The Full Wiki

Hypereosinophilic syndrome: Wikis

  

Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.

Encyclopedia

From Wikipedia, the free encyclopedia

Hypereosinophilic syndrome
Classification and external resources

An eosinophil, the white blood cell involved in hypereosinophilic syndrome, seen amongst red blood cells.
ICD-10 D72.1 (ILDS D72.12)
ICD-9 288.3
ICD-O: 9964/3
OMIM 607685
eMedicine med/1076 derm/920
MeSH D017681

The hypereosinophilic syndrome (HS) is a disease characterized by a persistently elevated eosinophil count (≥ 1500 eosinophils/mm³) in the blood for at least six months without any recognizable cause, with involvement of either the heart, nervous system, or bone marrow.[1]

HS is a diagnosis of exclusion, after clonal eosinophilia (such as leukemia) and reactive eosionophilia (in response to infection, autoimmune disease, atopy, hypoadrenalism or cancer) have been ruled out. [2]

There are some associations with chronic eosinophilic leukemia[3] as it shows similar characteristics and genetic defects.[4]

If left untreated, HS is progressively fatal. It is treated with glucocorticoids such as prednisone.[2] The addition of the monoclonal antibody mepolizumab may reduce the dose of glucorticoids.[5]

Contents

Classification

In the heart, there are two forms of the hypereosinophilic syndrome, endomyocardial fibrosis and Loeffler's endocarditis.

  • Endomyocardial fibrosis (also known as Davies disease) is seen in tropical areas.[6][7]
  • Loeffler's endocarditis does not have any geographic predisposition.

Signs and symptoms

As HS affects many organs at the same time, symptoms may be numerous. Some possible symptoms a patient may present with include:

Diagnosis

Numerous techniques are used to diagnose hypereosinophilic syndrome, of which the most important is blood testing. In HS, the eosinophil count is greater than 1.5 × 109/L.[4] On some smears the eosinophils may appear normal in appearance, but morphologic abnormalities, such as a lowering of granule numbers and size, can be observed.[4] Roughly 50% of patients with HS also have anaemia.[4]

Secondly, various imaging and diagnostic technological methods are utilised to detect defects to the heart and other organs, such as valvular dysfunction and arrhythmias by usage of echocardiography.[4] Chest radiographs may indicate pleural effusions and/or fibrosis[4], and neurological tests such as CT scans can show strokes and increased cerebrospinal fluid pressure.[4]

A proportion of patients have a mutation involving the PDGFRA and FIP1L1 genes on the fourth chromosome, leading to a tyrosine kinase fusion protein. Testing for this mutation is now routine practice, as its presence indicates response to imatinib, a tyrosine kinase inhibitor.[8]

Treatment

Treatment primarily consists of reducing eosinophil levels and preventing further damage to organs.[4] Corticosteroids, such as Prednisone, are good for reducing eosinophil levels and antineoplastics are useful for slowing eosinophil production.[4] Surgical therapy is rarely utilised, however splenectomy can reduce the pain due to spleen enlargement.[4] If damage to the heart (in particular the valves, then prosthetic valves can replace the current organic ones.[4] Follow-up care is vital for the survival of the patient, as such the patient should be checked for any signs of deterioration regularly.[4] After promising results in drug trials (95% efficiency in reducing blood eosinophil count to acceptable levels) it is hoped that in the future hypereosinophilic syndrome, and diseases related to eosinophils such as asthma and Churg-Strauss syndrome, may be treated with the monoclonal antibody Mepolizumab currently being developed to treat the disease.[5] If this becomes successful, it may be possible for corticosteroids to be eradicated and thus reduce the amount of side effects encountered.[5]

Epidemiology

HS is very rare, with only 50 cases being noted and followed up in the United States between 1971 and 1982.[4] The disease is even more uncommon within the paediatric population.[4]

Patients who lack chronic heart failure and those who respond well to Prednisone or a similar drug have a good prognosis.[4] However, the mortality rate rises in patients with anaemia, chromosomal abnormalities or a very high white blood cell count.[4]

References

  1. ^ Chusid MJ, Dale DC, West BC, Wolff SM (1975). "The hypereosinophilic syndrome: analysis of fourteen cases with review of the literature". Medicine (Baltimore) 54 (1): 1–27. doi:10.1097/00005792-197501000-00001. PMID 1090795. 
  2. ^ a b <New England Journal of Medicine 360:2005 (2009)
  3. ^ a b c d e f g h Longmore, Murray; Ian Wilkinson, Tom Turmezei, Chee Kay Cheung (2007). Oxford Handbook of Clinicial Medicine. Oxford. p. 316. ISBN 0-19-856837-1. 
  4. ^ a b c d e f g h i j k l m n o p Rothenberg, Mark E. "Treatment of Patients with the Hypereosinophilic Syndrome with Mepolizumab". http://www.emedicine.com/med/topic1076.htm. Retrieved 2008-03-17. 
  5. ^ a b c Scheinfeld, Noah S. "Hypereosinophilic Syndrome". http://content.nejm.org/cgi/content/full/NEJMoa070812. Retrieved 2008-02-15. 
  6. ^ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease. St. Louis, Mo: Elsevier Saunders. pp. 606. ISBN 0-7216-0187-1. 
  7. ^ Smedema JP, Winckels SK, Snoep G, Vainer J, Bekkers SC, Crijns HJ (December 2004). "Tropical endomyocardial fibrosis (Davies' disease): case report demonstrating the role of magnetic resonance imaging". Int J Cardiovasc Imaging 20 (6): 517–22. doi:10.1007/s10554-004-1095-9. PMID 15856635. http://www.kluweronline.com/art.pdf?issn=1569-5794&volume=20&page=517. 
  8. ^ Cools J, DeAngelo DJ, Gotlib J, et al. (2003). "A tyrosine kinase created by fusion of the PDGFRA and FIP1L1 genes as a therapeutic target of imatinib in idiopathic hypereosinophilic syndrome". N. Engl. J. Med. 348 (13): 1201–14. doi:10.1056/NEJMoa025217. PMID 12660384. http://content.nejm.org/cgi/content/full/348/13/1201. 

External links








Got something to say? Make a comment.
Your name
Your email address
Message