Measurement of thrombin generation intra-operatively and its association with bleeding tendency after cardiac surgery

Abstract Variety clinical conditions may cause systemic activation of coagulation, ranging from insignificant laboratory changes to severe disseminated intravascular coagulation (DIC). DIC consists of widespread systemic activation of coagulation, resulting in diffuse fibrin deposition in small and midsize vessels. However, little is known about thrombin generation capacity in patients with DIC. To investigate the thrombin generation capacity, we measured thrombin generation in septic patients with DIC (n=20) and acute promyelocytic leukemia (APL)-induced DIC (n=5). Thrombin generation was determined by the Throbogram-Thrombinoscope assay (Thermo Electron Corporation, Netherlands). The analyzed TG parameters ware the peak of thrombin activity (Peak) and endogenous thrombin potential (ETP). The thrombin antithrombin complexes (TAT) levels were higher in both DIC patients as reported by others. In the septic patients with DIC, we found significant elevations in peak of thrombin activity and ETP as compared with normal controls (determined in 17 healthy males and 14 healthy female). However, the peak of thrombin activity and ETP levels were severely decreased by 60% n the APL patients with DIC. There was slightly correlation between the ETP and TAT levels in septic patients with DIC. Also, there was correlation between the ETP and bleeding tendency in APL patients with DIC. These results suggest that assess of thrombin generation capacity may be helpful in the making the diagnosis in septic patients with DIC. It appears that assess of ETP may contribute to evaluate bleeding tendency in APL patients with DIC. Sepsis with DIC APL with DIC Controls (n=31) *(P<0.05) significantly different controls Peak (nM) 325.3 ± 55.5* 88.2 ± 47.2* 281.2 ± 40.9 ETP (nM.min) 1 ± 326.1* 652.1 ± 274.5* 1469.2 ± 227.3 TAT (μg/ml) 28.4 ± 17.5* 22.5 ± 15.3* <3

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Increased Thrombin Generation in Severe Hemophiliacs with Mild Clinical Phenotype

Blood ◽

10.1182/blood.v112.11.515.515 ◽

2008 ◽

Vol 112 (11) ◽

pp. 515-515

Author(s):

Elena Santagostino ◽

Maria Elisa Mancuso ◽

Armando Tripodi ◽

Veena Chantarangkul ◽

Gianluigi Pasta ◽

...

Keyword(s):

Thrombin Generation ◽

Clinical Phenotype ◽

Platelet Rich Plasma ◽

Gene Mutations ◽

Clinical Score ◽

Bleeding Tendency ◽

Spontaneous Bleeding ◽

Chromogenic Assay ◽

Bleeding Episodes ◽

The Impact

Abstract Introduction: Some severe hemophiliacs (FVIII/FIX<1%) exhibit a mild bleeding tendency, but the basis for this clinical heterogeneity is poorly understood. This study investigated the relationship between the values of endogenous thrombin potential (ETP) and clinical phenotype in severe hemophiliacs. The impact of FVIII/FIX gene mutations and thrombophilic polymorphisms was also evaluated. Methods: severe hemophiliacs older than 18 years without inhibitor history and treated on demand were eligible. Mild bleeders (MB) and severe bleeders (SB) were defined as follows: spontaneous bleeding episodes per year ≤2 (MB) or 25 (SB) and concentrate consumption <500 (MB) or >2000 (SB) IU/Kg/year. Patients who did not fit these criteria were considered as intermediate bleeders (IB). FVIII was measured by chromogenic assay and ETP was measured in platelet-rich plasma after addition of tissue factor. Results: 22MB, 22SB and 28IB were enrolled. MB had lower clinical and radiological scores when compared with both IB and SB (p<0.005). MB showed an older age at first bleed compared to SB (p < 0.005) and p for trend among the 3 groups was also significant (p < 0.05). The prevalence of severe FVIII/FIX gene defects (null mutations) was lower and ETP values were higher in MB compared with both IB and SB (p<0.05; table 1). Conclusions: our results indicate an extremely low prevalence of null mutations in severe hemophiliacs with mild bleeding diathesis. The measurement of thrombin generation in platelet-rich plasma may allow to identify this subgroup of patients, not otherwise distinguishable by conventional functional assays. SB (#22) IB (#28) MB (#22) p Age (yr) 38 (21–76) 38 (23–62) 32 (22–73) NS Age 1st bleed (yr) 1 (0–4) 2 (0–6) 3 (1–10) < 0.005 Bleeding episodes/yr 36 (25–60) 10 (3–20) 0 (0–2) < 0.0005 Factor use (IU/Kg/yr) 2207 (2040–8696) 1068 (207–2400) 60 (25–487) < 0.0005 Clinical score 18 (10–35) 10 (0–34) 3 (0–17) < 0.005 Pettersson score 44 (14–62) 28 (0–48) 17 (3–40) < 0.0005 Null mutations (%) 59 70 6 < 0.005 PTG20210A (%) 0 7 5 NS FV Leiden (%) 5 7 0 NS Median ETP (nM) 414 478 850 < 0.05

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Defective TAFI Activation in Hemophilia Worsens Joint Bleeding

Blood ◽

10.1182/blood.v128.22.3752.3752 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3752-3752

Author(s):

Tine L Wyseure ◽

Esther J Cooke ◽

Paul J Declerck ◽

Joost CM Meijers ◽

Annette von Drygalski ◽

...

Keyword(s):

Board Of Directors ◽

Thrombin Generation ◽

Hemophilia A ◽

Bleeding Tendency ◽

Protective Effects ◽

Acquired Hemophilia ◽

Advisory Committees ◽

Fviii Inhibitor ◽

Vascular Beds ◽

The Difference

Abstract Background: Joint bleeds are common in hemophilia A or B and cause hemophilic arthropathy. It is clinically well recognized that patients with acquired hemophilia generally do not suffer from joint bleeding, but the molecular mechanisms responsible for the difference in joint bleeding tendency between acquired and congenital hemophilia are ill defined. FVIII deficiency causes defective thrombin generation, impaired coagulation, and increased fibrinolysis. The latter is caused by impaired activation of thrombin activatable fibrinolysis inhibitor (TAFI). Our previous plasma-based analyses showed that clotting and thrombin generation were readily inhibited by an anti-FVIII antibody, whereas a 10-fold higher antibody concentration was required to inhibit thrombin-mediated TAFI activation. We hypothesize that residual TAFI activation occurring in acquired hemophilia, but not in congenital hemophilia, protects against joint bleeding. Here, we determine whether TAFI activation prevents joint bleeding in a mouse model of acquired hemophilia. Methods and results: A transient (anti-FVIII) acquired hemophilia A model was set up to compare joint bleeding in wild type (WT) vs. TAFI-/- mice. Joint bleeding was induced by a subpatellar needle puncture in the right knee. This model caused considerable joint bleeding in FVIII-/- mice as evidenced by the decreased hematocrit (Hct) 2 days post injury (D2 Hct) (D2 Hct= 29 ± 11 % (n= 9) vs. baseline Hct (46 ± 2 %); p< 0.0001). A single injection of the FVIII inhibiting antibody (GMA-8015; 0.25 mg/kg) in WT mice caused acquired hemophilia for up to 72 hours as evident from increased tail bleeding similar to that observed in FVIII-/- mice. Consistent with clinical findings, only minimal joint bleeding was observed in inhibitor-treated WT mice (D2 Hct= 44 ± 4 % (n= 15) for BALB/c and 40 ± 4 % (n= 17) for C57Bl/6J). Significant joint bleeding (D2 Hct= 36 ± 9% (n= 12) for C57Bl/6J; p< 0.05) could be induced by a higher dose of inhibitor (1 mg/kg), however bleeding remained considerably less severe than that observed in FVIII-/-mice. In vitro, the FVIII inhibitor readily inhibited thrombin generation but was relatively ineffective in inhibiting TAFI activation. Therefore, we tested our hypothesis that continued TAFI activation prevented severe joint bleeding in the inhibitor-treated WT mice. Indeed, administration of the FVIII inhibitor (0.25 mg/kg) in TAFI-/-mice resulted in excessive joint bleeding (D2 Hct= 25 ± 8 %; n= 14; p< 0.0001). Similarly, joint bleeding in WT mice was increased significantly when the FVIII inhibitor was co-administered with an inhibitory antibody against TAFI (D2 Hct= 34 ± 7 %; n= 13; p< 0.01). In contrast, TAFI deficiency did not increase tail bleeding with or without FVIII inhibitor, as determined by acute blood loss, 24-hour mortality, and Hct of the survivors at 24 hours post tail resection. These data clearly demonstrate that different vascular beds empower different mechanisms to curb bleeding and suggest that the protective effects of TAFI are specifically relevant for the vascular beds of the synovial joint. Activated TAFI (TAFIa) conveys multiple functions, including anti-fibrinolytic effects and numerous anti-inflammatory activities. Interestingly, tranexamic acid (TXA), a Lys analogue and potent anti-fibrinolytic agent, added at 50 mg/ml to the drinking water, did not reduce joint bleeding in FVIII-/- mice or TAFI-/- mice with the FVIII inhibitor, whereas TXA did correct tail bleeding in these mice. This suggests that the protective effects of TAFI on joint bleeding were independent of its anti-fibrinolytic effects and may result from its anti-inflammatory activities. This is supported by histological analysis at day 7 showing increased stromal proliferation and inflammatory cell recruitment in the joints of TAFI-/-mice. Conclusions:TAFI activation is impaired in congenital hemophilia but not in acquired hemophilia. Abrogation of TAFIa activity, either genetically or pharmaceutically, increased joint bleeding in mice with acquired hemophilia, indicating that TAFI may be responsible for the difference in joint bleeding tendency between acquired and congenital hemophilia. Protective effects of TAFI were vascular bed specific and independent of its anti-fibrinolytic effects, suggesting that one or more of TAFIa's other substrates promote hemophilic joint bleeding. Disclosures von Drygalski: Novo Nordisk: Consultancy, Honoraria, Speakers Bureau; CSL-Behring: Consultancy, Honoraria, Speakers Bureau; Hematherix LLC: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Speakers Bureau; Biogen: Consultancy, Honoraria, Speakers Bureau; Bayer: Consultancy, Honoraria, Speakers Bureau; Baxalta/Shire: Consultancy, Honoraria, Speakers Bureau. Mosnier:The Scripps Research Institute: Patents & Royalties; Hematherix LLC: Membership on an entity's Board of Directors or advisory committees; Bayer: Honoraria, Speakers Bureau; Baxalta: Honoraria, Speakers Bureau.

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Laboratory Characterization of Unclassified Bleeding Disorders By Non-Conventional Tests

Blood ◽

10.1182/blood-2021-151203 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 4235-4235

Author(s):

Paula Acuña ◽

Elena Monzón Manzano ◽

Elena G Arias-Salgado ◽

María Teresa Alvarez Román ◽

Mónica Martín ◽

...

Keyword(s):

Tissue Factor ◽

Platelet Function ◽

Research Funding ◽

Thrombin Generation ◽

Bleeding Tendency ◽

Contact Activation ◽

Normal Range ◽

Coagulation Tests ◽

In Vitro Treatment

Abstract Introduction: Hematologists frequently face a percentage of patients with a mild bleeding tendency due to a haemostatic abnormality that cannot be identified with conventional laboratory techniques. Such patients are termed as having an unclassified bleeding disorder (UBD). A good diagnosis is important in order to prevent bleedings during invasive processes and/or childbirth by choosing the optimal therapeutic treatment. We aimed to investigate hemostatic parameters that may be altered in patients with UBD in order to determine the cause of their bleeding symptoms. In particular, possible defects in the tissue factor (TF)-mediated regulation of coagulation or in the plasmin generation during the fibrinolysis, as well as the possible beneficial effects of treatment with antibodies blockers of TFPI. Methods: This is a single-centre, case-control, non-interventionist, prospective study. During an 8 months-period, 40 patients with bleeding symptoms (evaluated with ISTH-BAT score) were studied. Routine coagulation tests (aPTT and PT) and platelet function testing [aggregometry, PFA-100, flow cytometry and Total Thrombus-formation Analysis System (T-TAS; Zarcos, Japan)] were performed. In 17 patients, no abnormalities were detected in platelet function and/or in coagulation tests; so the following procedures were performed: Thrombin generation test by Calibrated automated thrombography (CAT) in samples of platelet poor plasma with corn trypsin inhibitor (CTI), an inhibitor of contact activation phase, using a low amount of TF (1 pM TF and 4 µM phospholipids) as a trigger to allow the evaluation of the TF-dependent pathway. Plasmin generation (PG) test with a kit from Synapse Research Institute (Maastricht, The Netherlands), using Thrombinoscope software. TFPI activity in plasma, measured with ACTICHROME® TFPI kit (Biomedica Diagnostics, USA). The effects of rFVIIa (Novoseven, NovoNordisk; 90 µg/kg) and of a human Anti-TFPI recombinant Ab (clon mAb2021, Creative Biolabs; 400 ng/ml) were tested in CAT, PG and TFPI activity tests. Results: Those patients with aPTT, PT and a platelet function within normal range were further studied performing thrombin generation, plasmin generation and TFPI activity tests. Table 1 shows the results obtained. Samples from patients 1, 2, 4, 7, 8, 9 and 10 had a diminished generation of thrombin, and in vitro treatment with anti-TFPI and rFVIIa only ameliorated thrombin generation in samples from patients 4, 7, 8 and 9. Plasma from patients 8 and 10 had increased activity of TFPI. Generation of thrombin in samples from patients 3, 5, 6 and 11 was within normal range. Plasmin generation was increased and not