Hypereosinophilic syndrome

Activated Eosinophils in Idiopathic Hypereosinophilic Syndrome (9125007255)

Hypereosinophilic syndrome (HES) is a group of rare blood disorders characterized by the overproduction of eosinophils, a type of white blood cell. This condition can lead to damage in various organs and tissues due to the accumulation of eosinophils. HES is typically diagnosed when a patient has a persistently high eosinophil count (greater than 1,500 eosinophils per microliter of blood) for more than six months without a known cause.

Classification

HES can be classified into several subtypes based on the underlying cause and clinical presentation:

• Myeloproliferative HES - associated with genetic mutations such as the FIP1L1-PDGFRA fusion gene.
• Lymphocytic HES - associated with abnormal T cells that produce eosinophil-stimulating factors.
• Idiopathic HES - where no specific cause can be identified.

Symptoms

The symptoms of HES can vary widely depending on the organs affected. Common symptoms include:

• Fatigue
• Fever
• Cough
• Shortness of breath
• Skin rash
• Muscle pain
• Weight loss

Diagnosis

The diagnosis of HES involves several steps:

• Complete blood count (CBC) to measure eosinophil levels.
• Bone marrow biopsy to examine the production of eosinophils.
• Genetic testing to identify mutations such as the FIP1L1-PDGFRA fusion gene.
• Imaging studies (e.g., CT scan, MRI) to assess organ involvement.

Treatment

Treatment for HES aims to reduce eosinophil levels and prevent organ damage. Common treatments include:

• Corticosteroids - to reduce inflammation and eosinophil production.
• Tyrosine kinase inhibitors (e.g., imatinib) - particularly effective in cases with the FIP1L1-PDGFRA mutation.
• Immunosuppressive drugs - to control the immune system.
• Interferon-alpha - to modulate the immune response.

Prognosis

The prognosis for HES varies depending on the subtype and response to treatment. Early diagnosis and appropriate therapy can improve outcomes and reduce the risk of complications.

Related Pages

• Eosinophilia
• Myeloproliferative neoplasms
• Chronic eosinophilic leukemia
• Systemic mastocytosis
• Autoimmune diseases