Development of Diffuse Large B Cell Lymphoma in a Patient with Systemic Lupus Erythematosus within Two Years after the Initiation of Anifrolumab and Mycophenolate Mofetil Treatment

Anifrolumab is a newly developed biological agent for patients with moderate-to-severe systemic lupus erythematosus (SLE). Anifrolumab neutralizes the signaling pathways mediated by type I interferons (IFNs), which are involved in viral clearance and anticancer immunity. Although susceptibility to viral infections has been reported in patients treated with anifrolumab, whether anifrolumab treatment increases the cancer risk in patients with SLE is unknown. We herin report a case of SLE that manifested as aggressive diffuse large B-cell lymphoma (DLBCL) after treatment with anifrolumab. The neutralization of type I IFNs by anifrolumab may promote the development of DLBCL owing to defective anticancer immunity.