Genetic basis of pregnancy-associated decreased platelet counts and gestational thrombocytopenia.

ABSTRACT: Platelet count reduction occurs throughout pregnancy, with 5% to 12% of pregnant women being diagnosed with gestational thrombocytopenia (GT), characterized by a more marked decrease in platelet count during pregnancy. However, the underlying biological mechanism behind these phenomena remains unclear. Here, we used sequencing data from noninvasive prenatal testing of 100 186 Chinese pregnant individuals and conducted, to our knowledge, the hitherto largest-scale genome-wide association studies on platelet counts during 5 periods of pregnancy (the first, second, and third trimesters, delivery, and the postpartum period) as well as 2 GT statuses (GT platelet count < 150 × 109/L and severe GT platelet count < 100 × 109/L). Our analysis revealed 138 genome-wide significant loci, explaining 10.4% to 12.1% of the observed variation. Interestingly, we identified previously unknown changes in genetic effects on platelet counts during pregnancy for variants present in PEAR1 and CBL, with PEAR1 variants specifically associated with a faster decline in platelet counts. Furthermore, we found that variants present in PEAR1 and TUBB1 increased susceptibility to GT and severe GT. Our study provides insight into the genetic basis of platelet counts and GT in pregnancy, highlighting the critical role of PEAR1 in decreasing platelet counts during pregnancy and the occurrence of GT. Those with pregnancies carrying specific variants associated with declining platelet counts may experience a more pronounced decrease, thereby elevating the risk of GT. These findings lay the groundwork for further investigation into the biological mechanisms and causal implications of GT.

Pathophysiological, immunogenetic, anatomopathological profile of thrombophilia in pregnancy.

Thrombophilic states have been associated with early and/or late pregnancy loss and possibly other severe obstetrical complications. Pregnancy-induced hypercoagulability, increased stasis, and the consequences of inherited and acquired thrombophilia are just a few of the factors that contribute to the development of thrombosis in pregnancy. In this review, we illustrate the impact that these factors have on the development of thrombophilia during pregnancy. We also explore how thrombophilia impact pregnancy outcomes. Next, we discuss how human leukocyte antigen G plays a part in thrombophilia during pregnancy by regulating cytokine release to prevent trophoblastic cell invasion and maintain local immunotolerance constant. Human leukocyte antigen class E is briefly explored with thrombophilia in pregnancy. Regarding the anatomopathologic aspect, we describe the different histopathological lesions of the placenta found in women with thrombophilia.

Recombinant ADAMTS13 for Hereditary Thrombotic Thrombocytopenic Purpura.

A 27-year-old patient with a history of severe obstetrical complications and arterial thrombosis received a diagnosis of hereditary thrombotic thrombocytopenic purpura (TTP) due to severe ADAMTS13 deficiency when she presented with an acute episode in the 30th week of her second pregnancy. When the acute episode of hereditary TTP became plasma-refractory and fetal death was imminent, weekly injections of recombinant ADAMTS13 at a dose of 40 U per kilogram of body weight were initiated. The patient's platelet count normalized, and the growth of the fetus stabilized. At 37 weeks 1 day of gestation, a small-for-gestational-age boy was delivered by cesarean section. At the time of this report, the patient and her son were well, and she continued to receive injections of recombinant ADAMTS13 every 2 weeks. (Funded by the Swiss National Science Foundation.).

Thrombophilia screening in women with recurrent first trimester miscarriage: is it time to stop testing? - a cohort study and systematic review of the literature.

