Fluctuations in levels of antiphospholipid antibodies and increased coagulation activation markers in normal and heparin-treated antiphospholipid syndrome pregnancies

Uncovering the pharmacological mechanism of Shou Tai Wan on recurrent spontaneous abortion: A integrated pharmacology strategy-based research

ETHNOPHARMACOLOGICAL RELEVANCE

Shou Tai Wan (STW), a traditional Chinese medicine formula, has been historically used for the treatment of recurrent spontaneous abortion (RSA). Despite its long-standing usage, the exact mechanism underlying the therapeutic effects of STW remains unclear in the existing literature.

AIMS OF THIS STUDY

To explore the Pharmacological Mechanism of STW on RSA.

METHODS

A network pharmacological methodology was utilized to predict the active compounds and potential targets of STW, collect the RSA targets and other human proteins of STW, and analyze the STW related networks. The animal experiments were also performed to validate the effect of STW on RSA.

RESULTS

The results of network analysis showed that STW may regulate PI3K/AKT, MAPK, FoxO signaling pathways and so on. Animal experiment established the RSA model with CBA/J × DBA/2 mice. It was found that STW can reduce the embryo absorption rate of RSA group (p < 0.05) and balance the expression of Th 1/Th2 type cytokines compared with the model group. After 14 days of administration, the decidual and placental tissues were taken and the CD4+ T cells were isolated, and the phosphorylation level of signaling pathway was detected by Springbio720 antibody microarray. This experiment found that STW can significantly up-regulate the phosphorylation levels of STAT3 and STAT6 proteins in the STAT signaling pathway, and down-regulating the phosphorylation level of STAT1 protein. STW also significantly up-regulated the phosphorylation levels of Raf1, A-Raf, Ask1, Mek1, Mek2, JKK1, ERK1, ERK2, c-fos, c-Jun and CREB proteins in the MAPK signaling pathway, and down-regulate the phosphorylation levels of MEK6 and IKKb proteins. Compared with the RSA group, the STW group increased the expression levels of ERK1/2 mRNA and proteins and p-ERK1/2 proteins, and there was a statistical difference (p < 0.05). This is consistent with the chip results.

CONCLUSION

STW may achieve therapeutic effects by interfering with the signaling pathways, biological processes and targets discovered in this study. It provides a new perspective for revealing the immunological mechanism of STW in the treatment of RSA, and also provides a theoretical basis for the clinical use of STW in the treatment of RSA.

Deciphering the clinical significance of longitudinal antiphospholipid antibody titers

In antiphospholipid syndrome (APS), the risk of clinical manifestations increases with higher titers of antiphospholipid antibodies (aPL). Despite the adoption of aPL titers in the classification approach to aPL-positive subjects, the value of longitudinal monitoring of those titers in the follow-up is still debated, being well studied only in systemic lupus erythematosus (SLE). The literature suggests that the rate of aPL positivity decreases during follow-up in primary APS, estimating that seroconversion occurs in between 8.9 and 59% of patients over time. Negativisation of aPL occurs more frequently in asymptomatic aPL carriers than in patients with full-blown APS as well as in subjects with single aPL positivity or low aPL antibody titers. In patients with SLE, aPL typically behave fluctuating from positive to negative and back again in the course of follow-up. The few studies assessing the longitudinal course of aPL positivity with no associated systemic connective tissue disease reported a progressive decrement of aPL titers over time, in particular of antibodies against β2 glycoprotein I (antiβ2GPI) and cardiolipin (aCL) of IgG isotype. After a thrombotic event, aPL titers tend to decrease, as emerged from cohorts of both primary and secondary APS. Hydroxychloroquine has been identified as the most effective pharmacological agent to reduce aPL titers, with multiple studies demonstrating a parallel reduction in thrombosis rate. This review addresses available evidence on the significance of aPL titer fluctuation from clinical, therapeutic and pathogenic perspectives.

Pathogenesis, Diagnosis and Management of Obstetric Antiphospholipid Syndrome: A Comprehensive Review

Antiphospholipid syndrome is an autoimmune disorder characterized by vascular thrombosis and/or pregnancy morbidity associated with persistent antiphospholipid antibody positivity. Cases fulfilling the Sydney criteria for obstetric morbidity with no previous thrombosis are known as obstetric antiphospholipid syndrome (OAPS). OAPS is the most identified cause of recurrent pregnancy loss and late-pregnancy morbidity related to placental injury. Cases with incomplete clinical or laboratory data are classified as obstetric morbidity APS (OMAPS) and non-criteria OAPS (NC-OAPS), respectively. Inflammatory and thrombotic mechanisms are involved in the pathophysiology of OAPS. Trophoblasts, endothelium, platelets and innate immune cells are key cellular players. Complement activation plays a crucial pathogenic role. Secondary placental thrombosis appears by clot formation in response to tissue factor activation. New risk assessment tools could improve the prediction of obstetric complication recurrences or thromboses. The standard-of-care treatment consists of low-dose aspirin and prophylactic low molecular weight heparin. In refractory cases, the addition of hydroxychloroquine, low-dose prednisone or IVIG improve pregnancy outcomes. Statins and eculizumab are currently being tested for treating selected OAPS women. Finally, we revisited recent insights and concerns about the pathophysiology, diagnosis and management of OAPS.

