Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042384 (vasculitis)
 20,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Essential thrombocythemia (ET) is a rare clonal myeloproliferative disorder with a prevalence rate of approximately 1-3 cases per 100 000 individuals per year. ET is characterized by a persistent increase in the platelet count with hyperplasia of bone marrow megakaryocytes. It is difficult to make a diagnosis of ET, because most thrombocythemia are reactive to certain disease conditions including iron deficiency anemia, infection, collagen diseases and malignant tumors. Mutation in the Janus kinase (JAK)2 gene is present in approximately 50-70% of ET patients, and somatic mutations in the calreticulin (CALR) gene were recently discovered in approximately 20-25% of sporadic patients with ET or primary myelofibrosis. Various cutaneous manifestations of ET often occur by microvascular thrombosis and precede severe arterial and venous thromboembolic events in other organs. Therefore, in order to prevent such severe events, it is important to make an early diagnosis of ET based on a number of cutaneous manifestations. Here, we report two cases of ET diagnosed based on livedo racemosa on feet with gene mutations in JAK2 and CALR, respectively, and show the pathological and immunohistological findings of the livedo resulting from platelet thrombosis rather than vasculitis. We also review the cutaneous manifestations in current published reports of Japanese ET patients. Our patients were successfully treated with low-dose aspirin, a vasodepressor and hydroxyurea, following regressed livedo and reduced platelet counts.
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PMID:Clinical and histological characteristics of livedo racemosa in essential thrombocythemia: A report of two cases and review of the published works. 2757 91

Proteinase 3 (PR3) is the autoantigen in granulomatosis with polyangiitis, an autoimmune necrotizing vasculitis associated with anti-neutrophil cytoplasmic antibodies (ANCAs). Moreover, PR3 is a serine protease whose membrane expression can potentiate inflammatory diseases such as ANCA-associated vasculitis and rheumatoid arthritis. During apoptosis, PR3 is co-externalized with phosphatidylserine (PS) and is known to modulate the clearance of apoptotic cells through a calreticulin (CRT)-dependent mechanism. The complement protein C1q is one mediator of efferocytosis, the clearance of altered self-cells, particularly apoptotic cells. Since PR3 and C1q are both involved in the clearance of apoptotic cells and immune response modulation and share certain common ligands (i.e., CRT and PS), we examined their possible interaction. We demonstrated that C1q binding was increased on apoptotic rat basophilic leukemia (RBL) cells that expressed PR3, and we demonstrated the direct interaction between purified C1q and PR3 molecules as shown by surface plasmon resonance. To better understand the functional consequence of this partnership, we tested C1q-dependent phagocytosis of the RBL cell line expressing PR3 and showed that PR3 impaired C1q enhancement of apoptotic cell uptake. These findings shed new light on the respective roles of C1q and PR3 in the elimination of apoptotic cells and suggest a novel potential axis to explore in autoimmune diseases characterized by a defect in apoptotic cell clearance and in the resolution of inflammation.
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PMID:Proteinase 3 Interferes With C1q-Mediated Clearance of Apoptotic Cells. 2975 60