Case report: dramatic response to lamivudine therapy following corticosteroid priming in chronic hepatitis B

Impact of dose and duration of corticosteroid on the risk of hepatitis flare in patients with chronic hepatitis B

BACKGROUND

Systemic corticosteroid is used for different medical conditions and may cause hepatitis B virus (HBV) reactivation.

AIMS

To study the impact of duration and peak dose of corticosteroid on the risk of hepatitis flare in patients with chronic hepatitis B (CHB).

METHODS

All patients who received corticosteroid from January 2001 to December 2004 were retrieved from the Hospital Authority, Hong Kong. We stratified patients by daily dose prednisolone equivalents (<20 mg, 20-40 mg, >40 mg) and durations (<7; 7-28; >28 days). The primary endpoint was hepatitis flare (alanine aminotransferase >2×upper limit of normal, ie 80 IU/L) at 1 year.

RESULTS

A total of 85 763 patients fulfilled the inclusion criteria (5254 CHB, 80 509 non-CHB). CHB patients had higher risk of hepatitis flare (388/5254 [7.8%]) than those without CHB (2728/80 509 [4.2%]; P < 0.001 by log-rank test). Among CHB patients, peak daily dose >40 mg compared to <20 mg prednisolone equivalents (adjusted hazard ratio [aHR] 1.64, 95% CI 1.26-2.14; P < 0.001) was an independent risk factor of hepatitis flare. Risk of hepatitis flare started to increase in those receiving corticosteroid of peak daily dose >40 mg prednisolone equivalents even for <7 days (aHR 1.55, P = 0.026), which was also increased for 7-28 days and >28 days (aHR 1.90 and 1.64 respectively, both P < 0.001).

CONCLUSION

Even short courses of high-dose corticosteroid increase the risk of hepatitis flare in CHB patients. Patients receiving high-dose corticosteroid should be considered for antiviral prophylaxis regardless of the duration of treatment.

Spontaneous HBeAg seroconversion and loss of hepatitis B virus DNA after acute flare due to development of drug resistant mutants during entecavir monotherapy

AIMS

Patients with chronic hepatitis B virus (HBV) infection under entecavir (ETV) treatment develop resistant mutants with viral rebound. Here, we report an interesting case of spontaneous loss of HBV-DNA and seroconversion following an acute flare after the development of ETV-resistant mutants. This patient received ETV after lamivudine breakthrough.

METHODS

Cloning and sequence analysis of the HBV reverse transcriptase (RT) region were performed with seven samples during ETV therapy. In addition, two full-length HBV genomes derived from samples before and after the emergence of ETV resistance were sequenced.

RESULTS

ETV resistant mutants appeared at week 228, with virological and biochemical rebound at the same time. Unexpectedly, HBeAg seroconversion occurred 8 weeks later. The viral load decreased and became undetectable from week 252. Analysis of HBV isolates in the patient at week 124 revealed that wild-type HBV was predominant at that time and ETV resistant mutants were not found among 20 clones. Interestingly, a new mutant type with rtL180M+rtT184L was found alongside rtL180M+rtT184L+rtM204V/I at week 228 and appeared to develop independently, according to the sequence analysis. In contrast to the previously identified ETV resistant mutants, it did not carry the rtM204V/I mutations.

CONCLUSION

The data presented here indicates that the flare following the emergence of ETV resistant mutants may reflect immune-mediated control of HBV infection, leading to a spontaneous loss of HBV-DNA and seroconversion.

Hepatitis B virus reactivation following immunosuppressive therapy: guidelines for prevention and management

It is well known that immunosuppressive drugs or cancer chemotherapy can stimulate replication of hepatitis B virus (HBV) and precipitate severe flares of HBV infection. The risk of this syndrome of 'reactivation hepatitis B' is highest in haematopoietic stem cell or solid organ transplant recipients and in those undergoing chemotherapy for haematological malignancies; however, it has been described following almost any form of immunosuppressive treatment. Fortunately, it can be largely prevented by prophylactic therapy with oral anti-HBV nucleoside/nucleotide analogues. Importantly, chronic HBV infection is usually asymptomatic, and most patients at risk are likely to be unaware that they carry the infection. Thus, the key to avoiding this potentially fatal complication of immunosuppressive treatment is to ensure that all patients at risk of chronic HBV infection are screened for the disease before commencing immunosuppressive treatment or chemotherapy.

Hepatitis B infection in China

Chronic HBV infection is a serious health threat in the Asian-Pacific region. The introduction of lamivudine has greatly improved the hope of these patients and is undoubtly a milestone in the management of chronic HBV infection. The combination of lamivudine with another nucleotide or nucleoside analogue or immunomodulatory agent to improve its therapeutic efficacy further must be investigated. Also, the use of lamivudine to prevent HBV reactivation on withdrawal of immunosuppressive therapy should be explored.

