Eosinophilia

Eosinophilia is defined as an abnormally high level of eosinophils in the blood, this is usually defined as >500 cells/μL (normal eosinophil level: <450 cells/μL). Hypereosinophilia is defined as >1500 cells/μL and is usually due to hematological malignancy .

This article includes recommendations and material from the "Guideline for the investigation and management of eosinophilia" published by the British Society for Hematology in 2017 .

Etiology

The number of eosinophils is increased in neonates, cf. adults, with a gradual tailing off of blood counts in advanced age; no gender/ethnic variation is known .

The known causes of elevation of the eosinophil count is very broad, and usefully the etiology can be subdivided into secondary, primary and idiopathic forms. Secondary (reactive) type is by far the commonest.

Secondary

• allergic
  • asthma
  • atopic eczema
  • hayfever, allergic rhinitis
• non-allergic skin
  • Wells syndrome
• medications
  • antibiotics
  • anticonvulsants
• infections
  • parasitic
  • fungal
• GI
  • primary eosinophilic GI diseases
  • chronic pancreatitis
  • inflammatory bowel disease (IBD)
  • celiac disease
• vasculitides
  • polyarteritis nodosa (PAN)
  • eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
• rheumatological
  • systemic lupus erythematosus (SLE)
  • eosinophilic fasciitis (Shulman disease)
  • rheumatoid arthritis
• pulmonary
  • eosinophilic pneumonias: acute and chronic types
• neoplastic
  • solid organ malignancies
  • lymphoma and acute lymphoblastic leukemia (ALL)
  • systemic mastocytosis
• others
  • atheroembolic disease
  • chronic graft-versus-host disease (GvHD)
  • episodic angioedema with eosinophilia (EAE)
  • rare immunoregulatory syndromes
    • hyper IgE syndrome
    • DOCK8 deficiency
    • PGM3 deficiency

Primary

A large number of primary hematological neoplastic conditions are associated with a clonal expansion of eosinophils.

• myeloid and lymphoid neoplasms

  • chronic eosinophilic leukemia, not otherwise specified (CEL, NOS)

  • atypical chronic myeloid leukemia with eosinophilia (aCML-Eo)

  • chronic myelomonocytic leukemia with eosinophilia (CMML-Eo)

  • chronic myelogenous leukemia in accelerated phase or transformation

  • other myeloproliferative neoplasm in transformation

  • acute myeloid leukemia with eosinophilia (AML-Eo)

    • especially t(8;21)(q22;q22.1) or inv(16)(p13.1q22)

  • acute lymphoblastic leukemia, only if eosinophils demonstrated to be part of the neoplastic clone

  • systemic mastocytosis

Idiopathic

Siehe auch:

• idiopathic hypereosinophilic syndrome