Liver failure due to recombinant alpha interferon

Severe acute exacerbation of chronic hepatitis B during pegylated interferon treatment and early intervention with corticosteroid

Severe acute exacerbation or liver failure induced by standard interferon-α(IFN-α) therapy had been reported to occur in few patients with chronic hepatitis B. However, no report showed that pegylated interferon-α therapy was able to induce severe acute exacerbation of chronic hepatitis B. Here, we describe three patients with severe acute exacerbation of chronic hepatitis B during pegylated interferon-α2a (Pegasys) treatment. One patient progressed into acute-on-chronic liver failure (ACLF) at the second week of Pegasys treatment. Two patients progressed into acute-on-chronic pre-liver failure (pre-ACLF) at the second and eighth week of Pegasys treatment, respectively. Three patients recovered after early combined intervention with corticosteroid and lamivudine. Our data indicated that there was a risk of severe acute exacerbation among patients with chronic hepatitis B during receiving Pegasys treatment. Importantly, early combined intervention with corticosteroid and lamivudine should be introduced to prevent the disease progression and improve their prognosis once severe acute exacerbation was diagnosed.

Antiviral drugs for viruses other than human immunodeficiency virus

Most viral diseases, with the exception of those caused by human immunodeficiency virus, are self-limited illnesses that do not require specific antiviral therapy. The currently available antiviral drugs target 3 main groups of viruses: herpes, hepatitis, and influenza viruses. With the exception of the antisense molecule fomivirsen, all antiherpes drugs inhibit viral replication by serving as competitive substrates for viral DNA polymerase. Drugs for the treatment of influenza inhibit the ion channel M(2) protein or the enzyme neuraminidase. Combination therapy with Interferon-α and ribavirin remains the backbone treatment for chronic hepatitis C; the addition of serine protease inhibitors improves the treatment outcome of patients infected with hepatitis C virus genotype 1. Chronic hepatitis B can be treated with interferon or a combination of nucleos(t)ide analogues. Notably, almost all the nucleos(t) ide analogues for the treatment of chronic hepatitis B possess anti-human immunodeficiency virus properties, and they inhibit replication of hepatitis B virus by serving as competitive substrates for its DNA polymerase. Some antiviral drugs possess multiple potential clinical applications, such as ribavirin for the treatment of chronic hepatitis C and respiratory syncytial virus and cidofovir for the treatment of cytomegalovirus and other DNA viruses. Drug resistance is an emerging threat to the clinical utility of antiviral drugs. The major mechanisms for drug resistance are mutations in the viral DNA polymerase gene or in genes that encode for the viral kinases required for the activation of certain drugs such as acyclovir and ganciclovir. Widespread antiviral resistance has limited the clinical utility of M(2) inhibitors for the prevention and treatment of influenza infections. This article provides an overview of clinically available antiviral drugs for the primary care physician, with a special focus on pharmacology, clinical uses, and adverse effects.

Hepatic reactions during treatment of multiple sclerosis with interferon-beta-1a: incidence and clinical significance

BACKGROUND

Hepatic dysfunction, manifested as liver enzyme elevations, occurs frequently in patients who are treated with interferon, however, data for patients with multiple sclerosis are limited.

OBJECTIVE

To retrospectively assess the safety profile of interferon-beta-1a therapy with respect to liver function during clinical trials and postmarketing surveillance in the treatment of multiple sclerosis.

PATIENTS AND METHODS

Adverse effects and laboratory abnormalities were analysed from six randomised, controlled clinical trials (five of which were placebo-controlled) that assessed the use of interferon-beta-1a in patients with multiple sclerosis. Treatment data were collected for 2819 patients for up to 12 months, of whom 1995 received interferon-beta-1a (337 [12%] received Avonex intramuscular therapy, and 1658 [59%] received Rebif subcutaneous therapy), and 824 (29%) received placebo. Data for 2 years were collated for 1178 patients (from two studies). Total weekly interferon doses were 22-132 microg. Postmarketing surveillance data were also analysed.

