Hepatitis B Virus Genotype C Is Associated with More Severe Liver Fibrosis than Genotype B

SUMMARY: Patients with hepatitis B virus (HBV) genotype C are more likely to experienced severe liver fibrosis than those with genotype B, perhaps because they tend to have a longer period of active disease, researchers reported in the December 2009 issue of Clinical Gastroenterology and Hepatology.

By Liz Highleyman

Henry Lik-Yuen Chan from the Chinese University of Hong Kong and colleagues performed a prospective analysis to investigate the relationship between HBV genotype and liver fibrosis progression.

They study included 1106 treatment-naive chronic hepatitis B patients. Slightly less than half (524 patients or 49%) had HBV genotype B and the remainder (582 patients or 51%) had genotype C. Overall, 711 (64%) were older than 40 years, but the mean age of patients with genotype C was a bit higher than that of genotype B patients (41 vs 36 years, respectively).

The investigators estimated fibrosis stage using transient elastography (FibroScan), which uses sound waves to measure liver "stiffness." A validated liver stiffness algorithm was used to define insignificant (absent to moderate) and advanced fibrosis.

Results

	370 patients (34%) were hepatitis B "e" antigen (HBeAg) positive.
	386 participants (35%) had increased serum alanine aminotransferase (ALT) levels.
	Participants with genotype C were significantly less likely to have insignificant fibrosis than those with genotype B (42% vs 55%; P < 0.0001).
	Conversely, genotype C patients were more likely than genotype B patients to have advanced fibrosis (25% vs 19%; P = 0.015).
	The difference in severity of liver fibrosis between the 2 genotypes was most pronounced among patients older than age 40 and among those who were HBeAg negative.
	Among patients who were older than age 40 and HBeAg negative, those with genotype C had higher HBV DNA and ALT levels than those with genotype B.

"Genotype C HBV was associated with more severe liver fibrosis than genotype B HBV," the study authors concluded, suggesting that this was "probably because of delayed HBeAg seroconversion and prolonged active disease" in the genotype C group.

Department of Medicine and Therapeutics, Institute of Digestive Disease, Chinese University of Hong Kong, Hong Kong SAR, China.

12/15/09

Reference
HL Chan, GL Wong, CH Tse, and others. Hepatitis B Virus Genotype C Is Associated With More Severe Liver Fibrosis Than Genotype B. Clinical Gastroenterology and Hepatology 7(12): 1361-1366 (Abstract). December 2009.