Recent advances in pathogenesis and management of hypereosinophilic syndromes

Abstract

Idiopathic hypereosinophilic syndrome is a largely heterogeneous disorder defined until now as persistent marked hypereosinophilia of unknown origin generally complicated by end‐organ damage. Recent studies clearly indicate that many patients fulfilling the diagnostic criteria of this syndrome can now be classified as presenting one of two major disease variants: the myeloproliferative or the lymphocytic variant. Research in cellular and molecular biology has provided firm evidence for the existence of discrete hematological disorders underlying these variants, questioning the pertinence of continued reference to ‘idiopathic’ hypereosinophilic syndrome in such patients. Furthermore, identification of these variants has a number of prognostic and therapeutic implications that must be taken into consideration for adequate management of these patients.

Five years since the discovery of FIP1L1–PDGFRA: what we have learned about the fusion and other molecularly defined eosinophilias

“…2 Lymphocyte-variant hypereosinophilia relates to the existence of clonal, pathogenetic T-cell subsets with an aberrant surface immunophenotype (for example, CD3 À CD4 þ , CD4 þ CD7 À , CD3 þ CD4 À CD8 À ), which overproduce eosinophilopoietic cytokines such as interleukin-5 (IL-5) and other Th2 cytokines such as IL-4, IL-13 and granulocyte macrophage colonystimulating factor. 3,4 In these cases, the eosinophilia is nonclonal. In rare instances, transformation of the clonal T cells to T-cell lymphoma has been reported, although lymphocytevariant hypereosinophilia generally follows a benign course.…”

Multisystemic eosinophilic epitheliotropic disease in a horse in Brazil

“…Hypoproteinemia is a common finding in equine MEED cases (LA PERLE et al, 1998;GEHLEN et al, 2003;ROUFOSSE et al, 2004). According to HENSON et al (2002), it is detected in 58% of MEED cases, and reflects the protein-losing enteropathy seen in affected horses.…”

“…Eosinophilia occurs in approximately 14% of MEED cases (BOSSELER et al, 2013;MAULDIN & PETERS-KENNEDY, 2016), and leukocytosis was also previously reported (GEHLEN et al, 2003;BOSSELER et al, 2013). Etiopathogenesis of MEED is unknown; various factors could be involved in the stimulation and chemotaxis of eosinophils that ultimately lead to multisystemic infiltrates (LA PERLE et al, 1998;ROUFOSSE et al, 2004;MAULDIN & PETERS-KENNEDY, 2016). Deregulated production of eosinophilopoietic cytokines (granulocyte-macrophage colonystimulating factor, interleukin-3, and interleukin 5 [IL-5]) is responsible for hypereosinophilic syndromes in humans (ROUFOSSE et al, 2004).…”

“…Etiopathogenesis of MEED is unknown; various factors could be involved in the stimulation and chemotaxis of eosinophils that ultimately lead to multisystemic infiltrates (LA PERLE et al, 1998;ROUFOSSE et al, 2004;MAULDIN & PETERS-KENNEDY, 2016). Deregulated production of eosinophilopoietic cytokines (granulocyte-macrophage colonystimulating factor, interleukin-3, and interleukin 5 [IL-5]) is responsible for hypereosinophilic syndromes in humans (ROUFOSSE et al, 2004). The authors of a report on equine MEED concurrent with intestinal lymphoma have suggested that the clonal proliferation of T lymphocytes triggers proliferation of eosinophils through secretion of IL-5 (LA PERLE et al, 1998).…”

A Third Locus for Eosinophilia on Chromosome 1 of the MES Rats

“…Eosinophilia may occur in a number of diseased conditions, which include parasitic infections, allergies, collagen vascular diseases, and neoplastic disorders. Another morbid condition distinct from these secondary eosinophilias, idiopathic hypereosinophilic syndrome (idiopathic HES), is a condition in which eosinophilia persists without any apparent etiology [7]. …”