Lamivudine is effective in suppressing viral replication, normalizing alanine aminotransferase, and improving histological appearance in Hepatitis B e-positive and negative hepatitis.
It is unclear whether Hepatitis B virus genotype influences the response to lamivudine.
Dr Moskovitz and colleagues from Canada investigated the long-term response of lamivudine.
|74% of YMDD mutations detected had no association with a particular genotype|
|Journal of Viral Hepatitis|
The researchers included patients with chronic Hepatitis B with and without cirrhosis at baseline treated with lamivudine according to Hepatitis B genotype.
The research team retrospectively reviewed charts of all patients treated with lamivudine monotherapy between 1993 and 2002.
Response to therapy was defined as alanine aminotransferase in the normal range, and undetectable Hepatitis B DNA.
The team defined response to therapy in the Hepatitis B e antigen positive group as loss of Hepatitis B e antigen and/or the development of anti-Hepatitis B e.
The researchers measured Hepatitis B DNA by the Digene Hybrid capture assay at a sensitivity of 1.4 with 106 copies/mL.
YMDD mutation at rtL180M and rtM204V/I were measured by restriction digest of amplified products.
The researchers performed genotyping by sequencing and phylogenetic tree analysis of the preS region of the virus genome.
The team reported that 71 patients were treated with lamivudine for 6 months or more, of which 53 were male with an average age of 47 years.
The researchers also reported that 38 of the patients were Hepatitis B e antigen-positive and 33 were Hepatitis B e antigen-negative.
The team noted that mean baseline Hepatitis B DNA viral titre was 1280 copies/mL and 518 copies/mL respectively.
Cirrhosis was present in 30 patients.
The researchers examined sera for YMDD mutations at last patient visit in 86%, and were detected in 74%, there being no association with a particular genotype.
The team observed that data from up to 5 years on lamivudine indicated no difference in biochemical or virological response between genotypes.
The research team found that cirrhosis was more prevalent with specific genotypes.
Dr Moskovitz's team concludes , “We found no influence of Hepatitis B genotype on the development of resistance to lamivudine, however liver disease severity was influenced by genotype.”