Clinical significance of cytomegalovirus reactivation in patients with plasma cell dyscrasia who were treated with anti-CD38 monoclonal antibody: A retrospective analysis in a single institution

Introduction Anti-CD38 monoclonal antibodies (mAbs) have improved the prognosis of patients with plasma cell dyscrasia (PCD), but are also associated with increased infectious adverse events. Cytomegalovirus (CMV) is a common latent pathogen that is reactivated in immunocompromised individuals. Although CMV reactivation has mostly been reported after high-dose chemotherapy followed by stem cell transplantation in patients with PCD, cases of reactivation during anti-CD38 mAb therapy have been reported recently. Due to limited studies, we aimed to determine the frequency and impact of CMV reactivation during anti-CD38 mAb therapy. Patients and Methods This retrospective analysis included 154 consecutive patients with PCD who were treated with anti-CD38 mAbs at a single institution. Results Seventy six patients were evaluated for CMV reactivation by CMV pp65 antigen testing, and 29 (38%) patients, including nine with newly diagnosed PCD, showed positive results. Patients who tested positive for the CMV pp65 antigen had substantially lower serum albumin levels than those who tested negative. However, the two groups showed no marked difference in the concurrent anti-PCD medications or baseline absolute lymphocyte count. Although most patients showing positive results in the CMV pp65 antigen test had mild or no symptoms, with fever being the most common symptom, some patients developed CMV end-organ disease. In addition, CMV reactivation interfered with the course of anti-PCD treatment in most patients, necessitating dose reductions, delays, and discontinuation of chemotherapy. Conclusion This study provides an overview of the clinical impact of CMV reactivation in patients with PCD treated with anti-CD38 mAb-containing regimens. Micro Abstract This retrospective study assessed cytomegalovirus (CMV) reactivation in chemotherapy-treated patients using anti-CD38 monoclonal antibody. Among 76 patients tested with CMV pp65 antigen, 29 individuals (38%), including nine newly diagnosed with plasma cell dyscrasia (PCD), showed positive results. CMV reactivation substantially affected anti-PCD treatment, often leading to dose reductions, treatment delays, and chemotherapy discontinuation in most cases.