Clinical course after stopping lamivudine in chronic hepatitis B patients with lamivudine-resistant mutants.

BACKGROUND: The efficacy of lamivudine therapy in chronic hepatitis B is well established. However, drug-resistant YMDD mutants emerge with extended therapy. This may result in the resurgence of viral replication, the return of hepatitis and histological deterioration. AIM: To study the safety of stopping lamivudine when the drug is no longer effective. METHODS: In the 5-year Asian Lamivudine Study, 34 patients from a single centre were included in this study. They had harboured YMDD mutants for at least 2 years. Lamivudine was discontinued and they were followed up at regular intervals. Clinical symptoms, liver biochemistry and viral serology were monitored. RESULTS: In a median follow-up of 20 months after stopping lamivudine (range, 7-39 months), 20 of the 34 patients (58.8%) had elevated alanine aminotransferase (ALT), 13 patients (38.2%) had elevated ALT one to five times the upper limit of normal and seven patients (20.6%) had an ALT flare (ALT more than five times the upper limit of normal with detectable hepatitis B virus DNA). There was no liver decompensation. ALT flare could be predicted by ALT over twice the upper limit of normal at the time of stopping lamivudine (P = 0.037). CONCLUSIONS: It is relatively safe to stop lamivudine after YMDD mutants have emerged. ALT levels greater than or equal to twice the upper limit of normal at the time of stopping lamivudine have a higher risk for ALT flare.

The role of lamivudine and predictors of mortality in severe flare-up of chronic hepatitis B with jaundice.

Patients with chronic hepatitis B (CHB) may develop severe disease exacerbations (flare) with jaundice, and some may progress to fulminant hepatic failure. Whether early administration of lamivudine can prevent liver failure and mortality is uncertain. We investigated the role of lamivudine treatment in severe hepatitis B virus (HBV) exacerbations. Consecutive patients presented with severe flare-up of HBV (new onset of jaundice plus alanine aminotransferase greater than five times upper limit of normal) treated with lamivudine and historical controls who did not receive lamivudine were studied. All patients had no hepatic encephalopathy on admission. Univariate analysis and multivariate logistic regression were performed on various clinical and laboratory factors for the prediction of mortality. Twenty-eight patients treated with lamivudine and 18 controls were identified. Overall, nine patients died and two other received liver transplants for fulminant hepatic failure. Six of 28 (21.4%) lamivudine-treated patients vs five of 18 (27.8%) controls died or received a liver transplant (P = 0.62). On multivariate analysis, platelet < or = 143 x 10E9/L (odds ratio 22.4, 95% CI 1.8-281.6) and bilirubin > 172 micromol/L (odds ratio 18.4, 95% CI 1.5-228.5) were independent predictors of liver-related mortality. The mortality of patients who had thrombocytopenia and high bilirubin, thrombocytopenia, high bilirubin, and no risk factor were 69.2%, 11.1%, 12.5% and 0% respectively. Hence lamivudine confers no survival benefit to conventional treatment in severe exacerbations of CHB. Patients with thrombocytopenia and high bilirubin should be considered for liver transplantation.

Relationship of clinical and virological factors with hepatitis activity in hepatitis B e antigen-negative chronic hepatitis B virus-infected patients.

To investigate the factors associated with active disease among hepatitis B surface antigen (HBsAg) positive/hepatitis B e antigen (HBeAg)-negative chronic hepatitis B virus (HBV) infection we studied chronic HBV infected patients who had undetectable HBeAg at the first visit. HBV DNA was determined by the cross-linking assay (NAXCOR) and polymerase chain reaction (PCR). Mutations in the core promoter and precore regions and viral genotypes were studied. Clinical outcome of these patients were followed and categorized as: (i) relapse (ALT > 200 IU/L or three times the previous levels); (ii) active hepatitis (elevated ALT < 200 IU/L with concomitant detectable HBV DNA); or (iii) remission. A total of eighty-five patients were followed up for 5.5 +/- 1.0 years. At first visit, 31 (36.5%) patients had elevated ALT levels, 12 (14.1%) had measurable HBV DNA by the cross-linking assay and 26 (30.6%) by PCR. Sixteen (18.8%) patients had hepatitis relapse, 13 (15.3%) had active hepatitis, and 56 (65.9%) remained in remission. Core promoter and precore stop codon mutants were found in 27 and 12 patients, respectively. Eleven and 20 had genotype B and C HBV, respectively. Initial elevated ALT and detectable HBV DNA were associated with active liver disease. Patient demographics, viral mutants or genotypes failed to predict disease activity. Hence, serum ALT and HBV DNA levels offer the best prediction of natural course of HBeAg-negative chronic HBV infection.

