title: Plasma from patients with thrombotic thrombocytopenic purpura induces activation of human monocytes and polymorphonuclear neutrophils.
abstract: Thrombotic thrombocytopenic purpura (TTP) is a rare but severe disorder characterized by microangiopathic haemolytic anaemia, consumptive thrombocytopenia, neurological involvement and formation of platelet thrombi in the small vessels. The aetiopathology of TTP and the mechanism behind the beneficial effect of plasma exchange with plasma infusion have not yet been fully elucidated. We have studied the effect of plasma from four patients with TTP on human blood phagocyte activation, as measured by reactive oxygen species (ROS) production and CD11b expression. TTP plasma obtained in the acute phase of the disease induced ROS production by human monocytes and enhanced CD11b expression on neutrophils. This activation effect remained in the cryosupernatant but not in the cryoprecipitate made from TTP plasma, and disappeared when a complete response was achieved by plasma exchange. These findings suggest that activated blood phagocytes may be involved in the pathophysiology of TTP.
authors.affiliation: Service of Haematotherapy and Haemostasis, Hospital Clínic and IDIBAPS, Barcelona, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Alvarez-Larrán
authors.forename: Jordi
authors.initials: J
authors.lastname: Petriz
authors.forename: Antonio
authors.initials: A
authors.lastname: Martínez
authors.forename: Cristina
authors.initials: C
authors.lastname: Sanz
authors.forename: Arturo
authors.initials: A
authors.lastname: Pereira
mesh_terms: D039481:CD11b Antigen / Q000032:analysis; D005434:Flow Cytometry; D006801:Humans; D008262:Macrophage Activation; D008264:Macrophages / Q000378:metabolism; D018375:Neutrophil Activation; D009504:Neutrophils / Q000276:immunology; D010951:Plasma Exchange; D011697:Purpura, Thrombotic Thrombocytopenic / Q000097:blood* / Q000276:immunology / Q000628:therapy; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D039481:CD11b Antigen; D017382:Reactive Oxygen Species