From the Guidelines
Sickle cell anemia causes a decrease in hemoglobin levels primarily due to the chronic hemolysis of red blood cells, which is a result of the abnormal hemoglobin S protein leading to red blood cell destruction, as evident in the study by 1. The condition is characterized by a genetic mutation affecting the beta-globin chain of hemoglobin, causing it to form rigid, sickle-shaped red blood cells when oxygen levels are low. These abnormally shaped cells are fragile and prone to premature breakdown in the spleen and other organs, a process called hemolysis, which results in shortened red blood cell lifespan, typically 10-20 days instead of the normal 120 days. The bone marrow cannot adequately compensate for this loss despite increased production, and repeated sickling episodes damage the cell membrane, further accelerating destruction. Key factors contributing to the decrease in hemoglobin levels include:
- Chronic hemolysis
- Premature breakdown of red blood cells
- Shortened red blood cell lifespan
- Inadequate compensation by the bone marrow
- Damage to the cell membrane from repeated sickling episodes, as described in the guideline on the peri-operative management of patients with sickle cell disease by 1. Management of sickle cell anemia focuses on preventing sickling crises through hydration, avoiding triggers, pain management, and in some cases medications like hydroxyurea that increase fetal hemoglobin production, which inhibits sickling, ultimately aiming to reduce the frequency of hemolysis and improve hemoglobin levels.
From the Research
Sickle Cell Anemia and Hemoglobin Levels
- Sickle cell anemia is a hereditary blood disorder characterized by the production of abnormal hemoglobin molecules, which cause red blood cells to take on a crescent or sickle shape 2.
- The primary cause of sickle cell anemia is a mutation in the gene responsible for producing hemoglobin, leading to the production of abnormal hemoglobin called hemoglobin S 2.
- This abnormal hemoglobin causes red blood cells to become stiff and sticky, leading to various health complications, including anemia 2.
- Anemia in sickle cell anemia is caused by the premature destruction of red blood cells, which are unable to survive for their normal lifespan due to their abnormal shape and stiffness 3.
Mechanism of Decreased Hemoglobin
- The sickling of red blood cells leads to their premature destruction, resulting in a decrease in hemoglobin levels 3.
- The abnormal hemoglobin molecules in sickle cell anemia are poorly soluble when deoxygenated, leading to intracellular gelation of sickle hemoglobin and subsequent hemolysis 3.
- The repeated cycles of sickling and unsickling cause damage to the red cell membrane, leading to hemolysis and a decrease in hemoglobin levels 3.
Treatment Options
- Hydroxyurea is a medication that increases the production of fetal hemoglobin, which can help reduce the frequency and severity of pain crises in sickle cell anemia 2, 4, 5, 6.
- Hydroxyurea has been shown to decrease the transfusion burden in patients with sickle cell anemia, and may also help increase hemoglobin levels 5.
- Other treatment options for sickle cell anemia include blood transfusions, pain management, and hydration, which can help manage symptoms and prevent complications 2.