Supplementary Material for: Recapitulated late-onset inflammatory toxicities and progressive dysautonomia with persistence of central memory CD4+ chimeric antigen receptor T cells in a case of transformed follicular lymphoma: case report

CD19-directed chimeric antigen receptor (CAR) T-cell therapy has been widely used and highly effective for B-cell lymphoid malignancies. Immune-mediated adverse effects such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) occur in the acute phase and are monophasic after CAR T-cell therapy. However, late-onset inflammatory and neurological toxicities have not been well studied. We encountered a patient with recurrent late-onset inflammatory toxicities and progressive dysautonomia after CD19-directed CAR T-cell therapy. A 69-year-old man was treated with CD19-directed CAR T-cell therapy for transformed follicular lymphoma. Triphasic inflammation with stomatitis, cytopenia, and non-infectious pneumonia was first observed 7 months after CAR T-cell infusion. Progressive dysautonomia was also observed and eventually fatal. Residual CAR T cells, predominantly central memory CD4+ cells, were detectable in peripheral blood approximately one year after CAR T-cell infusion. The cytokine profile with the lack of tumor necrosis factor-α, interferon-γ, and interleukin-1β elevation in the peripheral blood and cerebrospinal fluid was inconsistent with that of typical CRS or ICANS. The persistence of central memory CD4+ CAR T cells might be associated with unique manifestations of late-onset immune-mediated adverse effects. More cases should be accumulated to elucidate the mechanism and establish the optimal management strategy of late-onset immune-mediated toxicities previously unrecognized.