RESULTS

In patients receiving interferon-beta-1a, there were significant elevations of alanine aminotransferase (ALT) levels, of all grades of severity, in up to 59% of patients at 6 months, up to 64% of patients at 12 months and up to 67% of patients at 24 months; ALT elevations were asymptomatic and dose related. More than 50% of elevations in liver enzymes occurred during the first 3 months of treatment, and more than 75% occurred during the first 6 months. Elevated enzyme levels resolved spontaneously or with dosage adjustment. Although the overall incidence of liver enzyme elevation was high during the early months of therapy, after 2 years, the proportion of patients with abnormal liver enzyme levels was 11% of those receiving Rebif 44 microg three times weekly compared with 6% of placebo-treated patients. Only 0.4% of patients discontinued interferon-beta-1a treatment because of hepatic adverse effects. Serious symptomatic interferon-related hepatic toxicity occurs, but is uncommon. Concomitant medication use was not associated with increased risk.

CONCLUSION

Asymptomatic hepatic dysfunction is common in patients with multiple sclerosis who are treated with interferon-beta-1a, and is dose related. Adverse effects are mainly mild and transient, with little impact on adherence to therapy, although rare serious events can occur. Regular liver function monitoring during the first 6 months is recommended.

Lamivudine treatment in patients with severely decompensated cirrhosis due to replicating hepatitis B infection

BACKGROUND/AIMS

Lamivudine is highly effective in suppressing hepatitis B viral replication and hepatic necroinflammatory activity. The potential for recovery of hepatic decompensation in patients with chronic hepatitis B infection treated with lamivudine has not been established. The aim of this study was to evaluate the effectiveness of lamivudine treatment in severely decompensated cirrhosis due to chronic hepatitis B.

METHODS

Thirteen consecutive patients with chronic hepatitis B infection, Child's-Pugh-Turcotte (CPT) score of > or =10 (median score=11) and detectable circulating hepatitis B DNA (range 15 to 9634 pg/ml) were included and treated with lamivudine 150 mg once daily. Hepatitis B envelope antigen (HBeAg) was positive in 9 of 13 patients pre-treatment.

RESULTS

Two patients underwent liver transplantation at 4 and 6 weeks after starting lamivudine treatment. The remaining 11 patients were followed for a mean of 17.5 months without liver transplantation (range 3 to 39 months). Significant improvement of liver function, defined as a decrease in CPT score of > or =3, was observed in 9 of 13 patients (69%). In five patients, CPT score improved to <7 and they were placed on the inactive status (UNOS status 7) for liver transplantation. Hepatitis B DNA remained negative in all except one patient who developed breakthrough viral replication 12 months after starting lamivudine treatment, while maintaining stable liver function. Three of seven HBeAg-positive patients who did not undergo liver transplantation lost HBeAg during follow-up, but none had sustained seroconversion to hepatitis B e antibody.

CONCLUSION

Lamivudine appears highly effective in reversing severe hepatic decompensation due to replicating hepatitis B infection.

Interferon tau-induced hepatocyte apoptosis in sheep

Clinical applications of Type I interferon (IFN) are limited by adverse side effects mediated largely by unknown mechanisms. This study examined the mechanisms of acute hepatic injury in lambs treated with systemic administration of IFN-tau, a Type I IFN. Liver tissues were collected at 24, 48, or 96 hours after treatment with either IFN-tau or saline. Histopathology revealed acute hepatopathy including cellular swelling, cytoplasmic aggregates, and apoptosis in all IFN-tau-treated lambs, which were accompanied by elevation of aspartate transaminase (AST) (P <.01). The number of apoptotic hepatocytes in IFN-tau-treated lambs was higher than for control lambs (P <.001). Immunohistochemistry for proliferating cell nuclear antigen (PCNA) revealed that IFN-tau induced hepatocyte growth arrest at the G0/G1 phase of the cell cycle and that the majority of hepatocytes in S or G2 phase were eliminated by apoptosis. We investigated expression of bax-alpha and bcl-2, acting as pro- and antiapoptotic molecules, in IFN-tau-induced apoptosis. Northern blot analysis revealed increased expression of bax-alpha messenger RNA (mRNA) in IFN-tau-treated lambs (P <.01) compared with control lambs, consistent with the expression pattern for bax-alpha protein. However, there was no detectable difference in expression of bcl-2 proteins between control and IFN-tau-treated lambs. The levels of bax-alpha associated with the mitochondria also increased during IFN-tau treatment. Bax-alpha immunostaining showed scattered immunoreactive hepatocytes with morphological hallmarks of apoptosis. These results suggest that IFN-tau induces growth arrest as well as apoptosis by regulating bax-alpha expression. These pathological effects of IFN-tau on sheep liver indicate potential mechanisms of Type 1 IFN-induced hepatotoxicity in animals and humans.

