Coagulation factors in chronic liver disease

Coagulation studies were carried out on 30 patients with chronic liver disease. The clotting defect was complex and involved factors V, VII, IX (Christmas factor), and prothrombin. Some patients showed a significant depression of factor IX in the presence of a normal one-stage prothrombin time. Thrombotest was found to be a good indicator of factor IX deficiency in this group of patients and may be of use as an additional liver function test. The screening of patients with liver disease for surgery or liver biopsy should assess the coagulation factors involved in both intrinsic and extrinsic thromboplastin generation.     

Coagulation parameters of captive mountain gazelle (Gazella gazella Pallas, 1766; Bovidae: Antilopinae) and Nubian ibex (Capra ibex nubiana Cuvier, 1825; Bovidae: Caprinae)

The coagulation profiles of 36 mountain gazelles (Gazella gazella) aged 2–6?years, and 17 Nubian ibexes (Capra ibex nubiana), aged 1–4?years, were evaluated and compared. The following parameters were determined in both species: prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen concentration (FIB), and clotting factors VII, VIII:C, IX, X, and XI. Thrombin clotting time (TCT) was also determined in mountain gazelles. The results indicated significant interspecies differences in most parameters, with lower PT, aPTT, and factors VII, IX, and XI and higher factor XIII:C activities in the Nubian ibex than the mountain gazelle. Gender seemed to have a limited influence on these parameters within each species. Both species had higher plasma FIB and factor VIII:C activity relative to humans. This study is the first record of coagulation variables in these two species of wild Arabian desert ruminants.     

Intraindividual comparison of the impact of two selective apheresis methods (DALI and HELP) on the coagulation system

We performed an intraindividual comparison of the effect on the coagulation system of two selective apheresis procedures: Direct Adsorption of Lipoproteins (DALI) and Heparin-induced Lipoprotein Fibrinogen Precipitation (HELP). Six patients suffering from heterozygous familial hypercholesterolemia have been treated with 2 sessions of each procedure. Anticoagulation was carried out according to usual recommendations. Blood samples were taken before, immediately after and on the second day after the sessions. We assessed global coagulation tests (prothrombin time, activated partial thromboplastin time), fibrinogen, prothrombin fragment F 1 + 2 and a variety of factors (Factors II, V, VII, XIII, IX, X, XI, XII, XIIa; von Willebrand Factor; collagen-binding activity, prekallikrein, high-molecular weight kininogen) and antagonists (antithrombin III, protein S activity, free protein S). In fact, all parameters measured have been influenced by the apheresis treatment. Fibrinogen is lowered more by HELP which also has a more definite impact on factors belonging to the prothrombin complex (II, VII, X). In contrast, the major effects of the DALI system have been seen on the intrinsic pathway of the coagulation system (IX, XI, prekallikrein, high-molecular-weight kininogen). With both systems, no increases in activated Factor XII or in prothrombin fragment F 1 + 2 have been observed. These data provide a solid basis for individual adaptations of anticoagulant doses.     

Use of the etonogestrel-releasing implant is associated with hypoactivation of the coagulation cascade

BACKGROUND: The role of progestogens in haemostasis is controversial. Our objective is to evaluate the haemostatic effects of an etonogestrel-releasing implant. METHODS: This open-label, self-controlled, longitudinal study involved 20 healthy women receiving subcutaneous etonogestrel-releasing implants. At baseline, 1, 3 and 6 months, we measured the following: activated partial thromboplastin time; prothrombin time; thrombin time; fibrinogen; coagulation factors II, V, VII, VIII, IX, X and XI; von Willebrand factor; activated protein C (APC); antithrombin; free protein S; plasminogen activator inhibitor type 1 (PAI-1); alpha2-antiplasmin; thrombin-antithrombin (TAT) complex; prothrombin fragment 1 + 2 (F1 + 2); D-dimers; APC resistance. Statistical analyses included the Friedman test and ANOVA. RESULTS: Levels of APC (P < 0.01), factor II (P = 0.02), factor VII (P = 0.006), factor X (P = 0.01) and F1 + 2 (P < 0.001) were reduced, whereas those of PAI-1 (P = 0.01) and factor XI (P = 0.006) were transitory increased. All of these values, however, remained within normal ranges. Surprisingly, TAT concentrations fell below the normal range (P < 0.001). CONCLUSIONS: Our findings suggest that the etonogestrel-releasing implant does not induce a prothrombotic pattern during the first six months of use, and that its use is associated with a reduction in thrombin generation.     

