A Systematic Review of Efficacy and Safety of Plasma-Derived von Willebrand Factor/Factor VIII Concentrate (Voncento) in von Willebrand Disease

BACKGROUND

 For the treatment of von Willebrand disease (VWD), von Willebrand factor (VWF) concentrates can be used in on-demand, long-term prophylaxis, and surgical prophylaxis regimens.

METHODS

 This systematic literature review was conducted to evaluate the efficacy, consumption, and safety of plasma-derived human coagulation FVIII/human VWF (pdVWF/FVIII; Voncento/Biostate) for the treatment of patients with any inherited VWD type. An electronic search was conducted in MEDLINE and Cochrane Library databases on VWD therapies. All retrieved publications were assessed against predefined inclusion/exclusion criteria following the Cochrane group recommendations. Associated pharmacovigilance data were collected across the same time period.

RESULTS

 Eleven publications from eight study cohorts were identified for data retrieval. All were from multicenter studies and included both pediatric and adult patients. Eight publications included evaluations of the efficacy of pdVWF/FVIII for on-demand treatment, eight included long-term prophylactic treatment, and eight included surgical prophylaxis. Treatment protocols and VWF administration methods differed between studies, as did safety evaluations. The clinical response was rated as excellent/good for on-demand treatment in 66 to 100% of nonsurgical bleeds, 89 to 100% in the treatment of breakthrough bleeds during long-term prophylaxis treatment, and hemostatic efficacy in surgical procedures was 75 to 100%. Pharmacovigilance data confirmed a low incidence of adverse events in treated patients.

CONCLUSION

 This review provides a comprehensive summary of studies that evaluated the use of pdVWF/FVIII in VWD demonstrating the long-term effectiveness and safety of this pdVWF/FVIII across all ages, types of VWD, and treatment settings.

Surgery in rare bleeding disorders: the prospective MARACHI study

Background

Despite the wide use of bleeding scores and the reliability of clotting factor level measurement, bleeding risk stratification before surgery remains challenging in patients with rare inherited bleeding disorders.

Objectives

This multicenter observational prospective study assessed in patients with rare coagulation factor deficiency, the perioperative hemostatic management choices by hemostasis experts and the bleeding outcomes after surgery.

Methods

One hundred seventy-eight patients with low coagulation activity level (factor [F] II, FV, combined FV-FVIII, FVII, FX, or FXI <50%) underwent 207 surgical procedures. The bleeding outcome, Tosetto's bleeding score, and perioperative hemostatic protocols were collected.

Results

Among the 81 procedures performed in patients with severe factor deficiency (level ≤10%), 27 were done without factor replacement (including 6 in patients at high bleeding risk), without any bleeding event. Factor replacement therapy was used mainly for orthopedic procedures. In patients with mild deficiency, 100/126 surgical procedures were carried out without perioperative hemostatic treatment. In patients with FVII or FXI deficiency, factor replacement therapy was in function of the procedure, bleeding risk, and to a lesser extent previous bleeding history. Tranexamic acid was used in almost half of the procedures, particularly in case of surgery in tissues with high fibrinolytic activity (76.8%).

Conclusions

The current perioperative hemostatic management of patients with rare bleeding disorders appears to be adapted. Among the 207 procedures, only 6 were associated with excessive bleeding. Our findings suggest that rather than the bleeding score, factor level and surgery type are the most relevant criteria for perioperative factor replacement therapy.

Multicolor flow cytometry in clinical samples for platelet signaling assessment

Background

Availability of multichannel cytometers and specific commercial antibodies makes flow cytometry a new option to simultaneously assess multiple intracellular platelet signaling pathways for clinical purposes, in small volume of blood or low platelet count.

Objectives

To describe a multicolor flow cytometry with fluorescent barcoding technique for screening signaling pathways downstream membrane receptors of major platelet agonists (adenosine diphosphate, thrombin, thromboxane, and collagen).

Methods

By comparison with immunoblotting, we first selected the target phosphoproteins, AKT, P38MAPK, LIMK, and SPL76; the times of stimulation; and phosphoflow barcoding conditions. We then performed a clinical study on whole blood of patients without evidence of blood platelet disorder on standard biological screening, consulting for trivial or occasionally provoked bleeds without familial antecedent (bleeding of unknown origin, n = 23) or type-1 von Willebrand disease (n = 9). In addition, we included a small group of patients with definite platelet disorders (Glanzmann thrombasthenia, δ-storage pool deficiency, and immune glycoprotein VI-related disease with granule secretion defect).

Results

The range, kinetics, and distribution of fluorescence intensity were established for each agonist-target protein combination. Principal component analysis indicates a correlation in response to a target phosphoprotein (AKT and P38MAPK) to different agonists but no correlation in the response of different target phosphoproteins to the same agonist. The heterogeneity of individual responses in the whole population displayed was analyzed using clustering algorithm. Patients with platelet storage pool deficiency were positioned as lowest responders on the heatmap.

Conclusion

In complement of functional tests, this study introduces a new approach for rapid platelet signaling profiling in clinical practice.

Management of rare inherited bleeding disorders: Proposals of the French Reference Centre on Haemophilia and Rare Coagulation Disorders

INTRODUCTION

The rare coagulation disorders may present significant difficulties in diagnosis and management. In addition, considerable inter-individual variation in bleeding phenotype is observed amongst affected individuals, making the bleeding risk difficult to assess in affected individuals. The last international recommendations on rare inherited bleeding disorders (RIBDs) were published by the United Kingdom Haemophilia Centre Doctors' Organisation in 2014. Since then, new drugs have been marketed, news studies on surgery management in patients with RIBD have been published, and new orphan diseases have been described.

