Mortality in hypereosinophilic syndrome: 19 years of experience at Mayo Clinic with a review of the literature

Remodeling and fibrosis in chronic eosinophil inflammation

Chronic eosinophilic inflammation has been associated with tissue remodeling in a number of disease states including the hypereosinophilic syndrome (HES), asthma, and, more recently, eosinophilic esophagitis (EoE). Remodeling occurs in the epithelial and subepithelial esophageal tissue, and includes basal zone hyperplasia, epithelial mesenchymal transition, fibrosis, angiogenesis, and smooth muscle hypertrophy/hyperplasia. Previously, research on the clinical impacts of tissue remodeling has been limited by a paucity of human tissue. However, in EoE, recurrent biopsies are required for diagnosis and management. As such, investigators are able to study the associations between tissue changes and clinical disease features. A number of profibrotic and proangiogenic factors are elevated in EoE, including TGF-β1, CCL-18, FGF-9, VEGF, and VCAM-1. Both eosinophils and mast cells produce a number of these factors. TGF-β1 appears to be a master regulator of end-organ dysfunction in EoE and can cause esophageal epithelial mesenchymal transition, fibrosis, and smooth muscle contraction. The requirement for eosinophils, the eosinophilopoietic interleukin, IL-5, and the canonical TGF-β1 signaling pathway for EoE-associated fibrosis, has been invoked using gene-deficient mice. The clinical consequences of eosinophil-associated tissue fibrosis can be devastating, such as endomyocardial fibrosis and heart failure in HES. In EoE, tissue remodeling appears to be the mechanism for multiple cardinal disease complications including esophageal rigidity, strictures, narrowing, and food impactions, as well as the clinical hallmark of dysphagia. Therapies that may be able to reduce or reverse EoE-associated remodeling include topical corticosteroids, anti-IL-5, and food antigen avoidance.

The Differential Diagnosis of Eosinophilia in Neoplastic Hematopathology

Eosinophilia in the peripheral blood is classified as primary (clonal) hematologic neoplasms or secondary (nonclonal) disorders, associated with hematologic or nonhematologic disorders. This review focuses on the categories of hematolymphoid neoplasms recognized by the 2008 World Health Organization Classification of Tumours and Haematopoietic and Lymphoid Tissues that are characteristically associated with eosinophilia. We provide a systematic approach to the diagnosis of these neoplastic proliferations via morphologic, immunophenotypic, and molecular-based methodologies, and provide the clinical settings in which these hematolymphoid neoplasms occur. We discuss recommendations that eosinophilia working groups have published addressing some of the limitations of the current classification scheme.

Loeffler's endocarditis with biventricular mural thrombi

A 42-year-old man presented to clinic with 1-week history of cough, malaise, loss of appetite and fever. Symptoms started acutely with cough and generalised weakness followed by fever, chills, nausea, vomiting and diarrhoea. He has been healthy before with no chronic illnesses. Further workup disclosed, leucocytosis with 87% eosinophilia, bilateral lung infiltrate, deep venous thrombosis, pulmonary embolism and both right and left biventricular mural thrombi. Extensive workup was done and was consistent with hypereosinophilic syndrome, which explained all his clinical findings. The patient was started on high-dose steroids and responded very well with a complete resolution of symptoms over the course of a few weeks.