Pregnancy in mother with Glanzmann's thrombasthenia and isoantibody against GPIIb–IIIa: Is there a foetal risk?

Obstetric and Gynaecological Challenges and Outcomes in Women and Girls With Glanzmann's Thrombasthenia

INTRODUCTION

Glanzmann's thrombasthenia (GT) is an inherited platelet function disorder that may manifest with significant bleeding symptoms; in women and girls (W&Gs), heavy menstrual bleeding (HMB) is very common. GT in pregnancy is associated with an increased risk of postpartum haemorrhage (PPH).

AIM

This study highlights the gynaecological and obstetric challenges experienced by W&Gs with GT, and reviews available treatment options.

METHODS

Data regarding 38 W&Gs with GT were analysed from the ISTH REDCap registry, an international multi-centre database.

RESULTS

Among 38 W&Gs, 76% of Middle Eastern ethnicity, 100% reported HMB; 92% HMB since menarche, and 82% presented with acute HMB and were treated with platelets and packed red blood cells (pRBCs) transfusions in addition to hormonal therapies. Management of chronic HMB required a combination therapy including antifibrinolytics (tranexamic acid [TXA]), hormonal therapies, and recombinant factor VIIa (rFVIIa); rFVIIa was used in 50% of W&Gs. In 16 pregnancies, PPH was reported in 63% of deliveries, of which 83% required blood and platelet transfusions. Despite prophylactic haemostatic agents during labour and delivery in 8/9 pregnancies of women with known GT diagnosis, 78% experienced PPH. Thirty-one percent of neonates developed neonatal alloimmune thrombocytopenia (NAIT).

CONCLUSION

HMB and PPH are common bleeding complications in GT. Effective management of HMB and PPH in W&Gs with GT is challenging but can be achieved by a multidisciplinary team, often requiring a combination of haemostatic agents with hormonal therapies. Use of rFVIIa may limit the need for platelet transfusion, thus reducing alloimmunisation and the risk of developing NAIT.

Should HLA and HPA-matched platelet transfusions for patients with Glanzmann Thrombasthenia or Bernard-Soulier syndrome be standardized care? A Dutch survey and recommendations

BACKGROUND

Glanzmann thrombasthenia (GT) and Bernard-Soulier syndrome (BSS) patients require frequent platelet transfusions and hence have an increased risk for alloimmunization against donor Human Leukocyte Antigens (HLA) when no HLA-matching is performed. Knowing that Human Platelet Antigens (HPA) are located on the platelet glycoproteins that can be absent in these patients, preventive HPA-matching may also be considered. Uniform recommendations on this topic lack in transfusion guidelines making standard practice unclear, therefore, we aimed to provide a framework for matched platelet transfusions.

STUDY DESIGN AND METHODS

We conducted a targeted literature search and a national survey of Dutch (pediatric) hematologists from July to September 2021.

RESULTS

We found 20 articles describing platelet transfusion policies in 483 GT-patients and 29 BSS-patients, both adults and children. Twenty surveys were returned for full analysis. All responders treated patients with platelet disorders, including GT (n = 36 reported) and BSS (n = 29 reported). Of respondents, 75% estimated the risk of antibody formation as "likely" for HLA and 65% for HPA. Formation of HLA antibodies was reported in 5 GT and in 5 BSS-patients, including one child. Fifteen respondents gave preventive HLA-matched platelets in elective setting (75%). Three respondents additionally matched for HPA in GT-patients (15%). Main argument for matched platelet transfusions was preventing alloimmunization to safeguard the effectivity of 'random' donor-platelets in acute settings.

CONCLUSION

Elective HLA-matching for GT and BSS-patients is already conducted by most Dutch (pediatric) hematologists. HPA-matching is mainly applied when HPA-antibodies are formed. Based on the current literature and the survey, recommendations are proposed.

Emergency management of patients with Glanzmann thrombasthenia: consensus recommendations from the French reference center for inherited platelet disorders

Glanzmann thrombasthenia (GT) is a genetic bleeding disorder characterised by severely reduced/absent platelet aggregation in response to multiple physiological agonists. The severity of bleeding in GT varies markedly, as does the emergency situations and complications encountered in patients. A number of emergency situations may occur in the context of GT, including spontaneous or provoked bleeding, such as surgery or childbirth. While general management principles apply in each of these settings, specific considerations are essential for the management of GT to avoid escalating minor bleeding events. These recommendations have been developed from a literature review and consensus from experts of the French Network for Inherited Platelet Disorders, the French Society of Emergency Medicine, representatives of patients' associations, and Orphanet to aid decision making and optimise clinical care by non-GT expert health professionals who encounter emergency situations in patients with GT.