AIM

Therefore, the two main objectives of this review, based on the recent recommendations published by the French Reference Centre on Haemophilia and Rare Bleeding Disorders, are: (i) to briefly describe RIBD (clinical presentation and diagnostic work-up) to help physicians in patient screening for the early detection of such disorders; and (ii) to focus on the current management of acute haemorrhages and long term prophylaxis, surgical interventions, and pregnancy/delivery in patients with RIBD.

Effectiveness of long-term prophylaxis using pdFVIII/VWF concentrate in patients with inherited von Willebrand disease

Background

Patients with symptomatic von Willebrand disease (VWD) should be offered long‐term prophylaxis (LTP) to prevent recurrent bleedings. Our objective was to evaluate the effectiveness and safety of Voncento®, a plasma‐derived FVIII/VWF concentrate (ratio 1:2.4), administrated in LTP.

Methods

We included patients from the OPALE study (May 2016 to April 2021), a French multicenter observational study following patients with inherited VWD, who received a Voncento® LTP during the study period.

Results

Among the 130 OPALE‐study patients, 23 patients (12 women) received a LTP and were therefore included. The median (range) age was 16 (1–85) years; 16 patients were type 3, 1 was type 2A, 6 were type 2B. Before inclusion, 19 (83%) were under LTP and 4 (17%) received on‐demand (OD) treatment. The indications for initiating prophylaxis in the overall population were joint bleeding (43%), ear, nose, and throat (ENT) bleeding including epistaxis or oral bleeding (39%), and recurrent muscle hematoma (22%). The medians (ranges) dose of Voncento® per infusion, frequency, and weekly dose were 45 (33–109) IU/kg, 2 infusions per week, and 96 (44–222) IU/kg/week, respectively. The median (range) annualized bleeding rate (ABR) was 0.8, 0.7 (0–3.5), and 0 (0–2.3) for type 2A, 2B, 3 patients, respectively. There was no difference regarding to the dose, frequency of infusion, or in terms of ABR in 9/19 patients who replaced previous concentrates with Voncento®. During the study period, no adverse event was reported.

Conclusion

These results suggest that Voncento® is effective to prevent recurrent bleedings in patients symptomatic VWD.

Continuous Infusion of Factor VIII and von Willebrand Factor in Surgery: Trials with pdFVIII LFB or pdVWF LFB in Patients with Bleeding Disorders

INTRODUCTION

A plasma-derived factor VIII product (pdFVIII, Factane 100 or 200 IU/mL) and a plasma-derived von Willebrand factor product (pdVWF, Wilfactin 100 IU/mL) are approved for replacement therapy by intravenous bolus injections in haemophilia A (HA) and von Willebrand disease (VWD), respectively. However, in situations requiring intensive treatment, continuous infusion (CI) may be desirable to better control target plasma factor levels.

AIM

To evaluate the perioperative haemostatic efficacy and safety of these concentrates administered by CI.

METHODS

Three phase III trials were conducted. Adults with HA (FVIII:C <1%) (Studies 1 and 2) or VWD (VWF:RCo <20%) (Study 3) received a preoperative bolus followed by CI of undiluted concentrate for at least 6 days. Bolus doses and CI rates were based on individual recovery and clearance, respectively. Initial infusion rate had to be higher for 48 hours for HA and 24 hours for VWD patients to anticipate potential fluctuations of factor concentrations during major surgery. Target levels of FVIII:C in HA and VWF:RCo in VWD were 80 and 70 IU/dL, respectively. Efficacy was assessed using a global haemostatic efficacy score.

RESULTS

Studies 1, 2, and 3 included 12, 4 and 6 patients, respectively. Efficacy outcomes were excellent/good in all 22 major surgeries including 18 orthopaedic procedures. Most daily measured FVIII and VWF levels (92%) were on target. No safety concerns, thrombotic events or inhibitors were identified.

CONCLUSION

pdFVIII and pdVWF administered by CI represent an effective and safe alternative to bolus injections in patients with severe HA or VWD undergoing surgery.

Report of surgeries, their outcome and the thrombin generation assay in patients with Factor XI deficiency: A retrospective single-centre study

BACKGROUND

In patients with FXI deficiency, the risk of surgery-related bleeding is poorly correlated with plasma FXI activity (FXI:C); the latter can therefore not be used as a reliable predictor of bleeding in surgeries.

OBJECTIVES

The aim of this retrospective study was to determine whether thrombin generation assay (TGA) could be used to evaluate the risk of surgery-related bleeding in FXI-deficient patients. TGA parameters were compared to FXI:C values, haemostatic treatments and surgical outcomes.

PATIENTS

All patients followed at the haemophilia treatment care centre (Lyon, France) with a FXI:C < 50IU/dL, and for whom a baseline TGA was performed between January 2014 and December 2019, were included.

RESULTS

Among the 175 surgeries reported herein in 49 patients, FXI concentrates were used for 11 (6%) surgeries and fresh frozen plasma was used for five (3%) surgeries; these surgeries were performed in patients with two or three impaired TGA parameters. No haemostatic treatment was prescribed for 119 (68%) surgeries. A surgery-related bleeding occurred in 12 patients during 21 (12%) surgeries. Thrombin generation was significantly reduced or delayed in patients who reported surgery related-bleeding. Among the 34 (68%) surgeries performed without haemostatic treatment in patients with three impaired TGA parameters, a surgery-related bleeding was reported in 44% of cases (15 surgeries out of 34).

CONCLUSION

The present study confirmed that TGA is an interesting laboratory test in FXI deficiency, for determining the bleeding risk and guiding the haemostatic management of surgeries, while taking into account the surgical bleeding risk and the history of bleeding.

Acquired factor V inhibitor: a nation-wide study of 38 patients

Acquired factor V inhibitor (AFVI) is an extremely rare disorder that may cause severe bleeding. To identify factors associated with bleeding risk in AFVI patients, a national, multicentre, retrospective study was made including all AFVI patients followed in 21 centres in France between 1988 and 2015. All patients had an isolated factor V (FV) deficiency <50% associated with inhibitor activity. Patients with constitutional FV deficiency and other causes of acquired coagulation FV deficiencies were excluded. The primary outcome was incident bleeding and factors associated with the primary outcome were identified. Thirty-eight (74 [36-100] years, 42·1% females) patients with AFVI were analysed. Bleeding was reported in 18 (47·4%) patients at diagnosis and in three (7·9%) during follow-up (7 [0·2-48.7] months). At diagnosis, FV was <10% in 31 (81·6%) patients. Bleeding at diagnosis was associated with a prolonged prothrombin time that strongly correlated with the AFVI level measured in plasma {r = 0·63, 95% confidence interval (CI) [0·36-0·80], P < 0·05}. Bleeding onset during follow-up was associated with a slow AFVI clearance (P < 0·001). The corresponding receiver operating characteristics curve showed that AFVI clearance was predictive of bleeding onset with an AFVI clearance of seven months with a sensitivity of 100% (95% CI: 29-100) and a specificity of 86% (95% CI: 57-98, P = 0·02). Kaplan-Meier analysis showed that AFVI clearance >7 months increased the risk of bleeding by 8 (95% CI: [0·67-97], P = 0·075). Prothrombin time at diagnosis and time for clearance of FV inhibitor during follow-up are both associated with bleeding in patients with AFVI.

Comparative Analysis of a French Prospective Series of 144 Patients with Heparin-Induced Thrombocytopenia (FRIGTIH) and the Literature

Background Heparin-induced thrombocytopenia (HIT) is a rare complication of heparin treatments, and only a few large patient cohorts have been reported. In this study, biological and clinical data from 144 French patients with HIT were analyzed in comparison with the literature.

Methods The diagnosis of HIT was confirmed in all patients by an immunoassay combined with serotonin release assay. In the literature, only cohorts of at least 20 HIT patients published from 1992 were selected for a comparative analysis.

Results Two-thirds of patients were hospitalized in surgery and most were treated with unfractionated heparin (83.2% vs. 16.8% with low molecular weight heparin only). Thrombotic events in 54 patients (39.7%) were mainly venous (41/54). However, arterial thrombosis was more frequent after cardiac surgery (13.2% vs. 2.4% in other surgeries, p = 0.042) with a shorter recovery time (median = 3 vs. 5 days, p < 0.001). The mortality rate was lower in our series than in the 22 selected published studies (median = 6.3% vs. 15.9%). Three genetic polymorphisms were also studied and homozygous subjects FcγRIIA RR were more frequent in patients with thrombosis (37.8 vs. 18.2% in those without thrombosis, p = 0.03).

Conclusion This study shows that the mortality rate due to HIT has recently decreased in France, possibly due to earlier diagnosis and improved medical care. It also confirms the strong association between polymorphism FcγRIIA H131R and thrombosis in HIT.

Gynecological and obstetric outcome in the French cohort of women with factor XIII deficiency

INTRODUCTION

Congenital factor XIII deficiency is a very rare bleeding disorder affecting 33 patients in France. Besides its role in fibrin clot stabilization, factor XIII is involved in placental attachment. Fetal miscarriages represent a frequent and concerning issue for these patients. The aim of the present study was to describe clinical characteristics of women presenting severe congenital FXIII deficiency in France, to focus on gynecological and obstetrical events, and to report the management of these rare situations.

METHODS

We conducted a retrospective study in the French Hemophilia Comprehensive Care and Clinical Hemostasis Centers. Women between 15 and 65 years with factor XIII activity <10 IU dL^-1 were included. Biological, clinical and therapeutic events that occurred to these patients during their gynecological and obstetrical period were recorded.

RESULTS

Among 31 centers, eleven patients were included. The median age at diagnosis was 1.5 years (range: 0-35), and at inclusion it was 30 years (range: 15-63). Fetal miscarriage was the primary manifestations in 2 (18%) patients, the remaining were diagnosed during hemorrhage. Menorrhagias were reported by 2 women (27%), 13 pregnancies were reported by 9 women including one abortion. Every pregnancy was conducted under factor XIII substitution, no hemorrhagic episode was reported. Four patients (36%) experienced at least one fetal miscarriage with a total amount of 30 miscarriages with 6 occurring during substitution.

CONCLUSION

Altogether, our data confirmed the high incidence of miscarriage in women with factor XIII deficiency. Good outcome of pregnancies required prophylaxis in accordance with international guidelines.

A Prolonged Treatment Response in Acquired Von Willebrand Syndrome

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder. We report herein a case of AVWS due to a monoclonal gammopathy of undetermined significance, in which a transient but prolonged response to a treatment by intravenous immunoglobulin (IVIG) was observed. The diagnosis was fortuitously made in a preoperative setting for neurosurgery, after biological exploration of an isolated prolonged activated partial thromboplastin time. AVWS was confirmed by an accelerated clearance of an infused plasma-derived von Willebrand factor (VWF) concentrate. High doses of IVIG were used to perform the neurosurgery. Fifty-four days after IVIG, the patient was still responding to treatment with normal levels of factor VIII and VWF.

