Kaoruko Katsura

Platelet-derived microparticles may influence the development of atherosclerosis in diabetes mellitus.

We investigated the association between low-density lipoprotein (LDL), triglycerides, and platelet activation in 18 patients with hypertension age 41-64 years and 18 with diabetes mellitus aged 43-70 years. Platelet P-selectin positivity and the microparticle level (indicators of activation) were both significantly higher in the diabetics than in healthy controls (P-selectin: 28.0% +/- 7.5% vs. 7.3% +/- 4.2%, P < 0.001; microparticles: 1900 +/- 966 vs. 526 +/- 158/10(4) platelets, P < 0.01). In contrast, there was no significant increase of either parameter in the patients with hypertension. Plasma microparticle levels were also significantly greater in the diabetics with high LDL levels than in those with low LDL levels (2375 +/- 949 vs. 1519 +/- 796/10(4) platelets, P < 0.05), and in those with high rather than low triglyceride levels (2188 +/- 845 vs. 1492 +/- 783/10(4) platelets, P < 0.05). However, platelet positivity for P-selectin was not significantly different between these two subgroups. Microparticle and P-selectin levels both showed no significant difference between the hypertensive patients with high and low LDL or triglyceride levels. These results suggest that platelet-derived microparticles may participate in the development or progression of atherosclerosis in patients with diabetes mellitus.

Participation of αIIbβ3 in platelet microparticle generation by collagen plus thrombin

We investigated the role of αIIbβ3 in microparticle generation by normal and thrombasthenic platelets stimulated with collagen plus thrombin. Microparticle generation by normal p

Significance of cytokines and CD68‐positive microparticles in immune thrombocytopenic purpura

Abstract: We investigated the significance of cytokines (soluble interleukin‐2 receptor, granulocyte‐macrophage colony‐stimulating factor, interleukin‐6, and interferon‐gamma) and CD68‐positive microparticles in immune thrombocytopenic purpura. Cytokines were measured by enzyme‐linked immunosorbent assay and microparticles were detected by flow cytometry. CD68 expression by histiocytic U937 cells incubated with lipopolysaccharide or cytokines was also assessed in a control study. The level of CD68‐positive microparticles was significantly higher in the patients with thrombocytopenia than in normal controls (p<0.01). The soluble interleukin‐2 receptor level was also significantly higher in patients than in controls (p<0.01), but the other cytokines did not show a significant difference. However, patients with severe thrombocytopenia (platelet count >20000/μl) had significantly higher levels of granulocyte‐macrophage colony‐stimulating factor and interleukin‐6 than the controls (p<0.05). When opsonized platelets were incubated with activated U937 cells, lipopolysaccharide and granulocyte‐macrophage colony‐stimulating factor caused an increase of CD68‐positive microparticles in the supernatant. These results suggest that granulocyte‐macrophage colony‐stimulating factor is released by activated T cells in immune thrombocytopenic purpura and activates monocyte/macrophage phagocytosis, resulting in an increase of circulating CD68‐positive microparticles and enhanced platelet destruction.

Serum levels of soluble CD30 in autologous peripheral blood stem cell transplantation

Abstract High-dose chemotherapy with peripheral blood stem cell transplantation (PBSCT) has become an important method of treatment for hematological and solid tumors. We examined levels of interleukin(IL)-4, interferon (IFN)γ, soluble (s) CD30, and sIL-2 receptor (R) before and after autologous PBSCT, and compared findings for PBSCT with those for bone marrow transplantation (BMT). We found significantly higher IL-4 levels 1 and 3 weeks after PBSCT than before PBSCT, while IFNγ levels remained almost unchanged after PBSCT. IFNγ levels were increased 3 weeks after BMT, although no increase in IL-4 level was observed. The serum sCD30 level was significantly higher 3 weeks after PBSCT, but not following BMT. For 34 samples on days 0 and 21 from 17 patients undergoing PBSCT, a strong correlation was observed between sCD30 and sIL-2R levels (r = 0.43, P < 0.01). However, no significant correlation between sCD30 and sIL-2R levels was found for BMT patients. These findings suggest that sCD30 is a useful marker for evaluating immunological activity following autologous PBSCT, and that the immunological conditions after autologous PBSCT may be associated with helper-T-cell-2-type immune responses.

