Tomotaka Yoshida

A familial factor XIII subunit B deficiency

A 32‐year‐old woman with a bleeding tendency born of a consanguineous marriage, was found to have factor XIII subunit B deficiency. An abnormally low level of factor XIII activity was initially noticed and this finding led to further studies of the proband and her family. The notable features were: undetectable subunit B of factor XIII in the proband and her brother and reduced levels of subunit B, 34–52%, in her parents and children. The probands brother had a markedly decreased level of subunit A protein. The level of factor XIII subunit A in platelets of the proband was normal. The half‐life of subunit A determined from the disappearance curve of infused factor XIII subunit A concentrate was approximately 3 d and this is the shortest estimate of the half‐life of factor XIII to date. From these results, it is suggested that subunit A is unstable in plasma deficient in subunit B and subunit B stabilizes the A protein.

Immature platelet fraction for prediction of platelet engraftment after allogeneic stem cell transplantation.

Platelet regeneration represents an important and separate element in the engraftment process for allogeneic stem cell transplantation. Fully automated flow cytometry using blood cell counters now allows reliable quantification of reticulated platelets, expressed as the immature platelet fraction (IPF). We studied the kinetics of IPF in six patients grafted with allogeneic peripheral blood stem cell transplantation (PBSCT), 12 patients with bone marrow transplantation (BMT) and seven patients with cord blood transplantation (CBT). Preconditioning therapy caused an immediate and rapid fall in tri-lineage hematopoiesis. IPF rose transiently above 3% after a mean duration of 11 days post-PBSCT, 18 days post-BMT and 19 days post-CBT. This was 1, 4 and 13 days earlier than platelet engraftment, respectively. A linear correlation model showed a close association between the rise of IPF and tri-lineage engraftment after transplantation. IPF counting may thus provide an accessible measure of thrombopoietic activity, leading to early evaluation of marrow function and allowing monitoring of platelet regeneration.

Decreased plasma activity of antithrombin or protein C is not due to consumption coagulopathy in septic patients with disseminated intravascular coagulation

Abstract: We investigated whether depressed plasma antithrombin and protein C activity, considered as a specific finding of disseminated intravascular coagulation (DIC), is due to consumption coagulopathy in septic patients with DIC. An analysis of hemostatic parameters was performed in 139 septic patients (68 with DIC and 71 without DIC). Plasma activity of antithrombin and protein C tended to be significantly decreased in septic patients with DIC but not in those without DIC (p < 0.001). However, when the septic patients were classified into three groups according to the albumin (or choline esterase) level, no significant differences in antithrombin activity or protein C activity were observed between the patients with and without DIC in any of the subgroups. Notably, neither the plasma activity of antithrombin nor protein C was decreased even in septic patients with DIC who had normal plasma levels of albumin (or choline esterase). No significant correlation was observed between plasma levels of thrombin–antithrombin complex (TAT) and antithrombin activity, or between plasma levels of TAT and protein C activity either in septic patients with DIC or without DIC. It is reasonable to conclude that the markedly reduced plasma activity of antithrombin and protein C is not due to consumption coagulopathy in septic patients with DIC.

Mechanism on Disorders of Coagulation and Fibrinolysis in Diabetes

Determination of various important parameters of coagulation and fibrinolysis, clinical characteristics, and levels of serum lipid were compared in 193 patients with NIDDM and 50 control subjects. Levels of fibrinogen, tissue factor pathway inhibitor (TFPI), thrombin-antithrombin complex, and plasminogen activator inhibitor 1 in plasma increased significantly in the diabetic patients. Levels of TFPI correlated significantly with levels of total cholesterol. In the patients with coronary heart disease or cerebral infarction, levels of lipoprotein(a) increased significantly. From these results, we have concluded that there is a thrombotic tendency or at least an imbalance between the hemostatic and thrombosis-protecting system in diabetic patients, especially in patients with angiopathy.

