Stem Cell Can Help
Sickle Cell Disease
CIRM funds many projects seeking to better understand sickle cell disease and to translate those discoveries into new therapies.
Around 100,000 Americans have sickle cell disease and despite decades of research the average life expectancy has dropped from 42 in 1995 to 39 today. It is a disease that largely targets the African-American community and to a lesser degree the Hispanic community.
Sickle cell disease is a genetic disorder that causes red blood cells to assume a sickle shape under stress, clogging blood vessels and producing episodes of excruciating pain, called crises, and leading to progressive organ damage. By twenty years of age about 15 percent of people with sickle cell disease have had major strokes and by 40 almost half of the patients have significant mental dysfunction.
The most common recommendation for people with sickle cell disease is to stay hydrated. The more water a person drinks, the less likely it is that their abnormal blood cells will clog their blood vessels. Another effective treatment is a medication called hydroxyurea, which reduces crises by 50 percent and death by 40 percent, but most adults are not treated. The populations most effected by sickle cell disease also suffer from significant health care disparities, which lower the quality of care they receive for their disease.
Bone marrow transplants are used to treat children with the most severe cases of the disease. In fact one of CIRM’s board members, Bert Lubin, MD, the President and CEO of Children’s Hospital and Research Center Oakland, has been a leader in developing this therapy for kids with sickle cell disease (his bio is here). The replacement bone marrow cells generate an entirely new blood system for the patient. However, bone marrow transplants are extremely risky and require a matched sibling donor and even under the best conditions there is always the risk of rejection.
Research funded by California’s stem cell agency focuses on making bone marrow transplants safer and more effective for treating people with sickle cell disease. In one project, the researchers intend to remove bone marrow from the patient and fix the genetic defect in the blood-forming stem cells. Then those cells can be reintroduced into the patient to create a new, healthy blood system. Because the cells come from the patient this technique avoids the issue of rejection. Other researchers are developing ways of making bone marrow transplants safer.
Clinical Stage Programs
University of California, Los Angeles
This team of researchers plans to remove bone marrow cells from people with sickle cell disease and fix the genetic mutation that causes the disease. The team will then reintroduce the new cells into the patient. Those cells will then generate new, healthy blood cells.
City of Hope, Duarte
Scientists at the City of Hope are going to transplant blood-forming stem cells from a donor into a patient who has received a milder, less toxic chemotherapy treatment that removes some but not all of the patient’s diseased bone marrow stem cells. This allows the donor stem cells to engraft and create a healthy supply of non-diseased blood cells without causing an immune reaction in the patient. The hope is that this treatment will cure patients with more severe forms of SCD who aren’t able to benefit from currently available blood stem cell transplants that require the administration of more toxic chemotherapy drugs.