Glanzmann's thrombasthenia during pregnancy complicated by large subchorionic hematoma managed with antifibrinolytics, human leukocyte antigen-matched platelet transfusion, and primary cesarean delivery: a case report

A 29-year-old primipara with Glanzmann's thrombasthenia presented for prenatal care at 8 weeks of gestation. Pregnancy remained uncomplicated until 22 weeks of gestation when a subchorionic hematoma, measuring 5.8 × 4.1 × 6.7 cm, was diagnosed and managed outpatient. At 28 weeks of gestation, the subchorionic hematoma was significantly expanding to 11 × 13 × 3.7 cm (∼30% of the placental surface). The patient was admitted for antepartum surveillance and steroid treatment. Fetal and maternal status were reassuring. At 36 weeks of gestation, there was active extravasation from the subchorionic hematoma, prompting interdisciplinary discussion with neonatal intensive care unit, blood bank, pharmacy, anesthesia, hematology, and the patient regarding her options. Immediate delivery risked platelet sensitization because of unavailable human leukocyte antigen-matched platelets. The patient opted for medical management with aminocaproic acid. At 37 weeks of gestation, she underwent a scheduled cesarean delivery. Human leukocyte antigen-matched platelets and additional aminocaproic acid were administered preoperatively. Intrapartum hemorrhage of 1200cc was controlled with uterotonics in addition to the above measures. Antifibrinolytics were continued. The neonate had an uncomplicated postpartum course. The patient had symptomatic anemia on postoperative day 1, which prompted red blood cell transfusion. Discharge was delayed until postoperative day 6 to further monitor her bleeding; oral antifibrinolytics were continued for 2 weeks. This case adds to the growing use of adjuvant medications, including antifibrinolytics such as aminocaproic acid and tranexamic acid, to reduce the reliance on platelet transfusion. This is critical for maintaining a favorable response to platelet transfusions and minimizing the risk of fetal neonatal alloimmune thrombocytopenia in current and subsequent pregnancies among women with lifelong bleeding disorders.

Profiling the Genetic and Molecular Characteristics of Glanzmann Thrombasthenia: Can It Guide Current and Future Therapies?

Glanzmann thrombasthenia (GT) is the most widely studied inherited disease of platelet function. Platelets fail to aggregate due to a defect in platelet-to-platelet attachment. The hemostatic plug fails to form and a moderate to severe bleeding diathesis results. Classically of autosomal recessive inheritance, GT is caused by defects within the ITGA2B and ITGB3 genes that encode the αIIbβ3 integrin expressed at high density on the platelet surface and also in intracellular pools. Activated αIIbβ3 acts as a receptor for fibrinogen and other adhesive proteins that hold platelets together in a thrombus. Over 50 years of careful clinical and biological investigation have provided important advances that have improved not only the quality of life of the patients but which have also contributed to an understanding of how αIIbβ3 functions. Despite major improvements in our knowledge of GT and its genetic causes, extensive biological and clinical variability with respect to the severity and intensity of bleeding remains poorly understood. I now scan the repertoire of ITGA2B and ITGB3 gene defects and highlight the wide genetic and biological heterogeneity within the type II and variant subgroups especially with regard to bleeding, clot retraction, the internal platelet Fg storage pool and the nature of the mutations causing the disease. I underline the continued importance of gene profiling and biological studies and emphasize the multifactorial etiology of the clinical expression of the disease. This is done in a manner to provide guidelines for future studies and future treatments of a disease that has not only aided research on rare diseases but also contributed to advances in antithrombotic therapy.

Glanzmann Thrombasthenia: Perspectives from Clinical Practice on Accurate Diagnosis and Optimal Treatment Strategies

Glanzmann thrombasthenia (GT) is a rare autosomal recessive disorder of fibrinogen-mediated platelet aggregation due to a quantitative or qualitative deficit of the α_IIbβ₃ integrin at the platelet surface membrane resulting from mutation(s) in ITGA2B and/or ITGB3. Patients tend to present in early childhood with easy bruising and mucocutaneous bleeding. The diagnostic process requires consideration of more common disorders of haemostasis and coagulation prior to confirming the disorder with platelet light transmission aggregation, flow cytometry of CD41 and CD61 expression, and/or exon sequencing of ITGA2B and ITGB3. Antifibrinolytic therapy, recombinant activated factor VII, and platelet transfusions are the mainstay of therapy, although the latter may trigger formation of anti-platelet antibodies in GT patients and inadvertent platelet-refractory disease. The management of these patients therefore remains complex, particularly in the context of trauma, labour and delivery, and perioperative care. Bone marrow transplantation remains the sole curative option, although the venue of gene therapy is being increasingly explored as a future alternative for definitive treatment of GT.

Platelet antibodies in immune thrombocytopenia and related conditions

Platelet autoantibodies are a common finding in immune thrombocytopenia (ITP) and in rare cases of antibody-mediated platelet function (“acquired thrombasthenia”). In drug-induced immune thrombocytopenia, antibodies react with platelets only in the presence of the offending drug. Alloantibodies reacting with platelets are induced by transfusion of cellular blood products or during pregnancy. They are responsible for fetal/neonatal alloimmune thrombocytopenia (FNAIT), they are able to cause febrile, nonhemolytic transfusion reactions and they give rise to insufficient platelet increments following platelet transfusions. Two rare transfusion reactions: post-transfusion purpura (PTP) and passive alloimmune thrombocytopenia (PAT) are triggered by platelet alloantibodies. This review discusses the clinical value of tests for platelet antibodies in various clinical situations related to insufficient primary hemostasis.

Menstrual and obstetrical bleeding in women with inherited platelet receptor defects-A systematic review

INTRODUCTION

Women with inherited platelet receptor defects (IPRD) may have an increased risk of heavy menstrual bleeding (HMB) and postpartum haemorrhage (PPH).

AIM

To present a systematic overview of the literature on the prevalence and management of menstrual and obstetrical bleeding in women with IPRD.

METHODS

Electronic databases were searched for original patient data on the prevalence and management of HMB and PPH in women with known IPRD or who were being investigated for IPRD.

RESULTS

Sixty-nine papers (61 case reports/series and 8 cohort studies) were included. Overall, studies were rated as 'poor quality'. The included cohort studies reported HMB in 25% (13/52) of women with Bernard-Soulier syndrome and in 22.1% (34/154) of women with Glanzmann thrombasthenia. In total, 164 deliveries in women with IPRD were described. Excessive bleeding occurred in 16.9% (11/65) of deliveries described in the largest cohort. PPH occurred in 63.2% (55/87) of deliveries described in case reports/series. PPH occurred in 73.7% (14/19) of deliveries that were not covered by prophylaxis compared with 54.2% (32/59) of deliveries that were (OR = 2.36, 95% CI 0.75-7.40). Neonatal bleeding complications were reported in 10.0% (8/80) of deliveries. In all (6/6) deliveries with neonatal bleeding complications wherein the presence of alloantibodies was investigated, either antiplatelet or anti-HLA antibodies were detected.

DISCUSSION/CONCLUSION

Menstrual and particularly obstetrical bleeding problems frequently occur in women with IPRD, based on small case reports and series of poor quality. International collaboration, preferably on prospective studies, is needed to improve clinical management of women-specific bleeding in IPRD.

From thrombasthenia to next generation thrombocytopenia: Neonatal alloimmune thrombocytopenia induced by maternal Glanzmann thrombasthenia

BACKGROUND

Glanzmann thrombasthenia (GT) is a rare autosomal recessive disorder of platelet function caused by mutations in the genes coding for integrin αIIbβ3. The aim of this study was to examine the outcome of newborns of GT mothers, with emphasis on thrombocytopenia and bleeding manifestations and their relation to maternal antiplatelet antibodies.

PROCEDURE

Medical files of all female patients with GT treated in a single tertiary center from 1999 to 2017 were searched for details on pregnancy and birth. The medical files of their newborns were retrieved, and data on the postnatal course were collected.

RESULTS

Nine babies were born to five patients with GT at our center during the study period. Three of the nine newborns had severe thrombocytopenia, and all three were offspring of GT mothers who were positive for antiplatelet antibodies.

CONCLUSION

Pregnant GT patients should be examined for platelet antibodies. Assessment and management protocols (including treatment with intravenous immunoglobulins) for fetal and neonatal alloimmune thrombocytopenia should be considered.

Acquired Antibodies to αIIbβ3 in Glanzmann Thrombasthenia: From Transfusion and Pregnancy to Bone Marrow Transplants and Beyond

Patients with the inherited bleeding disorder Glanzmann thrombasthenia (GT) possess platelets that lack αIIbβ3 integrin and fail to aggregate, and have moderate to severe mucocutaneous bleeding. Many become refractory to platelet transfusions due to the formation of isoantibodies to αIIbβ3 with the rapid elimination of donor platelets and/or a block of function. Epitope characterization has shown isoantibodies to be polyclonal and to recognize different epitopes on the integrin with β3 a major site and αvβ3 on endothelial and vascular cells a newly recognized target. Pregnancy in GT can also lead to isoantibody formation when fetal cells with β3 integrins pass into the circulation of a mother lacking them; a consequence is neonatal thrombocytopenia and a high risk of mortality. Antibody removal prior to donor transfusions can provide transient relief, but all evidence points to recombinant FVIIa as the first choice for GT patients either to stop bleeding or as prophylaxis. Promoting thrombin generation by rFVIIa favors GT platelet interaction with fibrin, and the risk of deep vein thrombosis also associated with prolonged immobilization and catheter use requires surveillance. Although having a high risk, allogeneic bone marrow transplantation associated with different stem cell sources and conditioning regimens has proved successful in many cases of severe GT with antibodies, and often, the associated conditioning and immunosuppressive therapy leads to loss of isoantibody production. Animal models of gene therapy for GT show promising results, but isoantibody production can be stimulated and CRISPR/Cas9 technology has yet to be applied. Up-to-date consensus protocols for dealing with isoantibodies in GT are urgently required, and networks providing patient care should be expanded.

Anti-αIIb β3 immunization in Glanzmann thrombasthenia: review of literature and treatment recommendations

Glanzmann thrombasthenia (GT) is caused by inherited defects of the α_IIb β₃ platelet glycoprotein. This bleeding disorder can be treated with platelet transfusion therapy, but some patients will be immunized and begin to form anti-human leucocyte antigen (HLA) and/or anti-α_IIb β₃ antibodies. These antibodies can bind and interfere with the function of the transfused platelets, rendering treatment ineffective. However, platelet transfusion refractoriness attributable to HLA antibodies may be managed by the selection of compatible donors, although they are not always readily available, particularly in an emergency. Thus, anti-α_IIb β₃ antibodies represent one of the most severe complications in GT. Both genetic and environmental factors may contribute to the risk of anti-α_IIb β₃ development, but the underlying pathogenic mechanisms are still unknown. This review will summarize the current knowledge of the risk factors for development of anti-α_IIb β₃ antibodies in patients with GT and discuss how these findings may influence the clinical management of patients.

Immunisation against αIIbβ3 and αvβ3 in a type 1 variant of Glanzmann’s thrombasthenia caused by a missense mutation Gly540Asp on β3

Treatment of bleeding in patients with Glanzmann’s thrombasthenia (GT) can be hampered by iso-antibodies against the αIIbβ3 integrin, which cause rapid clearance of transfused donor platelets. Type 1 GT patients with a total absence of αIIbβ3 from the platelet surface are known to be susceptible to form such isoantibodies. In this study, we describe a type 1 GT patient with a missense mutation (Gly540Asn) located in the EGF3 domain of the β3 integrin subunit. Cotransfection analysis in CHO cells demonstrates total absence of αIIbβ3 from the surface, based on inappropriate αIIb maturation. The patient’s serum was reactive with αIIbβ3 and αvβ3 integrins in a capture assay, when platelets and endothelial cells were used. Two specificities could be isolated from the patient’s serum, anti-αIIbβ3 and anti-αvβ3 isoantibodies. Both specificities did not interfere with platelet aggregation. In contrast, isoantibodies against αvβ3, but not against αIIbβ3, were able to disturb endothelial cell adhesion onto vitronectin, triggered endothelial cell apoptosis and interfered with endothelial tube formation. This intriguing finding may explain more recently observed features of fetal/neonatal iso-immune thrombocytopenia in children from type 1 GT mothers with intracranial haemorrhage, which could be related to anti-endothelial activity of the maternal antibodies. In conclusion, we give evidence that two isoantibody entities exist in type 1 GT patients, which are unequivocally different, both in an immunological and functional sense. Further research on the clinical consequences of immunisation against αvβ3 is required, predominantly in GT patients of childbearing age.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Glanzmann thrombasthenia in pregnancy: Optimising maternal and fetal outcomes

Glanzmann thrombasthenia is a rare autosomal recessive haemorrhagic disorder. The risks of miscarriage, antepartum and postpartum haemorrhage, and neonatal complications are all increased in individuals presenting with the disease in pregnancy. Some individuals may develop antibodies to platelet glycoproteins; the presence of these antibodies is a rare cause of neonatal alloimmune thrombocytopenia and potential intracranial haemorrhage. Multidisciplinary care is paramount for ensuring optimal fetal and maternal outcomes in such cases. We report a case of neonatal alloimmune thrombocytopenia secondary to maternal Glanzmann thrombasthenia in pregnancy.