Nonovert disseminated intravascular coagulation (DIC) in pregnancy: a new scoring system for the identification of patients at risk for obstetrical hemorrhage requiring blood product transfusion

BACKGROUND

Nonovert disseminated intravascular coagulation (DIC) is a subclinical hemostatic dysfunction that has not yet reached the decompensation stage. The detection of pregnant patients at this stage may assist in the identification of those who will develop severe obstetrical hemorrhage, as it is one of the leading causes for preventable maternal mortality. Currently, nonovert DIC is diagnosed by a scoring system based on nonpregnant patients, originally generated by the International Society on Thrombosis and Hemostasis (ISTH), which does not address the physiologic changes of the hemostatic system during pregnancy.

OBJECTIVES

(1) To develop a pregnancy-specific nonovert DIC score, (2) to determine the diagnostic performance of this score in detecting women at risk for obstetrical hemorrhage requiring blood product transfusion, and (3) to compare it to the existing ISTH nonovert DIC score.

STUDY DESIGN

This retrospective study has longitudinal and cross-sectional components and includes three steps: (1) characterization of the longitudinal changes in the components of modified ISTH nonovert DIC scores, including these parameters - fibrinogen, antithrombin III, protein C, prothrombin time (PT), platelets, thrombin-antithrombin (TAT) complex, and D-dimer - during gestation in a group of normal pregnancies (n = 50); (2) development of a pregnancy-specific nonovert DIC score in a cross-sectional design of high-risk (n = 152) and control (n = 50) pregnancies, based on the predictive performance of each analyte for the detection of women at risk for obstetrical hemorrhage requiring blood product transfusion and a logistic regression model; and (3) comparison between the diagnostic performance of the pregnancy-specific nonovert DIC score and the modified ISTH nonovert DIC score to detect, upon admission, women who are at increased risk for subsequent development of obstetrical hemorrhage requiring blood product transfusion.

RESULTS

(1) The study cohort included 202 patients, of which 21 (10%) had obstetrical hemorrhage that required blood product transfusion and were considered to have nonovert DIC; (2) using the nonpregnant ISTH nonovert DIC score, 92% of the patients had a D-dimer concentration above the 0.5 mg/L threshold, and only 2% were identified to have a low fibrinogen concentration (<100 mg/dL); thus, this scoring system was unable to identify any of the patients with nonovert DIC based on the suggested cutoff of a score of ≥5; (3) the parameters included in the pregnancy-specific nonovert DIC score were selected based on their contribution to the performance of the model for the prediction of women at risk for obstetrical hemorrhage requiring blood product transfusion; as a result, we excluded the PT difference parameter from the score and the TAT complex concentration was added; and (4) a pregnancy-specific nonovert DIC score of ≥3 had a sensitivity of 71.4% and a specificity of 77.9% to identify patients at risk for obstetrical hemorrhage requiring blood product transfusion.

CONCLUSION

We propose (1) a pregnancy-specific nonovert DIC score adjusted for the physiologic changes in the hemostatic system during gestation; and (2) that the pregnancy-specific nonovert DIC score can be a useful tool for the identification of patients at risk for obstetrical hemorrhage requiring blood product transfusion.

Meta-analysis on aspirin combined with low-molecular-weight heparin for improving the live birth rate in patients with antiphospholipid syndrome and its correlation with d-dimer levels

BACKGROUND

Antiphospholipid antibody syndrome (APS) is a systemic, autoimmune, prothrombotic disease characterized by persistent antiphospholipid antibodies, thrombosis, recurrent abortion, complications during pregnancy, and occasionally thrombocytopenia. At present, there is no consensus on the treatment of this disease. Long-term anticoagulation is recommended in most cases in patients with thrombotic APS. This study aimed to evaluate whether aspirin combined with low-molecular-weight heparin (LMWH) can improve the live birth rate in antiphospholipid syndrome and its correlation with D-dimer.

