Occult HBV Coinfection Associated with Poorer Response to Hepatitis C Treatment

Occult, or hidden, coinfection with hepatitis B virus (HBV) may worsen liver disease progression and decrease the effectiveness of hepatitis C treatment, according to a study published in the August 2007 Journal of Medical Virology.

Occult HBV is common in people with chronic hepatitis C, but its significance and consequences are still poorly understood. The present study aimed to evaluate the prevalence of occult HBV among chronic HCV patients and to assess its impact on liver histology and response to antiviral therapy.

The researchers collected data from a cohort of 203 patients in France who had chronic hepatitis C without hepatitis B surface antigen (HBsAg). Despite the lack of detectable HBsAg, serum HBV DNA was detected using a highly sensitive polymerase chain reaction (PCR) with primers located in the S and X genes. HBV viremia levels were further determined by real-time PCR.

Results

• 47 of 203 patients (23%) patients had occult HBV infection with a low HBV viral load (102 to 104 copies/mL), but significantly higher HCV RNA levels (P < 0.05).

• No significant differences in age, sex, serum ALT level, HCV genotype, or presence of anti-HBc antibodies were observed between patients with or without occult HBV.

• Patients with occult HBV infection had higher histological activity scores (A2-A3 in 53% vs 38%; P < 0.01) and more advanced liver fibrosis (60% vs 33%; P < 0.001) than patients without detectable HBV DNA.

• 11 of 40 treated patients (28%) with occult HBV achieved sustained response to combination therapy for chronic hepatitis C, compared with 65 of 144 (45%) patients without undetectable HBV DNA (P < 0.05).

• Among the 144 HCV patients without undetectable HBV DNA, those with HCV genotype 1 responded less frequently to therapy as compared to those with other genotypes (38% vs 55%; P < 0.05).

• Surprisingly, however, when considering all patients studied, irrespective of HBV DNA status, there was no significant observed difference with regard to genotype in response to combination anti-HCV therapy (39% vs 44%; P > 0.05).

Conclusion

In conclusion, the authors wrote, "HBV DNA is found in 1/4 of French chronic hepatitis C patients regardless of the presence of anti-HBc. Such an occult HBV coinfection is associated with more severe liver disease, higher HCV viral load and decreased response to antiviral therapy irrespective of HCV genotypes."

09/14/07

Reference
S Mrani, I Chemin, K Menouar, and others. Occult HBV infection may represent a major risk factor of non-response to antiviral therapy of chronic hepatitis C. J Med Virology 79(8): 1075-1081. August 2007.

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