Immune effects of alpha-interferon in chronic liver disease

Efficacy of pegylated interferon α2a in patients without HBeAg loss after the withdrawal of long-term lamivudine therapy

Background

Improving the HBe seroconversion rate of patients without HBeAg loss after long-term lamivudine therapy has become an urgent clinical problem that we have to face. Unfortunately, there is no consensus on the mananement of these patients. The aim of this study was to evaluate the efficacy of pegylated interferon (PEG-IFN) α2a in patients without HBeAg loss after the withdrawal of long-term lamivudine therapy.

Methods

Fifty patients with chronic hepatitis B without the loss of HBeAg after ≥96 weeks of lamivudine treatment were enrolled to withdraw from treatment to induce a biochemical breakthrough. Patients who achieved a biochemical breakthrough within 24 weeks received 48-weeks of PEG-IFN α2a therapy, and were then assessed during a subsequent 24-week follow-up period.

Results

Forty-three (86.0%) patients achieved a biochemical breakthrough within 24 weeks of lamivudine withdrawal. The rates of combined response (both undetectable HBV DNA and HBeAg loss) and HBsAg loss were alone 51.2% and 20.9%, respectively after 48 weeks of PEG-IFN α2a therapy, and 44.2% and 18.6%, respectively, at 24 weeks after treatment cessation. The end-of-treatment combined response rate was 65.4% among patients with a baseline HBsAg <20,000 IU/mL, which was significantly higher than 29.4% of patients with HBsAg ≥20,000 IU/mL (P=0.031). For patients with HBsAg levels <1,500 IU/mL at 12 and 24 weeks therapy, the end-of-treatment combined response rate was 68.2% and 69.0%, which were both significantly higher than patients with HBsAg ≥1,500 IU/mL (33.3% and 14.3%; P=0.048 and 0.001). The end-of-treatment combined response rate was significantly higher among patients with HBV DNA<10⁵ copies/mL (76.2%) compared to patients with HBV DNA ≥10⁵ copies/mL (27.3%) after 24 weeks of therapy (P=0.004).

Conclusion

Retreatment with PEG-IFN α2a was effective and safe for patients without HBeAg loss after the withdrawal of long-term lamivudine therapy. HBsAg levels at the baseline, 12 and 24 weeks of therapy, and HBV DNA levels at 24 weeks of therapy, can predict the effect of PEG-IFN α2a after 48 weeks of therapy.

Effect of nucleoside analog-interferon sequential therapy on patients with acute exacerbation of chronic hepatitis B

AIM

Nucleoside analog (NA)-interferon (IFN) sequential therapy may enable the long-term control of chronic hepatitis B (CHB) and the withdrawal of the nucleoside analog. We evaluated the efficacy of NA-IFN sequential therapy for acute exacerbation of CHB.

METHODS

A total of 12 patients with acute exacerbation of CHB, nine of whom were positive for hepatitis B e antigen (HBeAg), were enrolled in this study. All the patients were treated with lamivudine 100 mg/day alone for 20 weeks, then with both IFN-alpha 6 megaunits three times per week and lamivudine for 4 weeks, and lastly, with IFN-alpha alone for 20 weeks. Patients whose serum alanine aminotransferase (ALT) level was normalized, whose serum hepatitis B virus (HBV) DNA level decreased to less than 5 log copies/mL, and HBeAg level was absent 24 weeks after the end of treatment were defined as having sustained virological response (SVR). The other patients were defined as having no response (NR).

RESULTS

Four out of nine (44.4%) HBeAg-positive and all three HBeAg-negative patients achieved SVR. The levels of serum alanine aminotransferase (ALT), HBV DNA and HBV core-related antigen were similar between SVR and NR patients at baseline. Three of four patients (75.0%) whose serum HBeAg became negative at the end of treatment achieved SVR, while one of five (20.0%) whose serum HBeAg remained positive achieved SVR.

CONCLUSION

NA-IFN sequential therapy for patients with acute exacerbation of CHB enables the withdrawal of treatment and is particularly effective for patients whose serum HBeAg has become undetectable by the end of the IFN treatment.

