Reassessment of von Willebrand factor (VWF), VWF propeptide, factor VIII:C and plasminogen activator inhibitors 1 and 2 during normal pregnancy

von Willebrand factor propeptide-to-antigen ratio in HIV-infected pregnancy: Evidence of endothelial activation

BACKGROUND

Endothelial activation has been proposed as a potential mechanism for the increased risk of venous thromboembolism (VTE) in human immunodeficiency virus (HIV)-infected pregnancy.

OBJECTIVES

To assess the state of endothelial activation in HIV-infected pregnancy by measuring the von Willebrand factor (VWF) propeptide-to-antigen ratio, as an index of acute endothelial activation.

METHODS

VWF antigen and VWF propeptide were measured in HIV-negative participants (n = 85), HIV-infected virologically suppressed participants, (n = 89) and HIV-infected participants with HIV viral load (VL) of >50 copies/ml (n = 63) in each trimester. Results were correlated with multimer patterns and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13) antigen, activity, and antibody levels.

RESULTS

VWF propeptide-to-antigen ratio was increased, in the first, second, and third trimester, in the HIV-infected virologically suppressed group (1.7 ± 0.7, 1.7 ± 0.4, 1.6 ± 0.5) and the HIV-infected group with VL > 50 copies/ml (1.9 ± 0.9, 1.7 ± 0.9, 1.6 ± 1.1) compared to the HIV-negative group (1.4 ± 0.6, 1.3 ± 0.4, 1.2 ± 0.3, P < .05). Increased high molecular weight multimers were observed in the HIV-infected groups, despite only a mild reduction in ADAMTS-13 activity compared to the HIV-negative group (P < .001). No correlation was observed between VWF antigen or VWF propeptide and ADAMTS-13 activity.

CONCLUSION

HIV-infected virologically suppressed pregnant participants showed persistent endothelial activation. Future research should focus on whether endothelial activation contributes to the excess risk of pregnancy-related VTE.

How I treat thrombotic thrombocytopenic purpura in pregnancy

Thrombotic thrombocytopenic purpura (TTP) is an acute, life-threatening thrombotic microangiopathy (TMA) caused by acquired or congenital severe deficiency of ADAMTS13. Pregnancy is a recognized risk factor for precipitating acute (first or recurrent) episodes of TTP. Differential diagnosis with other TMAs is particularly difficult when the first TTP event occurs during pregnancy; a high index of suspicion and prompt recognition of TTP are essential for achieving a good maternal and fetal outcome. An accurate distinction between congenital and acquired cases of pregnancy-related TTP is mandatory for safe subsequent pregnancy planning. In this article, we summarize the current knowledge on pregnancy-associated TTP and describe how we manage TTP during pregnancy in our clinical practice.

[Von Willebrand disease]

Von Willebrand factor is involved in primary hemostasis (adhesion of platelets to subendothelium and platelet aggregation) and acts as the carrier of coagulation factor VIII. Von Willebrand disease, resulting from a quantitative or qualitative defect of this factor, is the most frequent inherited bleeding disorder. It is mainly responsible for symptoms such as mucocutaneous bleeding and excessive bleeding after trauma or invasive procedures, but can also cause gastro-intestinal bleeding or hemarthrosis in the most severe forms of the disease. There are numerous causes of physiological variation of von Willebrand factor plasma levels which can be responsible for diagnostic difficulty or changes in symptoms over time. Diagnosis relies primarily on clinical symptoms but requires the use of several laboratory analyses: von Willebrand factor activity and antigen testing and factor VIII activity. More specialized assays allow classification of the disease in various types and subtypes which imply different management strategies (types 1, 2A, 2B, 2M, 2N, and 3). Treatment is based on desmopressin, responsible for an increase in plasma concentration of von Willebrand factor, and plasma-derived von Willebrand factor concentrates which can be combined with factor VIII.

Pregnancy in Upshaw-Schulman syndrome

The Upshaw Schulman syndrome (MIM #274150) is a hereditary deficiency of the von Willebrand factor cleaving protease (ADAMTS13) due to homozygous or compound heterozygous mutations in the ADAMTS13 gene. Patients are prone to bouts of thrombotic thrombocytopenic purpura. However, disease manifestation needs a second trigger event. Pregnancy is a known risk factor for TTP. Patients with USS may manifest during pregnancy and the postpartum period or relapse with a TTP bout. Before plasma therapy mortality for both the mother and the fetus was high, but even nowadays when plasma is delivered, therapy is challenging, still bearing a high risk for miscarriage or long term sequelae for the mother.

In this report on pregnancies in three mothers with USS, plasma therapy was increased in frequency and amount given with regard to platelet count or ADAMTS13 activity, thus leading to a successful outcome.

Von Willebrand Disease type 2 in pregnancy - A critical clinical association

Von Willebrand disease (vWD) is the most common inherited bleeding disorder. Its association with pregnancy is infrequent. Here we report three cases of vWD associated with pregnancy. The clinical features of this combination are very suggestive. However, difficulties are still encountered during the diagnosis process. The first case was diagnosed for the first time during the patient's second pregnancy despite several episodes of vaginal bleeding and suggestive clinical symptomatology. The second case was diagnosed during childhood and the patient was properly managed during this pregnancy. The third case was diagnosed at a pre-anesthesia consult, at 36 weeks gestation, before performing a cesarean section on request, despite a clinical suggestive symptomatology. All of the cases received prophylactic treatment with Haemate P^® (CSL Behring, Marburg, Germay) 24hours before birth. No serious bleeding episodes were noticed during delivery or postpartum period. Two healthy babies were delivered from the cases Nos. 2 and 3. It is acknowledged that vaginal bleeding is common during first trimester of pregnancy. However, this study indicates that repeated bleeding episodes corroborated with a clinical suggestive symptomatology (epistaxis, heavy menstrual period, and easy bruising after minor trauma) should orient the diagnosis to vWD.

Obstetric bleeding among women with inherited bleeding disorders: a retrospective study

INTRODUCTION

Women with inherited bleeding disorders are at increased risk for bleeding complications during pregnancy and the postpartum period, particularly postpartum haemorrhage (PPH).

AIM

This retrospective study evaluates pregnancy management through the Inherited Bleeding Disorders Clinic of Southeastern Ontario, the clinical factors associated with pregnancy-related abnormal bleeding and assesses tranexamic acid use in the postpartum treatment of bleeding disorder patients.

METHODS

A chart review of 62 pregnancies, from 33 women, evaluated patient characteristics (age, haemostatic factor levels) and delivery conditions (mode of delivery, postpartum treatment) in relation to abnormal postpartum bleeding.

RESULTS

This cohort revealed increased risk of immediate PPH with increased age at delivery (mean age: 30.1 years with PPH, 26.5 years without PPH, P < 0.013), and birth by vaginal delivery (P < 0.042). Low von Willebrand factor (VWF) antigen or factor VIII (FVIII) in the third trimester was not associated with an increased risk of PPH; however, low VWF:RCo was associated with increased immediate PPH despite treatment with continuous factor infusion (P < 0.042). Women treated with tranexamic acid postpartum had less severe bleeding in the 6-week postpartum (P < 0.049) with no thrombotic complications.

CONCLUSIONS

This study contributes to the growing body of work aimed at optimizing management of bleeding disorder patients through pregnancy and the postpartum period, showing patients are at a higher risk of PPH as they age. Risk factors such as low third trimester VWF:RCo have been identified. Treatment with tranexamic acid in the postpartum period is associated with a reduced incidence of abnormal postpartum bleeding.

De novo mutation and somatic mosaicism of gene mutation in type 2A, 2B and 2M VWD

Background

Von Willebrand disease (VWD) is not uncommon in Taiwan. In type 2 or type 3 VWD hemorrhagic symptoms are severer and laboratory data relatively more distinctive. De novo mutation and somatic mosaicism of type 2 VWD gene were rarely reported. Therefore clinical, laboratory and genetic studies of only type 2A, 2B and 2M VWD will be presented and issues of de novo mutation and somatic mosaicism will be explored.

Methods

Fifty-four patients belonging to 23 unrelated families from all around the country in whom type 2 VWD exclusive of type 2N has been diagnosed not only by clinical and routine laboratory studies but also by genetic confirmation during 1990–2015 were investigated. A novel technique named amplification refractory mutation system-quantitative polymerase chain reaction (ARMS-qPCR) was used to confirm the presence of somatic mosaicism. Informed consent was obtained for study.

Results

De novo mutation was identified in 4 families among 15 families (26.7 %) in whom family members including parents were available for examination. All their parents were free from bleeding symptoms and had no similar mutation as their respective affected daughter.

