Dameshek W, Miller EB. The megakaryocytes in idiopathic thrombocytopenic purpura, a form of hypersplenism. 1946.

This paper, by one of the legends of hematology, William Dameshek, and his colleague Edward Miller, is from the inaugural issue of Blood. By studying bone marrow specimens from controls, patients with acute or chronic immune thrombocytopenia, or patients with other thrombocytopenic disorders, the authors concluded that, in idiopathic thrombocytopenic purpura (ITP), production of platelets from megakaryocytes is defective, even while marrow megakaryocytes are greatly increased in number. This defect resolved after splenectomy. The authors appropriately credit E. Frank with having proposed defective platelet production from megakaryocytes in ITP in 1915. The idea that platelet production was defective in ITP was superseded or ignored for decades, but it has now been validated by the therapeutic effectiveness of the thrombopoietin mimetics in ITP.

Treatment of immune thrombocytopenia with intravenous immunoglobulin and insights for other diseases. A historical review.

Since 1946 the development of fractionation and purification methods of human plasma led to biologic immunoglobulin for intravenous use (IVIG). In 1980 a child with refractory immune thrombocytopenia (ITP), bleeding and secondary hypogammaglobulinaemia due to long term immunosuppressive treatment got IVIG. His platelet counts dramatically increased. In 13 consecutive children with ITP, but without hypogammaglobulinaemia, similar rapid platelet increases were observed and confirmed in a controlled, multicentre study. During the past three decades this biologic treatment modality evoked clinical and laboratory research on the mechanisms of action and in disorders with similar immune pathogenesis. It was recognised that IVIG modulates the disturbed immune response in multiple, synergistic ways between the different components of the immune system. Beside other immune hematologic disorders other inflammatory and autoimmune diseases, mainly in the field of neurology and dermatology, IVIG showed beneficial effects. The worldwide consumption of IVIG increased from 300 kg per year in 1980 to 100 tonnes per year in 2010. Due to the heterogeneity of immunopathological mechanisms of autoimmune diseases evidence based indications of IVIG remain rare and off label use high. Registries of large numbers of patients and first endpoints of defining less heterogenous subgroups in immune related disorders are the next steps toward establishment of evidence based IVIG indications.

ITP: a historical perspective.

A clinical syndrome of bleeding and purpura consistent with a diagnosis of immune thrombocytopenia (ITP) was described by Werlhof long before platelets were identified as the cellular component of blood playing an essential role in primary haemostasis. Although a role for the spleen was suggested nearly a century ago, the pathophysiology of ITP has remained elusive for many decades. During this time Werlhof's disease was renamed idiopathic thrombocytopenic purpura, from which the acronym ITP originally derives. The second half of the 20th century brought recognition of the autoimmune components of ITP, and hence the need for a new standard nomenclature, which has recently been accepted. ITP currently stands for Immune Thrombocytopenia, a name that more appropriately reflects the low platelet count rather than purpura as the main feature of the disease, as well as to defining its underlying nature. Advances in our knowledge of the disease have paralleled the availability of new therapeutic agents, and we are now entering an era of pathophysiologically-based treatment options.

Development of romiplostim for the treatment of patients with chronic immune thrombocytopenia: from bench to bedside.

Immune thrombocytopenia (ITP) is an autoimmune disorder characterised by abnormally low platelet counts (<100 x 10(9)/l), purpura, and bleeding episodes, and can be categorised in three phases: newly-diagnosed, persistent, and chronic. As many patients become refractory to standard treatments (corticosteroids, danazol, azathioprine, splenectomy), there is an urgent need for alternative treatments. The successful isolation and cloning of thrombopoietin (TPO) in the mid-1990s and identification of its key role in platelet production was a major breakthrough, rapidly followed by the development of the recombinant thrombopoietins, recombinant human TPO and a pegylated truncated product, PEG-rHuMGDF. Both agents increased platelet counts but development was halted because of the development of antibodies that cross-reacted with native TPO, resulting in prolonged treatment-refractory thrombocytopenia. Experimentation with novel platforms for extending the circulating half-life of therapeutic peptides by combining them with antibody fragment crystallisable (Fc) constructs led to the development of a new family of molecules termed 'peptibodies'. The 60Da recombinant peptibody romiplostim was finally produced by linking several copies of an active TPO-binding peptide sequence to a carrier Fc fragment. In clinical trials, romiplostim was effective in ameliorating thrombocytopenia in patients with chronic ITP, was well tolerated and did not elicit cross-reacting antibodies. Romiplostim has recently been approved for the treatment of adults with chronic ITP.

Historical review. The light and shadow of Paul Kaznelson: his life and contribution to hematology.