Autoimmunity induced by interferon-alpha therapy for chronic viral hepatitis

Type I interferons, which are mostly alpha-interferons (either as single agents or in combination with antiviral drugs), are currently the standard therapy for chronic viral hepatitis B, B/D, and C. Side-effects are not uncommon and include exacerbation of pre-existing autoimmune disorders or the de novo induction of autoimmunity. These adverse effects are attributed to the immunomodulatory properties of type I interferons, and should be distinguished from autoimmunity associated with chronic viral hepatitis in which interferon treatment may indeed be beneficial. The major autoimmune side-effects of interferon therapy for chronic viral hepatitis are thyroid or liver disease. Therefore, screening for thyroid antibodies and auto-antibodies indicative of autoimmune hepatitis both before, during, and after interferon therapy is strongly recommended. The presence of high concentrations of thyroid auto-antibodies or antibodies associated with autoimmune hepatitis can be contraindicative to interferon therapy. However, treatment is not contraindicated in viral hepatitis (in particular chronic hepatitis C) associated with autoimmune phenomena--including low-titer thyroid antibodies or other non-organ specific auto-antibodies. If interferon-induced autoimmunity occurs, the necessity of therapy has to be balanced carefully against the risks of autoimmune disease. Further research is needed to identify the factors which determine susceptibility to interferon-associated autoimmunity in individual patients.

Acute hepatitis induced by alpha-interferon, associated with viral clearance, in chronic hepatitis C

We describe the cases of two patients with chronic hepatitis C who developed acute hepatitis with marked amino-transferase elevations and jaundice 3 and 5 months after initiation of interferon treatment. Hepatitis resolved rapidly after cessation of interferon. No autoantibodies were detected. Hepatitis was followed by viral clearance, demonstrated by clearance of hepatitis C viraemia. We propose that hepatitis may be due to an immune lysis of hepatocytes and suggest that this immune response may contribute to viral clearance.

A survey of adverse events in 11,241 patients with chronic viral hepatitis treated with alfa interferon

AIMS

The aim of this study was to assess the incidence of fatal, life-threatening side effects and the de novo appearance of non-hepatic morbidity during interferon alfa therapy for chronic viral hepatitis. The relationship of these adverse events to actual total dose and duration of interferon was also evaluated.

METHODS

We conducted a retrospective study at 73 Italian centers of 11,241 consecutive patients with chronic viral hepatitis who underwent interferon alfa treatment.

RESULTS

Five patients died during interferon therapy due to liver failure (n = 4) or complications arising from sepsis. Life-threatening side effects were observed in eight patients: two cases where depression developed and led to a suicide attempt and six patients with bone marrow suppression (granulocytes < 500/mm3 or platelets < 25,000/mm3). These symptoms and signs completely disappeared after interferon withdrawal. During interferon treatment, 131 patients developed the following de novo non-hepatic disorders: symptomatic thyroid disease (n = 71), impotence (n = 5), systemic autoimmune disease (n = 5), immune-mediated dermatologic disease (n = 14), diabetes mellitus (n = 10), cardiovascular disease (n = 7), psychosis n = 10), seizures (n = 4), peripheral neuropathy (n = 3) and hemolytic anemia (n = 2). Most of these complications are reversible or can be ameliorated. Fatal or life-threatening side effects were not related to actual total dose or duration of interferon alfa, while the majority of patients with de novo non-hepatic morbidity received medium/high doses (> 200 million units) of interferon alfa or were treated for periods longer than 16 weeks (68% and 80%, respectively).

