Seminars in hematology
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Myeloproliferative diseases (MPD) include polycythemia vera (PV), essential thrombocythemia, agnogenic myeloid metaplasia, and chronic myelogenous leukemia. The focus of this report is on PV, which is characterized by an increase in red blood cells, granulocytes, and platelets. Complications associated with PV are an increased risk of thrombosis and abnormal bleeding. ⋯ It is clear that no single agent satisfies all the needs for cytoreduction that arise during the course of PV. Future protocols should be designed that draw on the large body of experience already gained with these drugs to transcend the limitations of single-agent therapy and to improve quality of life as well as survival. Semin Hematol 38(suppl 2):25-28.
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Seminars in hematology · Jan 2001
Multicenter StudyIron overload is a determinant of morbidity and mortality in adult patients with sickle cell disease.
Patients with sickle cell disease (SCD) often require blood transfusion starting in early childhood. Multiple blood transfusions on a chronic basis lead to excessive accumulation of iron, especially in adults with sickle cell anemia (SS) that is progressively increasing in size. Blood exchange transfusion and the use of iron chelation therapy may prevent or delay the onset of iron overload. ⋯ Patients with low values of serum ferritin and % Sat had lower incidence of acute painful episodes (38% v 64%) and organ failure (19% v 71%) than those who had iron overload, respectively. Mortality was significantly higher in the iron overload group: 64% versus 5%, respectively. Taken together, the data indicate that (1) the status of iron stores in adults with SS is best determined by keeping accurate records of the amount of blood transfused and serial determinations of ferritin levels in the steady state; (2) a significant number of adults with SS have iron overload; and (3) iron overload seems to be a predisposing factor of disease severity.
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Seminars in hematology · Apr 2000
ReviewCurrent issues with platelet transfusion in patients with cancer.
For the past 30 years, platelet transfusions have been used in the treatment of thrombocytopenia caused by decreased production, inadequate function, or increased destruction of platelets. The number of platelet transfusions has increased more than transfusions of other blood components, shifting from whole blood use for the platelet source to plateletpheresis. Hematology/oncology patients are among the largest group receiving platelet transfusions, primarily because the more aggressive chemotherapies produce more acute and prolonged thrombocytopenia. ⋯ As a result, prophylactic transfusions are less likely to be administered at higher platelet counts, reducing platelet use and cost of platelet transfusions. However, cancer patients receiving intensive chemotherapy or myeloablative regimens require multiple platelet transfusions. For these patients, alternate strategies are needed so that platelet transfusions can be significantly reduced or eliminated.
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Seminars in hematology · Jul 1999
ReviewCellular origin and clonality of classic Hodgkin's lymphoma: immunophenotypic and molecular studies.
The cellular origin of Hodgkin and Reed-Sternberg (HRS) cells, the neoplastic cells of classic Hodgkin's lymphoma (HL), resisted clarification until the second half of this decade. One major obstacle to successful experimental investigations was the rarity of the HRS cells in the tissue affected by HL. Immunophenotypical studies using monoclonal antibodies already pointed in the early 1980s towards a lymphocytic origin for HRS cells, but were not definitive because of the usually variable expression of B-cell and/or T-cell antigens, and the additional expression of markers typical for other cell lineages, especially dendritic cells. ⋯ Molecular investigation of three cases of HL occurring in association with non-Hodgkin's lymphomas (NHLs) showed that all of the lymphoma lesions had an identical precursor with the molecular features of a germinal center B cell. In summary, these findings indicate that (1) approximately 95% of classic HLs originate from B cells; (2) the direct cellular precursors of the HRS cells are germinal center B cells; (3) the transforming event that causes HL leads to the complete morphologic and immunophenotypical change of the HRS cell precursors; and (4) the HRS cell population of a given case exclusively arises from a single transformed cell and expands by clonal growth. It remains to be shown whether the 5% of HLs for which a B-cell derivation could not be demonstrated are T-cell related.
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Monoclonal antibody therapy has emerged as a viable treatment option for patients with lymphoma and some leukemias. It is now beginning to be investigated for treatment of multiple myeloma. There are relatively few surface antigens on the plasma cells that are suitable for antibody-directed treatment. ⋯ Although CD20 is present only on 20% of myeloma cells, it may be present on myeloma precursor cells. This treatment has met with success in follicular lymphoma and is now being evaluated in clinical trials in both Europe and the United States for myeloma. Although these clinical trials are in very early stages, researchers are beginning to understand that antibody therapy can be used not only as a carrier molecule of radioisotopes and toxins, but also as molecules that can trigger tumor cells and promote growth arrest or apoptosis.