Donate to Science & Enterprise

S&E on Mastodon

S&E on LinkedIn

S&E on Flipboard

Please share Science & Enterprise

Blood Stem Cell Transplants Tested as Sickle Cell Therapy

Donald Kohn (University of California in Los Angeles)

Donald Kohn (University of California in Los Angeles)

Researchers at University of California in Los Angeles, University of Southern California, and hospitals in California tested a technique that harnesses a patient’s own blood-producing stem cells as a potential treatment for sickle cell disease. The team led by UCLA’s Donald Kohn published its findings today online in the Journal of Clinical Investigation, under a program for developing regenerative therapies on an accelerated schedule.

Sickle cell disease is an inherited collection of related disorders caused by a malforming of red blood cells from round into a shape resembling a crescent or sickle. This sickling process in turn causes red blood cells to break down, become stiff and inflexible,  and interfere with their normal flow through capillaries. People wth sickle cell disease often suffer from anemia, repeated infections, and painful episodes, although the severity of symptoms can vary from one person to the next.

Sickle cell disease is the most common inherited blood disorder in the U.S. affecting 70,000 to 80,000 people. The disorders occur most frequently with people whose ancestors come from sub-Saharan Africa, the Mediterranean, and Spanish-speaking regions in Caribbean, as well as Central and South America.

Transplants of stem cells to treat sickle cell disease is possible with donor stem cells, but the practice is considered risky because of immune rejection. Only a few patients, usually children with severe symptoms, have undergone this procedure, usually with matched sibling donors.

The technique developed by Kohn and colleagues introduces a human hemoglobin gene engineered to prevent sickling into blood-forming stem cells extracted from the patient’s bone marrow. The patient’s stem cells culture with the engineered anti-sickling gene to produce healthy blood-forming stem cells, which are then transplanted back into the bone marrow of the patient. Once transplanted, the new stem cells begin generating normal, non-sickling, red blood cells.

Kohn’s team tested the technique with human stem cells in the lab, which showed a lower percentage of sampled red blood cells becoming sickled compared to untreated samples. The researchers also transplanted the engineered stem cells into mice, using the mice as a culture to grow red blood cells. After two to three months, the human cells extracted from the mice showed genetic evidence — in the form of messenger RNA — similar to the cells cultured in the lab.

Kohn’s research is supported in part by the California Institute for Regenerative Medicine, under a program that calls for the researchers to file an an investigational new drug application to the U.S. Food and Drug Administration within four years. Clinical trials of the stem cell technique are planned for early next year.

Read more:

*     *     *

Comments are closed.