METHODS

The data were retrieved from the WanFang Data, CBM, VIP, CNKI, the Cochrane Library, PubMed, EMBASE, OVID, and Web of Science databases. We collected data on randomized controlled trials of aspirin combined with LMWH in the treatment of pregnant women with APS. The "Risk of Bias Assessment" tool and the "Jadad Scale" provided by the Cochrane Collaboration were used to evaluate the risk of bias and quality of the collected literature. The risk ratio (RR) and its 95% confidence interval (CI) were determined using Statase-64 software.

RESULTS

In this study, a total of 11 studies were included, comprising a total of 2101 patients. The live birth rate in pregnant women with APS was higher on administration of aspirin combined with LMWH than with aspirin alone (RR = 1.29, 95% CI = 1.22-1.35, P < .001). d-dimer concentration in plasma predicted the live birth rate, which was higher below the baseline than above it (RR = 1.16, 95% CI = 1.09-1.23, P < .001). The subgroup analysis of the live birth rate was carried out based on the course of treatment, and the results were consistent with the overall results. Begg funnel plot test revealed no publication bias. Sensitivity analysis showed that deleting any study did not affect the results.

CONCLUSION

Aspirin combined with LMWH for APS may improve live birth rate, and detection of d-dimer levels in APS pregnant women may predict pregnancy complications and guide the use of anticoagulants.

Placental abruption as a trigger of DIC in women with HELLP syndrome: a population-based study

BACKGROUND

Disseminated Intravascular Coagulation (DIC) is a life-threatening condition. Hemolysis, Elevated Liver enzymes and Low Platelets (HELLP) syndrome is one of the obstetrical syndromes mostly associated with DIC and thus, high rates of fatal complications. There is a lack of information regarding epidemiologic and clinical characteristics of women who developed HELLP syndrome with and without DIC. Additionally, until now, there is no adapted and widely accepted way to diagnose DIC among pregnant women presenting with HELLP syndrome, despite the evident maternal mortality linked to the disease.

Objectives: (1) Address the gaps in knowledge regarding the prevalence, epidemiologic and clinical characteristics of women with HELLP syndrome who develop DIC; and (2) determine the risk factors for the development of DIC among women with HELLP syndrome.

STUDY DESIGN

This was a population-based retrospective cohort study, including all women who delivered at the Soroka University Medical Center between the years 2001-2017. The study population was divided into three groups: (1) comparison group (n = 207,266 deliveries); (2) HELLP syndrome without DIC (n = 320); (3) HELLP syndrome with DIC (n = 21). The diagnosis of DIC was based on the ICD-9 code as recorded in the obstetrical database of the Soroka University Medical Center. The coding is based on the diagnosis made by the attending physician during hospitalization.

RESULTS

(1) The rate of HELLP syndrome in the study population was 0.16% (341/207,607), of them 6.16% (21/341) had DIC; (2) among patients with HELLP syndrome, those with DIC had a higher median gravidity and parity; (3) a higher rate of severe maternal morbidity including blood product transfusion, placental abruption, eclampsia, acute renal failure and maternal death was observed in those who had HELLP syndrome and DIC compared to those with HELLP syndrome without DIC and the comparison group (p-value <.001 for comparison among the three groups); (4) among women with HELLP syndrome, those with DIC had a longer median PT difference, higher serum creatinine and lower AST as well as ALT median concentrations than those without DIC; (5) patients with HELLP syndrome and DIC had a higher rate of stillbirth and postpartum death than patients in the other groups (p-value <.001 for comparison among the three groups); and (6) placental abruption was an independent risk factor for the development of DIC in women with HELLP syndrome (p-value <.001).

CONCLUSIONS

(1) Among women with HELLP syndrome, those who developed DIC had a higher rate of maternal and neonatal morbidity and mortality than those without DIC; and (2) placental abruption, but not abnormal liver function, was an independent risk factor for the development of DIC in women with HELLP syndrome.

Clinical and laboratory practice for lupus anticoagulant testing: An International Society of Thrombosis and Haemostasis Scientific and Standardization Committee survey

BACKGROUND

Current guidelines have contributed to more uniformity in the performance and interpretation of lupus anticoagulant (LA) testing. However, points to reconsider include testing for LA in patients on anticoagulation, cut-off values, and interpretation of results.

OBJECTIVES

The aim of this International Society of Thrombosis and Haemostasis Scientific and Standardization committee (ISTH SSC) questionnaire was to capture the spectrum of clinical and laboratory practice in LA detection, focusing on variability in practice, so that the responses could inform further ISTH SSC recommendations.

