What is Sickle Cell Disease (SCD)?

From the Guidelines

Sickle Cell Disease (SCD) Definition

Sickle Cell Disease (SCD) is a genetic disorder characterized by chronic hemolytic anemia, painful vaso-occlusive crises, and acute and chronic end-organ damage.

Key Characteristics

• It is caused by a mutation in the beta-globin gene, leading to the production of abnormal hemoglobin (HbS) that polymerizes in deoxygenated conditions, causing red blood cells to deform into a sickle shape 1.
• This deformation leads to vaso-occlusion, ischemia-reperfusion injury, and end-organ damage, resulting in a range of complications, including stroke, pulmonary hypertension, and priapism 1.
• The disease can present in different forms, including sickle cell anemia (HbSS), sickle-C disease (HbSC), and sickle-beta thalassemia (HbS β-thal) 1.

Prevalence and Impact

• SCD is one of the most common serious inherited conditions globally, with a significant prevalence in populations of African, Caribbean, and Middle Eastern descent 1.
• It is estimated that there are approximately 14,000 patients with SCD in the UK, with a significant impact on healthcare resources and individual quality of life 1.

Management and Complications

• Management of SCD focuses on prevention and treatment of complications, including pain crises, infections, and end-organ damage 1.
• Hematopoietic stem cell transplantation (HSCT) is currently the only curative approach for SCD, although it is typically reserved for patients with severe disease or significant morbidity 1.
• Peri-operative care for patients with SCD requires meticulous planning and management to reduce the risk of complications, including sickle-related and non-sickle-related events 1.

From the Research

Definition and Characteristics of Sickle Cell Disease

• Sickle Cell Disease (SCD) is a hereditary blood disorder characterized by the production of abnormal hemoglobin molecules that cause red blood cells to take on a crescent or sickle shape 2.
• It is a lifelong condition caused by a mutation in the gene responsible for producing hemoglobin, resulting in the formation of abnormal, sickle-shaped red blood cells 3.
• SCD is an inherited disorder of hemoglobin structure, characterized by the formation of long chains of hemoglobin when deoxygenated within capillary beds, resulting in sickle-shaped red blood cells, progressive multiorgan damage, and increased mortality 4.

Causes and Symptoms of Sickle Cell Disease

• The primary cause of SCD is a mutation in the gene responsible for producing hemoglobin, which has abnormal hemoglobin called hemoglobin S, causing red blood cells to become stiff and sticky, leading to various health complications 2.
• Patients with SCD may experience recurrent pain, fatigue, anemia, and increased infection susceptibility 2.
• SCD is characterized by repeated episodes of severe acute pain and acute chest syndrome, and by other complications including stroke, chronic pain, nephropathy, retinopathy, avascular necrosis, priapism, and leg ulcers 4.

Treatment Options for Sickle Cell Disease

• Treatment options for SCD focus on managing symptoms and preventing complications, including pain management with analgesics, hydration, and blood transfusions to improve oxygen delivery 2.
• Hydroxyurea, a medication that increases the production of fetal hemoglobin, is commonly used to reduce the frequency and severity of pain crises 2, 4.
• Hematopoietic stem cell transplant is the only curative therapy, but it is limited by donor availability, with best results seen in children with a matched sibling donor 4.
• Other therapies, such as L-glutamine, crizanlizumab, and voxelotor, have been approved as adjunctive or second-line agents for the treatment of SCD 4.