Effect of heparin on chronically induced intravascular coagulation in dogs.

When intermediate-strength thromboplastin was continuously infused into dogs for 10 days or more, platelet counts decreased sharply and factor VIII concentrations decreased by more than 50%. There was little change in plasma fibrinogen, prothrombin, factor V, antithrombin III, plasminogen, prothrombin time, and thrombin time values. When heparin was infused (25-50 U/kg per h) along with the same thromboplastin, there was no change in onset or degree of thrombocytopenia. However, the decrease in factor VIII was abolished and there were significant increases in fibrinogen, prothrombin, and factor V. The absolute concentrations of the various clotting factors seemed to give no indication of their turnover rates. Unexplained is the remarkable heparin tolerance that developed in these dogs.     

Reactions of Blood with Nonbiologic Surfaces: Ultrastructural and Clotting Studies with Normal and Coagulation Factor Deficient Bloods

Interaction of normal and coagulation factor deficient bloods with glass, Teflon and silicone-coated glass surfaces have been studied. The morphology of the blood-surface interaction was observed by scanning electron microscopy. Activation of the intrinsic coagulation system and progression of these changes, monitored by use of the partial thromboplastin time test, were influenced by both the type of surface to which blood was exposed and the deficiencies of coagulation Factors I, VIII, IX, or XII. Deficiency of fibrinogen appears to enhance, minimally, activation of the coagulation sequences by test materials. However, deficiency of fibrinogen markedly reduces adhesion of platelets to foreign surfaces. Deficiency of Factor XII, but not of Factors VIII or IX, decreases platelet adhesion to nonbiologic surfaces but to a lesser extent than does deficiency of fibrinogen. Roughness of test surfaces appears to encourage cellular deposition from blood. An ex vivo model designed for screening materials for their compatibility with blood is described.     

Effects of membrane plasma exchange on the hemostatic system and on thyroid hormones in critically ill patients

The present study examined the effects of repeated plasma exchanges with membrane filtration (Plasmaflux P2 membrane, 4.3 I human albumin solution) on the hemostatic system and on thyroid hormones in critically ill patients. Clotting factors V, VII, VIII, IX, X, XI, XII, XIII, fibrinogen, antithrombin III (ATIII), prothrombin time (PT), activated partial thromboplastin time (PTT), total (TT3) and free tri-iodothyronine (FT3), total (TT4) and free thyroxine (FT4), and thyroxine binding globulin (TBG) were determined before, immediately after, 1, 3, 6 and 24 h after plasma exchange in 6 patients (3 with glomerulonephritis, 2 with IgG myeloma, 1 with chronic polyneuritis) during 18 plasma exchanges. After plasma exchange levels of clotting factors and ATIII were markedly lowered but except for fibrinogen and factor XIII, they were not reduced by repeated exchange procedures. Thyroid hormones and TBG were reconstituted after 24 h. Pre-exchange levels, except for TT4 and TBG, were not lowered by repeated exchange procedures. Risk of bleeding or thrombosis is small and there is no appreciable risk of loss of thyroid hormones during repeated plasma exchanges.     

Evaluation of the automated coagulation analyzer Sysmex(®) CS-2100i (Siemens)

The Sysmex(?) CS-2100i is a fully automated multiparameter hemostasis analyzer equipped with a photo-optical clot detection unit, a cap-piercing system and a pre-analytical check screens for interfering substances such as bilirubin, lipids and haemolysis (HIL system). It is designed to perform coagulation tests as well as chromogenic and immunologic assays. The aim of the present study was to evaluate its performance. The tests performed were routine coagulation (prothrombin time, activated partial thromboplastin time, fibrinogen, factor VIII and factor V), chromogenic (antithrombin) and immunologic assays (D-Dimer). The intra-assay and inter-assay coefficients of variation (CV) were below 5% for most parameters both in the normal and in the pathological range (exceptions: intra-assay CV = 5.65% for the fibrinogen in the low range of concentrations; and inter-assay CV = 6% for clotting factor). The measured lower limits of linearity for factor VIII and factor V were satisfactory. No sample or reagent carryover was detected in the conditions of the study. Our results demonstrated that using the CS-2100i analyzer, routine coagulation testing can be performed with satisfactory precision.     