METHODS

Members of the ISTH SSC on Lupus Anticoagulant/Antiphospholipid Antibodies and participants of the Lupus Anticoagulant/Antiphospholipid Antibodies Programme of the External quality Control of diagnostic Assays and Tests Foundation were invited to complete a questionnaire on LA testing that was placed on the ISTH website using RedCap, with data tallied using simple descriptive statistics.

RESULTS

There was good agreement on several key recommendations in the ISTH and other guidelines on LA testing, such as sample processing, principles of testing, choice of tests, repeat testing to confirm persistent positivity and the use of interpretative reporting. However, the results highlight that there is less agreement on some other aspects, including the timing of testing in relation to thrombosis or pregnancy, testing in patients on anticoagulation, cut-off values, and calculation and interpretation of results.

CONCLUSIONS

Although some of the variability in practice in LA testing reflects the lack of substantive data to underpin evidence-based recommendations, a more uniform approach, based on further guidance, should reduce the inter-center variability of LA testing.

Predictive value of thromboelastography parameters combined with antithrombin III and D-Dimer in patients with recurrent spontaneous abortion

PROBLEM

To investigate the value of thromboelastography (TEG) combined with antithrombin III (AT-III) and D-Dimer in predicting the occurrence of recurrent spontaneous abortion (RSA).

METHOD OF STUDY

One hundred and five RSA patients and 40 fertile women were enrolled. The subjects were subjected into four groups: group 1 (40 fertile women), group 2 (58 women with 2 abortions), group 3 (30 women with 3 abortions), and group 4 (17 women with four abortions). TEG was conducted on all subjects. Clotting time, reaction time, angle degree, coagulation index, and maximum amplitude were measured. The levels AT-III, D-Dimer, platelet counts, and fibrinogen concentration were determined. The ROC curve analysis was done using MedCalc software to analyse the diagnosis accuracy of the parameters of interest and the combined approach.

RESULTS

The AT-III level in all group 4 was significantly lower than in fertile women. The D-Dimer concentration, platelet count, and MA in patients with four prior abortions were significantly higher than the other three groups. CI and fibrinogen concentration in patients with four prior pregnancy losses were significantly higher than group 1. The ROC curves suggested that combined use of CI, MA, AT-III, and D-Dimer was with the highest accuracy 92.8%, thus predicting the most accurate diagnosis for RSA.

CONCLUSION

Recurrent spontaneous abortion is associated with abnormal coagulation and anticoagulation. TEG combined with detection of AT-III and D-Dimer levels can distinguish patient with RSA from those with normal fertility and highly possibly predict the occurrence of RSA.

Antiphospholipid Antibodies Overlapping in Isolated Neurological Syndrome and Multiple Sclerosis: Neurobiological Insights and Diagnostic Challenges

Antiphospholipid syndrome (APS) is characterized by arterial and venous thrombosis, pregnancy morbidity and fetal loss caused by pathogenic autoantibodies directed against phospholipids (PL) and PL-cofactors. Isolated neurological APS may represent a significant diagnostic challenge, as epidemiological, clinical and neuroimaging features may overlap with those of multiple sclerosis (MS). In an open view, MS could be considered as an organ-specific anti-lipid (phospholipid and glycosphingolipid associated proteins) disease, in which autoreactive B cells and CD8+ T cells play a dominant role in its pathophysiology. In MS, diverse autoantibodies against the lipid-protein cofactors of the myelin sheath have been described, whose pathophysiologic role has not been fully elucidated. We carried out a review to select clinical studies addressing the prevalence of antiphospholipid (aPL) autoantibodies in the so-called MS-like syndrome. The reported prevalence ranged between 2% and 88%, particularly aCL and aβ2GPI, with predominant IgM isotype and suggesting worse MS prognosis. Secondarily, an updated summary of current knowledge on the pathophysiological mechanisms and events responsible for these conditions is presented. We draw attention to the clinical relevance of diagnosing isolated neurological APS. Prompt and accurate diagnosis and antiaggregant and anticoagulant treatment of APS could be vital to prevent or at least reduce APS-related morbidity and mortality.

Brief Report: Changes in Antiphospholipid Antibody Titers During Pregnancy: Effects on Pregnancy Outcomes

OBJECTIVE

To measure variance in antiphospholipid antibody (aPL) levels during pregnancy and to determine if variation affects pregnancy outcomes.

