Platelet storage pool disorder in pregnancy: Utilising thromboelastography to guide a risk-based delivery plan

We present a case of a 33-year-old woman in her third pregnancy diagnosed with platelet storage pool disorder who had previously suffered two postpartum major obstetric haemorrhages. Platelet storage pool disorder is a rare bleeding disorder where the platelet count is normal but platelet function is impaired due to deficiency of dense granules. A peripartum plan devised by an extensive multi-disciplinary team using principles for managing other bleeding and platelet function disorders helped minimise her risk of major haemorrhage. We also describe how point-of-care thromboelastography can help guide management and enable an individualised risk-benefit discussion with the woman about her anaesthetic choices.

The odds and implications of coinheritance of hemophilia A and B

We report 2 patients with coinheritance of the X-linked bleeding disorders hemophilia A and hemophilia B. We describe the family pedigrees, clinical features, and genotyping. The case report addresses the key clinical questions of how to manage patients with both hemophilia A and B and how to counsel families regarding recurrence risk. The patients with coinherited hemophilia A and B require a combination of factor VIII and factor IX replacement to achieve hemostasis. We calculated the estimated genomic meiotic recombination frequency between F8 and F9 to be 38%. The findings in these cases are consistent with this calculation. These findings provide critical information for management of families with coinherited hemophilia A and B.

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.