Benefits and risks of interferon therapy for hepatitis B

Alpha interferon is the only licensed drug for hepatitis B with immunomodulatory as well as viral inhibitory properties. Potential advantages of interferon compared to nucleoside analogs include a lack of drug resistance, a finite and defined treatment course, and a higher likelihood for hepatitis B surface antigen (HBsAg) clearance. Approximately 30% of hepatitis B e antigen (HBeAg)-positive and 40% of HBeAg-negative cases have a sustained virological response (when defined as HBeAg seroconversion and/or hepatitis B virus (HBV) DNA levels below 20,000 copies/mL, respectively) 6 months after completion of a 48-week course of peginterferon alfa-2a These responses remain durable in 80% and 50% of cases, respectively, when evaluated several years later. Recent studies have shown that changes in HBsAg and HBeAg concentration during treatment predict sustained virological response and serial monitoring of HBsAg is helpful in predicting HBsAg clearance. HBeAg-positive patients with genotype A have higher rates of HBeAg and HBsAg clearance, whereas HBeAg-negative patients with genotype D have the lowest rate of response to interferon therapy. Long-term follow-up of virological responders to either standard alpha interferon or peginterferon has demonstrated a progressive increase in the rate of HBsAg clearance, particularly in patients who were initially HBeAg-positive. Future studies need to address if specific virological benchmarks during therapy can be used to tailor treatment duration.

CONCLUSION

Peginterferon alfa has a place as first-line therapy of hepatitis B in patients who are carefully selected on the basis of pretreatment serum HBV DNA and aminotransferase levels, safety considerations, and viral genotype.

Hepatitis B: reflections on the current approach to antiviral therapy

This article summarizes the current state of antiviral therapy of hepatitis B with special attention given to areas that remain controversial or poorly defined. Strict adherence to liver association practice guidelines may result in missed opportunities to treat patients with significant underlying liver disease. In particular, recommended ALT thresholds may not appropriately reflect disease activity or degree of fibrosis. There is growing evidence that an alternative treatment paradigm for preventing late-stage disease complications may be indicated in highly viremic patients with early life exposure to hepatitis B. Pegylated interferon therapy is often a better choice for young to middle-aged patients with genotype A and B because of the higher rate of HBeAg seroconversion and a greater chance for HBsAg seroconversion in both HBeAg-positive and -negative patients as compared to nucleoside analogs. Nucleoside analog monotherapy is the current standard of care for many patients. However, long-term monotherapy results in resistance to a variable degree and sequential monotherapy may result in multi-drug resistant virus. Which patients would specifically benefit from early combination therapy also remains poorly defined. The rapidity and robustness of the suppression of HBV DNA while on a nucleoside analog should be monitored relatively early during treatment because it affects treatment outcome and the rate of resistance. While great progress has been made in treating hepatitis B, many important issues require further study.

Clinical and immunological efficacy of intradermal vaccine plus lamivudine with or without interleukin-2 in patients with chronic hepatitis B

To evaluate therapeutic immunostimulation nine chronic hepatitis B patients received six monthly intradermal vaccinations with HBsAg in combination with daily lamivudine. Another five patients received six doses of the vaccine and daily lamivudine together with daily Interleukin-2 (IL-2) s.c. within 3 months in an open-labeled trial. Clinical efficacy was assessed by alanine transaminase levels and HBV serology. The induction of specific T and B cell responses was analyzed serially by 3H-thymidine uptake, ELISA and ELISPOT assays. After the therapy was stopped, seven of nine vaccine/lamivudine and two of five vaccine/lamivudine/IL-2 recipients did not have detectable HBV DNA. Four complete responders cleared the virus and had normalized ALT levels, however, one of these patients showed transient disease reactivation followed by spontaneous viral clearance and normal ALT five months later. Low frequencies of anti-HBs producing B cells and HBV specific T helper cells secreting predominantly interferon-gamma were induced by i.d. vaccine therapy. The ELISPOT technique demonstrated transient induction of HBV peptide specific cytotoxic T cells in seven HLA-A2 positive chronic HBV carriers. The preliminary data from this study demonstrate that the HBV surface antigen vaccine in combination with antiviral or immunomodulating drugs induced antiviral immune responses and consequently viral elimination may be achieved in patients with unfavorable prognosis.