Paul Kaznelson is credited with describing the first case of pure red cell aplasia. He was also known for his contribution to the discovery of the therapeutic role of splenectomy in idiopathic thrombocytopenic purpura. Most of his academic works appeared in 1910s and 1920s, when he used to work in Karl-Ferdinand University in Prague. Trail of his rather tragic postwar life is briefly added.

Parviz Lalezari: an autobiography.

Doctor Parviz Lalezari, currently a clinical professor of Medicine and Pathology at Albert Einstein College of Medicine in New York, describes highlights of his research career since 1958. He became the director of the blood bank at Montefiore Hospital in New York City in 1961, director of the Division of Immunohematology until 1996, and then until 2001, was President and chief executive officer of the Bergen Community Regional Blood Center in New Jersey. Doctor Lalezari was born in Iran in 1931, and after graduation from Medical School, he came to the United States in 1956. His initial research was on leukocyte antibodies. After modifying the available antibody detection techniques, he discovered that like hemolytic disease of the newborn and neonatal immune thrombocytopenia, fetal-maternal neutrophil incompatibility can cause neonatal neutropenia. He identified the targets of these antibodies and showed that they were expressed only on peripheral blood neutrophils. Doctor Lalezari also discovered that a common form of neutropenia in early childhood was caused by development of autoantibodies, which surprisingly were directed against the same neutrophil-specific antigens involved in fetal-maternal incompatibility. In 1959, a heparin-neutralizing drug (Polybrene) was introduced to be used after open-heart surgery. Lalezari discovered that Polybrene, a quaternary ammonium polymer, reacted with sialic acid molecules on the red blood cell (RBC) surface, causing the RBCs to aggregate. Later, realizing that the repelling forces generated by the RBC surface membrane charges were responsible for failure of the small IgG antibody molecules to agglutinate the RBCs, he used Polybrene to neutralize the RBC surface negative charge to allow the IgG antibody molecules to induce hemagglutination. This became The Polybrene test, which is to be used in RBC antibody detection.

Idiopathic thrombocytopenic purpura: pathophysiology and management.

Our understanding of the pathophysiology of ITP owes to pioneering work of W J Harrington in 1951, delineating the immunologic nature of platelet destruction. In ITP, antibody-coated platelets are destroyed by macrophages of RES. However, other mechanisms are also implicated: C-mediated platelet lysis and newly described C-independent peroxide injury. Both induce platelet fragmentation and lysis, generating procoagulant platelet microparticles (PMP). A third mechanism of platelet consumption in the microvasculature is proposed, based on overlapping syndromes of ITP and TTP in some patients. In assessing hemostasis in ITP, platelet counts alone is not sufficient. Evaluation of platelet clumping, giant platelets, and platelet activation, marked by increased PMP is useful. Patients with platelet activation or giant platelets bleed less and detection of clumping prevents unwarranted therapy. Thrombotic complications may develop in ITP. A syndrome, characterized by recurrent TIA-like symptoms, progressive memory loss due to ischemic small vessel disease is described. The management of ITP should include the search for and elimination of underlying causes and careful evaluation of hemostasis. Therapy is divided into definitive vs symptomatic measures. The former including splenectomy, danazol, chemotherapy offers lasting remission after therapy was stopped, while the later including glucocorticoids, gammaglobuin, antiD antibodies and others increases platelet counts but seldom sustains remission upon withdrawal. Danazol therapy is up-dated since it is an effective and safe definite measure in ITP.

Idiopathic thrombocytopenic purpura (ITP): a historical odyssey.

Purpura has been recognized since ancient times and its clinical syndromes were refined by important observations in the sixteenth, seventeenth and eighteenth centuries. It required the development of adequate microscopes in the nineteenth century, however, to recognize the platelet, leading to the recognition of the thrombocytopenic component of ITP. The twentieth century brought recognition of the pathophysiology of the disorder and further defined the clinical states and treatments for ITP. The latter half of the twentieth century has focussed on the autoimmune components of ITP, initially on the humoral immune aspects and more recently on dysregulation of cellular immunity.

The history of idiopathic thrombocytopenic purpura (ITP).

Purpura, initially recognized in ancient times, was defined into clinical syndromes in the 16th, 17th and 18th centuries. With advances in microscope science in the nineteenth century, the platelet was identified, leading to the recognition of the thrombocytopenic component of idiopathic thrombocytopenic purpura (ITP). The 20th century brought recognition of the pathophysiology of the disorder and the clinical states were refined and treatments for ITP developed. The latter half of the 20th century has focused on the autoimmune components of ITP, attempting to develop diagnostic tests, apply new therapies, and elucidate the immune dysregulation associated with, and underlying, the disorder.