Absence of pretreatment markers that predict the emergence of YMDD mutants during lamivudine treatment--the results of a prospective multi-center study.
OBJECTIVE
The emergence of YMDD mutants in patients who are treated with lamivudine may determine the clinical prognosis. However, currently there are no clinical or virological factors that predict specifically the emergence of the mutants.


METHODS
To define these factors, we analyzed 69 patients with chronic hepatitis B infection who were treated with lamivudine (LAM) and followed prospectively for at least 12 months.


RESULTS
Of the 69 patients, 12 (17.4%) developed YMDD mutants up to 12 months after the start of LAM. The incidence of YMDD mutants was slightly higher in those who were younger, had higher HBV DNA titers, lower ALT levels, genotype C, and mutations in the core promoter before treatment. However, we could not find any significant factors that correlated with the appearance of the mutants.


CONCLUSIONS
Currently, using conventional virological assays, it is difficult to predict the development of mutants before LAM treatment. Management of flare-ups of hepatitis, due to the appearance of mutants, should always be envisaged when LAM treatment is started.
Yano
Masahiko
M
Gastroenterology Division, Graduate School of Niigata University, Japan.
Ohkoshi
Shogo
S
Suzuki
Kenta
K
Ito
Shin-ichi
S
Wakabayashi
Hiroto
H
Sugiyama
Motoya
M
Watanabe
Toshiaki
T
Maeda
Hironobu
H
Hatakeyama
Shige-aki
SA
Hatano
Tohru
T
Kobayashi
Yuka
Y
Takei
Shin-ichi
S
Kohjiro
Hata
H
Tsuboi
Yasunori
Y
Takahashi
Tohru
T
Ishikawa
Tohru
T
Kamimura
Tomoteru
T
Ichida
Takafumi
T
Aoyagi
Yutaka
Y
D000328:Adult; D020816:Amino Acid Motifs / Q000235:genetics*; D005260:Female; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*
D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine