title: Pathogenesis and Therapeutic Mechanisms in  Immune Thrombocytopenia (ITP).
abstract: Immune thrombocytopenia (ITP) is a complex autoimmune disease characterized by low  platelet counts. The pathogenesis of ITP remains unclear although both antibody-mediated and/or  T cell-mediated platelet destruction are key processes. In addition, impairment of T cells, cytokine  imbalances, and the contribution of the bone marrow niche have now been recognized to be  important. Treatment strategies are aimed at the restoration of platelet counts compatible with  adequate hemostasis rather than achieving physiological platelet counts. The first line treatments  focus on the inhibition of autoantibody production and platelet degradation, whereas second-line  treatments include immunosuppressive drugs, such as Rituximab, and splenectomy. Finally, thirdline treatments aim to stimulate platelet production by megakaryocytes. This review discusses the  pathophysiology  of  ITP  and  how  the  different  treatment  modalities  affect  the  pathogenic  mechanisms.
authors.affiliation: Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada. Bakos@crchudequebec.ulaval.ca.|The Toronto Platelet Immunobiology Group, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada. Bakos@crchudequebec.ulaval.ca.
authors.forename: Anne
authors.initials: A
authors.lastname: Zufferey
authors.affiliation: Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada. kapurri@smh.ca.|The Toronto Platelet Immunobiology Group, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada. kapurri@smh.ca.|Canadian Blood Services, Toronto, ON M5B 1W8, Canada. kapurri@smh.ca.
authors.forename: Rick
authors.initials: R
authors.lastname: Kapur
authors.affiliation: Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada. john_w.semple@med.lu.se.|The Toronto Platelet Immunobiology Group, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada. john_w.semple@med.lu.se.|Canadian Blood Services, Toronto, ON M5B 1W8, Canada. john_w.semple@med.lu.se.|Department of Pharmacology, Medicine, and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5B 1W8, Canada. john_w.semple@med.lu.se.|Division of Hematology and Transfusion Medicine, Lund University, 221 84 Lund, Sweden. john_w.semple@med.lu.se.
authors.forename: John W
authors.initials: JW
authors.lastname: Semple
keywords: immune thrombocytopenia (ITP);  B cells;  T cells;  autoimmunity;  platelets