Late haemophagocytic lymphohistiocytosis in a patient treated with Axicabtagene ciloleucel.

Secondary haemophagocytic lymphohistiocytosis (sHLH) is a life-threatening disorder described in the setting of infections, neoplastic and immune dysregulations. Recently, sHLH has been reported following chimeric antigen receptor T-cell (CAR-T) therapy as a severe manifestation of cytokine release syndrome (CRS) which generally occurs during the early phase after a CAR-T infusion. CAR-T therapy for both relapse/refractory acute lymphoblastic B-cell leukaemia (B-ALL) and non-Hodgkin lymphoma, (diffuse large B-cell lymphoma (DLBCL) and primary mediastinal B-cell lymphoma (PMBCL)), has been approved by FDA and EMA as a third line treatment. CRS is on-target off-tumour side effect of CAR-T therapy which results in an acute state of hyperinflammation due to both tumour lysis and the proliferation of CAR-T cells. Its clinical presentation has a wide spectrum of severity, in the worst case it could rapidly lead to a multiorgan failure and progress to a fatal sHLH. Here, we present a late occurrence of sHLH after CAR-T treatment.