Outcome of allogeneic haematopoietic cell transplantation in eosinophilic disorders: A retrospective study by the chronic malignancies working party of the EBMT
Abstract
Hypereosinophilic syndrome (HES) and chronic eosinophilic leukaemia (CEL), not otherwise specified (NOS) are rare haematological disorders.1 Allogeneic haematopoietic cell transplantation (allo-HCT) has been reported in single case reports or small case series only for both refractory HES or CEL, NOS and outcomes remain ill-defined.1-3 HES normally demonstrates a male predominance, likely underrecognized, with a variable clinical course. Fulminant cases, however, are frequently associated with significant morbidity and indeed mortality.
Even less common, CEL, NOS is an extremely rare myeloproliferative neoplasm (MPN), frequently demonstrating an aggressive clinical course with significant rates of acute transformation. We hereby report outcomes from a retrospective, European Group for Blood and Marrow Transplantation (EBMT)-registry-based study of 77 adult patients with a confirmed diagnosis of either HES or CEL, NOS who underwent allo-HCT, representing the largest cohort reported to date.