An interesting example of somatic mosaicism of VWF gene mutation was found in a large family with type 2A VWD. The father carrying a mutated VWF gene, p.Arg1597Trp, transmitted this mutation to his 3 daughters, 1 son, 3 granddaughters and 2 grandsons. However, the father had normal laboratory findings and experienced no abnormal bleeding, while his offspring who inherited the mutation showed abnormal laboratory findings compatible with type 2A VWD and had history of abnormal bleedings. ARMS-qPCR revealed that the father had only 25.5 % mutant in his blood cells and 31.1 % mutant in his oral mucosal cells, while all his offspring had about 49 % mutant in their blood cells.

Conclusion

De novo mutation of type 2 VWD gene was identified in 4 out of 15 families (26.7 %) examined. Since only one child was affected in each family, germline mosaicism was not likely. A somatic mosaicism of type 2A VWD gene was documented in a big family by a newly in-house developed technique ARMS-qPCR.

Complex changes in von Willebrand factor-associated parameters are acquired during uncomplicated pregnancy

Background

The coagulation protein von Willebrand Factor (VWF) is known to be elevated in pregnancy. However, the timing and nature of changes in VWF and associated parameters throughout pregnancy are not well understood.

Objectives

To better understand the changes in VWF provoked by pregnancy, we studied VWF-associated parameters in samples collected over the course of healthy pregnancies.

Methods

We measured VWF antigen (VWF:Ag), VWF propeptide (VWFpp), Factor VIII (FVIII), and ADAMTS13 activity in samples collected from 46 women during pregnancy and at non-pregnant baseline. We also characterized pregnant vs. non-pregnant VWF multimer structure in 21 pregnancies, and performed isoelectric focusing (IEF) of VWF in two pregnancies which had samples from multiple trimesters.

Results

VWF:Ag and FVIII levels were significantly increased during pregnancy. ADAMTS13 activity was unchanged. VWFpp levels increased much later in pregnancy than VWF:Ag, resulting in a progressive decrease in VWFpp:Ag ratios. FVIII:VWF ratios also decreased in pregnancy. Most pregnancies exhibited a clear loss of larger VWF multimers and altered VWF triplet structure. Further evidence of acquired VWF qualitative changes in pregnancy was found in progressive, reversible shifts in VWF IEF patterns over gestation.

Conclusions

These data support a new view of pregnancy in which VWF can acquire qualitative changes associated with advancing gestational age. Modeling supports a scenario in which both increased VWF production and doubling of the VWF half-life would account for the data observed. We propose that gestation induces a prolongation in VWF survival, which likely contributes to increased total VWF levels and altered VWF structure.

Periodicity in the levels of serum plasminogen activator inhibitor-1 is a robust prognostic factor for embryo implantation and clinical pregnancy in ongoing IVF cycles

CONTEXT:

Plasminogen activator inhibitor-1 (PAI-1) has been inversely correlated to proteolytic extracellular-matrix degradation exerted by urokinase-type (u-PA) and tissue-type plasminogen activators (t-PA). Any pathological disturbance in PAI-1 levels may lead to several pregnancy complications.

AIMS:

To assess the influence of periodicity in serum PAI-1 levels on embryo implantation and clinical pregnancy outcome in IVF cycles

SETTINGS AND DESIGN:

Prospective study of 120 IVF cycles at private infertility centre.

MATERIAL AND METHODS:

Endometrial response (ER) assessment by measuring Endometrial thickness (cm) and echopattern (grade). Serum PAI-1(ng/ml) measurement by ELISA method on day of hCG, day of ET and days 7 and 14 of ET. Main outcome measure was clinical pregnancy.

STATISTICAL ANALYSIS:

Student “t” test, ANOVA, Post-test for linear trend, Pearson Correlation.

RESULTS:

PAI-1 levels declined from dhCG to dET (318.8 ± 36.1 to 176.1 ± 28.4) whereas they increased steadily from dET to d7 to d14ET (176.1 ± 28.4 to 285.2 ± 30.4 to 353.5 ± 150.4; P = 0.0004) in pregnant group (n = 31). Conversely, dhCG to dET levels increased in both nonpregnant (n = 75; 173.8 ± 18.3 to 280.8 ± 26.1) and biochemical pregnancy BCP (n = 14; 172.7 ± 31.1 to 216 ± 30.1) groups. The rising pattern from dET to d7 to d14ET was not observed in non-pregnant and BCP groups. ER thickness and grade shared significant correlation with serum PAI-1 on dET (Pearson r: ER = 0.28, Grade = 0.29) and d7ET (Pearson r: ER = 0.40, Grade = 0.23).

