Hypereosinophilic Syndromes

Hypereosinophilic syndromes (HESs)

• Classify into one of the following forms → Myeloproliferative forms · Lymphocytic forms · Overlap · Undefined · Associated · Familial

Myeloproliferative forms

• → Myeloproliferative HES: Features of myeloproliferative disease without proof of clonality
• → CEL: Clonal eosinophilia including FIP1L1/PDGFRA positive CEL

Lymphocytic forms

• Populations of T cells secreting eosinophil hematopoietins
• → Clonal T cells: T cells often exhibit an abnormal immunophenotype
• → No T cell clone: Aberrant immunophenotype or evidence of marked T cell activation

Overlap

• Organ restricted eosinophilic disorders

Undefined

• → Benign: Asymptomatic with no evidence of organ involvement
• → Episodic: Cyclic angioedema and eosinophilia
• → Other: Symptomatic without features of myeloproliferative or lymphocytic forms

Associated

• Eosinophilia in association with a defined diagnosis, such as IBD or CSS

Familial

• Family history of documented persistent eosinophilia of unknown cause