METHODS

We used data from the PROMISSE (Predictors of Pregnancy Outcome: Biomarkers in Antiphospholipid Antibody Syndrome and Systemic Lupus Erythematosus) study, a multicenter prospective study of pregnant women with aPL and/or systemic lupus erythematosus (SLE). Antiphospholipid antibodies were considered present if any of the following were positive: anticardiolipin (aCL), anti-β2 -glycoprotein I (anti-β2 GPI) titers ≥40 IgG phospholipid (GPL) or IgM phospholipid (MPL) units, and/or lupus anticoagulant (LAC). Antiphospholipid antibodies were measured every trimester and postpartum. Adverse pregnancy outcomes were defined as fetal/neonatal death, preterm delivery (<36 weeks) due to preeclampsia or placental insufficiency, or growth restriction.

RESULTS

One hundred fifty-two aPL-positive patients were studied. Fifty-seven percent had clinical antiphospholipid syndrome (APS) and 36% had SLE. IgG aPL levels were significantly lower during the second and third trimesters compared to initial screening, but IgG aCL and anti-β2 GPI remained high-positive through pregnancy in 93% of patients during the second trimester, and in 85% of patients during the third trimester. IgM aPL titers were negative in the majority of patients and decreased modestly during pregnancy among patients who were positive. LAC frequency also decreased, but 75% of patients remained positive through the second trimester. Only 4% of patients with aPL at baseline did not have aPL in either the second or third trimesters. Changes in aPL levels or aPL status were not associated with adverse pregnancy outcomes. LAC was the only aPL associated with adverse pregnancy outcomes.

CONCLUSION

The aPL in the cohort decreased marginally during pregnancy, and changes were not associated with pregnancy outcomes. Our results suggest that, among women with aPL and/or SLE, measuring aPL early in pregnancy is sufficient to assess risk. Repeat aPL testing through pregnancy is unnecessary.

The pattern and magnitude of "in vivo thrombin generation" differ in women with preeclampsia and in those with SGA fetuses without preeclampsia

OBJECTIVE

We aimed to determine the differences in the pattern and magnitude of thrombin generation between patients with preeclampsia (PE) and those with a small-for-gestational-age (SGA) fetus.

METHODS

This cross-sectional study included women in the following groups: (1) normal pregnancy (NP) (n = 49); (2) PE (n = 56); and (3) SGA (n = 28). Maternal plasma thrombin generation (TGA) was measured, calculating: (a) lag time (LT); (b) velocity index (VI); (c) peak thrombin concentration (PTC); (d) time-to-peak thrombin concentration (TPTC); and (e) endogenous thrombin potential (ETP).

RESULTS

(1) The median TPTC, VI, and ETP differed among the groups (p = .001, p = .006, p < .0001); 2) the median ETP was higher in the PE than in the NP (p < .0001) and SGA (p = .02) groups; 3) patients with SGA had a shorter median TPTC and a higher median VI than the NP (p = .002, p = .012) and PE (p < .0001, p = .006) groups.

CONCLUSIONS

(1) Patients with PE had higher in vivo thrombin generation than women with NP and those with an SGA fetus; (2) the difference in TGA patterns between PE and SGA suggests that the latter group had faster TGA, while patients with PE had a longer reaction, generating more thrombin. This observation is important for the identification of a subset of patients who might benefit from low molecular-weight heparin.

DIC score in pregnant women--a population based modification of the International Society on Thrombosis and Hemostasis score

Objectives

The objectives of this study were: 1) To determine the component needed to generate a validated DIC score during pregnancy. 2) To validate such scoring system in the identification of patients with clinical diagnosis of DIC.

Material and Methods

This is a population based retrospective study, including all women who gave birth at the ‘Soroka University Medical Center’ during the study period, and have had blood coagulation tests including complete blood cell count, prothrombin time (PT)(seconds), partial thromboplastin time (aPTT), fibrinogen, and D-dimers. Nomograms for pregnancy were established, and DIC score was constructed based on ROC curve analyses.

Results

1) maternal plasma fibrinogen concentrations increased during pregnancy; 2) maternal platelet count decreased gradually during gestation; 3) the PT and PTT values did not change with advancing gestation; 4) PT difference had an area under the curve (AUC) of 0.96 (p<0.001), and a PT difference ≥1.55 had an 87% sensitivity and 90% specificity for the diagnosis of DIC; 5) the platelet count had an AUC of 0.87 (p<0.001), an 86% sensitivity and 71% specificity for the diagnosis of DIC; 6) fibrinogen concentrations had an AUC of 0.95 (p<0.001) and a cutoff point ≤3.9 g/L had a sensitivity of 87% and a specificity of 92% for the development of DIC; and 7) The pregnancy adjusted DIC score had an AUC of 0.975 (p<0.001) and at a cutoff point of ≥26 had a sensitivity of 88%, a specificity of 96%, a LR(+) of 22 and a LR(−) of 0.125 for the diagnosis of DIC.