CONCLUSIONS

Treatment with interferon alfa may have fatal or life-threatening side effects, their incidence in this study being low (0.04% and 0.07%, respectively) and perhaps no different than in untreated patients with chronic viral hepatitis. Moreover de novo non-hepatic morbidity occurred in 1.2% of patients, and the dose and duration of interferon therapy seem important in determining the frequency of this complication. The development of clinically-overt thyroid disease was most common.

Lack of benefit of escalating dosage of interferon alfa in patients with chronic hepatitis C

BACKGROUND & AIMS

In patients with chronic hepatitis C treated with interferon alfa, sustained normalization of alanine aminotransferase was observed in about 20%, and no predictive factor of response could be clearly identified. The aims of this study were to assess the efficacy of an escalating dose of interferon and to determine the predictive factors of response.

METHODS

Seventy-five patients were randomly assigned to two groups. Twenty-five patients received a dosage of 3 million units of recombinant interferon alfa-2b three times weekly for 24 weeks, and 50 patients received a dose that was increased to 5 million units at 8 weeks in nonresponders and to 10 million units 8 weeks later in persistent nonresponders. Multivariate analysis was performed to determine the features associated with response.

RESULTS

A sustained response was observed in 17% of the patients with constant dosage and in 19% of patients with an escalating dosage. Low pretreatment serum hepatitis C virus RNA levels and hepatitis C virus genotype were found to be independent predictive factors of sustained response.

CONCLUSIONS

In patients with chronic hepatitis C, an escalating dosage of interferon did not improve the overall rate of response. Low pretreatment serum hepatitis C virus RNA levels and genotype other than 1b were the only predictive factors of sustained response.

Clinical toxicity of the interferons

Since their initial description in 1957, the interferons (IFNs) have been increasingly used to treat a wide array of diseases. Acute adverse effects, i.e. 'flu-like' syndromes, hypo- or hypertension, tachycardia, headache, myalgias and gastrointestinal disorders, occur within the first hour or day after starting treatment. They are seldom treatment-limiting and are easily manageable. Sub-acute and chronic effects develop after several days, usually within 2 and 4 weeks of therapy. The most typical is neurological toxicity, including fatigue/asthenia, and behavioural and cognitive changes. Such symptoms may seriously impair quality of life and result in treatment discontinuation. Seizures have seldom been described. Other infrequent central nervous system adverse effects include vertigo, cramp and oculomotor nerve paralysis. Distal paraesthesias and peripheral neuropathy have been reported. IFN-associated autoimmunity is quite rare but a matter of concern. Biological or clinical manifestations usually require several months to become apparent. Autoantibodies have been shown to develop in most patients but have been inconsistently associated with clinical symptoms of systemic lupus erythematosus, rheumatoid-like arthritis and thyroiditis. Both hypo- and hyperthyroidism have been described but are usually reversible. Other infrequent autoimmune reactions include diabetes, pemphigus and worsening of multiple sclerosis. Although several patients present with a pre-existing autoimmune disorder, no predisposing factor has been clearly established. While hypotension and tachycardia are the most frequent acute cardiovascular complications, a few additional cases of cardiac arrhythmias and myocardial ischaemia have been reported after a short course or several weeks of treatment. These latter complications do not appear to be dose-dependent or age-related. Isolated cases of congestive heart failure have also been described. Mild proteinuria has been observed in 15 to 25% of patients, but acute renal toxicity is uncommon. A transient rise in serum aminotransferase levels is frequently noted during the first stage of therapy, especially in patients receiving the highest dosages. Direct hepatotoxicity is extremely rare. Autoimmune hepatitis, which is ill-diagnosed as chronic viral hepatitis, and de novo induction of autoimmune hepatitis, account for the majority of liver diseases. Haematotoxicity is relatively common but mild to moderate, and develops gradually during the first weeks of treatment. Neutropenia is the most common haematological toxicity, but is usually not dose-limiting and resolves rapidly upon drug discontinuation. Myelosuppression, autoimmune and immune allergic haemolytic anaemias and thrombocytopenias have seldom been described. Cutaneous adverse effects comprised nonspecific erythema and hair loss and, less frequently, vasculitis, local ulcerations at the site of injection and exacerbation of psoriasis.(ABSTRACT TRUNCATED AT 250 WORDS)