modified by in vitro treatment with anti-TFPI and rFVIIa in samples 3 and 11; whereas samples 5 (with normal plasmin generation) and 6 (with no data of plasmin generation due to lack of enough sample) had a high TFPI activity in plasma that was inhibited by anti-TFPI. Normal values in all these parameters evaluated were found in six patients, indicating the involvement of different mechanisms that are still unknown. Conclusions: UBD have a diverse pathological basis for the bleeding. So, a single laboratory test to make a correct diagnosis of this pathology cannot be recommended. In accordance with this fact, a personalized treatment should be applied for each patient. Non-conventional laboratory tests need to be standardized and included for studying possible defects in the regulation of TF and/or plasmin pathways that can be involved in very rare mild bleeding phenotypes. TFPI inhibition might emerge as a good therapy for some of these patients. Failure to detect the bleeding cause in some of these patients, suggests the need to perform further studies in this field. This work was supported by Novo Nordisk Pharma S.A. Table 1- Thrombin and plasmin generation and TFPI activity in samples of patients with UBD. Results out of normal range are shown in red. LT: lagtime; ETP: endogenous thrombin potential; EPP: endogenous plasmin potential; TFPI: Tissue factor pathway inhibitor. Figure 1 Figure 1. Disclosures Alvarez Román: Grifols: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Bayer: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; CSL-Behring: Consultancy, Honoraria, Research Funding; Biomarin: Consultancy, Honoraria, Research Funding; Novo-Nordisk: Consultancy, Honoraria, Research Funding; Octapharma: Consultancy, Honoraria, Research Funding; Sobi: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding. Martín: Novo Nordisk: Speakers Bureau; Pfizer: Speakers Bureau. Jiménez-Yuste: F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; BioMarin: Consultancy; Takeda: Consultancy, Honoraria, Research Funding; Bayer: Consultancy, Honoraria, Research Funding; Sobi: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; CSL Behring: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Octapharma: Consultancy, Honoraria, Research Funding; NovoNordisk: Consultancy, Honoraria, Research Funding; Grifols: Consultancy, Honoraria, Research Funding. Canales: Eusa Pharma: Consultancy, Honoraria; Sandoz: Honoraria, Speakers Bureau; Sanofi: Consultancy; Karyopharm: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Incyte: Consultancy; Gilead/Kite: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Speakers Bureau; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; iQone: Honoraria; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria. Butta: Novo-Nordisk: Speakers Bureau; Takeda: Research Funding, Speakers Bureau; Roche: Speakers Bureau; CSL-Behring: Research Funding.

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One-Stage FVIII Activity Is Inversely Correlated with Heavy Menstrual Bleeding in Hemophilia a Carriers

Blood ◽

10.1182/blood.v126.23.3542.3542 ◽

2015 ◽

Vol 126 (23) ◽

pp. 3542-3542

Author(s):

Robert F. Sidonio ◽

Shannon L. Meeks ◽

Hilary Baker Whitworth

Keyword(s):