OBJECTIVE: There are numerous studies reporting a disproportionally high prevalence of thrombophilia in women with a history of recurrent miscarriage (RM), which has led to overdiagnosis and treatment without an improvement in clinical outcomes. The objective of our study was to assess the prevalence of inherited and acquired thrombophilia in a large cohort of women with a history of early RM using internationally agreed diagnostic criteria and inclusion parameters and compare it to the meta-analysis results of existing literature. METHODS: DESIGN: Retrospective cohort study and systematic review of literature. SETTING: This is a retrospective cohort study set-up in two dedicated tertiary centres for women with RM in Southwest London and Surrey. We reviewed all the available literature related to causes of RMs. We ascertained the prevalence of thrombophilia in the study population and compared it with historical and published prevalence in the general population. PARTICIPANTS: 1155 women between 2012 and 2017. All patients had three or more first trimester miscarriages and a full thrombophilia screen. RESULTS: The overall prevalence of thrombophilia in our study population is 9.2% (106/1155) with 8.1% (94/1155) of cases positive for inherited thrombophilia, which is similar to the general population; Factor V Leiden (4.9%; 57/1155) and prothrombin gene mutation (2.9%; 34/1155) were the most common inherited thrombophilias, while only 1% (12/1155) tested positive for acquired thrombophilia. Persistent positive lupus anticoagulant (LA) was found in 0.5% (6/1155) and persistent positive anticardiolipin (ACL) antibodies with a value ≥40 U/mL was found in 0.5% (6/1155) of patients. Tests for LA/ACL were performed a minimum of 12 weeks apart thus meeting the revised Sapporo criteria for a diagnosis of antiphospholipid syndrome. CONCLUSION: The findings of our study demonstrate that the prevalence of inherited thrombophilia is similar in women with RM to that in the general population. Similarly, the prevalence of acquired thrombophilia, using the revised Sapporo criteria, in the cohort of RMs is similar to that in the general population. Therefore, we do not recommend investigation or treatment of inherited or acquired thrombophilia in women with RM. PROSPERO REGISTRATION NUMBER: CRD42020223554.

Development of a High Resolution Melting Curve Analysis for the Detection of Hemoglobin δ-Chain Variants in Thailand and Identification of Hb A2-Walsgrave [codon 52 (GAT>CAT), Asp→His; HBD:c.157G>C] in a Pregnant Woman from Southern Thailand.

Background: Delta-chain (δ-chain) variants are a group of rare hemoglobin (Hb) variants resulting from mutations within the δ-globin gene. Although quantification of Hb A2 levels is a useful screening tool for the beta-thalassemia trait, the coinheritance of a δ-globin gene mutation can lead to misinterpretation of diagnostic results. Objective: To identify an unreported Hb A2 variant in Thailand and to develop a high resolution melting (HRM) curve assay for the four δ-globin chain variants found in the Thai population. Materials and Methods: Allele-specific polymerase chain reaction (ASPCR) was used to analyze a total of 18 DNA samples for Hb variants comprising 10 wild-type controls, 4 Hb A2-Melbourne, 1 Hb A2-Lampang, 2 Hb A2-Kiriwong, and an unknown variant via HRM assays. Results: The unreported Hb A2 variant in Thailand was found to be Hb A2-Walsgrave resulting from δ-globin gene mutation at codon 52 (GAT>CAT). This was also confirmed using ASPCR. In addition, we demonstrated that the HRM curve profile for Hb A2-Melbourne, Hb A2-Lampang, Hb A2-Walsgrave, and Hb A2-Kiriwong could be identified so as to distinguish the mutant alleles from one another and from wild-type alleles. Conclusion: This HRM assay detected both known and unknown mutations with simultaneous differentiation between heterozygous and homozygous alleles on a polymerase chain reaction fragment spanning four of the δ-globin variants found in Thailand. This assay may help to support the prevention and control of thalassemias and hemoglobinopathies in Thailand.

Interferon therapy for pregnant patients with essential thrombocythemia in Japan.

Essential thrombocythemia (ET) mainly affects the elderly, but can also develop in women of childbearing age. The risk of miscarriage and other complications during pregnancy in ET patients are reported to be higher than that compared to the general population. Therefore, management of pregnancy in ET patients requires special considerations. Several groups recommend interferon (IFN) therapy for ET patients with high-risk pregnancies, but currently no guidelines are available in Japan. We report the outcomes of nine ET patients with ten consecutive high-risk pregnancies. All patients were successfully managed with IFN-α during their pregnancies. All patients also received aspirin and switched to unfractionated heparin around 36 weeks of gestation. As for the seven pregnancies in which IFN-α was started after detection of pregnancy, median platelet counts decreased from 910 to 573 × 109/L after 2 months of IFN-α therapy, and median platelet counts at the time of delivery for all ten pregnancies was 361 × 109/L. All patients gave birth to healthy children. IFN-α was well tolerated, safe, and effective as a cytoreductive therapy for all patients. Although evidence is limited and the use of IFN is not approved in Japan, we suggest considering IFN therapy for high-risk ET pregnancies.

Carriers of haemophilia: pregnancy, childbirth and postpartum.

Management of haemophilia carrier women during labour and postpartum is yet to be standardized. Pregnancy was accompanied by a marked rise in factor VIII levels compared with only a small rise in factor IX levels. After delivery, a carrier's factor level drops down to prepregnancy levels, which increases the chance of postpartum haemorrhage. Availability of management guideline and care provided in a multidisciplinary approach can help to minimize bleeding complications in carriers of haemophilia and their newborns.

