Hypereosinophilic syndrome
Hypereosinophilic syndrome | |
---|---|
Other names | HES. chronic myeloid leukemia, chronic myelomonocytic leukemia, and systemic mastocytosis with eosinophilia.[3] |
Treatment | Corticosteroids, Imatinib, medications to control eosinophil counts, and supportive care.[4] |
Frequency | 0.36 to 6.3 per 100,000.[3] |
Hypereosinophilic syndrome 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.[5]
Hypereosinophilic syndrome can manifest in many different ways from nonspecific symptoms and fatigue to neurological impairment and endomyocardial fibrosis, which may be fatal.[6]
There are three different variants of hypereosinophilic syndrome, myeloproliferative, lymphocytic, and idiopathic.[7]
HES is a diagnosis of exclusion, after
There are some associations with chronic eosinophilic leukemia[10] as it shows similar characteristics and genetic defects.[11] If left untreated, HES is progressive and fatal. It is treated with glucocorticoids such as prednisone.[8] The addition of the monoclonal antibody mepolizumab may reduce the dose of glucocorticoids.[12]
Signs and symptoms
Depending on eosinophil target-organ infiltration, the clinical presentation of hypereosinophilic syndrome (HES) varies from patient to patient.[13] Individuals with myeloproliferative variant HES may be more likely to experience mucosal ulcerations involving the genitalia or airways, while patients with lymphocytic variant HES typically exhibit prominent skin symptoms such as urticarial plaques, angioedema, and erythroderma.[14][15] Myeloproliferative variant HES is far more common in men and is typically linked to symptoms more typical of myeloproliferative disorders, including anemia, splenomegaly, hepatomegaly, and fibrotic disease (particularly of the heart).[16]
Patients can develop a range of nonspecific symptoms, including
The common and non-specific cutaneous manifestations are either erythematous, itchy
Cardiac involvement typically progresses through three phases. Rarely, the early necrotic stage involving the endo-myocardium manifests as acute
Both the peripheral (
When there are no radiological abnormalities, lung involvement can vary from a persistent dry cough and/or bronchial hyperreactivity to restrictive disease with pulmonary infiltrates. There have been isolated reports of acute respiratory distress syndrome development. Chronic illness may lead to the development of pulmonary fibrosis.[13]
Hematological manifestations include thrombocytopenia, anemia, splenomegaly, and hepatomegaly. Patients may occasionally exhibit mild lymphadenopathy.[13]
HES patients may experience coagulation problems. It is thought that long-term
Abdominal pain, diarrhea, nausea, and vomiting are a few examples of gastrointestinal symptoms. There may be colitis, enterocolitis, or eosinophilic gastritis; if eosinophilic infiltrates affect the intestinal wall's deeper layers, colitis may be linked to ascitis.[13]
Causes
While some HES patients have eosinophilia in conjunction with known myeloid malignancies, others do not have a known malignancy but do have laboratory or bone marrow abnormalities, such as thrombocytopenia, anemia, hepatosplenomegaly, and eosinophil-related tissue damage and fibrosis, that are frequently associated with myeloproliferative disease. The diagnosis of myeloproliferative HES is made for these individuals.[20]
Eosinophilia in lymphocytic HES is caused by populations of activated T lymphocytes producing more eosinophil hematopoietins, specifically interleukin-5 (IL-5).[20]
Severe eosinophilia with an unknown etiology that manifests in successive generations is known as familial hypereosinophilia syndrome (HES).[20]
Mechanism
It is possible that several mechanisms contribute to the pathophysiology of HES because of the clinical heterogeneity of its patients.[17]
Despite the lack of knowledge regarding the precise mechanism underlying eosinophil-induced tissue damage, eosinophil accumulation seems to have pathological outcomes.[17] Eosinophils cause direct cytotoxicity by releasing harmful substances locally, such as enzymes, pro-inflammatory cytokines, reactive oxygen species, cationic proteins, and factors derived from arachidonic acid.[7][21] The extent of end-organ damage varies, and the severity of organ damage is frequently unrelated to the degree or duration of eosinophilia.[6]
Diagnosis
Numerous techniques are used to diagnose hypereosinophilic syndrome, of which the most important is blood testing. In HES, the
Secondly, various imaging and diagnostic technological methods are utilised to detect defects to the heart and other organs, such as valvular dysfunction and
A proportion of patients have a mutation involving the
Chusid et al. developed empirical diagnostic standards for idiopathic HES in 1975:[23]
- More than 1,500/mL of blood eosinophilia for more than six months in a row, along with hypereosinophilic disease signs and symptoms.[23]
- Lack of an underlying cause for hypereosinophilia after a full diagnostic assessment.[23]
- Organ dysfunction or damage as a result of eosinophils' toxic contents being released locally.[23]
Since there isn't a particular diagnostic test for HES, the syndrome is diagnosed by exclusion.