Thrombin Generation ◽

Hemophilia A ◽

Menstrual Bleeding ◽

Bleeding Tendency ◽

One Stage ◽

Chromogenic Assay ◽

Fviii Activity ◽

Coagulation Assay ◽

Bleeding Score ◽

Risk For Bleeding

Abstract Introduction: The majority of carriers of hemophilia A have historically been considered to have normal hemostasis (FVIII:C >50%) and thus not have an increased bleeding tendency. However, our research group has demonstrated that some hemophilia A carriers can experience increased bleeding compared to normal women despite this normal FVIII activity. In our recently published study in adult hemophilia A carriers there was no correlation between FVIII:C, as measured by a one-stage coagulation assay, and bleeding phenotype, as measured by the MCMDM-1 VWD bleeding score. In this follow up study we sought to determine which of these hemophilia A carriers with normal FVIII:C are at risk for bleeding. The goal of this study is to determine the relationship between FVIII assays (one-stage and chromogenic) and thrombin generation with both menstrual bleeding and an overall bleeding tendency. Methods: We recruited mothers of children with hemophilia A in the Emory University pediatric bleeding disorders clinic. We included only adult (>18 year of age) obligate hemophilia A carriers that did not have a concomitant bleeding disorder or chronic disease that would increase their bleeding tendency. We gathered basic demographic information and evaluated the overall bleeding tendency using the ISTH Bleeding Assessment Tool (ISTH BAT), a semi-quantitative assessment of bleeding scored from 0 to 56. We considered a score of 6 or higher consistent with pathologic bleeding. In addition, we inventoried menstrual bleeding with the Pictorial Bleeding Assessment Chart (PBAC), a visual representation of menstrual blood loss. We considered a PBAC greater than 100 consistent with heavy menstrual bleeding. Plasma samples were collected from each subject at the time of the survey in sodium citrate tubes without corn trypsin inhibitor. Samples were double spun at 2,500 rpm for 15 minutes and stored at -80°C.Laboratory evaluation for each subject included FVIII:C, measured by one-stage coagulation assay (aPTT reagent with micronized silica) and chromogenic assay (COATEST SP4 FVIII kit, Chromogenix), as well as thrombin generation (Calibrated Automated Thrombogram, PPP-Reagent Low, FluCa Kit) to evaluate endogenous thrombin potential (ETP, nM*min), peak thrombin (nM) and lag time (min). We performed linear regression using GraphPad Prism; p<0.05 was considered significant. Results: Over a three-month period, we approached 32 adult obligate hemophilia A carriers; 23 agreed to participate in the survey, 16 consented to blood draw. One carrier was excluded in extreme outlier analysis and due to an autoimmune disorder, leaving 15 evaluable subjects. Our cohort is relatively young with a median age of 41 years (range 23-51), predominantly Caucasian (53%, 8/15) and the majority carry a severe mutation (10/15 severe, 2/15 moderate, 3/15 mild). Reproductive bleeding (post-partum hemorrhage and/or menstrual bleeding) was commonly reported (93%, 14/15). The median ISTH BAT bleeding score for subjects was 2 (range 1-8). The median PBAC score was 148 (range 10-608). The carriers had a relatively normal FVIII:C by one-stage assay with a median of 0.78 U/mL (range 0.30 - 1.06) and by chromogenic assay with a median of 1.15 U/mL (range 0.66 - 1.9). FVIII:C by one-stage assay was inversely correlated to PBAC (r2 =0.4; p=0.01, figure 1A). Conversely, FVIII:C by chromogenic assay did not correlate with PBAC, however trended toward significance (r2 = 0.19; p=0.10, figure 1A). Additionally, there was no correlation found between FVIII:C (one-stage or chromogenic assay) and ISTH BAT bleeding score (figure 1B). There was also no correlation found between bleeding score or PBAC and the parameters of the thrombin generation assay or between severity of the closest male relative's hemophilia and any of the assays performed. Conclusions: In our cohort of adult obligate hemophilia A carriers, as the FVIII:C (one-stage assay) decreased, the menstrual bleeding tendency increased as measured by the PBAC. We were unable to find a correlation between other measures of hemostasis, including the chromogenic assay and thrombin generation, and commonly used bleeding assessment tools. Further larger studies are warranted to help determine which hemophilia A carriers would be at risk for bleeding. Disclosures No relevant conflicts of interest to declare.

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Thrombin Generation in Two Families with Myh-9-Related Platelet Disorder

Blood ◽

10.1182/blood.v124.21.2783.2783 ◽

2014 ◽

Vol 124 (21) ◽

pp. 2783-2783

Author(s):

Eva Zetterberg ◽

Margareta S Carlsson Alle ◽

Juliane Najm ◽

Andreas Greinacher

Keyword(s):