Placental transcriptome profile of women with sickle cell disease reveals differentially expressed genes involved in migration, trophoblast differentiation and inflammation.

Sickle cell disease (SCD) is a group of disorders whose common characteristic is the presence of hemoglobin (Hb) S in erythrocytes. The main consequence of this abnormality is vaso-occlusion, which can affect almost all organs including the placenta. This study aimed to evaluate the gene expression profile in placentas of women with SCD by means of total RNA sequencing. For this, we proposed a case-control study, with three groups of pregnant women: HbSS (n = 10), HbSC (n = 14) and HbAA (n = 21). The results showed differences in expression in a number of genes such as NOS2 (fold change, FC = 4.52), HLAG (FC = 5.56), ASCL2 (FC = 3.61), CXCL10 (FC = -3.66) and IL1R2 (FC = 3.92) for the HbSC group and S100A8 (FC = -3.82), CPXM2 (FC = 4.57), CXCL10 (FC = -4.59), CXCL11 (FC = -3.72) and CAMP (FC = -4.55) for the HbSS group. Differentially expressed genes are mainly associated with migration, trophoblast differentiation and inflammation. The causes leading to altered gene expression in placentas of sickle cell patients are not fully understood, but the presence of intravascular hemolysis and vaso-occlusion, with cycles of ischemia and reperfusion, may contribute to the emergence of an environment which can be very harmful for placental physiology, altering the nutrient supply and metabolic exchange for fetal growth.

Hb H Disease Diagnosed During Adolescent Pregnancy.

Hb H disease is a moderate to severe form of α-thalassemia (α-thal). Patients with Hb H disease may become symptomatic, especially during infections and pregnancy, and may require transfusions. Herein, we present a 16-year-old female with Hb H disease who was initially diagnosed during adolescent pregnancy and was found to carry the -α3.7/-(α)20.5 deletions. The relatively mild presentation of this case highlights the milder phenotypic consequences of deletional α mutations. The case describes the screening and management of pregnancy with Hb H disease. Additionally, this case demonstrates that screening of some undiagnosed inherited blood disorders is important during pregnancy.

[Discrepancies in FVII:C levels depending on the thromboplastin: about a case]. / Discordances du taux de facteur VII:C selon la thromboplastine : à propos d'un cas.

Factor VII deficiency is the most common of the rare coagulation deficiencies. A hemorrhagic syndrome may occur in patients with FVII deficiency below 20%, although no correlation exist between the plasma FVII activity level (FVII:C) and the bleeding risk. Therefore, the management of surgery in patients with FVII deficiency remains challenging. Laboratory monitoring of FVII:C level may be helpful but should be interpreted with caution, because the dosage of FVII:C level may vary depending on the origin of the thromboplastin used. Herein, we report the case of the management of a woman who had been fortuitously diagnosed during pregnancy with FVII deficiency due to FVII variant Padua, which have induced discrepant results between two different laboratories.

Pregnancy-associated venous insufficiency course with placental and systemic oxidative stress.

The development of lower extremity venous insufficiency (VI) during pregnancy has been associated with placental damage. VI is associated with increased oxidative stress in venous wall. We have investigated potential disturbance/dysregulation of the production of reactive oxygen species (ROS) in placenta and its eventual systemic effects through the measurement of malondialdehyde (MDA) plasma levels in women with VI. A total of 62 women with VI and 52 healthy controls (HCs) were studied. Levels of nicotinamide adenine dinucleotide phosphate-oxidase 1 (NOX1), 2 (NOX2), inducible nitric oxide synthase (iNOS), endothelial (eNOS), poly(ADP-ribose) polymerase PARP (PARP) and ERK were measured in placental tissue with immunohistochemistry and RT-qPCR. Plasma and placental levels of MDA were determined by colorimetry at the two study times of 32 weeks of gestation and post-partum. Protein and gene expression levels of NOX1, NOX2, iNOS, PARP and ERK were significantly increased in placentas of VI. eNOS activity was low in both study groups, and there were no significant differences in gene or protein expression levels. Women with VI showed a significant elevation of plasma MDA levels at 32 weeks of gestation, and these levels remained elevated at 32 weeks post-partum. The MDA levels were significantly higher in placentas of women with VI. Placental damage that was found in the women with VI was characterized by overexpression of oxidative stress markers NOX1, NOX2, and iNOS, as well as PARP and ERK. Pregnant women with VI showed systemic increases in oxidative stress markers such as plasma MDA levels. The foetuses of women with VI had a significant decrease in their venous pH as compared to those from HC women. The situation of oxidative stress and cellular damage created in the placenta is in coexpression with the production of a pH acidification.

