HES are disorders marked by sustained over production of
eosinophils with damage to multiple organs due to eosinophil infiltration and
mediator protease. Cardiac involvement is present in 40% of cases.
For the diagnosis of HES the following criteria need to be met:
- Blood eosinophilia is >1500microliter for >6 months
- No other etiologies for eosinophilia like parasitic or allergic disorders
- Signs and symptoms of end organ dysfunction
There are 3 variants of HES
Variants with clonal abnormalities of
- Eosinophil lineage
- T lymphocytic variants,
- Myeloproliferative variant of HES.
Blast transformation could occur after many years.
True idiopathic hypereosinophilic syndrome is generally indolent;
however, patients with characteristics that are suggestive of a myeloproliferative/neoplastic
disorder and those who manifest CHF have a worse prognosis.
