What is the treatment for Polyarteritis nodosa (PAN) in a patient with Hepatitis B virus (HBV) infection?

From the Guidelines

The treatment of Hepatitis B virus (HBV) positive Polyarteritis nodosa (PAN) should involve a dual approach targeting both the viral infection and the inflammatory vasculitis, with antiviral therapy and immunosuppressive therapy being the cornerstone of treatment. The recommended regimen includes antiviral therapy with entecavir 0.5 mg daily or tenofovir 300 mg daily to suppress HBV replication, combined with immunosuppressive therapy consisting of glucocorticoids (typically prednisone 1 mg/kg/day, maximum 60-80 mg daily) and cyclophosphamide (2 mg/kg/day orally or 500-750 mg/m² IV monthly for 6 months) 1.

Key Considerations

• Plasma exchange (3-5 sessions over 5-10 days) may be added in severe cases with life-threatening manifestations, although its benefit is unclear in non-HBV associated PAN 1.
• Antiviral therapy prevents HBV reactivation that could occur with immunosuppression, while the immunosuppressants rapidly control the inflammatory vasculitis.
• Regular monitoring of liver function, HBV viral load, renal function, and clinical symptoms is essential throughout treatment 1.
• Patients should be monitored for potential side effects of both antiviral and immunosuppressive medications, including renal toxicity, bone marrow suppression, and opportunistic infections.

Treatment Approach

• The dual approach is necessary because HBV is the driving factor behind the vasculitis in HBV-PAN, and suppressing viral replication helps control the immune complex-mediated inflammation.
• Once remission is achieved (usually within 3-6 months), glucocorticoids should be tapered gradually while maintaining antiviral therapy long-term.
• Plasmapheresis, corticosteroids, and potentially other immune-suppressive drugs during the initial phase can be useful in addition to NA therapy in special cases 1.

From the Research

Treatment Strategies for HBV Positive Polyarteritis Nodosa

• The treatment of HBV-related polyarteritis nodosa (PAN) typically involves a combination of antiviral agents, corticosteroids, and plasma exchanges 2, 3, 4, 5, 6.
• Antiviral agents, such as lamivudine, vidarabine, and interferon-alpha, are used to reduce the production of HBV antigens and achieve hepatitis B early antigen (HBeAg) seroconversion 2, 3, 4, 5, 6.
• Corticosteroids, such as prednisone, are used to diminish inflammation, but their use must be carefully managed to avoid facilitating viral replication and the development of chronic HBV infection 2, 3, 4, 5, 6.
• Plasma exchanges are used to reduce the level of circulating immune complexes, but their effect has not been evaluated in controlled trials 2, 3, 4, 6.

Clinical Characteristics and Outcome

• HBV-PAN is a typical form of classic PAN, characterized by immune-complex deposition with antigen excess 6.
• The clinical characteristics of HBV-PAN include renal involvement, renal vasculitis, and the absence of antineutrophil cytoplasmic antibodies (ANCA) 6.
• The outcome of HBV-PAN is generally good, with a high rate of remission and a low rate of relapse, especially in patients who achieve HBe-anti-HBe seroconversion 3, 4, 5, 6.
• The major cause of death in HBV-PAN is gastrointestinal tract involvement 6.

Impact of Treatment

• The antiviral strategy, which combines an antiviral agent with plasma exchanges, facilitates seroconversion and prevents the development of long-term hepatic complications of HBV infection 6.
• The use of antiviral agents, such as lamivudine and interferon-alpha, has been shown to improve the outcome of HBV-PAN, with a higher rate of remission and a lower rate of relapse 3, 4, 5, 6.
• The frequency of HBV-PAN has decreased in recent years, likely due to improved blood safety and vaccination campaigns 6.