Sickle cell disease (SSD) is a genetically inherited disease affecting the red blood cells, causing them to change from a normal round form to a twisted shape. This adversely impacts their ability to carry oxygen throughout the body, and makes the cells more susceptible to be destroyed easily which can cause severe anemia. Additionally, patients with sickle cell disease can experience symptoms such as extreme paleness, fatigue and reduced physical and mental performance.
Sickle cell disease occurs when patients receive two altered copies of the gene for sickle hemoglobin – one from each of their parents. People who inherit only one mutated gene copy may not have any symptoms. They are called carriers, as they may pass the affected gene copy to their offspring.
Sickle cell disease is most commonly found in the African continent and areas around the Mediterranean Sea. In the United States, approximately 100,000 Americans are affected by sickle cell disease. Of those who are affected, it is more common among African Americans where approximately 1 of 365 babies are affected by the disease and 1 in 13 will be a carrier.
In sickle cell disease, the main problem with the altered red blood cells is that under certain conditions, such as stress and low blood oxygen concentrations, they are less elastic and tend to block small blood vessels. This blockage can lead to an abrupt lack of oxygen, causing extreme pain, often in the abdomen, muscles and back. This state is called sickle cell crisis and can lead to organ damage such as kidney, spleen and liver failure. Sometimes, this can cause stroke. The continuous organ damage leads to a reduced life expectancy to a mean of 47 years in the U.S., as well as an increased risk of death during childhood.
Sickle cell disease is usually treated with transfusions of healthy red blood cells, IV fluids and pain medication during a sickle cell crisis. SSD patients also receive medications to try to reduce the number of crises, however there is no drug that can reverse the sickling or cure the disease.
Currently, the only therapy with the potential to cure sickle cell disease is stem cell transplantation. A stem cell transplant is a procedure in which the patient’s stem cells, the progenitor cells that live in the bone marrow and divide into red cells, white cells (cell to defend us from infections) and platelets, are replaced from a healthy donor (usually from a sibling who does not have the disease). The new healthy stem cells are then able to generate normal red cells that do not sickle and are able to reverse the natural course of the disease. The transplant, however, has its own risks and is only indicated in very select group of patients. Ongoing research examining ways to genetically modify the SSD patients’ own stem cells so that they can produce normal “non-sickling” red cells.
At the Weill Cornell Medicine and NewYork-Presbyterian Bone Marrow and Stem Cell Transplant Program, we are at the forefront of the fight against SSD. We are carefully selecting SSD patients who are eligible for curative stem cell transplant procedures and we are finding new sources of healthy stem cells from umbilical cords. We are currently seeking patients to enroll in a new clinical trial comparing bone marrow transplantation to standard of care in adolescents and young adults with severe sickle cell disease.
For more information about our Bone Marrow and Stem Cell Transplant Program or to make an appointment, contact us at (646) 962-7950.
Special thanks to medical student Benjamin Trautz and WCM/NYP Hematology and Oncology Fellow Alexandra Gomez Arteaga, MD for their contributions to this article.