In vivo effects of stroma-free hemoglobin and polyhemoglobin on coagulation factors in rats

We studied the effects of rat stroma-free hemoglobin (rSFH), human stroma-free hemoglobin (hSFH), rat polyhemoglobin (rPoly), and human polyhemoglobin (hPoly) on coagulation factors in rats. Albumin and saline infused rats were controls. The infusion volume was 10% of the rat's blood volume. The concentrations of hemoglobin in this study were 7 g/dl. Measurements for prothrombin time (PT) and activated partial thromboplastin time (PTT) were at 5 minutes, 2, 6, 24 and 72 hours after infusion. Factor X, fibrinogen, plasminogen, antithrombin III, and antiplasmin were followed at 24 and 72 hours after infusion. Compared with saline infused rats PT and PTT did not change significantly in those rats infused with Hb preparations. There was a transient increase of PTT from 2 to 24 hours after infusion in albumin infused rats. Factor X, fibrinogen, antithrombin III and antiplasmin showed no significant differences between Hb infused groups and saline infused group. Twenty-four hours and 72 hours after infusion plasminogen decreased in all groups except the albumin infused rats at 24 hours after infusion when compared with normal rat plasma pool. However, there were no significant differences in plasminogen levels between the hemoglobin infused groups and the control saline group. Stroma-free and polyHb solutions (rSFH, hSFH, rPoly and hPoly) did not cause significant changes in prothrombin time and activated partial thromboplastin time in rats. The rats infused with hemoglobin solutions (rSFH, hSFH, rPoly, and hPoly) did not show significant differences in Factor X, fibrinogen, antithrombin III and antiplasmin levels compared with the control group.     

Horn fly (Diptera: Muscidae) saliva targets thrombin action in hemostasis

The horn fly, Hematobia irritans (L.), is an important pest of livestock because the adult stage of both sexes are aggressive blood-feeders. Remarkably, even though horn fly adults feed recurrently on their hosts as ectoparasites, these flies lack the ADP-responsive antiplatelet aggregation and vasodilatory antihemostatic systems described for other blood-feeding Diptera. Horn fly salivary gland extracts do interfere with the normal coagulation process as demonstrated by the recalcification time assay. Using this as a baseline, the effects of saliva on recalcification time, activated partial thromboplastin time, prothrombin time, and thrombin time were measured to determine which arm(s) of the coagulation cascade might be impacted. Factor-deficient plasma assays also were used to measure possible perturbations in clotting. Gland-free saliva delayed the recalcification time as well as the activated partial thromboplastin time, prothrombin time, and thrombin time. Saliva also further delayed clotting times of plasmas deficient in factor V, factor VIII, and factor XIII, indicating that other factors in the coagulation cascade were inhibited. Although horn fly saliva did not alter the ability of deficient plasma reconstituted with factor X to clot, it did inhibit deficient plasma reconstituted with factor II (thrombin). Antithrombin activity in saliva was confirmed by its ability to interfere with thrombin hydrolysis of fibrinogen, its normal substrate, and by its inhibition of thrombin action on a chromagenic substrate that mimics the hydrolytic site of fibrinogen. Thus, horn fly saliva contains a factor that specifically targets thrombin, a key component in the coagulation cascade. While the biochemical mechanisms of inhibition may vary, this antihemostatic characteristic is shared with other zoophilic Diptera such as black flies, Simulium spp., and tsetse, Glossina morsitans morsitans Westwood, that feed on ungulates.     