Natural history of platelet antibody formation against αIIbβ3 in a French cohort of Glanzmann thrombasthenia patients

Treatment of the bleeding syndrome in Glanzmann thrombasthenia (GT) is often complicated by naturally occurring isoantibodies directed against the αIIbβ3 integrin that cause the removal of or render ineffective transfused donor platelets. Such antibodies are produced after transfusion or pregnancy when the patient's immune system comes into contact with normal platelets. Despite many reports of anti-αIIbβ3 antibodies in GT patients, there is no consensus pertaining to their frequency, their long-term evolution in the circulation, or their formation in relation to either (i) the extent of the αIIbβ3 deficiency in the patient's platelets or (ii) the nature of the genetic defect (ITGA2B or ITGB3 genes). Antibody screening was performed on a large series of 24 GT patients in South-West France dividing the patients into two cohorts: (i) 16 patients with the French gypsy mutation (c.1544 + 1G>A) within ITGA2B that gives platelets totally lacking αIIbβ3 and (ii) 8 patients carrying other defects of ITGA2B or ITGB3 with different expression levels of αIIbβ3. Our results confirm that patients with premature termination mutations resulting in platelets lacking αIIbβ3 are the most susceptible to form isoantibodies, a finding that may be useful in deciding the choice of therapy between platelet transfusion and the use of recombinant factor VIIa (FVIIa).

A systematic review of the management and outcomes of pregnancy in Glanzmann thrombasthenia

Glanzmann Thrombasthenia (GT) is a rare autosomal recessive disorder which usually manifests as severe mucocutaneous bleeding and is caused by deficiency of the platelet glycoprotein IIb-IIIa. Pregnancy in women with GT presents particular challenges as there is increased risk of both maternal and foetal bleeding. To improve understanding and clarify the optimum management of pregnancy in this disorder, we performed a systematic review of the world literature of pregnancy and GT. This identified three single-centre case series of patients with GT that included brief descriptions of women in pregnancy and 31 detailed case reports of 40 pregnancies in 35 women that resulted in 38 live births. Among the detailed case reports, ante-natal bleeding was described in 50% of pregnancies but was usually mild and occurred at mucocutaneous sites. Primary postpartum haemorrhage (PPH) was reported in 34% of pregnancies and secondary PPH in 24%. PPH was frequently severe and occurred up to 20 days after delivery. There was a wide variation in approach to prevention and treatment of PPH but most women received platelet transfusion, sometimes with additional recombinant FVIIa and anti-fibrinolytics. Maternal alloimmunization against platelet antigens was reported in 73% of pregnancies and was associated with four neonatal deaths. These data emphasize the need for multidisciplinary management of pregnancy in women with GT. Delivery plans should recognize the need for prevention and aggressive treatment of PPH and should minimize foetal bleeding risk in pregnancies complicated by alloimmunization.

Physiologic and pathologic changes of platelets in pregnancy

Platelets are key players in haemostasis and thrombus formation. Defects affecting platelets during pregnancy can lead to heterogeneous complications, such as thrombosis, first trimester miscarriage and postpartum haemorrhage. The incidence of complications is increased in women who have heritable platelet function disorders. Modifications of platelet count or platelet functions during normal pregnancy and preeclampsia will be summarized and the management of pregnant women with heritable platelet function disorders will be discussed.

Inherited Platelet Disorders

The inherited platelet disorders are a heterogeneous collection of rare diseases that are infrequently encountered in clinical practice. They are, however, fascinating abnormalities, which have taught us a great deal about normal platelet biochemistry and physiology. In this section of the presentation we will review disorders of the platelet membrane, platelet granule packaging disorders, the hereditary macrothrombocytopenias, platelet signaling disorders and disorders of platelet coagulant function. The molecular basis of the disorders, the cardinal features of their clinical presentation and best methods to make their diagnosis and the latest information regarding therapy will be presented.