Therapy with genetically engineered
chimeric antigen receptor (CAR) T cells targeting the
CD19 antigen is promising for a number of refractory or relapsed B-cell
malignancies. Information on the infectious complications of this immunotherapeutic strategy is scarce and difficult to interpret, as many factors influence
infection incidence and outcomes. CAR T-cell therapy is usually given to patients with haematological
cancers who have been heavily pretreated and are severely immunosuppressed. Moreover, the risk of
infection is increased by the administration of lymphodepleting
chemotherapy before CAR T-cell infusion, and by the development of complications such as
cytokine release syndrome or
immune effector cell-associated neurotoxicity syndrome, which are managed with anti-interleukin-6
antibodies, or
corticosteroids, or both. On-target, off-tumour toxicities, such as B-cell aplasia, hypogammaglobulinaemia, and persistent or biphasic
cytopenia, are common. In this Review, we evaluate the reported infectious complications of CAR T-cell therapy and associated risk factors and offer perspectives on its
infection risk.