Congenital factor XIII deficiency: comprehensive overview of the FranceCoag cohort

This FranceCoag network study assessed 33 patients with congenital factor XIII (FXIII) deficiency presenting FXIII levels <10 iu/dl. Diagnosis was based on abnormal bleeding in 29 patients, a positive family history in 2, recurrent miscarriages in 1 and was fortuitous in 1. Eighteen patients (62·1%) presented life-threatening umbilical or intracranial haemorrhages (ICH). Seven of the 15 patients who experienced ICH were diagnosed but untreated, including 3 with secondary neurological sequelae. All pregnancies without prophylaxis (26/26) led to miscarriages versus 3/16 with prophylaxis. In patients exhibiting FXIII levels <10 iu/dl, prophylaxis could be discussed at diagnosis and at pregnancy. Further controlled prospective studies are needed.

Combined life-threatening thromboses and hemorrhages in a patient with afibrinogenemia and antithrombin deficiency

Background

Patients with congenital afibrinogenemia suffer from spontaneous recurrent severe bleeding. While fibrinogen concentrates are known to effectively treat bleeding episodes, thrombotic complications often occur upon replacement therapy, rendering clinical management highly challenging.

Case Presentation

We hereby report a case of combined afibrinogenemia and congenital antithrombin deficiency manifested by recurrent life-threatening bleeding, as well as spontaneous severe arterial occlusion, such as acute coronary syndrome and stroke, and venous thromboses like pulmonary embolism.

Secondary fibrinogen prophylaxis is recommended following any initial life-threatening bleeding episode in patients with afibrinogenemia, yet the high associated risk of thrombosis illustrates the complexity of choosing the most effective prophylaxis strategy combining fibrinogen concentrate with antithrombotic agent for optimal protection against the risk of both severe bleeding and thrombosis. For our patient, the thrombin generation assay objectively confirmed her prothrombotic tendency.

Conclusion

This case may help us better understand the pathophysiology of arterial thrombosis in afibrinogenemia, while highlighting the difficulty of managing such complications.

Comparison of an automated chemiluminescent assay to a manual ELISA assay for determination of von Willebrand Factor collagen binding activity on VWD plasma patients previously diagnosed through molecular analysis of VWF

INTRODUCTION

The correct diagnosis and classification of VWD (von Willebrand disease) is crucial and must be optimized by including the collagen binding assay (VWF:CB). VWF:CB remains an under-recognized tool, not fully automated. The objective of this study was to evaluate and to compare the previously evaluated automated chemiluminescent assay (HemosIL AcuStar VWF:CB) to the ELISA ASSERACHROM^® assay used routinely in our laboratory in patients with molecular diagnosis of VWD.

METHODS

A plasma sample from 49 patients previously diagnosed with VWD (type 1; type 2A, type 2M, type 2B) through phenotype and VWF (von Willebrand factor) analysis and 15 healthy controls was analysed. The VWF ristocetin cofactor activity (VWF:Rco) and VWF antigen (VWF:Ag) were performed simultaneously on the VWD plasma samples, and VWF:CB/VWF:Ag ratios were calculated.

RESULTS

The AcuStar VWF:CB assay was quickly performed with Pearson's correlation coefficient (r²) of .9571 between assays and a bias of +5.1U/dL (AcuStar > ELISA). Discrepancies of VWF:CB/VWF:Ag ratio were observed in type 2M-2A-like VWD (ratio <0.6 with AcuStar assay in 4/5 samples).

CONCLUSION

The AcuStar VWF:CB assay has demonstrated good performance to detect VWF mutational changes with capacity to discriminate quickly principal types of VWD.

Personalized thromboprophylaxis using a risk score for the management of pregnancies with high risk of thrombosis: a prospective clinical study

Essentials Pregnancy is a risk factor for thrombosis. Management of thrombosis risk in pregnancy remains a challenge. Prophylaxis needs to be personalized. Our score may be a helpful tool for the management of pregnancies at high risk of thrombosis.

SUMMARY

Background Patients with thrombophilia and/or a history of venous thromboembolism (VTE) are at risk of thrombosis during pregnancy. A risk score for pregnancies with an increased risk of VTE was previously described by our group (Lyon VTE score). Objectives The aim of this prospective study was to assess the efficacy and safety of our score-based prophylaxis strategy in 542 pregnancies managed between 2005 and 2015 in Lyon University Hospitals. Patients/Methods Of 445 patients included in the study, 36 had several pregnancies during the study period. Among these 445 patients, 279 had a personal history of VTE (62.7%), 299 patients (67.2%) had a thrombophilia marker, and 131 (29.4%) thrombophilic women had a personal history of VTE. During pregnancy, patients were assigned to one of three prophylaxis strategies according to the risk scoring system. Results In the antepartum period, low molecular weight heparin (LMWH) prophylaxis was prescribed to 64.5% of patients at high risk of VTE. Among them, 34.4% were treated in the third trimester only, and 30.1% were treated throughout pregnancy. During the postpartum period, all patients received LMWH for at least 6 weeks. Two antepartum-related VTEs (0.37%; one with a score of < 3 and the other with a score of > 6) and four postpartum-related VTEs (0.73%; three with scores of 3-5 and one with a score of > 6) occurred. No case of pulmonary embolism was observed during the study period. The rate of bleeding was 0.37%. No serious bleeding requiring transfusions or surgery occurred during the study period. Conclusion The use of a risk score may provide a rational decision process to implement safe and effective antepartum thromboprophylaxis in pregnant women at high risk of VTE.