Recombinant Factor VIIa

black triangle Recombinant factor VIIa is a preparation of activated coagulation factor VII (factor VIIa) that is produced by recombinant DNA technology. The drug expedites blood coagulation without the need for factors VIII and IX in patients with haemophilia. black triangle Indicators of activation of systemic coagulation of blood were unchanged and mean prothrombin times and activated partial thromboplastin times were decreased substantially after administration of recombinant factor VIIa at doses of up to 90 microg/kg in pharmacodynamic studies. black triangle Recombinant factor VIIa has been shown to be effective at doses ranging from 17.5 to 120 microg/kg in the control of joint, muscle and mucocutaneous bleeding in patients with haemophilia A or B with inhibitors of factor VIII or IX. black triangle Satisfactory postoperative haemostasis was achieved in all patients with haemophilia and inhibitors of factors VIII and IX who received multiple doses of recombinant factor VIIa 90 microg/kg during and after surgery. The drug has also demonstrated some efficacy in the control of internal or CNS bleeding in small numbers of patients. black triangle Self-administration of recombinant factor VIIa or administration by caregivers has been used successfully to control bleeding episodes in patients with haemophilia without the need for hospital or clinic admission in home treatment programmes in 3 countries. black triangle Recombinant factor VIIa is well tolerated. No thrombotic complications have been reported, and there is no evidence to date of the formation of antibodies to the drug in patients with haemophilia A or B or acquired inhibitors of factor VIII or IX.     

Evaluation of the automated coagulation analyser ACL TOP (instrumentation laboratory)

The ACL TOP is a fully automated random access analyser for coagulometric, chromogenic ou immunologic measurements. The aim of the present study was to evaluate its performances. The tests performed were: prothrombin time (PT), activated partial thromboplastin time (aPTT), prothrombin time derived fibrinogen (FibD), factor VIII (FVIII), antithrombin (AT) and free protein S antigen (PS). The comparison study was performed by analyzing patients samples in duplicate with ACL TOP and the analyser MDA II (BioMérieux) or CA 6000 (Dade-Behring). Imprecision (CV%) was < 4% for routine tests and < 5% for FVIII, AT and PS, except a between-run imprecision < 7,5% for low AT levels. The measured lower limits of linearity for FVIIII, AT and PS were satisfactory. The correlation observed between the ACL TOP and the other analysers was strict for PT and AT and good for TCA and FibD. Triglyceride levels > or = 6 mmol/L interfered with PT and FibD measurements. No sample or reagent carryover was observed in the conditions of the study. Overall, the ACL TO is an analyser with very satisfactory analytical and technical performances and is well suited for routine and specialized coagulation laboratories.     

Procoagulant, anticoagulant and fibrinolytic activities in llama plasma

The haemostatic profile of 46 healthy, adult female llamas was evaluated and compared to a human reference plasma. The results indicate that standard laboratory reagents and procedures are suitable for the determination of procoagulant, anticoagulant and fibrinolytic analytes in llama plasma. Human recombinant tissue factor is an effective reagent for the prothrombin time assay. With this reagent, llama plasma exhibited a clotting time similar to human reference plasma. The activated partial thromboplastin time results were shorter for llama plasma than for human plasma, and there was a significant (p<0.05) increase, in the order of tenfold, in factor VIII:C activity when human plasma was used as the reference standard. The activities of other procoagulant proteins, including factor VII, IX, X and Xl, were similar irrespective of whether llama or human reference standards were used.The anticoagulant or inhibitory activity, as determined by the amounts of 2-macroglobulin and antithrombin, the fibrinolytic activity, as estimated from the levels of plasminogen and plasminogen activators, as well as fibrinogen values are consistent with those reported for other domestic species such as the horse.     

