Sickle-Cell Anemia (SCA) is one of the most common genetically inherited disorders. The exact number of people affected by SCA is unknown but estimates are in the millions worldwide. Particularly susceptible are people of sub-saharan, southwest Asian, Indian, and mediterranean ancestry. People from spanish-speaking countries in the western hemisphere are also slightly more susceptible.
While there are no treatments for the disease, many people have used cannabis, specifically CBD, for sickle cell anemia. It normalizes many immune system and nervous system disruptions that exacerbate the symptoms caused by sicle cell anemia.
What is Sickle Cell Anemia?
Sickle cell anemia is a form of sickle cell disease. As its name suggests, sickle cell disease is characterized by a genetic change which causes red blood cells (RBCs) – which are responsible for transporting oxygen from our lungs to every other cell in our body – to become crescent-shaped. Normal red blood cells are flat and round, which allows them to be flexible enough to fit through the microscopic capillaries that deliver blood to all of our individual cells. In sickle cell disease, these cells are not only sickle-shaped, but also much more rigid than healthy RBCs.
This illness has no widely available treatment.This disease is associated with chronic and acute pain. But, a possible solution on the table is a bone marrow transplant which is both risky and unlikely because bone marrow donors are not readily available. Not to mention that the procedure itself is no walk in the park- death is plausible. For these reasons physicians work to keep the complications far and the symptoms silent.
Cause(s) of sickle cell anemia
Sickle-Cell Anemia is caused by the mutation of the gene which creates the hemoglobin protein. Hemoglobin allows our red blood cells to transport oxygen throughout our body. This mutation results in abnormal red blood cells, which are rigid, crescent-shaped, and incapable of holding oxygen efficiently. Anemia is caused by a lack of hemoglobin, and the immediate effect of reduced hemoglobin is oxygen deficiency. Patients with sickle cell anemia (SCA) report experiencing dizziness, tiredness, and an irritability to the cold.
Red blood cells are some of the only human cells which don’t contain a nucleus. Instead, they are filled with thousands of hemoglobin proteins that readily bind with oxygen in the lungs and transport it to the rest of the body. They are round and flexible, and this allows them to squeeze through tight capillaries.
In SCA, the defective hemoglobin causes red blood cells to become misshapen and rigid. Not only does this result in a reduced ability to transport oxygen, but it can lead to physical blockage of capillaries by the defective red cells. It is this clotting in the tiny capillaries which causes the symptoms and inherent danger of sickle cell disease.
Diagnosis and characteristics of sickle cell anemia
A blood test is the go-to diagnostic measure for sickle cell disease. Additionally, red blood cells in SCA are visibly deformed, taking the shape of a crescent/sickle. Due to the genetic nature of this condition, parents are generally aware of the risk prenatally. Thus, diagnosis usually occurs during or immediately following pregnancy, and several european countries encourage abortion of fetuses that are known to have active sickle cell disease.
80% of cases occur in sub-saharan Africa, where it is believed to be an advantageous trait, to some extent. This is because the defective hemoglobin prevents malaria parasites from infecting the blood and thus prevents the course of that disease.
Current treatment options and best practices for sickle cell anemia
Current treatments of sickle cell disease are supportive and palliative. When sickled red cells block capillaries, it leads to oxygen deprivation of the tissue served by the blocked vessel. This is known as sickle cell crisis, and it causes intense pain which is treated with opioids primarily. In the brain, it can lead to a stroke.
Morphine is used to reduce the inflammation and neurogenic pain produced by this disease. Unfortunately, although morphine is effective for most patients, it activates certain cells which produce more inflammation (mast cells).
Blood transfusions to replace defective blood cells and bone marrow transplants to allow for the natural production of healthy red blood cells are common, but they bring their own laundry list of risks and potential dysfunctions.
There is no cure for sickle cell disease, and even the best management generally leads to a lifespan of between 40 and 60 years; 25% shorter than average in the industrialized world.
Is endocannabinoid deficiency involved in sickle cell anemia?
The endocannabinoid system is not highly expressed throughout the vascular system, nor in bone marrow. However, endocannabinoid expression is increased in cases of SCA, and this results in increased activity of mast cells and endothelial cells. The resulting inflammation exacerbates the likelihood of clotting. It is unclear whether this is a result of the underlying disease, or if it has an effect in the ratio of normal to sickled red cells.
Does CBD improve cases of sickle cell anemia?
A recent study conducted by Lucile Vincent and company demonstrated that mice with a model of SCA experienced reduced pain and inflammation with activation of cannabinoid receptors. This finding fundamentally changed our understanding of the biology and underlying processes which contribute to sickle cell anemia.
The following figure supports the findings of the study.
While CBD certainly is not a cure for sickle cell disease, it can certainly improve quality of life, reduce the likelihood of opioid dependence, and reduce the damage caused by the ischemia resulting from capillary occlusion.
CBD will also improve respiratory efficiency within mitochondria through cannabinoid receptor-induced cAMP reduction. This has been shown to decrease baseline oxygen consumption without reducing output.