A single-centre study of haemostatic outcomes of joint replacement in von Willebrand disease and control patients and an analysis of the literature

INTRODUCTION

Haemostatic assessments of patients with von Willebrand disease (VWD) who undergo total knee arthroplasty (TKA) and total hip arthroplasty (THA) have mainly relied on subjective parameters.

AIMS

To compare objective haemostatic outcomes of TKA/THA in VWD patients and controls without bleeding disorders.

METHODS

We retrospectively analysed haemostatic outcomes in VWD patients undergoing TKA/THA from 1993 to 2011 and compared them with two matched controls per operation. Using one-way analysis of variance, we tested the effect of VWD on bleeding risk after TKA and THA.

RESULTS

Twelve VWD patients (6 type 1, 3 type 2M, 1 each of types 2A/2B/3) undergoing 19 operations (12 TKA, 7 THA) were matched to 38 controls. One (5%) of 19 operations in VWD patients and none of the control operations met clinical criteria for major bleeding. Baseline and postoperative day 1 haemoglobin levels, postoperative blood loss, transfused red blood cells (RBCs) and mean hospitalization days were not significantly different. More VWD patients than controls received RBC transfusions [12 (63%) vs. 12 (32%)]. Only 9 (47%) VWD patients vs. 38 (100%) controls received pharmacologic VTE prophylaxis. No postoperative symptomatic VTE occurred in either group.

CONCLUSION

In this largest, single-institutional study, von Willebrand factor replacement based on daily levels resulted in low frequency of major bleeding in VWD patients after TKA/THA. RBC transfusion was more frequent compared with matched controls, but other objective measures of haemostasis were similar. Lack of sufficient details in published reports precluded comparison of haemostatic outcomes.

Multiple arterial thromboses in a patient with primary antiphospholipid syndrome receiving a bromocriptine therapy

We report a patient with a previously known primary antiphospholipid syndrome who had life threatening multiple arterial thromboses. The patient experienced a myocardial infarction with intraventricular thrombi under bromocriptine therapy in the puerperium, despite prophylactic low molecular weight heparin therapy. In this patient, no microvascular involvement was identified, thus eliminating the diagnosis of catastrophic antiphospholipid syndrome. Arterial thromboses may be explained by peripheral emboli originating from the intraventricular thrombi. This case emphasizes the necessity of a careful evaluation of the risk-benefit balance of bromocriptine therapy in patients with arterial risk factors. It also emphasizes the need for a correct diagnosis of catastrophic antiphospholipid syndrome allowing to limit the prescription of aggressive therapies.

[Anesthetic management of severe or worsening postpartum hemorrhage]

INTRODUCTION

Risk factors of maternal morbidity and mortality during postpartum hemorrhage (PPH) include non-optimal anesthetic management. As the anesthetic management of the initial phase is addressed elsewhere, the current chapter is dedicated to the management of severe PPH.

METHODS

A literature search was performed using PubMed and Medline databases, and the Cochrane Library, for articles published from 2003 up to and including 2013. Several keywords related to anesthetic and critical care practice, and obstetrical management were used, in various combinations. Guidelines from several societies and organisations were also read.

RESULTS

When PPH worsens, one should ask for additional team personnel (professional consensus). Patients should be monitored for heart rate, blood pressure, skin and mucosal pallor, bleeding at skin puncture sites, diuresis and the volume of genital bleeding (grade B). Because of the possible rapid worsening of coagulapathy, patients should undergo regular evaluation of coagulation status (professional consensus). Prevention and management of hypothermia should be considered (professional consensus), by warming intravenous fluids and blood products, and by active body warming (grade C). Antibiotics should be given, if not already administered at the initial phase (professional consensus). Vascular fluids must be given (grade B), the choice being left at the physician discretion. Blood products transfusion should be decided based on the clinical severity of PPH (professional consensus). Priority is given to red blood cells (RBC) transfusion, with the aim to maintain Hb concentration>8g/dL. The first round of products could include 3 units of RBC (professional consensus), and the following round 3 units of RBC, and 3 units of fresh frozen plasma (FFP). The FFP:RBC ratio should be kept between 1:2 and 1:1 (professional consensus). Depending on the etiology of PPH, the early administration of FFP is left at the discretion of the physician (professional consensus). Platelet count should be maintained at>50 G/L (professional consensus). During massive PPH, fibrinogen concentration should be maintained at>2g/L (professional consensus). Fibrinogen can be given without prior fibrinogen measurement in case of massive bleeding (professional consensus). General anesthesia should be considered in case of hemodynamic instability, even when an epidural catheter is in place (professional consensus).

CONCLUSION

The anesthetic management aims to restore and maintain optimal respiratory state and circulation, to treat coagulation disorders, and to allow invasive obstetrical and radiologic procedures. Clinical and instrumental monitoring are needed to evaluate the severity of PPH, to guide the choice of therapeutic options, and to assess treatments efficacy.

Progressive endothelial damage revealed by multilevel von Willebrand factor plasma concentrations in atrial fibrillation patients

AIMS

Abnormal plasma concentrations of von Willebrand factor (vWF), a marker of prothrombotic risk, have been found in atrial fibrillation (AF) patients, but the extent of this variation is not clear. This study aimed to investigate the effect of different clinical forms of AF on plasma concentrations of vWF at different levels of the circulatory tree, both intracardiac and extracardiac.

