Expert Consensus on Cytomegalovirus Management in Recipients of CAR-T Cell and Bispecific Antibody Therapies

Cytomegalovirus (CMV) is an increasingly recognized complication of chimeric antigen receptor T-cell (CAR-T) and bispecific antibody (BsAb) therapies for hematologic malignancies, driven by therapy-related immunosuppression and cumulative exposure to lymphodepleting or steroid regimens. Given China's high adult CMV IgG seroprevalence (>90%), baseline risk, interpretation of low-level DNAemia, and operational thresholds differ from low-seroprevalence settings, requiring context-specific guidance. This China-adapted, evidence-graded consensus was developed by a multidisciplinary panel from major centers using a modified Delphi process and Oxford Centre for Evidence-Based Medicine levels to translate international guidance into a high-seroprevalence setting. Recommendations prioritize early risk stratification and pragmatic surveillance. We advise routine CMV monitoring by real-time quantitative PCR during the first 30 days after therapy, with risk-adapted extension thereafter. Interpretation and treatment triggers are anchored to WHO-traceable IU/mL and specified by specimen matrix to support comparability across assays. Consideration of prophylaxis is proposed for well-defined high-risk subgroups, acknowledging the need for prospective validation. Syndrome-based diagnostic and treatment algorithms are provided for tissue-invasive disease, including CMV pneumonia and encephalitis, with guidance on antiviral induction, step-down, and monitoring for virologic response and drug toxicity. This consensus explicitly adapts international recommendations to China's epidemiology, assay practice, and drug accessibility. By standardizing prevention, surveillance, and management in CAR T-cell and BsAb recipients, this consensus aims to lower non-relapse mortality and improve long-term outcomes. Priority research needs include harmonized viral-load thresholds, validation of risk-adapted prophylaxis strategies, and studies that clarify the significance of low-level DNAemia in this population.