Pathophysiology of disseminated intravascular coagulation (DIC) progresses at a different rate in tissue factor-induced and lipopolysaccharide-induced DIC models in rats

&NA; Tissue factor (TF) and lipopolysaccharide (LPS) are frequently used to induce disseminated intravascular coagulation (DIC) in experimental animal models. Although the pathophysiology of DIC may differ depending on which agent is used for induction, previous studies on models of DIC have not distinguished which DIC‐inducing agent was used. In the present paper, we evaluate the characteristics of TF‐induced and LPS‐induced DIC using two types of DIC models, with special reference to selected hemostatic parameters and pathological findings within the kidney. Male Wistar rats were administered TF (3.75 U/kg; sustained infusion for 4 h) or LPS (30 mg/kg; sustained infusion for 4 h) via the tail vein, and blood sampling was performed at 0, 1, 3, 4, 5, 7, 9, 11, and 28 h. Judging from changes in the levels of thrombin‐antithrombin complex, fibrinogen levels, and platelet counts, it is reasonable to conclude that the severity of both types of experimental DIC is similar with regard to hemostatic activation and consumption coagulopathy. A marked elevation in the level of D‐dimer was noted without any organ dysfunction or much fibrin deposition in the kidney upon administration of TF. However, a markedly prolonged period of elevation in plasminogen activator inibitor activity, a prolonged depression in antithrombin III activity, severe organ failure, and a markedly prolonged period of fibrin deposition in the kidney was observed following LPS administration. A modest number of the rats from the TF‐induced DIC model died during the experimental period, whereas a large number of rats died during LPS‐induced DIC, especially after 9 h. Since the time course of the pathophysiology differed remarkably among the TF‐induced and LPSinduced DIC models in rats, we recommend that TFinduced and LPS‐induced DIC be approached as distinct models in order to determine the implications of their experimental and clinical use. Blood Coagul Fibrinolysis 14:221‐228

Donor leucocyte transfusions for relapse in myelodysplastic syndrome after allogeneic bone marrow transplantation

A 31‐year‐old man with refractory anaemia of excess blasts, which had karyotypic abnormalities, received an allogeneic bone marrow transplant (BMT). At time of relapse, 3 months after BMT, he was treated with donor leucocyte transfusions (DLT). Grade III acute GVHD (graft‐versus‐host disease) occurred 35 d after DLT which was fully reversed with cyclosporin and prednisolone. His condition was complicated by a herpes zoster infection. 2 months after DLT, neutrophil and platelet count were increased and karyotypic abnormalities disappeared. This observation demonstrates that DLT is an effective treatment for relapse of myelodysplastic syndrome (MDS) after BMT.

Changes in molecular markers of hemostatic and fibrinolytic activation under various sampling conditions using vacuum tube samples from healthy volunteers

Molecular makers such as thrombin-antithrombin complex (TAT), prothrombin fragment 1+2 (F1+2), soluble fibrin (SF), and D-dimer, are useful markers in the diagnosis and assessment of various thrombotic conditions. These markers are measured in plasma after blood sampling. Difficult blood sampling is known to falsely elevate plasma TAT levels. However, it is not known exactly why this occurs. In the present study, we examined how levels of molecular markers of haemostatic and fibrinolytic activation change under various sampling conditions using vacuum tube samples from healthy volunteers. When blood was sampled continuously by taking 10 consecutive vacuum tube samples following application of a tourniquet, blood sampling resulted in an accurate assessment of these molecular makers. When blood was sampled continuously by taking vacuum tube samples every one minute over a total of 9 minutes to investigate possible changes in the levels of the molecular markers over time, plasma levels of TAT, SF, and F1+2 gradually increased with time. Plasma levels of TAT, F1+2, and SF increased beyond the normal range over the course of nine minutes. When blood was sampled using three alternative methods, which varied in terms of the duration of needle puncture (sampling B), duration of tourniquet use (sampling C), or both (sampling A), plasma TAT and SF levels were significantly increased with all three methods, compared to control samples. Plasma F1+2 levels were significantly increased with sampling methods A and B, compared to control samples, but not with sampling method C. On the other hand, plasma D-dimer levels were not significantly altered by any of the sampling methods. In conclusion, the results suggest that molecular markers of haemostatic and fibrinolytic activation, except for D-dimer, may be affected by sampling method, particularly the duration of needle puncturing. Therefore, care needs to be taken when using TAT, F1+2, and SF levels to diagnose and estimate activation of the coagulation system.

Beneficial effects of urokinase on lipopolysaccharide-induced disseminated intravascular coagulation in rats: focus on organ function and endothelin levels.