Evaluation of Factor V Leiden and prothrombin G20210A mutations in Sudanese women with severe preeclampsia.

BACKGROUND: Preeclampsia (PE) is a common pregnancy complication and one of the main causes of maternal and fetal morbidity and mortality, worldwide. While the pathogenesis of PE is unclear, it has been suggested that hypercoagulability due to Factor V Leiden (FVL) and prothrombin gene mutation (FII G20210A) play a role in its progression. PURPOSE: This study aimed to determine if there is an association between FVL and FII G20210A mutations and severe PE. PATIENTS AND METHODS: This case-control study enrolled 50 women with severe PE and 50 healthy pregnant women as the control, at Khartoum North Teaching Hospital, in Khartoum State, Sudan, from January 2017 to June 2017. The presence of point mutations in FVL and FII G20210A were determined for each of the participants. Deoxyribonucleic acid (DNA) was extracted, and then an allele-specific polymerase chain reaction (PCR) was used to detect the point mutations in FVL and FII G20210A. RESULTS: The results revealed a significant difference between the subjects in the severe PE group and the control group for the means of parity, gestational age/ week and hemoglobin concentration (P < 0.05). No statistically significant body mass index (BMI) differences were found between the groups (P > 0.05). Women with severe PE were found to have a significant difference in FVL (16%; P value = 0.0058; OR: 20.20; 95%CI: 1.132-360.5) and FII G20210A (14%; P value = 0.0125; OR: 17.41; 95%CI: 0.9659-314.0) in comparison to the women in the control group (0%). CONCLUSION: Our findings intensely indicate that there is a statistically proven significant association between FVL, FII G20210A mutations and the development of severe preeclampsia in Sudanese pregnant women.

A Rare Prothrombin Gene Mutation C20209T in a South African Patient with Pulmonary Embolism in Pregnancy: a Case Study and Systematic Review.

BACKGROUND: The G202010A prothrombin gene mutation is a documented prothrombotic risk factor in Caucasian patients. Several other mutations have been described within the prothrombin gene, predominantly in non-Caucasians, including the C20209T mutation. The clinical significance of this mutation is uncertain, but it has been associated with thrombotic events and pregnancy complications. METHODS: We describe a 28-year-old black South African woman who presented with pulmonary embolism during pregnancy. She was investigated for underlying prothrombotic biomarkers. RESULTS: Genetic screening for the prothrombin G202010A mutation by real-time polymerase chain reaction and melting curve analysis demonstrated an atypical mutant peak. Sequencing confirmed a variant C20209T prothrombin mutation. CONCLUSIONS: This is the first report of the C20209T mutation in the Southern African population. It remains uncertain whether genetic testing should be offered routinely to non-Caucasian patients in a resource-limited setting.

Women and inherited bleeding disorders - A review with a focus on key challenges for 2019.

The area of women and inherited bleeding disorders has undergone quick expansion in recent years. More patients are being identified and expertise to diagnose and manage these patients is now essential for practising physicians. Programs to help educate and empower patients and caregivers are now in place. Common inherited bleeding disorders affecting women include von Willebrand disease (VWD), inherited platelet disorders, and rare inherited bleeding disorders such as factor VII (FVII) deficiency and factor XI (FXI) deficiency. Specific clinical tools have been developed to help clinicians and patients screen for the presence of these bleeding disorders in both adult and pediatric populations. Affected women can experience heavy menstrual bleeding and resulting iron deficiency anemia, postpartum hemorrhage, and hemorrhagic ovarian cysts which need to be properly managed. Excessive bleeding can adversely affect quality of life in these women. Front line therapy for bleeding in mild cases focuses on the use of non-specific hemostatic agents such as DDAVP ®, tranexamic acid and hormonal agents but specific factor replacement and/or blood products may be required in more severe cases, in severe bleeding or as second line treatment when bleeding is not responsive to first line agents. Iron status should be optimised in these women especially in pregnancy and use of an electronic app can now help clinicians achieve this. These patients should ideally be managed by a multidisciplinary team whenever possible even remotely. Although clinical research has closed some knowledge gaps regarding the diagnosis and management of these women, there remains significant variation in practise and lack of evidence-based guidelines still exists in many spheres of clinical care in which caregivers must rely on expert opinion. Ongoing efforts in education and research will continue to improve care for these women and restore quality of life for them.

