Alterations in the von Willebrand factor/ADAMTS-13 axis in preeclampsia.

Background: Preeclampsia is a gestational hypertensive disorder characterized by maternal endothelial activation and increased ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) inhibitor to placental growth factor (PlGF). The von Willebrand factor (VWF)/ADAMTS-13 axis is of interest because of the underlying endothelial activation and clinical overlap with pregnancy-associated thrombotic thrombocytopenic purpura.

Objectives: To assess VWF, ADAMTS-13, and VWF/ADAMTS-13 ratio in preeclampsia and look for associations with sFlt-1/PlGF ratio and clinical features.

Commercial Immunoglobulin Products Contain Neutralizing Antibodies Against Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein.

Background: Patients with antibody deficiency respond poorly to coronavirus disease 2019 (COVID-19) vaccination and are at risk of severe or prolonged infection. They are given long-term immunoglobulin replacement therapy (IRT) prepared from healthy donor plasma to confer passive immunity against infection. Following widespread COVID-19 vaccination alongside natural exposure, we hypothesized that immunoglobulin preparations will now contain neutralizing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike antibodies, which confer protection against COVID-19 disease and may help to treat chronic infection.

Etiology and outcomes: Thrombotic microangiopathies in pregnancy.

A State of the Art lecture titled "Etiology and Outcomes of Thrombotic Microangiopathies in Pregnancy" was presented at the International Society on Thrombosis and Haemostasis Congress in 2022. First, it is important to understand changes in laboratory parameters in normal pregnancy, including complement levels, specifically the increase in C3, C4, C3a, and C4a throughout pregnancy. Complement is critical in normal pregnancy for implantation and for placental development.

Impaired exercise capacity in post-COVID-19 syndrome: the role of VWF-ADAMTS13 axis.

Post-COVID syndrome (PCS), or long COVID, is an increasingly recognized complication of acute SARS-CoV-2 infection, characterized by persistent fatigue, reduced exercise tolerance, chest pain, shortness of breath, and cognitive slowing. Acute COVID-19 is strongly linked with an increased risk of thrombosis, which is a prothrombotic state quantified by an elevated von Willebrand factor (VWF) antigen (Ag)/ADAMTS13 ratio that is associated with severity of acute COVID-19 infection. We investigated whether patients with PCS also had evidence of a prothrombotic state associated with symptom severity.

Atypical haemolytic uraemic syndrome in the eculizumab era: presentation, response to treatment and evaluation of an eculizumab withdrawal strategy.

The complement inhibitor, eculizumab, has revolutionised the management of atypical haemolytic uraemic syndrome (aHUS), although the optimum treatment duration is debated. Twenty-two cases of acute aHUS managed with eculizumab were retrospectively reviewed, including outcomes after eculizumab withdrawal. Although 41% had an associated complement genetic abnormality, mutation status did not affect severity of clinical presentation.

Severe refractory idiopathic warm autoimmune haemolytic anaemia responsive to complement inhibition with eculizumab.

We report a case of severe idiopathic warm autoimmune haemolytic anaemia (wAIHA) which was initially poorly responsive to treatment with corticosteroids, intravenous immunoglobulin, mycophenolate mofetil and rituximab, and required transfusion of more than 30 units of red cells over 12 weeks. Off-label use of the terminal complement pathway inhibitor, eculizumab, led to rapid amelioration of the haemolysis, presumably by the inhibition of an intravascular component, and allowed time for slower acting immunosuppressive agent to take effect. This novel approach warrants further evaluation, given the poor prognosis of multirefractory wAIHA.

Microangiopathic Hemolytic Anemia in Pregnancy.

Thrombotic microangiopathies (TMAs) are associated with microangiopathic hemolytic anemia and thrombocytopenia, resulting in microvascular thrombosis and end-organ damage. In pregnancy, this may be the result of pregnancy-related TMAs such as preeclampsia; hemolysis, elevated liver enzymes, and low platelets; or pregnancy-associated TMAs, specifically thrombotic thrombocytopenic purpura (TTP) or complement-mediated hemolytic uremic syndrome (CM HUS). TTP and CM HUS are rare disorders, and their diagnosis may be missed, no less because features at presentation may be misdiagnosed as a pregnancy-related TMA, such as hypertension, proteinuria, fetal growth restriction, or in utero fetal death.

How we manage patients with heparin induced thrombocytopenia.

Heparin induced thrombocytopenia (HIT) remains a rare, but significant, condition related to mortality and morbidity. The incidence has decreased with reduced use of unfractionated heparin, with the exception of cardiac surgery. Due to the high risk of thrombosis, a switch to a non-heparin anticoagulant is required, until platelet counts normalize.

Mycophenolate mofetil therapy for severe immune thrombocytopenia.

Severe immune thrombocytopenia purpura (ITP) presents a clinical challenge. Second-line treatment options are variable without a precise protocol. We present 46 severe ITP patients treated with mycophenolate mofetil (MMF), retrospectively identified from three London teaching hospitals.