In a rat model of lipopolysaccharide (LPS)-induced disseminated intravascular coagulation (DIC), we used urokinase (UK) in an attempt to clarify the role of fibrinolysis and to investigate changes in plasma endothelin levels. Two kinds of experiment were performed. The first one: experimental DIC was induced by sustained infusion of 30 mg/kg LPS for 4 h via the tail vein, and two doses of UK (2.0 or 10.0 IU/g/4.5 h) were administered to rats 30 min before infusion of LPS, after which UK infusion was continued for a further 4 h. The second one: experimental DIC was induced by sustained infusion of 1 mg/kg/10 min LPS for 10 min, and two doses of UK (2.0 or 10.0 IU/g/4 h) were administered to rats at 30 min after LPS infusion. The parameters described below were determined at 4 h in the first experiment, at 4 h and 8 h in the second one. The similar results were observed in both kinds of experiment. There were no significant differences in plasma thrombin-antithrombin complex, fibrinogen or platelet number among the three DIC groups, in both kinds of experiment. Plasma levels of D-dimer were significantly increased in the LPS + higher dose of UK group when compared with the LPS group. The increased plasma plasminogen activator inhibitor (PAI) activity seen in the LPS group was significantly suppressed in the groups receiving UK (especially higher dose of UK). In addition, the increased plasma levels of creatinine and alanine aminotransferase seen in the LPS group were significantly suppressed in the groups receiving UK (especially higher dose of UK). Plasma levels of endothelin, known to be a potent vasoconstrictive agent, were markedly elevated by LPS infusion, and were significantly suppressed in the groups receiving UK of both kinds of experiment, in a dose-dependent fashion compared with LPS group. Glomerular fibrin deposition was significantly suppressed in the groups receiving UK when compared with the LPS group. No manifestations of bleeding were observed in any of the groups. Enhanced fibrinolysis and depressed endothelin induced by UK thus appear to play an important role in preventing the development of organ failure in the LPS-induced DIC model.

Hypercoagulability and high lipoprotein(a) levels in patients with aplastic anemia receiving cyclosporine.

There is some clinical evidence that cyclosporine A (CyA) is associated with thrombotic complications of bone marrow and renal transplantation. We investigated plasma concentrations of lipoprotein(a) [Lp(a)], a potentially atherothrombotic lipoprotein, and hemostatic and vascular status in ten patients with aplastic anemia receiving CyA, eleven patients not taking it, and 38 age-matched healthy controls. Patients receiving CyA had significantly higher concentrations of plasma fibrinogen (P < 0.05), prothrombin fragment 1 + 2 (F1 + 2; P < 0.05), plasminogen activator inhibitor-1 (PAI-1; P < 0.05), and von Willebrand factor antigen (P < 0.05) than did patients not taking CyA. Plasma concentrations of Lp(a) were higher in CyA-treated patients than those not receiving it (P < 0.05) or healthy controls (P < 0.05). The difference in the Lp(a) concentration between controls and patients who did not receive CyA-treatment was not significant. Our results suggest that hypercoagulability is likely to occur during CyA therapy. Further, the presence of high concentrations of Lp(a) may accelerate the process of atherosclerosis and increase thrombotic events in patients receiving long-term CyA.

Beneficial effect of JTV-803, a new synthetic inhibitor of activated factor X, against both lipopolysaccharide-induced and tissue factor-induced disseminated intravascular coagulation in rat models.

We examined whether JTV-803, a specific activated factor X inhibitor independent of antithrombin III (ATIII), is effective against disseminated intravascular coagulation (DIC) in rat models induced by tissue factor (TF) or lipopolysaccharides (LPS). In male Wistar rats, DIC was induced by a 4 h infusion of thromboplastin (3.75 U/kg) or LPS (50 mg/kg). The rats were given JTV-803 (0.3 or 3 mg/kg, bolus intravenously) (JTV-803 groups) or low molecular weight heparin (LMWH groups) (200 U/kg, bolus intravenously) prior to an injection of TF or LPS. The results showed that JTV-803 was dose-dependently effective against DIC in both TF-induced and LPS-induced rat models. This anti-DIC effect of JTV-803 at higher doses was almost equivalent to that of LMWH in both types of DIC. Plasma ATIII activity was more prominent in the group treated with JTV-803 than in that treated with LMWH. None of rats died in the TF-induced DIC model with or without drug administration. On the contrary, seven of 22 rats died (mortality rate, 31.8%) in the LPS-induced DIC model without drug administration. Although the mortality rate of rats induced with LPS and treated with LMWH was quite high (6/16, 37.5%), none of the LPS-induced rats treated with JTV-803 died. These findings suggested that JTV-803 can treat both TF-induced and LPS-induced DIC models, and that this drug has greater potential in preserving ATIII and in improving the prognosis of DIC.