The effects of chronic cadmium toxicity on the hemostatic system

Cadmium, a highly toxic heavy metal, is distributed widely in the general environment. The characteristic clinical manifestations of chronic cadmium intoxication include renal proximal tubular dysfunction, osteomalacia and anemia. Accumulating evidence suggests that cadmium toxicity may also affect various organs such as the liver, lung, testis and hematopoietic system. The aim of this study was to determine the effect of chronic cadmium exposure on the anticoagulant system in rats. Fourty-five adult Wistar albino rats were randomly allocated into 2 groups. While the control group was given tap water, the animals in the cadmium group were treated with 15 ppm CdCl(2) for 4 weeks. Blood cadmium concentration, prothrombin time, activated partial thromboplastin time, plasma protein C and antithrombin activity, and platelet count were determined in the rats. Blood cadmium concentrations increased in the experiment group compared to the control group (p < 0.001). Results also show that cadmium exposure shortened prothrombin time (p < 0.05) and activated partial thromboplastin time (p < 0.01) in rats. Protein C (p < 0.001) and antithrombin (p < 0.001) decreased to statistically significantly lower levels in rat plasma after cadmium exposure when compared to the control group. When the number of thrombocytes was compared between 2 groups, a decrease was observed in the group treated with CdCl(2), which was, however, not statistically significant (p > 0.05). In conclusion, when the parameters of the hemolytic system are considered, the decrease in protein C and antithrombin activities and the shortening of prothrombin time and activated partial thromboplastin time suggests the presence of a hypercoagulable state during chronic cadmium intoxication. Therefore, it may be stated that chronic cadmium toxicity sets the stage for hypercoagulation and hence increases the risk of thrombosis.     

膝关节置换中应用骨水泥和止血带对凝血功能的影响

背景：有研究表明膝关节置换中骨水泥固定假体时骨水泥对患者的血液动力学及凝血功能的影响较大。 目的：观察膝关节置换中骨水泥和止血带对患者凝血功能的影响。 方法：采用随机对照研究方法,将骨性关节行单侧膝关节置换患者40例随机分成2组,置换时分别应用止血带和不用止血带。通过比较两组患者血浆凝血酶原时间、活化的部分凝血活酶时间、凝血酶时间、纤维蛋白原及血浆D-二聚体水平的变化,来观察膝关节置换中骨水泥和止血带对置换中凝血功能的影响。 结果与结论：两组患者在骨水泥置入后60,120 min,血浆凝血酶原时间值缩短(P < 0.05),纤维蛋白原和D-二聚体在注入骨水泥后增多(P < 0.05),其中止血带组的变化更为明显,两组患者在180 min时基本恢复正常,活化的部分凝血活酶时间及凝血酶时间在骨水泥注入前后均无明显变化,另外,所监测的凝血功能相关指标(血浆凝血酶原时间、活化部分凝血酶原时间、凝血酶时间、纤维蛋白原及D-二聚体的数值在注入骨水泥前后均在正常范围内。相比非止血带组,止血带组血浆凝血酶原时间缩短、纤维蛋白原及D-二聚体含量增多(P < 0.05)。说明膝关节置换中骨水泥应用后可以使单侧膝关节置换患者的凝血功能处于高凝状态,止血带可加重患者的高凝状态。     

Investigation of coagulopathy in three cases of tiger snake (Notechis ater occidentalis) envenomation

AIMS: To investigate the severe coagulopathy (fibrinogen < 1.0 g/l) that occurs in some cases of tiger snake envenomation. Specifically, to determine the concentration of clotting factors on presentation and during resolution of the coagulopathy. METHODS: Clotting factors II, V, VII, VIII, IX, XI were assayed on all coagulation samples received from three successive cases of severe tiger snake envenomations. Assays were performed at dilutions of 1:5 and 1:10 using an MLA 1600c automated coagulation analyser and Dade Behring factor-deficient plasmas, controls and standards. D-dimers were assayed using Agen Dimertest latex kit, fibrinogen was determined using the Clauss method and platelet counts were performed using Abbott Cell-Dyn 4000 analysers. RESULTS: The activity of the coagulation factors of the intrinsic pathway was reduced (factor VIII < 44% in all cases, factor IX < 33%, factor XI < 52% in Cases 1 and 2) but the results for the two dilutions were not parallel. In one case, factor VIII and factor IX activity increased 2-fold prior to the administration of blood products. Treatment with blood products corrected the coagulation indices in two out of the three cases but factor V remained low in one case (25%). CONCLUSIONS: The non-parallel results and the apparent increase in factor levels prior to treatment may result from the transient presence of an inhibitor to factors VIII, IX and XI in cases of tiger snake envenomation. Insight into the effects of snake venom on individual coagulation factors could be beneficial when considering new treatments for the coagulopathy induced by snake envenomation.     

Hemostatic abnormalities in malignancy, a prospective study of one hundred eight patients. Part I. Coagulation studies.