Conclusion

We could establish a sensitive and specific pregnancy adjusted DIC score. The positive likelihood ratio of this score suggests that a patient with a score of ≥26 has a high probability to have DIC.

Inherited thrombophilia and recurrent pregnancy loss

Background:

Recurrent pregnancy loss (RPL) is a common health problem. The polymorphisms G20210A of prothrombin gene (FII G 20210A), and G 1691A of factor V gene (Factor V Leiden, FVL) are the most extensively studied thrombophilic mutations in association to recurrent miscarriage.

Objectives:

To determine the frequency of FII G20210A and FVL polymorphisms as well as protein C and protein S deficiency in a series of patients with RPL compared with control group.

Patients and Methods:

The study group included 90 randomly selected patients with three or more consecutive miscarriages with the same partner in <20 weeks gestation in 2012. The control population consisted of 44 age-matched women with at least one live born children and no history of pregnancy loss. Functional activity of protein C and S, activated protein C resistance, FVL assay by polymerase chain reaction and prothrombin gene mutation were assessed. The polymorphism frequencies were recorded for each group and comparisons were made.

Results:

The mean functional activity of protein C and protein S were not significantly different between case and control groups (P >0.05). Frequency of protein C deficiency was also not significantly different between the case and control groups (P=0.906), but frequency of protein S deficiency was significantly higher in patients than controls (P=0.03). Genotype pattern of the patients and healthy individuals were not significantly different with regard to either FVL or Prothrombin G20210A (P > 0.05).

Conclusions:

We determined a significant higher frequency of protein S deficiency in patients with RPL compared with controls. But the frequency of protein C deficiency and the frequency of two common thrombophilic mutations (Factor V Leiden and Prothrombin G20210A), were not significantly different between patients with recurrent miscarriage and healthy women.

Impact of inherited bleeding disorders on pregnancy and postpartum hemorrhage

Inherited bleeding disorders are caused by various genetic defects in the proteins involved in haemostasis. Female patients or carriers are faced with the risk of haemorrhage throughout life. During pregnancy and postpartum, this complication affects the health of either the mother or the baby, or both. This retrospective cohort study was designed to assess the occurrence of obstetric bleeding in the three trimesters of pregnancy, along with primary and secondary postpartum haemorrhage among 100 women with inherited bleeding disorders. A questionnaire was designed in order to collect historical data. The patients were evaluated in three groups: haemophilia carriers, von Willebrand disease (VWD) and rare bleeding disorders. In comparison with normal women, significantly severe bleeding was observed among patients in all of the five stages. VWD patients showed a higher frequency of bleeding in first trimester but the rate of miscarriage was lower. Haemophilia carriers were threatened with bleeding complications during the prenatal period, but they also had the highest frequency of postpartum haemorrhage. Based on our results, vaginal bleeding is a serious threat in all three patient groups, especially during the first trimester of pregnancy and in the postpartum period.

The correlation of autoantibodies and uNK cells in women with reproductive failure

There is conflicting evidence on the role of autoimmune disorders in reproductive failure, including recurrent miscarriage (RM) and recurrent implantation failure (RIF), after in vitro fertilisation (IVF). Several commonly studied autoimmune markers in women with reproductive failure include antiphospholipid antibodies (APAs), thyroid peroxidase antibodies (TPA) and uterine natural killer (uNK) cells. However, there have not been any studies that have examined the correlation of these markers in women with reproductive failure. To determine if women who tested positive for autoantibodies (APA and thyroid peroxidase antibodies) have significantly higher uNK cell numbers than women who tested negative for these antibodies, the percentage of stromal cells that stained positive for CD56 was identified by immunocytochemistry in endometrial biopsies from 42 women with unexplained RM (29 women tested negative for autoantibodies and 13 women tested positive for autoantibodies) and 40 women with unexplained RIF (30 women tested negative for autoantibodies and 10 women tested positive for autoantibodies). Biopsies were obtained on days LH+7 to LH+9. There was no significant difference in uNK cell numbers between women with unexplained RM who tested negative and those who tested positive for autoantibodies. Similarly, there was no significant difference in uNK cell numbers between women with unexplained RIF who tested negative and those who tested positive for autoantibodies. In women with reproductive failure the presence of autoantibodies does not appear to affect the numbers of uNK cells in the endometrium around the time of implantation.

