A recent systematic review of the literature has confirmed that biologic therapies can reactivate hepatitis B virus (HBV) in patients with plaque psoriasis.  Although the study found that any prior HBV exposure was associated with the risk for viral reactivation, patients with chronic HBV were far more likely to experience reactivation than those with evidence of HBV exposure but without hepatitis. Antiviral prophylaxis greatly reduced the risk for viral reactivation in the chronic HBV cohort.  The study’s findings underscore the importance of screening all patients with psoriasis for HBV infection before prescribing a biologic drug or other immunosuppressive therapy.

Clinicians typically favor newer biologic agents for managing patients with psoriasis with liver dysfunction because they are less hepatotoxic than older immunosuppressive agents such as methotrexate and cyclosporine.  Classes of biologic agents used to treat psoriasis include tumor necrosis factor (TNF)-α inhibitors and monoclonal antibodies that block various interleukins (ILs). 

Studies in patients with chronic HBV and rheumatoid arthritis or Crohn disease have linked TNF-α inhibitors to a high risk for HBV reactivation.  The mechanism behind HBV reactivation is unclear, although evidence from vitro and in vivo studies suggests blocking TNF-α compromises the immune system’s ability to clear the virus.  Inhibition of TNF-α may also enhance HBV replication.

Read more…https://www.infectiousdiseaseadvisor.com/hepatitis-advisor/biologic-psoriasis-therapies-pose-limited-risk-for-hepatitis-b-reactivation/article/764835/