Acute flares in chronic hepatitis B: the natural and unnatural history of an immunologically mediated liver disease

Acute flares in chronic hepatitis B are common and may be caused by a number of identifiable and potentially treatable factors. The common link for many of these exacerbation episodes is a change in the immunologic response to hepatitis B virus (HBV), and this may have no identifiable cause or be triggered by an increase in viral replication or genotypic change. It is important to keep in mind the clinical situations in which patients are at increased risk of reactivated infection and secondary exacerbations. Reactivation is frequently induced by medical treatments such as cancer chemotherapy, antirejection drugs used in organ transplantation, and corticosteroids. The immunologic flares that often result from sudden withdrawal of these medications can be life-threatening unless recognized and treated promptly with antivirals, and there is increasing experience that preemptive antiviral treatment can diminish their occurrence and improve the outcome. The experience with lamivudine and other nucleoside analogues has increased our understanding of the molecular events behind hepatitis flares that occur when chronic hepatitis B is treated with drugs that potently inhibit HBV DNA polymerase. However, not all flares are explainable by events related to HBV infection alone. Depending on the population studied, as many as 20%-30% of flares may be caused by infection with other hepatotropic viruses, and this situation may inhibit HBV replication. Proper understanding of the etiology and effective treatment of acute flares in chronic hepatitis B requires an appreciation of high-risk clinical situations, assessment of HBV replication status, and testing for other viruses when appropriate.

Clinical potential of emerging new agents in hepatitis B

Treatment of chronic hepatitis B is directed at interrupting the natural history and clinical outcomes of the disease. It needs to take into account the virology and replication cycle of the hepatitis B virus (HBV), and the host immune response to HBV. Long term follow-up of patients treated with interferon supports the paradigm that a sustained, major suppression of HBV replication, particularly that associated with hepatitis B e antigen (HBeAg) seroconversion, interrupts the natural history of hepatitis B. The availability of potent but well tolerated and orally available HBV antivirals, of which lamivudine is the prototype, has allowed clearer treatment objectives to be formulated. These are: temporary or permanent reduction of hepatitis (necroinflammatory) activity, arrest of fibrotic progression, prevention of cirrhosis and liver failure, and prevention of recurrent HBV infection after liver transplantation. Lamivudine has good medium term efficacy in achieving each of these objectives. The only significant problem for the longer term is emergence of antiviral resistance conferred by mutations in the YMDD (tyrosine-methionine-aspartic acid-aspartic acid) motif of the HBV reverse transcriptase. As a result, contentious issues remain about defining when antiviral therapy is indicated, whether to treat for a defined interval or indefinitely, and when to stop treatment if HBeAg seroconversion is not achieved. Some personal views are expressed in this review. Among newer HBV antivirals in clinical studies, adefovir dipivoxil, entecavir and emtricitabine appear to be at least as potent as lamivudine in suppressing HBV replication. Famciclovir appears less potent. In vitro studies show that YMDD mutations confer cross-resistance between lamivudine, emtricitabine and beta-L-Fd4C (L-2',3'-didehydro-dideoxy-5-fluorocytidine). However, adefovir dipivoxil, lobucavir, entecavir, DAPD (beta-D-2,6-diaminopurine dioxolane) and possibly clevudine (L-FMAU) suppress replication of YMDD mutant HBV, as well as wildtype. Preliminary studies indicate clinical efficacy of adefovir dipivoxil once resistance to lamivudine has developed. Immunomodulatory approaches to treatment of chronic hepatitis B are conceptually attractive, but newer agents used to date (thymalfasin, interleukin-12, therapeutic vaccines) have not demonstrated sufficient efficacy for widespread use. The next challenge for HBV treatment is to use antivirals in combination and/or in cyclical therapy to reduce the emergence of drug resistance and increase efficacy, particularly to achieve sustainable post-treatment suppression of hepatitis B.

Nucleoside analogues in the treatment of chronic hepatitis B

Many nucleoside analogues have been investigated for the treatment of chronic hepatitis B. Some were withdrawn because of significant adverse effects and some are still in the early stage of clinical assessment. Lamivudine has been demonstrated to have consistent efficacy and safety in large-scale, phase III clinical trials. It has achieved a milestone in the treatment of chronic hepatitis B and is now commercially available in many countries. Being a potent inhibitor of hepatitis B viral replication, it achieved around 18% HBeAg seroconversion in HBeAg-positive patients after 1 year of therapy. HBeAg seroconversion is a good endpoint for therapy and has been shown to be 80% durable. The response was better among patients with raised pretreatment alanine aminotransferase levels. Liver necro-inflammation and fibrosis improved significantly after 1 year. Further improvement on extended therapy was observed together with an incremental increase in HBeAg seroconversion. Similar efficacy was demonstrated in HBeAg-negative viraemic patients. The main drawback is the emergence of drug-resistant variants starting from the sixth to ninth month of treatment. This can be associated with varying degrees of relapse of disease activity and may offset the benefit of therapy. With extended therapy, drug-resistant variants continue to emergence at a rate of around 20% per year. Adefovir dipivoxil and entacavir are nucleoside or nucleotide analogues shown to suppress both the wild-type and lamivudine-resistant virus. Combination of these nucleoside/nucleotide analogues with immune modulators may be the answer to eradicate the virus in short-term therapy and avoid the issue of drug resistance.