Antiphospholipid syndrome: laboratory detection, mechanisms of action and treatment

The antiphospholipid syndrome (APS) identifies a condition at increased risk of vascular occlusion and/or pregnancy complications. Patients are defined as having APS if they have at least one clinical (vascular occlusion and/or pregnancy complications) and one laboratory criterion at the same time. The laboratory criteria that define APS are repeated positivity (confirmed 12 weeks apart) for lupus anticoagulants and/or antibodies targeted against cardiolipin or β(2) -glycoprotein I immobilized on solid surfaces. Over the years, APS has attracted the interest of many medical specialties. The aim of this review is to provide an update on (i) the laboratory criteria that determine the presence of APS, (ii) how the antibodies increase the risk of vascular occlusion and foetal loss and (iii) the treatment of the related clinical events.

Pregnancy-triggered antiphospholipid syndrome in a patient with multiple late miscarriages

Antiphospholipid syndrome (APS) is a multisystemic disorder of coagulation-causing thrombosis in the arterial and venous system as well as pregnancy-related complications such as miscarriage, stillbirth, preterm delivery and pre-eclampsia. The disease is characterized by the autoimmune production of antibodies against phospholipid, a substance found in the cell membrane. We here report the case of a patient with four second trimester miscarriages, who apart from a heterozygous plasminogen activator-inhibitor-1 mutation, had no risk factors explaining her condition. In the subsequent pregnancy she was therefore put on low-molecular-weight heparin, aspirin and granulocyte colony-stimulating factor. Antiphospholipid antibodies (APL), which had been negative before gestation, increased and remained high throughout pregnancy, thus suggesting a pregnancy-induced or -aggravated APS. The patient was kept on the above-mentioned medication and delivered a healthy male baby by Caesarean section after an otherwise uneventful pregnancy. Thus, in order to diagnose and treat pregnancy-triggered APS in patients with unexplained recurrent miscarriage, screening for APL should also be performed at several time points after conception.

Changes in haemostasis during normal pregnancy: does homocysteine play a role in maintaining homeostasis?

Homocysteine, derived from the demethylation of the ammo acid methionine, is either further catabolised by trans-sulfuration to cysteine or remethylated to methionine. Remethylation to methionine requires the cofactors, folate and vitamin B12. Folate is an effective homocysteine-lowering agent and, thus, homocysteine and folate status are inversely related. Hyperhomocysteinaemia is a strong independent risk factor for venous thromboembolism (VTE) and is associated with adverse pregnancy outcomes such as pre-eclampsia, placental abruption, early pregnancy loss and neural-tube defects. Pregnancy is a risk factor for VTE as a result of prothrombotic changes in levels of haemostatic factors. However, despite this hypercoagulable state, the incidence of pregnancy-associated VTE is relatively low. Hyperhomocysteinaemia is associated with abnormalities in markers of coagulation activation, and recent research suggests that folic acid supplementation, as well as lowering homocysteine, lowers markers of coagulation activation and increases levels of coagulation inhibitors. Tissue factor (TF) is the initiator of blood coagulationin vivo, and homocysteine induces TF expressionin vitro. During pregnancy, monocyte TF expression is lower than that in the non-pregnant state, and this lowering of TF may act to counterbalance increases in coagulation activation. Furthermore, despite a high folate requirement, several studies have reported that homocysteine is lower in normal pregnancy than in the non-pregnant state. Although the exact mechanism of homocysteine lowering during pregnancy is unclear, one possible outcome of lower homocysteine may be the protection of women from pregnancy complications and VTE, and thus lower homocysteine may contribute to maintaining homeostasis in haemostasis.

Impaired factor XIIa-dependent activation of fibrinolysis in treated antiphospholipid syndrome gestations developing late-pregnancy complications

OBJECTIVE

The objective of the study was to investigate the potential role of impaired factor XII-dependent activation of fibrinolysis in treated antiphospholipid syndrome gestations developing late-pregnancy complications.

STUDY DESIGN

This was a prospective study in a third-level teaching hospital, including 75 patients: 25 pregnant patients having the antiphospholipid syndrome and carrying their pregnancies until 26 weeks' gestation or later (group 1); 25 pregnant patients having normal term pregnancies and delivery and no previous miscarriage (group 2); and 25 pregnant patients being diagnosed as having severe pre-eclampsia and/or intrauterine growth restriction but testing negative for antiphospholipid antibodies (group 3). Hemostatic evaluation was carried out from patients in groups 1 and 2 between 6 and 10 weeks, between 18 and 22 weeks, and between 28 and 32 weeks' gestation. Patients in group 3 were sampled between 28 and 32 weeks. An additional blood sample was obtained 4 to 6 months after delivery (baseline). The Mann-Whitney U test, the Friedman test, and the chi2 test were used.

RESULTS

Patients in group 1 were characterized by increased factor VIIa levels, increased prothrombin fragment 1+2 levels, reduced factor XIIa levels, diminished functional urokinase-type plasminogen activator levels, and decreased levels of plasmin/alpha-2-plasmin inhibitor complexes. These abnormalities were more evident in patients in group 1 developing pre-eclampsia and/or intrauterine growth restriction.