Myocardial Infarction ◽

Hearing Loss ◽

Platelet Count ◽

Arterial Thrombosis ◽

Inclusion Bodies ◽

Thrombin Generation ◽

Bleeding Tendency ◽

Endogenous Thrombin Potential ◽

Related Disease ◽

Low Platelet Count

Abstract MYH-9 related platelet disorders are inherited macrothrombocytopenias. Before the genetic cause was identified, four overlapping syndromes (May-Hegglin, Epstein, Fechtnerand Sebastian syndrome) described the additional clinical manifestations in MYH-9 disorders including renal failure, hearing loss, pre senile cataract and inclusion bodies in leucocytes that are present in different combinations. The MYH-9-gene codes for the cytoplasmic contractile protein non muscular myosin heavy chain IIA, present in several tissues, which explains the additional symptoms. The bleeding tendency is usually mild to moderate but rarely, thrombotic complications are also seen (1). We report on the thrombin generation potential (ETP) in MYH9 patients with and without arterial thrombosis. In the first family (family A) 4 members were evaluated: a 51 year old woman (platelet count 36), her 24 year old daughter (platelet count 46), and the brother of the woman (57 years; platelet count 39) and his 30 year old son (platelet count 44). All four were affected by MYH-9 disorder with macrothrombocytopenia and inclusion bodies in the leucocytes and a 5521G>A mutation, causing Glu1841Lys. 3 of them had a moderate bleeding tendency [ISTH /SSC bleeding scores 9, 13, 4 where <4 is normal) (3)] and in the 51 year old women and her brother, renal insufficiency and hearing loss were already present. Both patients had an arterial thrombosis (myocardial infarction and pons infarction respectively) before 50 year of age. Both showed hyperlipidemia and hyperhomocysteinemia. In the second family (Family B) macrothrombocytopenia and small to medium size inclusion bodies in the leucocytes were found in the mother (38 years; platelet count 36) and the daughter (age15 years, platelet count 46) caused by a c. 4679 T>G mutation resulting in p.Val1560Gly. Their bleeding tendency was mild (bleeding scores 4 and 3 respectively). Thrombelastography (ROTEM) was normal in all five individuals. ETP was seen to be below the normal range in family B. However, in family A, the two members affected by thrombosis had a normal ETP (Fig 1), indicating that other factors compensated for the low platelet count and clinically even led to a breakthrough of arterial thrombosis despite the low platelet count. We suggest that other centers also assess the ETP in their MYH-9 patients according tour protocol to gather data on the potential association of the ETP with the phenotype. References Althaus K, Greinacher A: MYH-9 Related Platelet Disorders: Strategies for Management and Diagnosis. Transfus Med Hemother. 2010 October; 37(5): 260–267. Girolami A , Vettore S, Bonamigo E, Fabris F: Thrombotic events in MYH9 gene-related autosomal macrothrombocytopenias (old May–Hegglin, Sebastian, Fechtner and Epstein syndromes) J Thromb Thrombolysis. 2011 Nov;32(4):474-73. Rodeghiero F, Tosetto A, Abshire T et al.; ISTH/SSC Joint VWF and Perinatal/Pediatric Hemostasis Subcommittees Working Group. ISTH/SSC bleeding assessmenttool: a standardizedquestionnaire and a proposal for a newbleedingscore for inherited bleeding disorders. J Thromb Haemost 2010; 8: 2063–5. Figure 1. Endogenous thrombin potential in two families with MYH-9 related disease Figure 1. Endogenous thrombin potential in two families with MYH-9 related disease Thrombin generation was performed on frozen platelet rich plasma on 5 members from two different families (family A and B) with MYH-9 related disease. Two members in the first family (A:1 and A:2) had a previous arterial thrombosis (pons infarction and myocardial infarction, respectively, marked with a star). Disclosures No relevant conflicts of interest to declare.

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Effects of aspirin and desmopressin on platelet reactivity in patients undergoing cardiac surgery with extracorporeal circulation

Thrombosis and Haemostasis ◽

10.1160/th10-07-0471 ◽

2011 ◽

Vol 105 (01) ◽

pp. 113-121 ◽

Cited By ~ 9

Author(s):

Eliane Kmitta ◽

Sami Kueri ◽

Tomasz Zietak ◽

Dietmar Trenk ◽

Cornelius Keyl

Keyword(s):