Variations of serum IgG subclass levels in hepatitis C virus infection during interferon-alpha therapy

Serum IgG1 levels are selectively increased in patients with chronic hepatitis C virus (HCV) infection. In 15 patients who received interferon (IFN)-alpha therapy, serum levels of immunoglobulin classes and IgG subclasses were measured during treatment and after it was discontinued. In spite of important individual variations, mean IgG, IgG1, IgA and IgM levels decreased during therapy and tended to return to pre-treatment levels afterwards, with no detectable correlation with clinical and biological parameters. These results suggest an effect of IFN-alpha on in vivo immunoglobulin production, in HCV carriers.

Effects of interferon-alpha treatment on hepatitis B virus antigen-specific immunologic responses in patients with chronic hepatitis B

Studies were undertaken to evaluate the relationship between the immune responses and the effectiveness of interferon-alpha treatment in 21 patients with HBeAg-positive chronic active hepatitis. Peripheral blood mononuclear cells (PBMC), obtained on four occasions during an 8-week course of IFN-alpha therapy, were cultured with recombinant HBcAg, purified HBeAg or pokeweed mitogen (PWM). During follow-up for 6 months after therapy, clearance of serum HBeAg was observed in eight patients designated as responders. Immunological responses of PBMC obtained before treatment did not differ between responders and non-responders. In responders, IFN-gamma and anti-HBc production was depressed during therapy, but recovered to above the pretreatment level at the end of and/or after cessation of therapy, while lymphocyte proliferation was enhanced during therapy with a subsequent decline to baseline value. In non-responders, such changes were modest throughout the study, and anti-HBc response remained decreased even after cessation of therapy. These results indicate that PBMC of responders have immunologically different responses to IFN-alpha therapy when compared with non-responders.

Alpha-interferon combined with immunomodulation in the treatment of chronic hepatitis B

Interferon has profound anti-viral, anti-proliferative and immunomodulatory effects. Future studies should be directed at observing how the immunomodulatory effects predict a response in certain groups of patients. Interferon is very useful in chronic hepatitis B but may require the addition of a steroid pulse. Individuals with low serum ALT appear to benefit most from a steroid pulse. Therapy should be given with a great deal of caution in patients with decompensated liver disease, as one may precipitate the untimely demise of the patient even though viral replication is decreased. One of the patients in the IFN study in fact did have decompensation after prednisone therapy, which subsequently led, a couple of months later, to a variceal haemorrhage. In summary, in treating hepatitis B viral infection, no single agent is totally effective and perhaps the combination of suppressing viral replication and augmenting the immune system is the optimal way to eradicate the virus. At present, an adequate response is found in only about 30-40% of patients even with 'optimal' therapy.

Effects of recombinant leukocyte interferon on serum immunoglobulin concentrations and lymphocyte subpopulations in chronic hepatitis B

To investigate immune effects of interferon (IFN) therapy in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, serum immunoglobulin concentrations and peripheral lymphocyte subpopulations were sequentially studied before, during, and after therapy in nine patients who were treated with recombinant human alpha-IFN in doses ranging from 3 to 10 million units per day for 28 days. Serum immunoglobulin A levels decreased significantly, from 414 +/- 23 mg/dl (mean +/- SE) to 379 +/- 28 mg/dl (P less than 0.05), after the first week of therapy and to a bottom value of 323 +/- 20 mg/dl (P less than 0.001) at the fourth week. Immunoglobulin G levels decreased significantly, from 2603 +/- 175 to 2328 +/- 169 mg/dl (P less than 0.005), after the first week of therapy and to a bottom value of 2005 +/- 199 mg/dl (P less than 0.001) at the fourth week. Immunoglobulin M levels were also reduced significantly after 3 weeks of therapy (from 229 +/- 23 to 188 +/- 15 mg/dl; P less than 0.01). These reductions in immunoglobulins A, G, and M returned to pretreatment levels by 4 months after the end of the therapy.(ABSTRACT TRUNCATED AT 250 WORDS)