In 1973, people with sickle cell disease (SCD) had an average lifespan of only 14 years. But the situation has improved dramatically for patients living with this rare, inherited blood disorder that is primarily prevalent amongst people of African descent. Currently, life expectancy for these patients can reach 50 years and over. Women with the disease tend to live longer than their male peers but ongoing research is giving all affected patients even more reason to hope.
Sickle cell disease primarily affects people of African descent, including 0.6 percent of the African American population in the U.S. (approximately 90,000 cases). It affects approximately one in every 350 African American newborns. Americans whose ancestry is Asiatic Indian, Italian, Greek or Mediterranean may also be affected by SCD Scientists now believe that the mutated gene that causes sickle cell disease occurred in hard-hit malaria populations because the sickle cell trait has been shown to confer some resistance to the mosquito-borne disease.
Treatments have been woefully inadequate and lead to a diminished quality of life for many sickle cell sufferers. Patients’ symptoms are managed mainly with narcotic pain medication and blood transfusions. There are several pharmaceutical companies developing therapies to lessen the frequency and severity of patients’ crises but a cure was out of reach for many individuals—until now.
NIH Study Spurs Hematologist to Undertake His Own
Just two and a half years ago, I penned a blog post about a promising new study taking shape at University of Illinois Hospital & Health Sciences System (UI Health) in Chicago. Dr. Damiano Rondelli, a hematologist, leveraged findings from a NIH study that reported it was possible to do stem cell transplants in sickle cell disease patients without using chemotherapy and still receive good results. That was good enough for Dr. Rondelli and he opened a trial mostly based on the large patient population in his clinic.
Out with the Old, in with the New
Doctors have known for some time that bone marrow transplants from a healthy donor can cure sickle cell disease but few adults were candidates for the procedure. Why? Prior to release of the NIH study findings, the prerequisite for stem cell transplantation was a course of chemotherapy to kill off the patient’s own cells and prepare the body to accept the new ones. The chemotherapy could leave patients with weakened immune systems and make them susceptible to infection. This was a very risky proposition for some patients, especially adults, who lived with the debilitating effects of the disease for years and already experienced organ damage as a result. The procedure was just too risky to undertake in many cases.
Patients receive a very low dose of total body irradiation and immunosuppressive drugs just before the transplant with the new technique. This is a much milder course of treatment, instead of chemotherapy, that results in fewer potentially serious side effects than ever before.
Cure for Adult Sickle Cell Patients Validated by UI Health
Dr. Rondelli and his team performed the first non-chemotherapy transplants outside of the NIH facility in Maryland, where the procedure was developed. Their trial results have been stunning and according to the press release they have “cured twelve adult patients of sickle cell disease using a unique (non-chemotherapy) procedure for stem cell transplantation from healthy, tissue-matched siblings.” The results of the phase I/II clinical trial at UI Health, in which 92 percent of treated patients were cured, are published online in the Biology of Blood & Marrow Transplantation journal. It should be noted that UI Health’s 92 percent cure rate eclipses the 87 percent success rate of the NIH study.
UI Health Furthers Advancement
It is one thing to leverage a study’s findings and replicate the results but another when you are able to improve upon the results and advance the findings. This is just what happened at UI Health. In addition to achieving a five percent higher success rate, UI Health successfully transplanted two patients with cells from siblings who matched for human leukocyte antigen (HLA) but had a different blood type.
According to the UI Health press release, one year after transplantation the 12 successfully transplanted patients had normal hemoglobin concentrations in their blood and better cardiopulmonary function. Four of the patients were able to stop post-transplantation immunotherapy without transplant rejection or other complications.
The Future is Brighter
An inspired hematologist from Chicago and his team pounced on a NIH study and brought its findings to their clinic for further investigation and trial. Several years later their validation that adults with SCD can undergo stem cell transplantation without harmful chemotherapy and be cured of this debilitating condition is very exciting news indeed and holds promise for a much brighter future for thousands of SCD patients and their families.
Image courtesy of Ed Uthman on Flickr (CC BY).