Eliezer A. Rachmilewitz
Wolfson Medical Center
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Featured researches published by Eliezer A. Rachmilewitz.
Thrombosis and Haemostasis | 2006
Ali Taher; Hussain Isma’eel; Ghassan Mehio; Daniela Bignamini; Antonis Kattamis; Eliezer A. Rachmilewitz; Maria Domenica Cappellini
Beta-thalassaemia is a congenital haemolytic anaemia characterized by partial (intermedia, TI) or complete (major, TM) deficiency in the production of beta-globin chains. The primary aim of this study was to determine the prevalence of thromboembolic events in patients with beta-thalassaemia. To achieve this, a multiple choice questionnaire was sent to 56 tertiary referral centres in eight countries (Lebanon, Italy, Israel, Greece, Egypt, Jordan, Saudi Arabia and Iran), requesting specific information on patients who had experienced a thromboembolic event. The study demonstrated that thromboembolic events occurred in a clinically relevant proportion (1.65%) of 8,860 thalassaemia patients (TI - 24.7% or TM - 75.3%) from the Mediterranean and Iran. Thromboembolism occurred 4.38 times more frequently in TI than TM (p < 0.001), with more venous events occurring in TI and more arterial events occurring in TM. Thrombosis in thalassaemia was also more common in females, splenectomized patients and those with profound anaemia (haemoglobin <9 g/dl). Due to the increased risk of thromboembolic events, the rationale for splenectomy should perhaps be re-assessed and the role of transfusion therapy for the prophylaxis of thrombosis, among other complications, be evaluated prospectively.
Blood | 2011
Eliezer A. Rachmilewitz; Patricia J. Giardina
The purpose of this article is to set forth our approach to diagnosing and managing the thalassemias, including β-thalassemia intermedia and β-thalassemia major. The article begins by briefly describing recent advances in our understanding of the pathophysiology of thalassemia. In the discussion on diagnosing the condition, we cover the development of improved diagnostic tools, including the use of very small fetal DNA samples to detect single point mutations with great reliability for prenatal diagnosis of homozygous thalassemia. In our description of treatment strategies, we focus on how we deal with clinical manifestations and long-term complications using the most effective current treatment methods for β-thalassemia. The discussion of disease management focuses on our use of transfusion therapy and the newly developed oral iron chelators, deferiprone and deferasirox. We also deal with splenectomy and how we manage endocrinopathies and cardiac complications. In addition, we describe our use of hematopoietic stem cell transplantation, which has produced cure rates as high as 97%, and the use of cord blood transplantation. Finally, we briefly touch on therapies that might be effective in the near future, including new fetal hemoglobin inducers and gene therapy.
Current Molecular Medicine | 2008
Eitan Fibach; Eliezer A. Rachmilewitz
The oxidative status of cells is determined by the balance between pro-oxidants and antioxidants. Pro-oxidants, referred to as reactive oxygen species (ROS), are classified into radicals and nonradicals. The radicals are highly reactive due to their tendency to accept or donate an electron and attain stability. When cells experience oxidative stress, ROS, which are generated in excess, may oxidize proteins, lipids and DNA - leading to cell death and organ damage. Oxidative stress is believed to aggravate the symptoms of many diseases, including hemolytic anemias. Oxidative stress was found in the beta-hemoglobinopathies (sickle cell anemia and thalassemia), glucose-6-phosphate dehydrogenase deficiency, hereditary spherocytosis, congenital dyserythropoietic anaemias and Paroxysmal Nocturnal Hemoglobinuria. Although oxidative stress is not the primary etiology of these diseases, oxidative damage to their erythroid cells plays a crucial role in hemolysis due to ineffective erythropoiesis in the bone marrow and short survival of red blood cells (RBC) in the circulation. Moreover, platelets and polymorphonuclear (PMN) white cells are also exposed to oxidative stress. As a result some patients develop thromboembolic phenomena and recurrent bacterial infections in addition to the chronic anemia. In this review we describe the role of oxidative stress and the potential therapeutic potential of anti-oxidants in various hemolytic anemias.
Biochemical Pharmacology | 1997
Leonid Grinberg; Harold L. Newmark; Nahum Kitrossky; Ezra Rahamim; Mordechai Chevion; Eliezer A. Rachmilewitz
Tea polyphenols (TPP) from black and green teas were evaluated for their antioxidant effects on normal red blood cells (RBC) and beta-thalassemic RBC membranes challenged with exogenous oxidants in vitro. The TPP of both types protected RBC against primaquine-induced lysis; they also protected the whole cells and the membranes against H2O2-induced lipid peroxidation so that about 80% protection was reached at [TPP] = 10 microg/mL. TPP from black tea at the same concentration protected normal RBC from morphological alterations caused by the peroxide treatment. The mechanism of the effects of TPP was investigated using a chemical system generating .OH (iron + ascorbic acid). TPP from both black and green teas inhibited the .OH fluxes in a concentration-dependent manner, indicating the possibility of iron chelation by TPP. Spectrophotometric titration revealed that TPP could stoichiometrically bind ferric iron to form a redox-inactive Fe-TPP complex. Quantitative analysis suggests that one or more major catechins from the TPP preparations are the likely iron-binding compounds accounting for the antioxidant effects of TPP on RBC.