Classification
Myeloproliferative HES (M-HES) and lymphocytic HES (L-HES) are the two main categories of HES, along with a few other clearly defined clinical entities.[20]
Treatment
As a first-line treatment for HES patients' symptoms, corticosteroids are recommended.[17] Because high-dose prednisone rapidly lowers eosinophil levels, it is usually started at a dose of 1 mg/kg/day.[6] Upon achieving appropriate control over eosinophilia, the medication can be gradually reduced.[25]
Steroid-refractory HES has been managed with a variety of cytotoxic treatments.
It has been demonstrated that
The U.S. Food and Drug Administration (FDA) has approved
An option for patients who have not responded to conventional treatment regimens is a
Outlook
The prognosis for HES was extremely poor when the syndrome was first described; however, due to a variety of factors, including earlier detection of complications, improved surgical management of cardiac and valvular disease, and the use of a wider range of therapeutic molecules to control
Patients without
Epidemiology
The European Medicines Agency (EMA) estimated the prevalence of HES at the time of granting orphan drug designation for HES in 2004 at 1.5 in 100,000 people, corresponding to a current case load of about 8,000 in the EU, 5,000 in the U.S., and 2,000 in Japan.[28][needs update]
History
In 1968, the term "hypereosinophilic syndrome" was created to group patients who had several closely related conditions that were all marked by persistently elevated peripheral blood eosinophil levels and organ damage from eosinophilic infiltration.[29]
See also
References
- ^ "Monarch Initiative". Monarch Initiative. Retrieved February 6, 2024.
- ^ "Symptoms and causes". Mayo Clinic. April 27, 2022. Retrieved February 6, 2024.
- ^ a b c d e "UpToDate". UpToDate. Retrieved February 6, 2024.
- ^ Liesveld, Jane (January 4, 2024). "Hypereosinophilic Syndrome". Merck Manuals Professional Edition. Retrieved February 6, 2024.
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- ^ S2CID 6037384. Retrieved 2008-03-17. Last updated: Updated: Oct 4, 2009 by Venkata Samavedi and Emmanuel C Besa
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- ^ European Medicines Agency, Committee for Orphan Medicinal Products. Public summary of opinion on orphan designation: mepolizumab for the treatment of hypereosinophilic syndrome. August 2010.
- PMID 5653621.
Further reading
- Simon, Hans-Uwe; Rothenberg, Marc E.; Bochner, Bruce S.; Weller, Peter F.; Wardlaw, Andrew J.; Wechsler, Michael E.; Rosenwasser, Lanny J.; Roufosse, Florence; Gleich, Gerald J.; Klion, Amy D. (2010). "Refining the definition of hypereosinophilic syndrome". Journal of Allergy and Clinical Immunology. 126 (1). Elsevier BV: 45–49. PMID 20639008.
- Ogbogu, Princess U.; Bochner, Bruce S.; Butterfield, Joseph H.; Gleich, Gerald J.; Huss-Marp, Johannes; Kahn, Jean Emmanuel; Leiferman, Kristin M.; Nutman, Thomas B.; Pfab, Florian; Ring, Johannes; Rothenberg, Marc E.; Roufosse, Florence; Sajous, Marie-Helene; Sheikh, Javed; Simon, Dagmar; Simon, Hans-Uwe; Stein, Miguel L.; Wardlaw, Andrew; Weller, Peter F.; Klion, Amy D. (2009). "Hypereosinophilic syndrome: A multicenter, retrospective analysis of clinical characteristics and response to therapy". Journal of Allergy and Clinical Immunology. 124 (6). Elsevier BV: 1319–1325.e3. PMID 19910029.