| HES variants | Subtypes/identified abnormalities/examples | Initial therapy | Second-line therapies |
| Myeloid variants | - PDGFRA or PDGFRB rearrangements
| - Imatinib (with concomitant systemic glucocorticoids if cardiac involvement is suspected)
| - Other tyrosine kinase inhibitors with activity against PDGFR (eg, dasatinib, sorafenib, or nilotinib) or HCT
|
- JAK2 point mutation and translocation
| - Hydroxyurea or JAK inhibitors
| |
- FGFR1 rearrangements and chronic eosinophilic leukemia, not otherwise specified, on the basis of blast count in peripheral blood and/or bone marrow or of a clonal cytogenetic abnormality
| | |
- HES with myeloid features but without a known mutation
- Must demonstrate at least four of the following eight findings to be classified as myeloid HES:
- Increased serum vitamin B12 levels
- Chromosomal abnormalities
- Anemia
- Thrombocytopenia
- Hepatomegaly
- Splenomegaly
- Circulating leukocyte precursors
- Increased serum tryptase
| | - Imatinib
- Interferon-alfa
- Hydroxyurea
|
| T cell lymphocytic variants (L-HES) | - Aberrant IL-5-producing T cells
| | - Interferon-alfa (first choice)
- If nonresponse or if poor tolerance, try other T cell active therapies (eg, cyclosporine or mycophenolate)
|
| Familial HES | | - Observation and monitoring
| - Treat like idiopathic HES if complications develop
|
| Idiopathic HES | | | - Hydroxyurea or interferon-alfa
|
| Overlap HES | - Examples of single organ overlap HES include eosinophilic gastrointestinal disease, chronic eosinophilic pneumonia, and others
- Example of multisystem overlap HES: HES with features of eosinophilic granulomatosis with polyangiitis (EGPA, formerly Churg-Strauss)
| - Treat based on specific disease; topical glucocorticoids may be useful
| |
| Specific/defined syndromes associated with hypereosinophilia | - Examples include episodic angioedema with eosinophilia, other disorders associated with immune dysregulation
| - Treat based on specific disease
| |