METHODS AND RESULTS

Peripheral (Pf), left atrial (LA), and coronary sinus (CS) blood samples were obtained during cardiac catheterization from 52 patients with paroxysmal AF (PAF), 36 with persistent AF (PsAF), and 17 control subjects (Ct) with left-sided accessory pathway Wolff-Parkinson-White syndrome. Plasma concentrations of vWF were determined by immunoturbidimetry. Compared with Ct, patients with PAF had higher LA plasma levels of vWF (P = 0.004), but similar Pf and CS levels (both P > 0.30). In contrast, patients with PsAF had higher plasma concentrations of vWF in Pf (P = 0.04), LA (P < 0.001), and CS (P = 0.04) samples compared with Ct. Left atrial plasma concentrations of vWF in patients with PsAF were also higher than in the PAF group (P = 0.04).

CONCLUSION

Regardless of the clinical form of the arrhythmia, AF patients presented significantly higher plasma concentrations of vWF compared with sinus rhythm controls. Multilevel vWF plasma concentration assessment suggests an association between the clinical evolution of AF and the progression of endothelial dysfunction. Further studies will have to establish the exact mechanisms that link endothelial dysfunction and stroke in the context of AF.

Early coagulopathy in trauma patients: an on-scene and hospital admission study

PURPOSE

Amongst trauma patients, early coagulopathy is common on hospital admission. No studies have evaluated the initial coagulation status in the pre-hospital setting. We hypothesise that the coagulopathic process begins at the time of trauma. We studied the on-scene and on hospital arrival coagulation profile of trauma patients.

METHODS

Prospective, observational study investigating the on-scene coagulation profile and its time course. We studied 45 patients at the scene of the accident, before fluid administration, and on hospital admission and classified their coagulopathy using the International Society on Thrombosis and Haemostasis score during a 2-month period. Prothrombin time, activated partial thromboplastin time, fibrinogen concentration, factors II, V and VII activity, fibrin degradation products, antithrombin and protein C activities, platelet counts and base deficit were measured.

RESULTS

The median injury severity score was 25 (13-35). On-scene, coagulation status was abnormal in 56% of patients. Protein C activities were decreased in the trauma-associated coagulopathy group (p=.02). Drops in protein C activities were associated with changes in activated partial thromboplastin time, prothrombin time, fibrinogen concentration, factor V and antithrombin activities. Only factor V levels decreased significantly with the severity of the trauma. On hospital admission, coagulation status was abnormal in 60% of patients. The on-scene coagulopathy was spontaneously normalised only in 2 patients whereas others had the same or a poorer coagulopathy status. All parameters of coagulation were significantly abnormal comparing to the on-scene phase. Decreases in protein C activities were related to the coagulation status (p<.0001) and changes in other coagulation parameters. Patients with base deficit ≤-6 mmol/L had changes in antithrombin, factor V and protein C activities but no significant coagulopathy.

CONCLUSION

Coagulopathy occurs very early after injury, before fluid administration, at the site of accident. Coagulation and fibrinolytic systems are activated early. The incidence of coagulopathy is high and its severity is related to the injury and not to hypoperfusion.

Thrombin-generating capacity in patients with von Willebrand's disease

BACKGROUND AND OBJECTIVES

on Willebrand's disease (VWD) is the most common hereditary bleeding disorder. Its severity can be classified on the basis of von Willebrand factor (VWF) and factor VIII (FVIII) plasma levels and according to the clinical relevance of bleeding episodes. However, patients with very low VWF activity may exhibit a mild bleeding tendency. The basis for this heterogeneous clinical expression of the deficit is still poorly understood. We investigated the relationship between thrombin generation and levels of factor VIII, VWF and clinical bleeding tendency.

DESIGN AND METHODS

Thrombin generation was measured in platelet-rich (PRP) and platelet-poor plasma (PPP) from 53 patients with VWD.

RESULTS

We observed a statistically significant higher risk of bleeding in patients with a low thrombin peak in PRP (OR=14.5; 95% CI=5-41.3). Similar results were found in PPP (OR=8.71; 95% CI=3.4-22.3). Two parameters of the thrombin generation curve, peak height and thrombin generation speed (slope), correlated significantly with VWF:RCo and FVIII levels both in PPP and in PRP. Regression analysis showed that thrombin generation was mainly dependent on plasma FVIII activity.

INTERPRETATION AND CONCLUSIONS

Our results suggest that the thrombin generation test, in combination with routine FVIII and VWF measurements, could be of interest in the assessment of the individual bleeding risk in patients with VWD.

Diagnosis of early coagulation abnormalities in trauma patients by rotation thrombelastography

BACKGROUND

Reagent-supported thromboelastometry with the rotation thrombelastography (e.g. ROTEM) is a whole blood assay that evaluates the visco-elastic properties during blood clot formation and clot lysis. A hemostatic monitor capable of rapid and accurate detection of clinical coagulopathy within the resuscitation room could improve management of bleeding after trauma.

OBJECTIVES

The goals of this study were to establish whether ROTEM correlated with standard coagulation parameters to rapidly detect bleeding disorders and whether it can help to guide transfusion.

METHODS

Ninety trauma patients were included in the study. At admission, standard coagulation assays were performed and ROTEM parameters such as clot formation time (CFT) and clot amplitude (CA) were obtained at 15 min (CA(15)) with two activated tests (INTEM, EXTEM) and at 10 min (CA(10)) with a test analyzing specifically the fibrin component of coagulation (FIBTEM).

RESULTS

Trauma induced significant modifications of coagulation as assessed by standard assays and ROTEM. A significant correlation was found between prothrombin time (PT) and CA(15)-EXTEM (r = 0.66, P < 0.0001), between activated partial thromboplastin time and CFT-INTEM (r = 0.91, P < 0.0001), between fibrinogen level and CA(10)-FIBTEM (r = 0.85, P < 0.0001), and between platelet count and CA(15)-INTEM (r = 0.57, P < 0.0001). A cutoff value of CA(15)-EXTEM at 32 mm and CA(10)-FIBTEM at 5 mm presented a good sensitivity (87% and 91%) and specificity (100% and 85%) to detect a PT > 1.5 of control value and a fibrinogen less than 1 g L(-1), respectively.