Glycosylation Profile of the Transferrin Receptor in Gestational Iron Deficiency and Early-Onset Severe Preeclampsia.

OBJECTIVE: To examine the expression of hypoxia-inducible factor-1α (HIF-1α), TfR1, and TfR1-attached terminal monosaccharides in placentas of women with IDAP and severe preeclampsia. METHODS: TfR1 and HIF-1α were detected by western blot. Immunoadsorption of TfR1 was performed to characterize the terminal monosaccharides by specific lectin binding. RESULTS: There was no difference in the expression of TfR1 and HIF-1α between groups. Lectin blot analysis pointed out an overexpression of galactose ß1-4 N-acetylglucosamine (Gal-GlcNAc) and mannose in severe preeclampsia. CONCLUSION: The increase in Gal-GlcNAc may be due to the increased presence of antennary structures and the mannose glycans of TfR1 may indicate the presence of misfolded or incomplete proteins. These findings may be associated with the low expression of placental TfR1 in women with preeclampsia.

Genetic risk assessment of thrombophilia in patients with adverse obstetric outcomes.

OBJECTIVES: To investigate the incidence of inherited thrombophilias in patients with adverse obstetric outcomes and to compare detection rates of thrombophilias between standard blood tests and a novel genetic test. METHODS: This is a case-control prospective study performed in Hospital Sant Joan de Déu in Barcelona, Spain. Cases had a history of intrauterine growth restriction requiring delivery before 34 weeks gestation, placental abruption before 34 weeks gestation, or severe preeclampsia. Controls had at least two normal, spontaneously conceived pregnancies at term, without complications or no underlying medical disease. At least 3 months after delivery, all case and control women underwent blood collection for standard blood tests for thrombophilias and saliva collection for the genetic test, which enables the diagnosis of 12 hereditary thrombophilias by analyzing genetic variants affecting different points of the blood coagulation cascade. RESULTS: The study included 33 cases and 41 controls. There were no statistically significant differences between cases and controls in the standard blood tests for thrombophilias in plasma or the TiC test for genetic variables. One clinical-genetic model was generated using variables with the lowest P values: ABO, body mass index, C_rs5985, C_rs6025, and protein S. This model exhibited good prediction capacity, with an area under the curve of almost 0.7 (P <0.05), sensitivity of almost 67%, and specificity of 70%. CONCLUSION: Although some association may exist between hypercoagulability and pregnancy outcomes, no significant direct correlation was observed between adverse obstetric outcomes and inherited thrombophilias when analyzed using either standard blood tests or the genetic test. Future studies with a larger sample size are required to create a clinical-genetic model that better discriminates women with a history of adverse pregnancy outcomes and an increased risk of poor outcomes in subsequent pregnancies.

The influence of specific mutations in the AT gene (SERPINC1) on the type of pregnancy related complications.

BACKGROUND: Inherited antithrombin (AT) deficiency is a rare autosomal dominant disorder, caused by mutations in the SERPINC1 gene. The most common clinical presentation in AT deficient patients includes venous thrombosis and pulmonary embolism, while the association of AT deficiency and its effect on the development of pregnancy complications has been less studied. The aim of our research was to evaluate the effect of AT deficiency types, determined by genotyping, on pregnancy outcomes. METHODS: A retrospective cohort study included 28 women with AT deficiency, and their 64 pregnancies were analyzed. RESULTS: With regard to live birth rate, a significant difference was observed among women who were carriers of different SERPINC1 mutations, as the rate varied from 100% in cases of type I to the extremely low rate of 8% for women with type II HBS (AT Budapest 3) in the homozygous variant, P = 0.0005. All pregnancies from the type I group, even untreated ones, resulted in live births. In women with AT Budapest 3 in homozygous variant the overall live birth rate increased to 28.5% in the treated pregnancies. In this group the highest incidence of fetal death was observed of 62%; repeated fetal losses in 30%; fetal growth restriction in 22% and placental abruption in 7% of all pregnancies. CONCLUSION: Our study results indicate a difference between type I and type II AT deficiency. The risk of pregnancy related VTE was equally present in both groups, except for AT Budapest 3 in the heterozygous variant, while adverse pregnancy outcomes were strictly related to type II, especially AT Budapest 3 in the homozygous variant.