Changes of immunological markers after autologous peripheral blood stem cell transplantation

Abstract Purpose: Recently high-dose chemotherapy with peripheral blood stem cell transplantation (PBSCT) has become an important treatment for hematological and solid tumors. Methods: Immunological parameters were examined before and after PBSCT in 9 patients with lung cancer and 13 patients with malignant lymphoma. Findings were compared with those for bone marrow transplantation (BMT). Peripheral blood cells were analyzed for phenotype and the levels of cytokines and soluble factors were measured. Results: After PBSCT, activated T cells (CD3+HLA-DR+ cells, CD8+HLA-DR+ cells) and suppressor/cytotoxic T cells (CD8+CD11b− cells) were significantly higher in the patients with lung cancer than in those with malignant lymphoma. Serum levels of interleukin-4 and soluble interleukin-2 receptor were also significantly higher in the patients with lung cancer than in those with lymphoma. On the other hand, the serum levels of interferon γ, tumor necrosis factor α, interleukin-6, soluble human leukocyte antigen class 1, and soluble thrombomodulin were significantly increased after bone marrow transplantation. The transfused peripheral stem cells of lung cancer and lymphoma patients had a similar number of granulocyte/macrophage-colony-forming units, but lung cancer patients had significantly more CD34-positive cells. Conclusion: By reinfusing large numbers of autologous immune cells, PBSCT may accelerate immune reconstitution, with T cells being likely to have a marked therapeutic potential. The changes after PBSCT were greater in patients with lung cancer than in lymphoma patients. These blood cells are potent mediators of anticancer activity and could play an important role in the elimination of autologous malignant cells.

HLA and HPA Typing in Idiopathic Thrombocytopenic Purpura Patients Treated with Kami-kihi-to

We performed human leukocyte antigen (HLA) and human platelet antigen (HPA) in patients with Kami-kihi-to-responsive idiopathic thrombocytopenic purpura. The HLA-A2, A61 and Cw1 were significantly increased in responders compared with nonresponders, as were HLA DRB1 *0901, DRB1 *1502, and DPB1 *0501. In contrast, HLA DPB1 *0201 and DPB1 *0901 were significantly decreased in responders. The a/b genotype of HPA-2 and a/a genotype of HPA-3 were markedly increased in nonresponders, and anti-GPIb antibody was also increased. These results suggest that HLA, HPA, and anti-GP antibody studies may predict the response of idiopathic thrombocytopenic purpura to Kami-kihi-to.

Thrombopoietin Levels in Patients Undergoing Autologous Peripheral Blood Stem Cell Transplantation

Background and Objectives: High–dose chemotherapy with peripheral blood stem cell transplantation (PBSCT) has become an important treatment for hematological and solid tumors. Several reports on endogeneous production of thrombopoietin (TPO) in patients undergoing intensive chemotherapy have been published. We measured TPO levels in patients undergoing autologous PBSCT in order to elucidate the role of TPO in megakaryopoiesis and platelet recovery following stem cell transplantation. We also examined whether PBSC from different patient groups (patients with lung cancer and malignant lymphoma) had different effects on TPO levels. Materials and Methods: Serum levels of TPO and other cytokines were determined by ELISA before and after PBSCT in 10 patients with lung cancer and 18 patients with malignant lymphoma. Results: Compared to platelet counts at 1 week after transplantation, those at 3 weeks were significantly increased (p<0.001). In contrast, serum TPO levels were significantly decreased 3 weeks after PBSCT (p<0.01). There were no significant differences in levels of other cytokines between 1 and 3 weeks after transplantation. A strong correlation was found between serum TPO levels and circulating platelet counts (r =–0.675; p<0.0001). Platelet counts exhibited a significant recovery and TPO levels also decreased significantly in malignant lymphoma patients after transplantation. There were no significant differences in TPO levels in lung cancer patients, although the same tendencies as for malignant lymphoma patients were observed for both platelet count and TPO level. On analysis of transfused PBSC, we found that the numbers of CFU–GM were similar in lung cancer and malignant lymphoma patients. However, the numbers of CD34+ cells were significantly higher in lung cancer patients than in malignant lymphoma patients. Conclusion: Our findings suggest that TPO plays a critical role in the reconstitution of megakaryopoiesis and platelet production following PBSCT, and that the type of stem cell, tumor, and preceding chemotherapy affect serum TPO levels after transplantation.

