HCC.
The
authors concluded, "We found a significant association between genotype F
and the development of HCC among Alaska Native people with chronic HBV infection
but no significant association between HCC and basal core promoter or pre-core
mutations in genotype F." 12/15/06 References R
N Chien, C Y Lin, C T Yeh, and others. Hepatitis B Virus Genotype B is Associated
with Better Response to Thymosin alpha1 Therapy than Genotype C. Journal of
Viral Hepatitis 13(12): 845-850. December 2006.
S E Livingston, J P
Simonetti, B J McMahon, and others. Hepatitis B Virus Genotypes in Alaska Native
People with Hepatocellular Carcinoma: Preponderance of Genotype F. Journal
of Infectious Diseases 195(1): 5-11. January 1, 2007.
Y Tanaka and
M Mizokami. Genetic Diversity of Hepatitis B Virus as an Important Factor Associated
with Differences in Clinical Outcomes. Journal of Infectious Diseases 195(1):
1-4. January 1, 2007. | 
