Vaso-occlusive disorders

Pulmonary embolism (PE) is a form of venous thromboembolism in which an embolus occludes pulmonary arteries. This Primer by Huisman and colleagues discusses the epidemiology, mechanisms, diagnosis and prevention of PE and describes patient management and quality of life.

Venous thrombosis and its potentially debilitating or even fatal consequences can pose diagnostic and therapeutic challenges. Here, Mackman and colleagues discuss not only the clinical implications of thrombosis but also new insights into thrombogenesis and how to inhibit this process.

Sickle cell disease includes genetic conditions that are caused by mutations in one of the genes encoding haemoglobin. Mutant haemoglobin molecules can polymerize, causing the red blood cells to acquire a characteristic crescent shape that gives the disease its name.

Antiphospholipid syndrome is an autoimmune disease associated with a variety of symptoms, including thrombosis and obstetrical complications. This Primer provides an update on the epidemiology, pathogenesis, diagnosis and therapeutic aspects and offers an outlook on future research topics.

Anaemia, thrombosis and smooth muscle dystonias are manifestations of paroxysmal nocturnal haemoglobinuria, a rare but potentially life-threatening haematological disorder. Inhibition of complement activation is the treatment of choice; stem cell transplantation is recommended for patients who also develop severe bone marrow failure.

Haemolytic anaemia, thrombocytopenia and microthrombi are hallmarks of thrombotic thrombocytopenic purpura (TTP), a rare microangiopathy that can cause severe ischaemic organ damage. The majority of cases have an autoimmune aetiology and, therefore, can be managed with immunosuppressive drugs, in addition to plasma therapy.

Disseminated intravascular coagulation can be caused by various infectious and non-infectious insults, such as sepsis and trauma, respectively. It is characterized by the widespread activation of coagulation and, depending on the underlying condition, can manifest as bleeding and/or thrombosis.

This illustrated PrimeView highlights the diagnosis and management of pulmonary embolism, and accompanies the Primer by Huisman and colleagues.

Activation of blood coagulation in veins leads to thrombosis. Deep-vein thrombosis is often asymptomatic and only becomes apparent when its consequences, such as pulmonary embolism and breathlessness, occur. In this PrimeView, we summarize the key points of the associated Primer.

This PrimeView highlights the complex pathophysiological mechanisms of sickle cell disease (SCD), which stem from the polymerization of sickle haemoglobin (HbS), a mutant haemoglobin variant. Erythrocytes containing HbS polymers assume the crescent shape that gives SCD its name.

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of antiphospholipid antibodies, such as lupus anticoagulant, anticardiolipin antibodies and anti-β2-glycoprotein 1 antibodies. This PrimeView focuses on the pathophysiology of APS, which is mainly characterized by thrombosis and obstetrical complications.

Somatic PIGA mutations in haematopoietic stem cells generate erythrocytes that are deficient in glycosylphosphatidylinositol-anchored proteins. These erythrocytes are susceptible to haemolysis by complement activation, which manifests as paroxysmal nocturnal haemoglobinuria. This PrimeView illustrates the complex pathological mechanisms.

This PrimeView highlights the difficulty in reaching a conclusive diagnosis of thrombotic thrombocytopenic purpura (TTP), a rare but potentially lethal microangiopathy characterized by thrombocytopenia, haemolytic anaemia and ischaemic organ damage.

Disseminated intravascular coagulation (DIC) is a medical emergency that can be caused by infectious or non-infectious conditions. The mechanisms underlying DIC — highlighted in this PrimeView — are an imbalance in the factors that control haemostasis.