Dose range study of pharmacokinetics, safety, and preliminary antiviral activity of emtricitabine in adults with hepatitis B virus infection.

A multicenter, open-label study was performed to evaluate the safety, anti-hepatitis B virus (anti-HBV) activity, and pharmacokinetics of emtricitabine therapy administered once daily for 8 weeks to patients infected with HBV. Clinical and virologic evaluations were completed at the baseline; at 7, 14, 28, 42, and 56 days during treatment; and at 24, 48, and 28 days posttreatment. Forty-nine patients were enrolled in five dose cohorts (doses of 25, 50, 100, 200, and 300 mg, all of which were administered once daily [q.d.]). Peak plasma emtricitabine concentrations occurred within 1.5 h following dosing. Plasma emtricitabine concentrations (maximum concentrations of drug in plasma and areas under the concentration-time curves) increased nearly dose proportionally over the 25- to 300-mg dose range, with relatively small intersubject variabilities. The plasma half-life of emtricitabine ranged from 6 to 9 h. HBV DNA levels were measured by the Digene HBV Hybrid Capture II assay. Viral suppression (reduction in log(10) serum HBV DNA levels) occurred in all dose cohorts. All doses demonstrated potent and rapid antiviral activities, with a trend toward a greater suppression with daily doses of 100 mg or greater. At 2 months, the median change in the serum HBV DNA level from the baseline level ranged from -1.7 log(10) for the 25-mg dose administered q.d. to -3.3 log(10) for the 300 mg dose administered q.d. Emtricitabine was well tolerated over the 2-month dosing period. These results support further clinical development of emtricitabine for the treatment of chronic hepatitis B infection.

Expression of cyclooxygenase-2 in chronic hepatitis B and the effects of anti-viral therapy.

BACKGROUND: Cyclooxygenase-2 may play a role in the development of hepatocellular carcinoma, but the relationship between cyclooxygenase-2 and chronic hepatitis B is unknown. AIM: To investigate the expression and cellular localization of cyclooxygenase-2 in chronic hepatitis B patients and the effects of anti-viral therapy. METHODS: Using immunohistochemistry, in situ hybridization, Western blot and reverse transcription polymerase chain reaction, protein and messenger RNA expression and cellular localization of cyclooxygenase-2 in 35 chronic hepatitis B patients were assessed. Fourteen histologically normal and non-viral-infected livers were used as controls. The cyclooxygenase-2 immunoreactivities of paired liver biopsies from 12 patients receiving anti-viral therapy were compared. RESULTS: Immunohistochemistry and in situ hybridization revealed that cyclooxygenase-2 expression was confined to hepatocytes. Patients with chronic hepatitis B had significantly higher cyclooxygenase-2 expression compared with controls. The cyclooxygenase-2 expression of hepatitis B e antigen-positive and -negative chronic hepatitis B patients was not significantly different, although the necro-inflammatory activity of the latter group was significantly lower. Over-expression of cyclooxygenase-2 in patients with chronic hepatitis B was further confirmed by Western blot and reverse transcription polymerase chain reaction. Twelve hepatitis B e antigen-positive chronic hepatitis B patients received anti-viral therapy: lamivudine in seven and interferon in five. Despite hepatitis B e antigen seroconversion, disappearance of hepatitis B virus DNA in serum, normalization of liver enzymes and a significant reduction in necro-inflammatory activity in all 12 patients, no significant change in cyclooxygenase-2 expression was found. CONCLUSIONS: Chronic hepatitis B is associated with elevated cyclooxygenase-2 levels in hepatocytes, and the over-expression of this enzyme does not reflect inflammatory activity. Up-regulation of cyclooxygenase-2 persists after successful anti-viral therapy.