Considered more efficacious and safer than traditional systemic
drugs, biologic therapies have dramatically improved the quality of life of patients with
psoriasis. Recently, there has been a proliferation of new targeted treatment options, including anti-interleukin-17, anti-
interleukin-12/23, as well as small-molecule drugs such as
apremilast. There are nevertheless some concerns regarding their use, especially in patients with
chronic infections such as hepatitis B virus (HBV) and hepatitis C virus (HCV). It has been estimated that two billion individuals are infected with HBV worldwide and approximately 240 million have chronic HBV
infection. Moreover, there are approximately 71 million individuals with chronic HCV
infection worldwide, with a high percentage of them unaware of being infected. As patients with HBV and HCV
infections are excluded from controlled clinical trials investigating new drugs, data regarding their safety in patients with
psoriasis are based almost exclusively on case reports and small retrospective cohort studies and need to be constantly updated. The risk of HBV reactivation can be defined as: high risk (≥ 10%), moderate risk (1-10%), and low risk (< 1%) depending on the type of immunosuppressive therapy stratified by the presence or absence of
hepatitis B surface antigen but positivity to anti-
hepatitis B core antigen.
Hepatitis B surface antigen-positive patients treated with
tumor necrosis factor-α inhibitors,
ustekinumab, or
cyclosporine carry a high or moderate risk of HBV reactivation and should be considered candidates for prophylactic anti-HBV
therapy. Once
therapy is commenced, it is important to check HBV
DNA levels every 3 months. Hepatitis B virus reactivation typically occurs with immune reconstitution and therefore
antiviral therapy should continue for 6-12 months after stopping immunosuppression.
Hepatitis B surface antigen-positive patients who are prescribed
methotrexate,
acitretin, or
apremilast have a low risk and need to be monitored for viral reactivation by determining
alanine aminotransferase and HBV
DNA levels every 3 months. No conclusive data are available for
interleukin-17 and
interleukin-23 inhibitors. Anti-
hepatitis B core antigen-positive patients treated with
tumor necrosis factor-α inhibitors,
ustekinumab, and
cyclosporine are linked to a moderate risk of reactivation, and they should preferably undergo HBV
DNA or
hepatitis B surface antigen and
alanine aminotransferase testing rather than be subjected to routine pre-emptive
therapy. Anti-
hepatitis B core antigen-positive patients receiving
methotrexate,
acitretin, or
apremilast have a low risk of reactivation and do not require anti-HBV
therapy, nor should monitoring be considered mandatory. No conclusive data are available for
interleukin-17 and
interleukin-23 inhibitors.