Thromboelastography measurements of whole blood from factor VIII‐deficient mice supplemented with rFVIII

Landskroner, Kyle; Olson, N. C.; Jesmok, Gary

doi:10.1111/j.1365-2516.2005.01104.x

Cited by 18 publications

(20 citation statements)

References 22 publications

(29 reference statements)

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“…Even if Fg was diminished by 50% (Fg ϩ/Ϫ ) as a result of LPS treatment, the TEG results would have been similar to WT mice ( Figure 5D, Table 1). On the other hand, previous TEG studies on FVIII Ϫ/Ϫ mouse blood have shown abnormal R and K values, 18 which is consistent with our data demonstrating large effects on whole blood clotting with consumption of intrinsic factors. In the case of LPS-treated PC Ϫ/Ϫ PC(tg4)/ TF Ϫ/Ϫ TF(tg) mice, both the FVIII and FIX levels are reduced, exacerbating the abnormal clotting of whole blood.…”

Section: Resultssupporting

confidence: 93%

An accompanying genetic severe deficiency of tissue factor protects mice with a protein C deficiency from lethal endotoxemia

Donahue

Navari

Ploplis

et al. 2011

Blood

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Mice with a severe genetic deficiency of protein C (PC), PC ؊/؊ PC(tg4), display enhanced susceptibility to lethal effects of gram-negative endotoxemia induced by lipopolysaccharide (LPS), whereas mice severely deficient in tissue factor (TF), TF ؊/؊ hTF(tg), are protected from LPSmediated lethality. In this study, we show that a simultaneous severe deficiency of TF protected low-PC mice from LPSinduced death, resulting in a survival profile similar to that experienced by wild-type (WT) mice. Plasma and whole blood coagulation assays, the latter measured by thromboelastography, demonstrated development of coagulopathies in LPS-treated mice, which were more severe in the case of the doubly deficient TF ؊/؊ hTF(tg)/PC ؊/؊ PC(tg4) mice, mainly reflecting earlier signs of disseminated intravascular coagulation in this latter cohort. Markers of inflammation were also elevated in response to LPS in both groups of mice at times just preceding death. We conclude that whereas coagulopathies are more exacerbated in LPStreated TF ؊/؊ hTF(tg)/PC ؊/؊ PC(tg4) mice, the lowering of TF levels in mice with an accompanying severe PC deficiency confers protection against death compared with mice with a single severe PC deficiency. This suggests that proteases generated as a result of factor VIIa/TFmediated thrombin generation play a mechanistic role in the enhanced lethality seen under very low PC conditions in an endotoxemia model in mice. (Blood. 2011; 117(1):283-289) IntroductionThe hemostasis system is intricately involved in the innate immune response, in part, via linkages between coagulation and inflammation. The interactions between these systems are profoundly displayed in sepsis/endotoxemia, wherein pathogenic challenge up-regulates tissue factor (TF) on monocytes 1 and endothelial cells, 2 that not only leads to a hypercoagulation potential, but also provides several proteases (eg, thrombin) that are capable of signaling the inflammatory response through interaction with cellular receptors. 3 The resulting inflammatory mediators downregulate anticoagulant activated protein C (aPC) generation and inhibit fibrinolysis, thus enhancing the hypercoagulable state. In severe cases of sepsis, lethal disseminated intravascular coagulation (DIC) occurs. Some success in treatment of severe sepsis has been achieved with aPC administration, 4 which is grounded in the anticoagulant, profibrinolytic, anti-inflammatory, endothelial barrier protective, and antiapoptotic activities of aPC. 5,6 A deficiency of PC is symptomatic in humans, resulting in conditions such as purpura fulminans, 7 and in experimental animals in a variety of challenge models. 6 It has also been previously shown that embryos with total deficiencies of PC (PC Ϫ/Ϫ ) do not live beyond the early neonatal stage, 8 but embryos can survive to adulthood with PC levels greater than approximately 1% of wild-type (WT). 9 In addition, maternal plasma PC levels are critical to embryonic survival. In that regard, we found that minimal maternal PC concentrations, approximating ...

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Section: Resultssupporting

confidence: 93%

An accompanying genetic severe deficiency of tissue factor protects mice with a protein C deficiency from lethal endotoxemia

Donahue

Navari

Ploplis

et al. 2011

Blood

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“…The TEG assay has a greater sensitivity than traditional clotting assays and allows the analysis of clot (fibrin) formation in real time, demonstrating that the rate of fibrin formation correlates to FVIII levels from 0.001% to 100%. 60,61 In these studies, all 8 dogs have maintained clinical chemistry and hematologic parameters within normal limits. No abnormal histopathologic findings were found in liver biopsies.…”

Section: Long-lived Therapeutic Activity In the Absence Of Toxicity Bmentioning

confidence: 99%

Multiyear therapeutic benefit of AAV serotypes 2, 6, and 8 delivering factor VIII to hemophilia A mice and dogs

