Pre- and post-treatment predictors of the early achievement of HBeAg loss in lamivudine-resistant patients receiving adefovir therapy

Prediction of early HBeAg seroconversion by decreased titers of HBeAg in the serum combined with increased grades of lobular inflammation in the liver

Background

Hepatitis B e antigen (HBeAg) seroconversion is an important hallmark in the natural course of chronic hepatitis B. This study was designed to predict early HBeAg seroconversion within 1 year, by not only biochemical and virological markers, but also pathological parameters in patients with chronic hepatitis B.

Material/Methods

In a retrospective cohort study, 234 patients with HBeAg were reviewed for demographic, biochemical, virological and pathological data at the time of liver biopsy. Then, the patients who accomplished HBeAg seroconversion within 1 year thereafter were compared with those who did not, for sorting out factors predictive of early HBeAg seroconversion.

Results

Early HBeAg seroconversion occurred in 58 (24.8%) patients. In univariate analysis, factors predictive of early HBeAg seroconversion were: alanine aminotransferase (ALT) (p=0.002), IP-10 (p=0.029), HBsAg (p=0.003), HBeAg (p<0.001), HBV DNA (p=0.001), HBcrAg (p=0.001), core-promoter mutations (p=0.040), fibrosis (p=0.033) and lobular inflammation (p=0.002). In multivariate analysis, only serum HBeAg levels <100 Paul Ehrlich Institute (PEI) U/ml and grades of lobular inflammation ≥2 were independent factors for early HBeAg seroconversion (odds ratio 8.430 [95% confidence interval 4.173–17.032], p<0.001; and 4.330 [2.009–9.331], p<0.001; respectively).

Conclusions

HBeAg levels < 100 PEIU/ml combined with grades of lobular inflammation ≥2 are useful for predicting early HBeAg seroconversion. In patients without liver biopsies, high ALT levels (≥200 IU/L) can substitute for lobular inflammation (grades ≥2).

Current status of liver diseases in Korea: hepatitis B

Hepatitis B virus (HBV) infection is the one of the most common causes of the liver diseases in Korea. Since the discovery of Australia antigen (hepatitis associated antigen, or HBsAg later), hepatitis associated antigen was tested widely. HBsAg was detected in 6.6-8.6% in 1980's. Later, it decreased to 5.7% in 1990's. Remarkably, seropositivity of the children deceased to 0.2% after the nationwide vaccination program. Although hepatitis B vaccines are highly effective, the failure rate of perinatal prophylaxis in babies born to HBsAg positive mother was reported to be 4.25%. Treatment of chronic hepatitis B was initiated after the introduction of interferon alpha. Lamivudine opened a new era of oral antiviral agent, and it has been widely used in Korea since 1999. Adefovir was proven to have a good efficacy for lamivudine-resistant chronic hepatitis B. Newer potent antiviral agents such as entecavir, clevudine, and telbivudine are available currently. Further studies are warranted for understanding factors influencing natural history, improving treatment outcomes, and overcoming vaccine non-response.

Avoiding and managing lamivudine resistance in chronic hepatitis B: current approaches and potential strategies including pegylated interferon

Since its approval for the treatment of chronic hepatitis B in 1998, lamivudine (LAM) has been used extensively throughout the world, because of its relatively low costs and favourable tolerability. However, clinical trials and cohort studies have demonstrated that a high rate of resistance to this drug develops and, as a result, it is no longer included as a first-line therapy in most current treatment guidelines. Nevertheless, because of its low cost, this drug continues to be used in many countries and the pool of patients who have developed resistance to LAM continues to increase. Thus, there is a clear need to develop coherent management strategies to treat such patients as well as limit the emergence of resistance in the first instance. The purpose of this review is to highlight the need to aim for long-term treatment success while limiting the emergence of drug resistance and its consequences for the future. In addition to add-on/switch strategies with other nucleos(t)ide analogs, currently available data suggest that interferon-based therapies, with their potential to induce a sustained response, are worthy of consideration not only for reducing de novo resistance but as an option for the management of those patients in whom drug resistance has already developed.

New paradigms for the treatment of chronic hepatitis B

The main goals of chronic hepatitis B treatment should be the long-term suppression of viral replication to minimize disease progression and the risk for the development of hepatocellular carcinoma. Treatment end-points, depending on surrogate markers alone, in particular hepatitis B e-antigen seroconversion, may not be ideal for patients who acquire the disease early in life. Currently-available drugs include interferons and oral nucleoside/nucleotide analogs. Although interferon therapy provides a finite treatment period, a significant proportion of patients may not respond, and long-term outcome is inconclusive. Long-term efficacy has been demonstrated for both lamivudine and adefovir. However, prolonged nucleoside/nucleotide analog therapy is associated with the emergence of drug-resistant mutations. Therefore, nucleoside/nucleotide analogs with a high genetic barrier and potent antiviral activity, such as entecavir, should be used to reduce the chance of developing drug-resistant mutations. Drugs with a low genetic barrier, including lamivudine and telbivudine, should be used in conjunction with early testing for antiviral response. This can predict favorable outcomes in the long term. The early detection of drug-resistant mutations should prompt clinicians to either add or switch to another agent with a different drug-resistance profile. There are currently no treatment models in the use of combination or sequential therapy in treatment-naïve patients. To date, long-term treatment appears to be the most effective option. Despite recent advances made with better understanding on the natural history of chronic hepatitis B infection and with newer antiviral drugs available, challenges remain with respect to treatment criteria, treatment end-points, and duration of treatment.