Hypereosinophilic syndrome: An update

Abstract

Hypereosinophilic syndrome (HES) is a rare disorder that is characterized by persistent and marked eosinophilia combined with organ system dysfunction. HES has substantial clinical heterogeneity but can be fatal without treatment, especially in patients who present with a myelodysplastic variant of the disorder. Although the pathophysiology of HES is poorly defined, dysregulation of cytokines (interleukin 5 [IL-5], IL-3, granulocyte-macrophage colony-stimulating factor [GM-CSF]) responsible for the maturation of eosinophils is a primary feature. Of these cytokines, IL-5 appears to have the greatest role in the regulation of eosinophil maturation. There is no Food and Drug Administration-approved treatment for HES as yet; current strategies are designed to lower blood eosinophils and attempt to limit end-organ damage. Historically, corticosteroids and cytotoxic agents have been the mainstays of therapy, with biological response modifiers such as interferon-alpha also effective in some patients. However, despite improvements in survival, available agents have significant limitations in terms of efficacy, tolerability, and long-term toxicity. More recently, new agents directed at specific targets in the pathogenesis of HES have been developed. These include imatinib mesylate, a tyrosine kinase inhibitor, and more recently, mepolizumab, an anti-IL-5 monoclonal antibody. In a small case series of patients, these agents have been shown to produce hematological and clinical responses in patients with HES, although they may be effective in different subsets of patients. These targeted therapies have the potential to improve clinical outcomes and to further the understanding the pathophysiology of this difficult-to-treat condition. Am.

Large Apical Thrombus in a Patient with Persistent Heart Failure and Hypereosinophilia: Löffler Endocarditis

“…A small subset of cases in which both reactive and clonal causes of eosinophilia are excluded may be classified as idiopathic HES 12 . Idiopathic HES is a multisystem disease with persistent peripheral eosinophilia with >1,500 eosinophils/mm3 for at least 6 months, multiple organ system involvement, and no evidence for other known causes of eosinophilia 13 . It affects mostly men between 20 and 50 years of age, with a peak in the 4th decade of life.…”

“…The patient also showed most of the principal clinical features of Löffler endocarditis, such as weight loss, fever, cough, and congestive heart failure. Since the World Health Organization classification recommends the exclusion of any cause of secondary eosinophilia like malignant or autoimmune diseases, parasitic disease, allergy, or drug reactions in the clinical workup of patients with Löffler endocarditis eosinophilia 13,22 , we explored any other cause that might explain the hypereosinophilia. Stool examinations were negative, and there was no sign of a malignancy, allergy, or drug reaction.…”

“…Routine cardiac therapy with digitalis, diuretics, afterload reduction, and anticoagulation are adjuncts in the management of these patients and should be initiated early 6 . However, the majority of deaths in patients with HES are as a result of thromboembolic events, which may lead to neurological and renal dysfunction, and cardiac complications 13 . Surgical therapy appears to offer significant palliation of symptoms when the fibrotic stage has been reached [35][36][37] .…”

A case of hypereosinophilic syndrome presenting withintractable gastric ulcers

“…However, followup endoscopy at 4, 6, 10 and 14 mo revealed persistent multiple gastric ulcers without significant improvement. The proportion of his eosinophil count increased to 43% (total count: 7903/mm 3 ). Abdominal-pelvic and chest computed tomography scans showed multiple small nodules in the liver and both lungs.…”

“…The diagnosis of HES is based on marked eosinophilia exceeding 1500/mm 3 , a chronic course longer than 6 consecutive months, exclusion of parasitic infestations, allergic diseases and other etiologies for eosinophilia, and signs and symptoms of eosinophil-mediated tissue injury [1,2] . While HES can involve multiple organ systems, including bone marrow, heart, lung, liver, lymph node, muscle, and nerve tissue [1] , gastrointestinal tract involvement is rare [1][2][3] .…”