OBJECTIVES: During treatment of chronic hepatitis B with lamivudine, changes in the level of hepatitis B virus (HBV) DNA were investigated using a real-time polymerase chain reaction (PCR) method with a detection limit of 1.7 log copies/ml (50 copies/ml) to clarify its clinical significance, particularly the association between HBV DNA levels and the emergence of tyrosine-methionine-aspartate-aspartate (YMDD) mutants. METHODS: Twenty-four patients who had received lamivudine therapy for >1 yr were studied. HBV DNA levels were determined using transcription-mediated amplification for sera with >3.7 log genome equivalents/ml, the Roche Monitor kit for sera with >/=2.6 log copies/ml, and real-time PCR for sera with < 2.6 log copies/ml (the detection limit was 1.7 log copies/ml). Patients were classified into three groups according to the minimal HBV DNA level attained during lamivudine therapy: the <1.7 log copies/ml group (eight patients), the 1.7-2.5 log copies/ml group (five patients), and the >/=2.6 log copies/ml group (11 patients). RESULTS: Pretreatment HBV DNA levels were significantly lower in the <1.7 copies/ml group than in the other two groups (p < 0.05). Neither the emergence of YMDD mutants nor a virological breakthrough of serum HBV DNA was observed in any of the eight patients in the <1.7 copies/ml group. In contrast, in the 1.7-2.5 copies/ml and >/=2.6 copies/ml groups, virological breakthroughs resulting from the emergence of YMDD mutants were observed in two of five patients and in all 11 patients, respectively (p < 0.001). Virological breakthroughs were observed at a mean of 49.6 +/- 18.4 wk in 11 the patients in the >/=2.6 copies/ml group and at wk 107 and 115 in two patients in the 1.7-2.5 copies/ml group. CONCLUSIONS: The real-time PCR method is useful for predicting the emergence of YMDD mutants and the estimated time of their emergence.
OBJECTIVES: During treatment of chronic hepatitis B with lamivudine, changes in the level of hepatitis B virus (HBV) DNA were investigated using a real-time polymerase chain reaction (PCR) method with a detection limit of 1.7 log copies/ml (50 copies/ml) to clarify its clinical significance, particularly the association between HBV DNA levels and the emergence of tyrosine-methionine-aspartate-aspartate (YMDD) mutants. METHODS: Twenty-four patients who had received lamivudine therapy for >1 yr were studied. HBV DNA levels were determined using transcription-mediated amplification for sera with >3.7 log genome equivalents/ml, the Roche Monitor kit for sera with >/=2.6 log copies/ml, and real-time PCR for sera with < 2.6 log copies/ml (the detection limit was 1.7 log copies/ml). Patients were classified into three groups according to the minimal HBV DNA level attained during lamivudine therapy: the <1.7 log copies/ml group (eight patients), the 1.7-2.5 log copies/ml group (five patients), and the >/=2.6 log copies/ml group (11 patients). RESULTS: Pretreatment HBV DNA levels were significantly lower in the <1.7 copies/ml group than in the other two groups (p < 0.05). Neither the emergence of YMDD mutants nor a virological breakthrough of serum HBV DNA was observed in any of the eight patients in the <1.7 copies/ml group. In contrast, in the 1.7-2.5 copies/ml and >/=2.6 copies/ml groups, virological breakthroughs resulting from the emergence of YMDD mutants were observed in two of five patients and in all 11 patients, respectively (p < 0.001). Virological breakthroughs were observed at a mean of 49.6 +/- 18.4 wk in 11 the patients in the >/=2.6 copies/ml group and at wk 107 and 115 in two patients in the 1.7-2.5 copies/ml group. CONCLUSIONS: The real-time PCR method is useful for predicting the emergence of YMDD mutants and the estimated time of their emergence.
Authors: M J Espy; J R Uhl; L M Sloan; S P Buckwalter; M F Jones; E A Vetter; J D C Yao; N L Wengenack; J E Rosenblatt; F R Cockerill; T F Smith Journal: Clin Microbiol Rev Date: 2006-01 Impact factor: 26.132
Authors: Jean-Michel Pawlotsky; Geoffrey Dusheiko; Angelos Hatzakis; Daryl Lau; George Lau; T Jake Liang; Stephen Locarnini; Paul Martin; Douglas D Richman; Fabien Zoulim Journal: Gastroenterology Date: 2007-11-28 Impact factor: 22.682