CONCLUSIONS

Impaired factor XIIa-dependent activation of fibrinolysis seems to be a key mechanism related to late-pregnancy complications in patients with the antiphospholipid syndrome.

Haemostasis in normal pregnancy: a balancing act?

Pregnancy is a risk factor for venous thrombosis and the incidence of venous thromboembolism during normal pregnancy is 6-fold higher during pregnancy than in the general female population of child-bearing age. This incidence is, however, remarkably low given the increases in markers of haemostatic activation observed during normal pregnancy. During normal healthy pregnancy there are substantial changes in the haemostatic system, many of which are procoagulant and supposed to be in preparation for the haemostatic challenge of delivery. Normal haemostasis requires a balance between coagulation and fibrinolysis to maintain the integrity of the vasculature, and complex physiological changes are evident during pregnancy which appear to ensure a constant coagulation/fibrinolysis balance. This balance is maintained, at least partly, by an increase in fibrinolytic activity, but decreases in other factors such as factor XI and monocyte tissue factor expression may also serve to counterbalance procoagulant changes.

Prognostic impact of anticardiolipin antibodies in women with recurrent miscarriage negative for the lupus anticoagulant

BACKGROUND

Anticardiolipin antibodies (ACA) are found with increased prevalence in women with unexplained recurrent miscarriage (RM) but their impact on future pregnancy outcome in lupus anticoagulant (LAC) negative patients needs better quantification.

METHODS

The impact of a repeatedly positive ACA test on the chance of live birth in the next pregnancy after adjustment for relevant prognostic factors was studied in 147 RM patients who had been included in placebo-controlled trials of immunotherapy. Patients with LAC were excluded and none of the patients received therapy with anticoagulation or prednisone.

RESULTS

60/147 patients (41%) were repeatedly ACA positive according to cut-off values derived from this study. The adjusted odds ratio (OR) for live birth among ACA positive patients was 0.36 (95% CI 0.2-0.7, P = 0.006). Using cut-off values derived from a normal population, the adjusted OR for live birth among ACA positive patients was 0.48 (95% CI 0.2-1.1, P = 0.10). Positivity for IgM ACA was found to be much stronger correlated to pregnancy outcome than IgG ACA.

CONCLUSIONS

In RM women not receiving anticoagulation or prednisone, the presence of ACA in the absence of LAC most likely reduces the chance of live birth by 36-48% compared with the absence of both ACA and LAC. This reduction is inferior to what has been reported from studies where no adjustments for prognostic variables were undertaken and LAC positive patients were included.

Haemostatic changes in pregnancy

Normal pregnancy is accompanied by changes in the coagulation and fibrinolytic systems. These include increases in a number of clotting factors (I, II, VII, VIII, IX and XII), a decrease in protein S levels and inhibition of fibrinolysis. As gestation progresses, there is also a significant fall in the activity of activated protein C, an important anticoagulant. While these physiological changes may be important for minimizing intrapartum blood loss, they entail an increased risk of thromboembolism during pregnancy and the post-partum period.

Is miscarriage a coagulopathy?

PURPOSE OF REVIEW

Pregnancy is a hypercoaguable state. The hypothesis has been developed that many cases of recurrent miscarriage and of later pregnancy complications are caused by a defective maternal haemostatic response leading to thrombosis of the uteroplacental vasculature and subsequent fetal loss. The evidence upon which this hypothesis is based is reviewed.

RECENT FINDINGS

The majority of studies report an increased prevalence of genetic thrombophilic mutations in the female partner of couples with recurrent miscarriage. It is important to note, however, that this is not a uniform finding. A sub-group of women with recurrent miscarriage has been demonstrated to be in a prothrombotic state before pregnancy, and that women in such a state are at an increased risk of miscarriage in future untreated pregnancies. Furthermore, the long-term health implications of this hypercoaguability have been highlighted in a large retrospective study reporting an increased risk of ischaemic heart disease among women with a history of pregnancy loss.

SUMMARY

Although recurrent miscarriage is a heterogeneous condition and no single abnormality will account for all cases of pregnancy loss, the relationship between abnormalities in the haemostatic pathways and pregnancy outcome is increasingly recognized. The challenges we face are how to discriminate between women with a thrombophilic defect who are destined to miscarry from those whose pregnancy will be successful, the pathology of pregnancy loss associated with thrombophilic defects, the role of the fetal genotype in determining pregnancy outcome, and the management of women with thrombophilic defects both during and beyond their reproductive years.