An unusual neurological presentation in a patient with primary hypereosinophilic syndrome.

Hypereosinophilic syndromes are characterized by an increased number of blood eosinophils (usually more than 1.5 × 109) infiltrating tissues and causing organ damage through over-production of pro-inflammatory cytokines with heterogeneous clinical presentation. Here we present a case of a 47 years old male, with an unremarkable previous medical history, with a sudden onset of subungual hemorrhage and low back pain. Admitted for right arm weakness and vomiting, was raised the suspicion of acute cerebrovascular syndrome, but a brain CT scan with angiogram and perfusion sequences did not show any signs of early ischaemic lesions; conversely, lab tests revealed an increased peripheral eosinophil blood count. Clinical conditions rapidly worsened and a brain MRI showed multiple sub-acute ischaemic lesions compatible with vasculitis while EEG was in favor of widespread cortical distress. Diagnosis of the hypereosinophilic syndrome was made through peripheral blood smear and osteo-medullar biopsy, which showed a rich prevalence of eosinophils. The molecular biology testing showed FIP1L1-PDGRA gene mutation. Despite the prompt therapy beginning with intravenous corticosteroids and tyrosine-kinase inhibitors with normalization of cell blood count in a few days, the patient remained in minimal consciousness. When facing unusual symptoms onset (low back pain with weakness in one limb) and a highly impaired WBC not consistent with other courses (such as infections, vasculitis, allergies, and other diseases involving the immune system) clinicians should take into account the possibility of a hematological disorder and treat it as soon as possible to avoid a poor prognosis.

Expression and function of Angiopoietins and their tie receptors in human basophils and mast cells.

The Angiopoietin/Tie system is a key regulator of vascular remodeling, maturation, angiogenesis and lymphangiogenesis. In humans there are three angiopoietins: Angiopoietin-1 (Ang1), Angiopoietin-2 (Ang2), and Angiopoietin-4 (Ang4). Ang1 and Ang2 are the best characterized angiopoietins. The angiopoietin receptor system consists of two type I tyrosine kinase receptors (Tie1 and Tie2). Tie2 binds all known angiopoietins. We sought to characterize Ang1, Ang2, Tie1 and Tie2 expression and functions in human basophils and mast cells. Basophils, LAD-2 cells and Human Lung Mast Cells (HLMCs) constitutively express Ang1 and Ang2 mRNA. Intracellular staining for Ang1 and Ang2 was stronger in basophils than in mast cells. Immunoelectron microscopy demonstrated Ang1 in cytoplasmic vesicles of basophils. The protein kinase C activators phorbol diester (PMA) and bryostatin 1 (Bryo1) stimulated basophils to rapidly release a large amount of Ang1. PMA-induced Ang1 release was inhibited by brefeldin A. Tie1 and Tie2 mRNAs were expressed in basophils, LAD-2 and HLMCs. Basophils, LAD-2 and HLMCs expressed Tie1 on the cell surface. HLMCs and LAD-2 expressed Tie2 on the cell surface, whereas basophils did not. Ang1, but not Ang2, induced migration of mast cells through the engagement of Tie2. Neither Ang1 nor Ang2 induced basophil chemotaxis. We have identified a novel mechanism of cross-talk between human basophils and mast cells mediated by the Ang1/Tie2 system that might be relevant in the orchestration of inflammatory and neoplastic angiogenesis.

Angiogenesis and lymphangiogenesis in bronchial asthma.

Neovascularization plays a prominent role in inflammation and tissue remodeling in several chronic inflammatory disorders. Vessel number and size, vascular surface area and vascular leakage are all increased in biopsies from patients with asthma. High levels of VEGF and other angiogenic factors have been detected in tissues and biological samples of patients with asthma and correlate with disease activity and inversely with airway hyper-responsiveness. Inflammation in the lung stimulates the growth of new blood vessels and these contribute to the airway obstruction or airway hyper-responsiveness, or both. Effector cells of inflammation (human lung mast cells, basophils, eosinophils, macrophages, etc.) are major sources of a vast array of angiogenic and lymphangiogenic factors. Inhaled corticosteroids reduce vascularity and growth factor expression and might modulate bronchial vascular remodeling in asthma. Specific antagonists to VEGF and other angiogenic factors and their receptors might help to control chronic airway inflammation and vascular remodeling and offer a novel approach for the treatment of chronic inflammatory lung disorders.

Dupilumab-associated conjunctivitis in patients with atopic dermatitis: a multicenter real-life experience

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Angiogenesis, lymphangiogenesis and atopic dermatitis.

Angiogenesis and morphological and functional alterations of microvessels are hallmark features of chronic inflammatory disorders, including certain skin diseases. Vascular endothelial growth factors (VEGFs) are key regulators of blood vessel growth. The VEGF family includes VEGF-A, -B, -C, -D and placental growth factor. VEGF-A and -B are the most important proangiogenic factors, while VEGF-C and -D primarily regulate lymphangiogenesis. Angiopoietins are promoters of neovascularization by interacting with Tie-1 and Tie-2 receptors present on endothelial cells. High levels of VEGF-A have been detected in skin tissue of atopic dermatitis (AD) patients and correlate with disease activity. The vascular changes in the skin of AD patients appear to be linked to the inflammatory process. Effector cells of skin inflammation (human mast cells, basophils, eosinophils, macrophages, lymphocytes, etc.) are major sources of a vast array of angiogenic and lymphangiogenic factors. The role of lymphangiogenesis in AD is largely unknown.