Severe cytopenia after chimeric antigen receptor‐T cell driven by large granular lymphocytes and responsive to steroids

Summary Immune effector cell‐associated hematotoxicity (ICAHT) is a common toxicity associated with an important morbidity after chimeric antigen receptor (CAR)‐T‐cell therapy. Multiple factors seem to be involved in the development of severe ICAHT, making its management difficult. Here, we report three cases of severe ICAHT after axicabtagene‐ciloleucel (axi‐cel) for diffuse large B‐cell lymphoma showing an expansion of large granular lymphocyte in the bone marrow with a CD3/CD57‐positive non‐CAR‐T immunophenotype. We show that it is possible to treat them with low‐dose steroids, obtaining a striking resolution of cytopenias with no deleterious impact on the underlying malignancy.