We compared the levels of microparticles, platelet activation markers, soluble cell adhesion molecules, and soluble selectins between hypertensive patients with and without type 2 diabetes and control subjects. Binding of anti-glycoprotein IIb/IIIa and anti-glycoprotein Ib monoclonal antibodies to platelets did not differ significantly between the hypertensive patients and controls, but platelet expression of activation markers (CD62P, CD63, PAC-1, and annexin V) was higher in the hypertensive patients. Platelet-derived microparticle (PDMP) and monocyte-derived microparticle (MDMP) levels were significantly higher in the hypertensive patients than in the controls. Soluble ICAM-1, VCAM-1, P-selectin, and E-selectin levels were also higher in the

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We investigated the levels of various chemokines and soluble CD40L (sCD40L) in ITP patients, in order to determine the influence of CD40-CD40L interaction on the pathogenesis of ITP. We found increases in MCP-1 and RANTES levels in ITP patients compared with those in healthy individuals. Thirty-eight of the 65 ITP patients (58.5%) had elevated levels of sCD40L. We found significant decreases in platelet counts in sCD40L-positive ITP patients. Although the sCD40L level did not differ significantly between the control and nonimmune thrombocytopenia groups, but among ITP patients. sCD40L level was significantly higher in those with untreated ITP than in those with treated ITP. In addition, significant increases in RANTES, MCP-1, sCD14, and sP-selectin levels were observed in sCD40L-positive ITP patients, although sE-selectin levels were not increased in such patients. For other factors examined, however, there were no differences in level between sCD40L-positive and -negative ITP patients. These findings suggests that there are two groups of ITP patients, one with elevated and one with normal of sCD40L. ITP cases in which sCD40L was increased appeared to involve changes in platelet counts and monocyte activation. The pathogenesis of ITP may in some patients include alterations of the CD40/CD40L pathway.

The kinetics of peripheral blood stem cell mobilization in response to recombinant human granulocyte colony‐stimulating factor is well established. However, there have been few investigations of platelet activation markers during peripheral blood stem cell harvest. We measured the levels of the platelet activation markers, chemokines, and soluble factors in plasma obtained from patients undergoing peripheral blood stem cell harvest. The number of leukocytes, CD34+ cells, neutrophils, monocytes, and lymphocytes peaked on day 5 after granulocyte colony‐stimulating factor treatment, but the numbers of eosinophils and basophils showed no significant change. Regulated on activation normally T‐cell expressed and secreted (RANTES) level increased through day 10, and the monocyte chemotactic peptide‐1 (MCP‐1) level peaked on day 5. Platelet counts continued to increase through day 10. The level of thrombopoietin significantly increased on day 3, peaked on day 5, and decreased slightly by day 10. The levels of soluble CD40 ligand and soluble P‐selectin increased up to day 5. The platelet‐derived microparticle level peaked on day 5, and then began to decline. CD34+ cell numbers significantly correlated with those of leucocytes, neutrophils, monocytes, and lymphocytes, as well as levels of MCP‐1, and the CD34+ cells exhibited changes similar to platelet‐derived microparticles. The patterns of change in MCP‐1, platelet‐derived microparticles, and the CD34+ cell count are similar in that each peaks on day 5 and decreases thereafter. Further study is required to determine if a cause‐and‐effect relationship in their pattern of change exists among them.