Jiang¹,

Lillicrap²,

Patarroyo-White³

et al. 2006

Blood

183

159

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IntroductionHemophilia A, a congenital deficiency or dysfunction of factor VIII (FVIII), is the most common severe inherited bleeding disorder in humans. Severe hemophilia A patients have less than 1% of normal FVIII activity, and suffer from spontaneous or traumatic joint and muscle hemorrhage, leading to a chronic painful and disabling arthropathy. Bleeding into body cavities or the brain can result in significant morbidity and mortality if not treated aggressively. 1 Current treatment in the developed world, FVIII protein replacement, has established that restoring circulating FVIII levels above 1% of normal prevents most spontaneous bleeding, and levels above 5% are sufficient to improve the disease from a severe to a mild form. However, the limited worldwide supplies of both plasma-derived and recombinant FVIII, its short half-life in vivo (ϳ 12 hours), and the high cost of treatment (Ͼ $150 000 per year) make gene therapy an attractive alternative to better manage and cure the disease.Previously, we have shown that gene therapy with an AAV2 vector encoding a B-domain-deleted (BDD) canine FVIII (cFVIII) cDNA under the control of a liver-specific promoter resulted in an average of 2% to 3% of normal canine FVIII activity in 2 hemophilia A dogs, 2 providing preliminary support for the feasibility of this approach in humans. In order to further improve the efficacy of liver-targeted AAV-cFVIII, we explored the possibility of using alternative serotypes of AAV. We also assessed the duration of therapeutic benefit following a single injection of AAV-cFVIII in hemophilia A dogs.Since the isolation of AAV2, many different AAV serotypes have been isolated from human and nonhuman primate tissues. 3 In comparison with the prototypic AAV2, AAV vectors pseudotyped with other serotypes show superior transduction efficiency in various tissues: AAV1 in muscle, 4 pancreatic islets, 5 heart, 6 vascular endothelium, 7 brain and central nervous system (CNS), 8,9 and liver 10 ; AAV3 in Cochlear inner hair cells 11 ; AAV4 in brain 12 ; AAV5 in brain and CNS, 8,13 lung, 14-16 eye, 17,18 arthritic joints, 19 and liver 20 ; AAV6 in muscle, 21,22 heart, 23 and airway epithelium 24 ; AAV7 in muscle 4 ; and AAV8 in muscle, 4,25 pancreas, 26 heart, 25 and liver. [27][28][29][30][31] The tissue tropism of different AAV serotypes may permit targeting of AAV vectors to human disease. However, as most of these tissue-specific tropisms have been reported in the rodent, it is important to evaluate cross-species fidelity of differential targeting among serotypes in larger animal modelsIn this report, we have compared the efficacy, gene transfer efficiency, and biodistribution of AAV-cFVIII vectors of serotypes 2, 5, 6, and 8 delivered by portal-vein injection in hemophilia A mice. Furthermore, since prior studies have demonstrated that the hemophilia dog model, compared with the mouse model, more accurately predicts the therapeutic outcomes in humans and other primates, 32,33 we have determined the long-term efficacy and safety of AAV2-cFVI...

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“…23 A similar picture is observed in murine blood. Thus, blood from FVIII knockout mice coagulates later than blood from normal mice 18 and after coagulation is initiated, the propagation of the clot formation is slower. When comparing the data from the mice with a normal coagulation system and FVIII knockout mice the thromboelastographic analysis revealed …”

Section: Discussionmentioning

confidence: 99%

“…16 Thus, the clotting process is significantly impaired in blood from haemophilic patients (and animals) compared with individuals with a normal coagulation system. 17,18 However, because blood coagulation initiates as soon as the blood is drawn from the vessel or gets in contact with intravascular tissue, the result of the following analysis is very sensitive to the preanalytical conditions such as the blood collection method.…”

mentioning

confidence: 99%

Impact of blood sampling technique on blood quality and animal welfare in haemophilic mice

Holmberg¹,

Kiersgaard

Mikkelsen

et al. 2011

Lab Anim

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Blood collection in mice can be a challenge, in particular for samples used for coagulation analysis as initiation of coagulation during the procedures can influence the results. Blood collection from the retrobulbar venous plexus is commonly used but the method remains controversial. Several alternatives exist but not all are applicable to mice with a compromised coagulation system because of subsequently excessive bleeding. We therefore wanted to explore whether blood collection by puncture of the submandibular vein could replace blood collected from the retrobulbar venous plexus during pharmacokinetic and pharmacodynamic studies in mice lacking coagulation factor VIII (FVIII). The plasma concentrations of recombinant activated factor VII were independent of the blood collection method in a pharmacokinetic study. The same applied to the thromboelastographic profile of mice with normal coagulation in a pharmacodynamic study. However, excessive haemorrhages were observed in all FVIII knockout mice after a single puncture of the submandibular vein and 60% of the mice were euthanized 2-4 h after the blood collection. In contrast, no or only slight haemorrhage was observed in animals subjected to blood collection from the retrobulbar venous plexus. No signs of distress determined by blood glucose level or clinical abnormalities of the eye were observed after puncture of the retrobulbar venous plexus. In conclusion, blood collected by puncture of the submandibular vein and retrobulbar venous plexus has a quality which allows it to be used in coagulation assays. However, because of excessive bleedings, puncture of the submandibular vein is not recommended in mice lacking FVIII.

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Thromboelastography measurements of whole blood from factor VIII‐deficient mice supplemented with rFVIII

Cited by 18 publications

References 22 publications

An accompanying genetic severe deficiency of tissue factor protects mice with a protein C deficiency from lethal endotoxemia

An accompanying genetic severe deficiency of tissue factor protects mice with a protein C deficiency from lethal endotoxemia

Multiyear therapeutic benefit of AAV serotypes 2, 6, and 8 delivering factor VIII to hemophilia A mice and dogs

Impact of blood sampling technique on blood quality and animal welfare in haemophilic mice

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