Thrombocytopenic conditions—autoimmunity and hypercoagulability: Commonalities and differences in ITP, TTP, HIT, and APS

Abstract

Immune thrombocytopenia purpura (ITP), thrombotic thrombocytopenia purpura (TTP), heparin‐induced thrombocytopenia (HIT), and antiphospholipid syndrome (APS) are clinical conditions associated with significant morbidity and mortality. These well‐defined clinical syndromes have in common several properties: (1) their pathogenesis is immune mediated, specifically by autoantibodies; (2) thrombocytopenia is a hallmark in these four conditions; (3) except for the case of ITP, platelet and endothelial cell activation occurs in TTP, HIT, and APS, resulting in a prothrombotic state and an increased risk of thrombosis. Although these four immune‐mediated syndromes are well‐defined diseases, several case reports and studies have documented the association of two diseases in the same patient, illustrating the concept of the kaleidoscope of autoimmunity. Am. J. Hematol. 80:232–242, 2005. © 2005 Wiley‐Liss, Inc.

Introducing the Tran Qol: A New Disease-Specific Quality of Life Measure for Children and Adults with Thalassemia Major

“…Inherited hemoglobin disorders are the most common monogenic disease worldwide with an estimated 7% of the global population being carriers for such disorders [1][2][3]. One severe form of hemoglobin disorder is thalassemia major, which typically presents in the first year of life with severe anemia and requires life-long red blood cell transfusions every 3-4 weeks [4].…”

Sequential occurrence of thrombotic thrombocytopenic purpura, essential thrombocythemia, and idiopathic thrombocytopenic purpura in a 42-year-old African-American woman: a case report and review of the literature

“…These include: circulating antibodies or antigen-antibody complexes caused by the primary autoimmune disorder and inducing endothelial dysfunction [9]; platelet damage by TTP and production of autoantibodies [4]; deficiency of Von-Willebrand factor cleaving protease activity [10] or autoantibody against VWF cleaving protease [11]; molecular mimicry or redundancy of the immune system, also known as the kaleidoscope of immunity, which is the co-occurrence of various autoimmune diseases within an individual [12]. …”

The physiopathology of the catastrophic antiphospholipid (Asherson's) syndrome: Compelling evidence

“…cAPS shares several features with MHAs. As an example, a common feature among cAPS, TTP and an additional entity, the heparin-induced thrombocytopenia (HIT), is the presence of antibody-mediated thrombosis [51]. Otherwise, another entity, the idiopathic thrombocytopenic purpura (ITP), is also characterized by the presence of autoantibodies reacting with platelet-specific antigens resulting in thrombocytopenia as well [52].…”