CONCLUSIONS

ROTEM is a point-of-care device that rapidly detects systemic changes of in vivo coagulation in trauma patients, and it might be a helpful device in guiding transfusion.

Molecular bases of antithrombin deficiency: twenty-two novel mutations in the antithrombin gene

Antithrombin (AT) is a major physiological inhibitor of hemostasis. We report 22 novel antithrombin gene (SERPINC1) mutations associated with antithrombin deficiency in 17 French and five German families. They were all present at the heterozygous state. Nine missense mutations accounted for type I deficiency, defined by equally low antithrombin activity and antigen level. Most of them (7/9) affected highly conserved serpin residues and were associated with venous thrombosis occurring at a young age (before age 32). One splice site, one nonsense mutation, three small deletions and one insertion were also identified as a cause for type I antithrombin deficiency. Seven other missense mutations were identified in type II or unclassified AT deficiency; g.5270C>T (p.T147I, T115I) and g.5281A>T (p.I151F, I119F) change residues in the heparin binding region, g.13267C>G (p.P439A, P407A) and g.13271T>C (p.F440S, F408S) affect amino acids in the pleiotropic region, g.2372G>A (p.G25D, G-8D) changes a signal peptide amino acid, g.2456G>C (p.C53S, C21S) affects one of the three disulfide bonds of the protein, and g.7585A>T (p.M347K, M315K) changes a nonconserved residue on strand 2C.

Management of pregnant women with increased risk of venous thrombosis

OBJECTIVE

To evaluate the usefulness of score based management of pregnancies with high risk of venous thromboembolism (VTE).

METHOD

116 consecutive pregnancies in 109 women with confirmed thrombophilia and/or history of VTE were studied. Patients were managed in accordance with international recommendations. Recently, a VTE risk prediction score was established. An independent group assessed retrospectively and in a blinded way the usefulness of this score.

RESULTS

Of the 116 pregnancies, an antithrombotic prophylaxis by low molecular weight heparin was prescribed in 61 cases (52.6%). All patients with a positive score (n=57, 49.1%) have been treated with an antenatal thromboprophylaxis. In the population where the score was negative (n=55 cases), none of the patients received antenatal prophylaxis. But, despite a negative score, four patients were treated by their general practitioner. During the study period, there was only one episode of VTE.

CONCLUSION

Implementing this scoring system has resulted in favorable outcomes and a low risk of recurrent thrombosis in this limited series of women with increased risk of VTE.

A new ELISA assay for diagnosis of acquired von Willebrand syndrome

The pathophysiology of acquired von Willebrand syndrome (AVWS), a rare bleeding disorder, is not fully understood. Circulating antibodies to Von Willebrand factor (VWF) are found in patients with AVWS associated with lymphoproliferative disorders but these autoantibodies are difficult to detect with routine laboratory tests and neutralisation assays. We have developed a simple enzyme-linked immunosorbent assay (ELISA) to detect serum antibody binding to VWF protein immobilized on polystyrene plates. Ten patients with AVWS were studied, eight of whom also had lymphoproliferative disorders. We found antibodies in eight patients; all of them were positive for IgG and five were also positive for IgM. This simple method appears to be more sensitive than functional assays, which failed to identify two of the patients who were positive with the ELISA. In conjunction with other tests, this ELISA method may be useful for demonstrating the immunological mechanism underlying some cases of AVWS. Such patients would qualify for intravenous immunoglobulin therapy, which can correct the clotting disorder.

Hemostasis and Thrombosis: Clinical Usefulness of Combined use of Platelet Aggregation Test and Anti PF4-H. Antibodies Elisa test for the Diagnosis of Heparin Induced Thrombocytopenia

Background. Heparin is the most commonly used drug in patients requiring therapeutic anticoagulation. But the use of heparin has serious side effects such as heparin-induced thrombocytopenia (HIT). The diagnosis of HIT is often difficult. This study was designed to test the diagnosis value of 2 laboratory tests: the platelet aggregation test and the ELISA test (Enzym Linked Immuno-Sorbent Assay). Methods and Results. In order to evaluate the diagnostic value of these 2 tests, we prospectively performed both tests in all patients referred to our laboratory with suspected type II HIT, and compared their results with clinical outcome. Plasmas from 60 patients suspected of HIT, were tested for heparin-dependent platelet-reactive antibodies with a platelet agregation test (PAT) and with an ELISA which detects anti heparin platelet factor 4 antibodies (Anti PF4-H Ab). Among the 60 explored patients, the clinical diagnosis of HIT was confirmed in 27 patients by clinical criteria. In 16 of these 27 patients, PAT and anti PF4-H. Ab were both positive, and in the 11 other patients, one of the 2 tests was negative. In 29 of the 33 patients with no clinical HIT, PAT and anti PF4-H. Ab were both negative, in the 4 remaining patients, one of the 2 tests was positive. Conclusion. For 75% of patients, biological results were concordant with the final clinical diagnosis. The combination of both tests is more reliable than the use of a single test; in the present series, all patients with positive results on both tests had clinically confirmed HIT, and all patients with negative results on both tests had not clinically confirmed HIT.