CONCLUSIONS:

Periodicity in serum PAI-1 levels offers a robust prognostic factor for predicting clinical pregnancy outcome. The dhCG to dET PAI-1 transition is a decisive factor for either transferring embryos in same/ongoing cycle or cryopreserving them and postponing ET to subsequent natural cycle.

Changes in the levels of factor VIII and von Willebrand factor in the puerperium

To determine changes in Factor VIII (FVIII) and von Willebrand Factor (VWF) in the first 3 days of the puerperium. A prospective study assessing FVIII clotting activity, VWF activity and antigen levels in 95 women (with singleton uncomplicated pregnancies) during labour and on days 1, 2 and 3 of the puerperium. There were no significant differences in FVIII, VWF:Ag and VWF:CB on days 1 and 2 of the puerperium compared with levels during labour. There was a significant decrease in VWF:Ag (P = 0.009) and VWF:CB (P = 0.04) on day 3. Age, ethnicity, duration of labour and mode of delivery did not have any significant effect on the changes in FVIII and VWF levels. The pregnancy induced increase in FVIII and VWF is maintained in the first 48 h after delivery. VWF levels start to decline on day 3 postdelivery.

Treatment of patients with von Willebrand disease

Von Willebrand disease (vWD) is the most common hereditary bleeding disorder. The aim of therapy is to correct the dual hemostatic defect, due to defective platelet adhesion-aggregation and abnormal coagulation due to Factor VIII (FVIII) deficiency. The choice of treatment depends on a number of factors, including the severity of the bleed, the procedure planned, the subtype and severity of the disease and the age and morbidity of the patient. Desmopressin (DDAVP) is the treatment of choice for type 1 vWD as it increases endogenous release of FVIII and von Willebrand factor (vWF) and is also used in some subtypes of type 2 vWD. In those patients in whom DDAVP is ineffective or contraindicated, levels can be restored by infusing vWF:FVIII concentrates. The role of antifibrinolytic treatment is an important adjunct to replacement therapy during minor or major surgery involving mucosal surfaces. The dosing and timing of vWF:FVIII concentrates is important depending on the nature of the surgical procedure. The role of secondary prophylaxis needs to be further defined.

Influence of gestational age on fibrinolysis from birth to postnatal day 10

OBJECTIVE

To compare components of the fibrinolytic cascade in newborns of gestational age ranging from extreme prematurity to full term, at birth and for the next 10 days, and in their mothers at delivery.

STUDY DESIGN

We studied 10 extremely preterm neonates, 10 very preterm neonates, 10 moderately preterm neonates, 10 full-term neonates, and their mothers (n = 40). We measured the antigen levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitors 1 (PAI-1) and 2 (PAI-2), and thrombin-activatable fibrinolysis inhibitor, as well as PAI-1 activity, in neonates at birth and on postnatal days 3 and 10 and in mothers at delivery.

RESULTS

On day 10, both PAI-1 antigen and activity were higher in extremely preterm neonates than in full-term neonates (P = .004 and <.0006, respectively), and the t-PA/PAI-1 activity ratio was lower in the extremely preterm and very preterm neonates compared with the full-term neonates (P = .002 and .017, respectively). No significant differences in the fibrinolytic system components were seen among the 4 groups of mothers.

CONCLUSIONS

The development of fibrinolysis suppression in extremely preterm infants within 10 days after birth may contribute to the increased risk of periventricular hemorrhagic infarction in these infants.

More than menorrhagia: a review of the obstetric and gynaecological manifestations of bleeding disorders

In women, menorrhagia may be the most common manifestation of a bleeding disorder, but it is not the only reproductive tract abnormality that women with bleeding disorders experience. Women with bleeding disorders appear to be at an increased risk of developing haemorrhagic ovarian cysts and possibly endometriosis. As they grow older, they may be more likely to manifest conditions, which present with bleeding such as fibroids, endometrial hyperplasia and polyps. Women with bleeding disorders are more likely to undergo a hysterectomy and are more likely to have the operation at a younger age. During pregnancy, they may be at greater risk of miscarriage and bleeding complications. At the time of childbirth, women with bleeding disorders appear to be more likely to experience postpartum haemorrhage, particularly delayed or secondary postpartum haemorrhage. Vaginal or vulvar haematomas, extremely rare in women without bleeding disorders, are not uncommon. While women with bleeding disorders are at risk for the same obstetrical and gynaecological problems that affect all women, they appear to be disproportionately affected by conditions that manifest with bleeding.