View clinical trials related to Thrombocytopenia.
Filter by:Plasma histidine-rich glycoprotein (HRG) binds to platelets in the presence of zinc (1). This binding is totally blocked by a monoclonal antibody directed against platelet membrane CD36. Therefore, CD36 is assumed to carry the platelet binding site for HRG (2). Because CD36 also has a variety of other ligands, including polyanionic lipids, it is also possible that it contains the binding site for heparin (also polyanionic) and might be involve in the pathogenesis of heparin-induced thrombocytopenia. Demonstrating absent HRG or heparin binding to platelets lacking CD36 would confirm that the binding sites for either or both of these ligands are located on this membrane protein. Because 3% to 11% of healthy Japanese are reported to lack CD36 on their platelets, this population is a practical source of cells for examining the physiologic role(s) for CD36. Therefore, we will recruit blood donors from the Japanese community on the NIH campus. Their platelets will tested for the presence of CD36. Recruitment will be closed after two individuals have been identified whose platelets lack CD36 and who are willing to donate 30 cc of blood on 4 or 5 subsequent occasions for binding studies with radiolabeled HRG and heparin.
Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Colony-stimulating factors such as sargramostim may increase the number of immune cells found in bone marrow or peripheral blood and may help a person's immune system recover from the side effects of chemotherapy. Phase I trial to study the effectiveness of bryostatin 1 combined with sargramostim in treating patients who have refractory myeloid cancer
OBJECTIVES: I. Assess the efficacy of recombinant human granulocyte colony-stimulating factor (G-CSF) in raising the absolute neutrophil count, platelet count, and hemoglobin level in patients with inherited bone marrow failure syndromes. II. Assess the efficacy of a reduced maintenance dose in patients who respond to daily G-CSF. III. Assess the toxic effects of G-CSF in these patients. IV. Measure bone marrow progenitor colonies before and after G-CSF. V. Measure CD34-positive cells in marrow and blood before and after G-CSF using flow cytometry and immunohistochemistry.
OBJECTIVES: I. Ascertain whether stem cell transplantation (SCT) is an effective method by which missing or dysfunctional enzymes can be replaced in patients with various inborn errors of metabolism. II. Determine whether clinical manifestations of the specific disease may be arrested or reversed by this treatment.
RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Colony-stimulating factors such as leridistim and filgrastim increase the number of immune cells found in bone marrow or peripheral blood and may help a person's immune system recover from the side effects of chemotherapy. PURPOSE: Randomized phase II trial to compare the effectiveness of leridistim with that of filgrastim to reduce side effects in older patients who are receiving cytarabine and daunorubicin for acute myeloid leukemia.
RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Peripheral stem cell transplantation may allow the doctor to give higher doses of chemotherapy drugs and kill more cancer cells. Isotretinoin may help cancer cells develop into normal white blood cells. PURPOSE: Phase I/II trial of topotecan, fludarabine, cytarabine, and filgrastim followed by peripheral stem cell transplantation or isotretinoin in treating patients who have acute myeloid leukemia, myelodysplastic syndrome, or recurrent or refractory acute lymphocytic leukemia.
RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Combining chemotherapy with bone marrow transplantation may allow the doctor to give higher doses of chemotherapy drugs and kill more cancer cells. PURPOSE: Phase II trial to study the effectiveness of combination chemotherapy with or without bone marrow transplantation in treating patients who have acute lymphocytic leukemia.
Platelets are particles found along with red and white blood cells in the blood that play a role in the process of blood clotting. Disorders affecting the platelets can lower the amount of platelets in the blood and put patients at risk of bleeding. The condition of low platelets is referred to as thrombocytopenia. Thrombocytopenia can be associated with a variety of diseases including cancer, leukemia, tuberculosis, or as a result of an autoimmune reaction. Autoimmune reactions are disorders in which the normal immune system begins attacking itself. Autoimmune thrombocytopenia (AITP) is a disorder of low blood platelet counts in which platelets are destroyed by antibodies produced by the immune system. Unfortunately, many patients with AITP do not respond to standard treatments for thrombocytopenia. Cyclophosphamide is a drug that works to suppress the activity of the immune system. Researchers believe that combining this drug with transplanted rescued blood stem cells may provide effective treatment for AITP. The purpose of this study is to explore the affordability and safety of this therapy for the treatment of AITP. The effectiveness of the therapy will be measured by the number of patients whose platelet levels rise greater than 100,000/m3. If this treatment approach appears affordable, this study will form the basis for a larger study to compare alternate treatment approaches.
T Cell Large Granular Lymphocyte (T-LGL) Lymphoproliferative Disorders are a heterogeneous group of uncommon diseases which may involve a polyclonal or a monoclonal T cell population, which bear characteristic surface markers corresponding to activated cytotoxic (CD3+, CD8+) lymphocytes. They are often associated with quite severe neutropenia, anemia, and thrombocytopenia which may be life-threatening. There is some evidence that the abnormal cytotoxic lymphocyte population may cause the cytopenias by suppressing hematopoiesis, although the mechanism is unclear. Case reports suggest that immunosuppressive therapy directed toward T cells may reverse the cytopenia. This pilot study involving up to 25 patients evaluates the clinical response to cyclosporine, an immunosuppressive drug, and seeks to elucidate the mechanism underlying the cytopenia.