Factor VII, tissue factor pathway inhibitor, and monocyte tissue factor in diabetes mellitus: influence of type of diabetes, obesity index, and age

Changes of the tissue factor (TF) pathway of blood coagulation have been described in diabetes and could be involved in its vascular complications. In order to evaluate the influence of the type of diabetes and of the obesity index and age on these changes, factor VII coagulant activity, factor VII antigen, activated factor VII, monocyte TF expression, and plasma Tissue Factor Pathway Inhibitor (TFPI) were examined in 18 Type 1 and 16 Type 2 diabetic patients compared to non-diabetic control subjects matched for age, sex, and obesity index (Types 1 and 2 controls, respectively). Multicomplicated patients were excluded. FVIIc, FVIIAg, and FVIIa were higher in Type 2 diabetic patients and controls than in Type 1 diabetic patients and controls (P< .03). However, FVIIc and FVIIAg were lower in diabetic patients than in their matched controls (P< .03). Monocyte expression of TF was not different between Types 1 and 2 diabetic patients and their matched controls except for LPS-stimulated monocyte TF activity which was lower in Type 2 diabetic patients than in Type 2 controls (P< .05). Plasma TFPI was slightly but significantly higher in Type 1 diabetic patients than in Type 1 controls (P= .01) and was correlated to glycemia. However, both in Type 2 diabetic patients and controls, TFPI was higher than in Type 1 controls and was correlated with BMI (P< .0003). These results indicate that in not multicomplicated patients, the increase of FVII and TFPI was highly dependent on obesity index and age rather than on diabetes by itself.

Basic fibroblast growth factor increases tissue factor expression in circulating monocytes and in vascular wall

BACKGROUND

Basic fibroblast growth factor (bFGF) promotes vascular repair and angiogenesis and can induce in vitro tissue factor (TF), a potent agent initiating thrombogenesis, which probably plays a role in angiogenesis. We investigated whether bFGF administration induced TF expression by monocytes and vascular cells.

METHODS AND RESULTS

We studied TF expression in normally fed (n=16) and cholesterol-fed (2% for 6 weeks, n=16) rabbits. Animals were then randomized to receive intravenous bFGF (2.5 microg twice weekly for 3 weeks) or saline injections. TF expression was evaluated in mononuclear cells from arterial blood and in aortic sections by an immunohistochemical assay using a monoclonal anti-rabbit TF antibody (activator protein 1). Monocyte TF expression was increased by bFGF administration in both normal and hypercholesterolemic rabbits (129+/-45 versus 19+/-3 mU TF/1000 monocytes, P<0.05, and 31+/-12 versus 7+/-1 mU TF/1000 monocytes, P<0.005, respectively) and was further increased by stimulation of monocytes by endotoxin in vitro. TF expression was lower in hypercholesterolemic rabbits than in normal rabbits. In the media of the vascular wall, bFGF induced strong TF expression in normal rabbits and only weak TF expression in hypercholesterolemic ones.

CONCLUSIONS

This study demonstrates that systemic administration of bFGF induces an impressive increase of TF expression in circulating monocytes and in the vascular wall in normal and to a lower extent in hypercholesterolemic rabbits. The significance of this observation in terms of inducing thrombosis in vivo needs clarification.

[Constitutional thrombophilias: indications of the biological profile and therapeutic consequences]

In laboratory screening in patients with clinical thrombophilia (early thromboembolism episode < 50 years, spontaneous thrombosis, recurrent thrombosis, unusual site of thrombosis, thrombotic family history or coumarin-induced skin necrosis complication), an isolated or combined inherited thrombophilia can be observed: antithrombin (0.5 to 4.9 per cent), protein C (1.4 to 8.6 per cent) and protein S (1.4 to 7.5 per cent) deficiencies or factor V Leiden (20 to 30 per cent). Special attention is mandatory in prescribing biological exploration because of the many physiological or pharmacological interferences which can modify the results. Identification of a genetic defect may induce specific management and individuals should receive counselling regarding the implications of this diagnosis. Further prospective studies should help to determine the thrombotic risk in symptomatic and non-symptomatic patients with inherited thrombophilia and the risk/benefit ratio of laboratory screening for hereditary thrombophilia and therapeutic intervention.

Monocyte tissue factor response is decreased in patients with hyperlipidemia

Monocytes are potent regulators of blood coagulation through the expression of tissue factor (TF) on stimulation and of tissue factor pathway inhibitor (TFPI), a selective inhibitor of TF pathway. As hyperlipidemia can modify some monocyte functions, we compared the TF and TFPI expression by circulating monocytes and the plasma TFPI levels between 65 healthy normolipemic controls and 38 nontreated hyperlipemic patients. TF and TFPI relationships with plasma lipoproteins are also examined. TF and TFPI expression were evaluated in peripheral mononuclear cells after isolation from blood by density gradient centrifugation and after short culture with or without lipopolysaccharide (LPS). TF and TFPI activity and antigen were measured in mononuclear cell lysates using amidolytic assay and enzyme-linked immunosorbent assay, respectively. TFPI activity and antigen were measured in plasma using the same methods. Plasma factor VII (FVII) activity and antigen were also determined. LPS-stimulated monocyte TF activity and antigen were lower in hyperlipidemic patients than in controls (0.0001<p<0.03). This decrease of monocyte TF expression in hyperlipidemic patients was not related to an increase of monocyte TFPI. Monocyte TF activity was negatively correlated to atherogenic fractions and positively correlated to protective fractions, specially after ex vivo LPS stimulation. Increased TFPI and FVII plasma levels were found in hyperlipidemic patients compared to controls. These results indicate an impairment of TF production by circulating monocytes from hyperlipidemic subjects, which is linked to the increase of atherogenic lipoprotein fractions. Further studies are required to elucidate the mechanism of this inhibition.