Research in the Department of Hematology is split so that each of the senior physicians and researchers has his or her own specific area of research. This allows the department to diversify and enables a sense of independence for each researcher. This method also allows each laboratory to contribute in its own unique way to patient care. This section presents a synopsis of the research carried out in the department.
Basic laboratory scientific research is performed by physicians (MD) and by researchers (Ph.D.) who are part of the department staff. One of the strong forces in furthering successful research is the continual collaboration between clinicians and researchers.
The Laboratory for Molecular Diagnosis and Research of Hematological Malignancies
The molecular diagnostic laboratory develops and implements diagnostic tests which detect specific gene changes associated with a wide range of leukemias and lymphomas. One of the fields of research in the department focuses on the Chronic Myeloid Leukemia (CML) disease. In Prof. Dina Ben-Yehuda's laboratory, a molecular modification, methylation, was identified on the ABL gene correlating to the onset of the acute disease. Another focus is on therapy-related leukemia which is one of the most difficult complications associated with chemotherapy and/or radiation therapy. Prof. Ben Yehuda's laboratory focused on the genes of the DNA repair system and recently, one of the pathways which causes these genes to malfunction in repairing DNA in these patients was discovered. More recently, this laboratory found a new gene which encodes to an inhibition of apoptosis protein (IAP).
Hereditary Anemias (thalassemia and hemoglobinopathies) Laboratory
The laboratory for molecular diagnosis of thalassemia is crucial in providing accurate diagnosis of patients referred for evaluation of anemia. This laboratory is carrying out research in molecular diagnosis of alpha and beta thalassemia; accurate assessment of the carrier-status based on hematological parameters; genetic analysis of Ashkenazic Jewry and alpha thalassemia; and the phenotype-genotype interactions of the patients. Scientific studies have also led to an understanding of the biology of globin gene regulation. Prof. Ariella Oppenheim and Prof. Deborah Rund are active in this research.
Multidrug Resistance and Genetic Predisposition to Leukemia
The laboratory has been performing a functional test of drug resistance based on the activity of the multidrug resistance gene (MDR1). The test was initially applied to the acute leukemias, as it has long been known that elevated MDR1 activity correlates with a poor prognosis. The laboratory has been performing research on the cellular mechanisms responsible for the activation of the MDR1 gene in order to understand the mechanisms of why some patients' leukemia cells are innately resistant to chemotherapy. Parallel to the above studies, the laboratory has begun to research the genetic basis for development of hematological malignancies, including primary and secondary leukemias. The laboratory analyzes and studies mutations in several genes: CYP3A, NQ01 and FLT3 which ultimately helps the clinicians select appropriate therapy. Studies on the use of SV40-based pseudoviral vectors for transfer of the MDR1 gene are being conducted.
This laboratory is headed by Prof. David Varon and studies the platelet interaction with vessel wall under physiological flow conditions. A new method and device that had been developed allowed the study of these interactions: the effect of several thrombogenic modulators (including homocystein (HC), and oxidized LDL (OX-LDL), on platelet adhesion to endothelial cells (EC), under defined flow conditions. These studies established the role of tissue factor (induced by HC), and ICAM-1 (induced by OX-LDL), in the thrombogenic effect of these two agents.
Other studies investigate the role of platelets in the complex interaction of tumor cells (TC) with vessel wall under flow conditions and the potential role of platelets, their receptors and granular content, in angiogenesis.
The Laboratory for Immunophenotyping of Leukemias/Lymphomas and Other Hematological Diseases
This laboratory is headed by Prof. Eitan Fibach. Panels of fluorescent conjugated antibodies are used to detect (by flow cytometry) surface and intracellular antigens on normal and malignant cells for quantification of sub-populations (e.g., sub-sets of lymphocytes or CD34+ stem cells in bone marrow or peripheral blood harvest), diagnosis of hematological malignancies, follow up of treatment, determination of minimal residual disease nd more. Other cellular parameters measured include analysis of cell cycle, aneuploidy, apoptosis, multi-drug resistance and telomere length. Other diseases diagnosed and monitored by flow cytometry include Paroxysmal Nocturnal Hemoglobinuria (CD55 and CD59), thalassemia (fetal hemoglobin containing RBC and reticulocytes) and fetal-maternal hemorrhage (RBC of fetal origin in the maternal circulation).
Recently, a flow cytometric technique was developed to measure the production of free radicals in various cell populations, such as in granulocytes for diagnosis of chronic granulomatous disease and in RBC for the study of their pathological effects in thalassemia and other diseases and to test for the efficacy of antioxidants.
Laboratory for Hematopoiesis
This laboratory is headed by Prof. Eitan Fibach. The laboratory has now developed unique techniques for ex-vivo culturing of hematopoietic stem and progenitor cells, such as using a two-phase liquid culture procedure erythroid progenitors derived from the peripheral blood proliferate and differentiate into hemoglobin-containing RBC. A similar method was devised for growing of myeloid cells. This procedure is used to diagnose and study diseases associated with abnormal hematopoiesis such as polycythemia, red cell aplasia, Fanconi's anemia etc. The growth patterns of the cells under various culture conditions (e.g., in the absence of erythropoietin) represent biological abnormalities and permit diagnosis. These cultures can also be used to study the therapeutic effect of various drugs, e.g., the effect of hydroxyurea on expression of the gamma-globin genes and production of fetal hemoglobin in thalassemic cells, or the effect of differentiating agents on acute myeloid leukemic cells.
