Influence of B cell-lineage targeted CAR-T cell therapy on humoral immunity and vaccine-induced antibody response

Humoral immune-related adverse events, including hypogammaglobulinemia and B cell depletion, pose long-term infection risks after chimeric antigen receptor T cell therapy (CARTx) for hematologic malignancies. This prospective study evaluates the kinetics of pathogen-specific humoral immunity prior to and up to a year after CARTx targeting CD19 and CD20 (B cells) or BCMA (plasma cells) in 100 and 28 individuals, respectively. Antibodies are tested for 12 vaccine-preventable pathogens and using comprehensive high-throughput antibody profiling. A subset of 72 participants are evaluated for post-CARTx vaccine responses. Here, we show pathogen-specific humoral immunity does not significantly change after CD19-, CD20-, or BCMA-targeted CAR-T cell therapy (CARTx). However, seroprotective antibodies are absent for up to one-third of routine vaccine-preventable pathogens in CD19- and CD20-CARTx recipients and for nearly half of vaccine-preventable pathogens in BCMA-CARTx recipients by one-year post-CARTx. Pre-vaccination B cell count is the main predictor of vaccine response.