Withdrawal reaction from Janus kinase inhibitor manifesting as hepatitis B virus outbreak: a case report.

This letter reports a case of a 60-year-old Chinese woman with rheumatoid arthritis who experienced a hepatitis B virus (HBV) outbreak after discontinuing treatment with a Janus kinase inhibitor (tofacitinib) and methotrexate. The patient had previously tested negative for HBV and had normal liver function tests during treatment. The abrupt discontinuation of the immunosuppressive medications led to the activation of HBV and severe liver dysfunction. The authors suggest that clinicians should avoid abruptly discontinuing JAK inhibitor therapy to prevent fulminant hepatitis and further research is needed to determine effective corticosteroid dosages for managing withdrawal reactions. [Extracted from the article]