A prospective study of hemostatic abnormalities in 108 cancer patients was undertken at an oncology clinic in a university teaching hospital. Tests included Quick prothrombin time, activated partial thromboplastin time, thrombin time, platelet count, modified Ivy bleeding time, fibrinogen, fibrin degradation products (FDP), euglobulin lysis time, protamine sulfate test, and factor V, VII, VIII and X assays. Ninety-eight per cent of the patients had one or more abnormal coagulation tests. The commonest abnormalities were elevated fibrin degradation products and prolonged thrombin time. Thrombocytosis occurred in 57% of patients, hyperfibrinogenemia in 46%, thrombocytopenia in 11%, and non had hypofibrinogenmia. It is suggested that platelet count, fibrinogen concentration, and serum FDP assay are the most useful tests in assessing the hemostatic abnormalities in cancer patients, although thrombin time, factor V assay, and bleeding time may also be helpful. The peripheral blood smears of 53 patients were reviewed, and only one showed microangiopathic hemolytic anemia. The data illustrate that subclinical coagulopathy is relatively frequent in patients with malignancy.     

Evaluation of APTT reagent sensitivity to factor IX and factor IX assay performance. Results from the College of American Pathologists Survey Program

Hereditary factor IX deficiency (hemophilia B) is among the more common hereditary bleeding disorders and factor IX assays are among the more common specific factor assays performed by coagulation laboratories. To assess the sensitivity of various reagents used for performance of activated partial thromboplastin times and factor IX assays, a series of samples with varying levels of factor IX were included in the 1988 College of American Pathologists Survey Program. We found significant differences in the sensitivity of reagents to factor IX deficiency. Surprisingly, the least sensitive reagents were among the most commonly used reagents. Significant differences in the classification of activated partial thromboplastin times as abnormal were noted between H1 and H2 survey participants. As with factor VIII assays, significant differences in the dose-response curves for factor IX deficiency were noted between reagents, with more responsive reagents giving more precise results for factor IX assays. Comparison of factor IX assay performance in 1988 with 1980 performance indicates a substantial improvement in assay precision. However, a further improvement in assay performance could be expected if current recommendations were followed.     

Sulfated Sericin is a Novel Anticoagulant Influencing the Blood Coagulation Cascade

Sulfated sericin's influence on factors in the blood coagulation cascade was investigated to elucidate its anticoagulant mechanism. Prolongation of the prothrombin time (PT) and activated partial thromboplastin time (APTT) were observed in the presence of sulfated sericin. Fluorogenic peptide substrates on thrombin (factor IIa) and factor Xa were used to study the influence of sulfate sericin on their respective activities. Sulfated sericin inhibited neither thrombin nor factor Xa in the presence of antithrombin III (AT III). Gel electrophoresis was used to examine fibrinogen–fibrin conversion by thrombin in the presence of sulfated sericin. FPA and FPB release from fibrinogen by thrombin proceeded in the presence of sulfated sericin. The behavior of polymerization of fibrin monomer (FM) was affected by the presence of sulfated sericin. No initial lag time in the polymerization process was observed by addition of sulfated sericin to FM. This result means that sulfated sericin will interfere in the build-up of normal double-strand fibrils of FM during formation of fibrin fiber. Scanning electron microscopy (SEM) observations supported this inference. The anticoagulant mechanism of sulfated sericin is inferred to interfere with the initial polymerization process of FM.     

Coagulation abnormalities in patients with end-stage renal disease treated with hemodialysis

Plasma levels of various blood coagulation factors, antithrombin III and plasminogen were measured in 18 patients with end-stage renal disease treated by longterm hemodialysis. The results were compared with those obtained in a group of normal volunteers. Factors XII, IX and II activities were significantly reduced; factors VIII, VII and X levels were increased; and factors XI and V activities and high molecular weight kininogen concentration were comparable to the control group. Antithrombin III activity and concentration were significantly reduced. The mean plasma fibrinogen concentration was normal although levels above and below normal limits were noted in a few patients. Similarly the mean platelet count was normal, although mild thrombocytopenia occurred in several patients and thrombocytosis in one. In conclusion, the present study confirms published results about factor VIII and AT-III, and provides new information on changes of other coagulation factors in uremia treated by long-term hemodialysis.