Long-Term Stopping Therapy T.B. Trung 1 , P.H. Phiet 1 1 University Medical Center, Hochiminh City, Vietnam Background: Among the approved nucleos(t)ide analogues therapies for chronic hepatitis B, lamivudine was used widely, sometime inappropriate in practice due to high safe and low price but lamivudine is associated with the highest rate of drug resistance. Objectives: the aim of the study was to determine the YMDD variants after long-term stopping treatment in lamivudine-resistant patients using more sensitive technique. Methods: 16 blood samples from lamivudine resistant patients were collected after long-term stopping therapy. The YMDD variants are detected using technique PCR Restriction Fragment Length Polymorphism (PCR-RFLP) at HCMC University Medical Center Results: After stopping lamivudine treatment 25 months (6-72 months) YMDD mutants were detected in 14 (87,5%) of 16 patients. Among them 13 (92.9%) had the most important M204V/I mutant, 1(7 1%) had accompanying L180M mutant. It means that once drug resistant mutants have been selected, they are archived for the long time even if treatment is stopped. Many of patients have the features characterized for the patients in immune tolerance phase (young age, HbeAg positive, normal ALT). The treatment of this group is not strongly recommended due to low efficacy and high risk of drug resistance. Conclusion: The most important M204V/I mutant was still detected with significant portion of the virus population after long-term stopping therapy in lamivudine resistant patients. The options of retreatment for this patients when necessary are limited due to cross-resistance. The management of chronic hepatitis B should be followed strickly the recommendations of specialized association to avoid this problem. Background/Aim: Whether liver stiffness measurement (LSM) using transient elastography is reliable to assess liver fibrosis in the settings of severe acute exacerbation of chronic hepatitis B (CHB) is uncertain. Methods: We prospectively recruited consecutive patients with severe acute exacerbation of CHB (alanine aminotransferase or ALT >10x upper limit of normal). The relationship of ALT levels and LSM were serially assessed and liver biopsy was performed after ALT normalization. Results: Eleven patients (10 male, median age 43 years) were followed up for 25 weeks; 9 patients received anti-viral therapy. Overall, LSM was positively correlated with ALT levels (r=0.67, P<0.001). At initial presentation, the median serum ALT and LSM was 1136 (581-2210) IU/l and 26.3 (11. 1-33. 3) kPa. A progressive reduction in LSM was observed during subsequent visits in parallel with the reduction of ALT levels. Even after the normalization of ALT at week 12, LSM of 9 patients continued to drop at week 25. At the last visit, the median ALT was 27 (11-52) IU/l and LSM was 7.7 (4.7-10.8) kPa. Among the 5 patients who had liver biopsy performed at week 25, 4 patients had F2 fibrosis (LSM 5.7-8.1 kPa) and 1 patient had F3 fibrosis (LSM 8.6 kPa). Conclusions: LSM using transient elastography may misdiagnose liver cirrhosis in patients suffering from severe acute exacerbation of chronic hepatitis B. LSM should be assessed after normalization of ALT levels in order to accurately assess the degree of fibrosis.