In addition, a new method, based on inhibition of differentiation, has been developed for ex-vivo expansion of hematopoietic stem cells and various sub-populations of progenitor cells. The use of expanded cord blood derived stem cells for transplantation is currently in clinical trials.
The Gene Therapy Laboratory
This laboratory is headed by Prof. Ariella Oppenheim who is leading research in several areas (in collaboration with investigators in Hadassah University Hospital and Hebrew University):
- Development of Somatic Gene Therapy: The development of an innovative SV40 pseudoviral vector, which can be produced in the test tube from recombinant viral capsid proteins and purified DNA. The research is conducted along two main lines: improvement of the generic vector, and the development of specific vectors for various target diseases.
- SV40 Virus Assembly: During studies on SV40 assembly the SV40 packaging signal was discovered and a working model for its role in regulating the viral life cycle and its assembly was formulated. The transcription factor Sp1 was found to participate in SV40 assembly by recruiting the capsid proteins to the viral minichromosome. This is the first example of the participation of a transcription factor in virus assembly. These studies led to the development of the in vitro packaging system for SV40 pseudovirions for gene therapy.
- Search for Genetic Modifiers of Globin Gene Expression: Studies have accomplished a comprehensive characterization of the genetic lesions underlying alpha- and beta-thalassemia in Israel, including the discovery of many novel mutations in alpha- and beta-globin genes. Further research indicates the existence of additional genes.
- Genetic Diversity of Israeli Ethnic Groups: Studies of mutational diversity in disease-causing genes as well as neutral polymorphic markers, in particular of the Y-chromosome, are being conducted.
- Genetics of Past Populations of Israel: Research of the genetics of past populations using ancient DNA technology are carried out. These studies will clarify the origins of ancient communities, their genetic interrelations and their affinities to present day populations.
Active research of Thalassemia by Dr. A. Goldfarb is primarily clinical.
Hypercoagulable State in Thalassemia
The concept of a life-long hypercoagulable state in thalassemia has been studied further, including the possible role of the monocyte in this process. In this context, in view of the observed microcirculatory disorders in thalassemia, the RBC rheological properties are concurrently being studied demonstrating pathology of the retinoconjunctival circulation.
Iron Overload - Chelation Therapy
Iron-kinetic studies as a basis for designing personalized combined desferal/L-1 treatment (in order to achieve optimal chelating for Thasassemic patients) is being tested.
Induction of Fetal Hb Synthesis for the Treatment of Thalassemia
Clinical trials using Heme arginate therapy, erythropoietin, and hydroxyurea is being pursued with NIH experts.
Oxidation and Macrophage Activation
The presence of oxidation and macrophage activation in thalassemia has so far been proven only indirectly. Measurements of cytokines levels, free radical scavengers in the plasma, skin and saliva are being performed for the understanding of the pathophysiology of the clinical phenomena.
Bone Disease in Thalassemia
Bone disease and severe osteoporosis have been the cause of severe morbidity in the adult thalassemics. An extensive study on 50 homozygous b- thalassemia patients, including bone mineral density and biochemical and genetic markers is being carried out.
Our aim is to provide the best in care for our patients using the most modern and up-to-date modalities of treatment possible. To do this, we participate in clinical trials whenever possible and we refer our patients for innovative therapies when appropriate. Some of these clinical trials are formal, multicenter treatment endeavors, which are planned on a national or even an international scale. Others are smaller scale, and may be unique to our institution or to Israel.
Before a new treatment is tested with patients, it is carefully studied for several years in the laboratory and tested for safety. This research identifies the new methods most likely to succeed and, as much as possible, shows how to use them safely and effectively. Although there is always a possibility that a new treatment will have disappointing results, the researchers and physicians who approve a study have reason to believe that it will be as good as, or better than, current treatments.
The Cone and Plate(let) Analyzer (CPA) is a novel point-of-care system for real-time, whole-blood platelet function testing.
The CPA, developed in our department's Coagulation Unit by Prof D Varon, was named after the shape and design of its disposable testing component, consisting of a cone and a plate. This unique design allows for platelet function testing under conditions that mimic the physiological flow within the human blood vessel, thus achieving the most accurate and authentic pattern of platelet function. The test requires minimal blood volume (0.1ml), no blood processing, and offers laboratories a fully-automated, brief (5 mins), and easily performed testing procedure.
Tests using the CPA allow performance of a series of basic and clinical studies. Basic works include characterization of platelet interactions with vessel flow conditions, and disease states including multiple arteries, cancer and bacterial infections. The measures are quantitatively expressed by a computerized image processing system, which is an integral part of the device.
Clinical applications of the system include diagnostic blood diseases, congenital diseases such as von-willebrand and thrombasthenia, diagnostic situations with a tendency for thrombosis such as diabetes, heart disease and excess fats, as well as monitoring drug treatments by platelet inhibitors. Additional clinical studies in the field include the stability of aspirin, monitoring patients undergoing catheterization, monitoring heart surgery and more.
The CPA System constitutes a breakthrough in the diagnosis and provides the physician with a useful and available diagnostic tool for platelet dysfunction and monitoring anti-thrombotic therapies.