Journal of Clinical Investigation | 2010
Sara Gardenghi; Pedro Ramos; Maria F. Marongiu; Luca Melchiori; Laura Breda; Ella Guy; Kristen Muirhead; Niva Rao; Cindy N. Roy; Nancy C. Andrews; Elizabeta Nemeth; Antonia Follenzi; Xiuli An; Narla Mohandas; Yelena Ginzburg; Eliezer A. Rachmilewitz; Patricia J. Giardina; Robert W. Grady; Stefano Rivella
Excessive iron absorption is one of the main features of β-thalassemia and can lead to severe morbidity and mortality. Serial analyses of β-thalassemic mice indicate that while hemoglobin levels decrease over time, the concentration of iron in the liver, spleen, and kidneys markedly increases. Iron overload is associated with low levels of hepcidin, a peptide that regulates iron metabolism by triggering degradation of ferroportin, an iron-transport protein localized on absorptive enterocytes as well as hepatocytes and macrophages. Patients with β-thalassemia also have low hepcidin levels. These observations led us to hypothesize that more iron is absorbed in β-thalassemia than is required for erythropoiesis and that increasing the concentration of hepcidin in the body of such patients might be therapeutic, limiting iron overload. Here we demonstrate that a moderate increase in expression of hepcidin in β-thalassemic mice limits iron overload, decreases formation of insoluble membrane-bound globins and reactive oxygen species, and improves anemia. Mice with increased hepcidin expression also demonstrated an increase in the lifespan of their red cells, reversal of ineffective erythropoiesis and splenomegaly, and an increase in total hemoglobin levels. These data led us to suggest that therapeutics that could increase hepcidin levels or act as hepcidin agonists might help treat the abnormal iron absorption in individuals with β-thalassemia and related disorders.
British Journal of Haematology | 2006
Johnny Amer; Hussam Ghoti; Eliezer A. Rachmilewitz; Ariel Koren; Carina Levin; Eitan Fibach
Sickle cell disease (SCD) is basically a red blood cell (RBC) disorder characterised by sickling and haemolysis, but platelets and polymorphonuclear neutrophils (PMN) are also involved. Oxidative damage may play a role in the pathogenesis of SCD. Using flow cytometry, we measured oxidative‐state markers simultaneously in RBC, platelets and PMN obtained from 25 normal donors, nine homozygous (SS) patients and six SS/beta‐thalassaemia patients. Reactive oxygen species (ROS) and reduced glutathione (GSH) were measured following staining of blood samples with fluorescence probes and gating on specific subpopulations based on size and granularity. Ten‐ to 30‐fold higher ROS production and 20–50% lower GSH content were found in RBC, platelets and PMN from SCD patients versus those of their normal counterparts. This could in part account for the clinical manifestations, such as haemolysis, a hypercoagulable state, recurrent bacterial infections and vaso‐occlusive incidences, in SCD. We further showed that exposure of SCD samples to antioxidants, such as N‐acetyl‐cysteine, vitamin C and vitamin E, decreased their oxidative stress. These results suggest that antioxidant treatment of patients with SCD could reduce oxidative damage to RBC, PMN and platelets, thereby alleviating symptoms associated with their pathology. The flow cytometry techniques presented herein could assist in monitoring the efficacy of such treatment.
Annals of the New York Academy of Sciences | 1974
T. H. J. Huisman; W. A. Schroeder; Georgi D. Efremov; H. Duma; B. Mladenovski; Carol B. Hyman; Eliezer A. Rachmilewitz; Nicole Bouver; Augustus Miller; Anne R. Brodie; J. Roger Shelton; Joan B. Shelton; Gerald Apell
t Laboratory o f Protein Chemistry, Department of Cell and Molecular Biology, Medical College of Georgia and Veterans Administration Hospital Augusta, Georgia 30902
British Journal of Haematology | 2007
Kenneth I. Ataga; Maria Domenica Cappellini; Eliezer A. Rachmilewitz
Division of Chetnistry and Chemical Engineering,
British Journal of Haematology | 1997
Andreas Ruf; Marjorie Pick; Varda Deutsch; Heinrich Patscheke; Ada Goldfarb; Eliezer A. Rachmilewitz; Marie C. Guillin
British Journal of Haematology | 2000
Rivka Dresner Pollak; Eliezer A. Rachmilewitz; Anat Blumenfeld; Maria Idelson; Ada Goldfarb
California Institute of Technology Pasadena, California 91 109 5 Department of Physiology and Biochemistry, Faculty o f Agriculture Department of Pediatrics, Faculty of Medicine University of Skopje Skopje, Yugoslavia Childrens Hospital of Los Angeles and Department of Pediatrics School of Medicine, University of Southern California Los Angeles. California 90027 * * Department of Hematology, Hadassah Medical School Hadassah University Hospital, Hebrew University Jerusalem, Israel