Cardiac Surgery ◽

Antiplatelet Therapy ◽

Extracorporeal Circulation ◽

Platelet Reactivity ◽

Therapy Group ◽

Artery Bypass ◽

Bleeding Tendency ◽

Platelet Aggregometry ◽

Group A ◽

Group B

SummaryThe effect of desmopressin on platelet function in patients with continued antiplatelet therapy undergoing cardiac surgery is discussed controversially. We assessed platelet reactivity in 86 patients undergoing elective coronary artery bypass grafting (CABG) under extracorporeal circulation. Twenty-nine of these patients were without preoperative antiplatelet therapy (group A), while 57 were treated with acetylsalicylic acid (ASA) 100 mg qd up to the day of surgery. Out of this cohort, 24 patients received no desmopressin perioperatively (group B), whereas 33 patients were treated with desmopressin 0.4 μg/kg after administration of protamine due to increased bleeding tendency (group C). Multiple electrode platelet aggregometry with arachidonic acid as agonist showed a marked decrease of platelet reactivity in patients without antiplatelet therapy immediately after extracorporeal circulation compared to preoperative control (375 ± 227 vs. 749 ± 330 AU*min, p<0.001). Platelet reactivity recovered to preoperative controls in group A at 24 hours after protamine administration (662 ± 295 AU*min). Platelet reactivity in patients on ASA was not decreased further after extracorporeal circulation (group B: 197 ± 126 vs. 251 ± 203 AU*min, p=0.14; group C: 212 ± 100 vs. 245 ± 248 AU*min, p=0.43) and improved significantly within 24 hours. A statistically significant effect of desmopressin, however, could not be determined (group B: 392 ± 223 AU*min; group C: 439 ± 324 AU*min at 24 hours after protamine, p=0.63 for between-subjects contrast). Our data suggest that desmopressin does not affect platelet reactivity in patients on ASA undergoing CABG and is, therefore, not useful in this clinical setting.

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Fibrin formation is more impaired than thrombin generation and platelets immediately following cardiac surgery

Thrombosis Research ◽

10.1016/j.thromres.2011.02.022 ◽

2011 ◽

Vol 128 (3) ◽

pp. 277-282 ◽

Cited By ~ 41

Author(s):

Cristina Solomon ◽

Niels Rahe-Meyer ◽

Benny Sørensen

Keyword(s):

Cardiac Surgery ◽

Thrombin Generation ◽

Fibrin Formation

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Abstract 200: Hypercoagulabilty Panel Testing in Neonates Undergoing Cardiac Surgery

Circulation Research ◽

10.1161/res.111.suppl_1.a200 ◽

2012 ◽

Vol 111 (suppl_1) ◽

Author(s):

Sirisha Emani ◽

David Zurakowski ◽

Christopher Baird ◽

Frank Pigula ◽

Trenor Cameron ◽

...

Keyword(s):

Cardiac Surgery ◽

Thrombin Generation ◽

Factor V Leiden ◽

Plasminogen Activator Inhibitor ◽

Protein S ◽

Coagulation Factors ◽

Factor V ◽

Factor V Leiden Mutation ◽

C Protein ◽

Cardiolipin Antibodies

Thrombosis is a crucial contributor of morbidity and mortality in neonates undergoing cardiac surgery. Although there is published data on several factors of the hemastatic system, there is no data correlating factor expression and/or function with thrombosis in neonates. We tested the hypothesis that hypercoagulability markers are predictive of thrombosis in neonates undergoing cardiac surgery. Sixty neonates undergoing cardiac surgery were tested for thrombin generation assay; coagulation factors; antithrombin III, protein C, protein S, and factor VIII; fibrinolytic inhibitors; thrombin-activatable fibrinolytic inhibitor, plasminogen activator inhibitor; and presence of cardiolipin antibodies by immunoassays. Factor V Leiden mutation was also tested in a few patients utilizing single nucleotide polymorphism assays. In this pilot study, thrombosis occurred in 15% of the neonates undergoing cardiac surgery. Significant risk factors associated with thrombosis were pre-mature birth, use of cardio pulmonary bypass, and single ventricle physiology. Hypercoagulability factors associated with thrombosis determined by univarent analysis were elevated thrombin generation, enhanced expression of thrombin-activatable fibrinolytic inhibitor and plasminogen activator inhibitor as well as presence of cardiolipin antibodies and factor V Leiden mutation. No correlation was observed between thrombosis and expression of coagulation factors antithrombin III, protein C, protein S, and factor VIII. Multivarient analysis has proven to show thrombin generation, thrombin-activatable fibrinolytic inhibitor, and presence of cardiolipin antibodies as multivariable predictors of thrombosis. These significant hypercoagulability markers are independent predictors of thrombosis. Thus thrombosis predictability can help in post-operative management and care for neonates undergoing cardiac surgery by regulating pro- and/or anti-coagulation therapy.

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