Platelet Procoagulant Activity During,Peripheral Blood Stem Cell Harvest

We used flow cytometry to measure platelet-derived microparticle levels in plasma obtained from 16 patients during peripheral blood stem cell harvest (PBSC) and in platelet concentrates prepared by apheresis from 10 normal controls. We also studied the binding of an anti-P-selectin antibody and annexin-V to platelets. When all 60 harvests were assessed, we noted a significant difference in microparticle levels between patients with a platelet count >10 x 104/μl and those with a platelet count <10 X 10 4/μl (12.3 ± 4.4 vs. 75 ± 3.9%). In both the first and total harvests, the percentage of platelets and microparticles positive for anti-P-selectin and annexin-V were significantly higher than the normal control levels. These results suggest that patients undergoing mobilization by granulocyte colony-stimulating factor (G-CSF) who have a platelet count >10 X 10 4/μl are at risk of increased procoagulant activity after retransfusion following PBSC harvest. Key Words: Platelet-derived microparticle— Peripheral blood stem cell harvest—Granulocyte colony-stimulating factor.

Microparticles and Raynaud's Phenomenon

membrane receptors for coagulation factor Va and provide a catalytic surface for the prothrombinase reaction (2). Microparticles have been detected in various clinical conditions associated with platelet activation, including immune thrombocytopenic purpura (3-5), thrombotic diseases (6,7), cardiopulmonary bypass (8), and peripheral blood stem cell harvest (9). These observations suggest that microparticles may be involved in modulating hemostasis and thrombosis. Raynaud’s phenomenon, however, is observed in patients with collagen vascular diseases and is associated with disorders of peripheral circulation. We sought microparticles in patients with symptoms of Raynaud’s phenomenon and investigated relationships among microparticles, cytokines, and platelet activation markers.

Effect of thrombopoietin on peroxidase activity of cryopreserved peripheral blood stem cells

Transplantation of mobilized peripheral blood stem cells is increasingly used to facilitate hematological recovery following high-dose chemotherapy. In general, peripheral blood stem cells can be maintained by cryopreservation, e.g., at −80°C, until the day of transplantation. We investigated the effect of thrombopoietin (c-Mpl ligand) on cryopreserved peripheral blood stem cells obtained from 10 patients with malignant disease by assessing peroxidase activity by ultrastructual technique. Leukocyte surface markers wre evaluated by flow cytometry. After peripheral blood stem cells had been purified by use of CD34 monoclonal antibody, cells whose size resembled that of monocytes showed low levels of positivity for CD7, CD41a, and CD42b, but high levels of positivity for CD13, CD14, and HLA-DR. The lymphocyte-size cells showed high levels of positivity for CD7 only. Recombinant human thrombopoietin, administered alone and in combination with various cytokines, promoted the expression of CD41a by CD34-positive progenitor cells. No increase in the expression of CD7, CD13, CD14, and HLA-DR was detected following exposure to cytokines. However, the expression of CD41a and CD42b was enhanced by thrombopoietin. Ultrastructural study of peroxidase activity detected CD41a-positive cells. as well as platelet peroxidase-positive cells, following stimulation with thrombopoietin. Stimulation by other cytokines failed to yield platelet peroxidase-positive cells. Results thus suggest that thrombopoietin may be useful for increasing the recovery of platelets following transplantation of cryopreserved peripheral blood stem cells.