Bone marrow transplants are expected to cure blood diseases

. U.S. scientists have found in a study that doubles the success rate of transplants with only a "half-match" from 50 percent to nearly 100 percent for patients receiving donor cell bone marrow transplants. The study was published online March 13 in The Lancet- Hematology. The findings raise a higher risk of cure for β and fatal hereditary blood diseases such as sickle cell anemia and thalassemia.
"We have succeeded in increasing the cure rate for sickle cell disease and thalassemia to 90 per cent, and this result is very encouraging. Robert Brodsky, professor of medicine and oncology at Johns Hopkins University School of Medicine and director of hematology, said, "Bone marrow transplantation is not just for patients who have exactly matched donor. It also works for 'semi-matched' patients. in the late
1980s, Francisco J. Bolanos-Meade and Brodsky, associate professors of oncology at Kimmel Comprehensive Cancer Center in Sydney, Australia, discovered the possibility of bone marrow transplants to cure sickle cell disease, which previously had little effective treatment and patients usually did not live to be 40 years old. However, few people had previously been treated with bone marrow transplants, which required bone marrow donor and recipient proteins distributed on the cell surface, i.e. human leukocyte antigens, to match exactly. Brodsky says that in the absence of an exact match, the subject sees the cells as foreign cells, which in turn attack them.
It is very difficult to find a perfect match for this type of patient, as less than 15% of siblings have exactly matched and no identical sickle cell disease gene defects, and less than 25% of patients can find registered donor that is not related by blood but can match exactly. Researchers at Johns Hopkins University developed a treatment plan in 2012 that allows patients to receive bone marrow transplants from only half-matched relatives. Brodsky said this progress has significantly expanded the range of potential supplies. In addition, under this transplant, it takes only half the normal time to produce fresh, healthy blood.
to improve the success of these semi-matched transplants, Bolanos-Meade and colleagues tested a new bone marrow transplant program for patients with severe sickle cell disease and β thalassemia. These two blood diseases, commonly known as hemoglobin disease, are caused by β the same blood globulin gene defect. The study recruited 17 patients, including 12 sickle cell patients and 5 β thalassemia patients, with an average age of 16. Each patient has a relative who can be used as a semi-matched bone marrow transplant donor.
, as in previous procedures, all patients received chemotherapy and systemic radiotherapy prior to the transplant in order to suppress the recipient's immune response to the donor bone marrow. Instead of using low-dose radiation of 200cGy, as in the previous scenario, the new study used 400cGy radiation, which is still a relatively small dose of radiation and is well-resistant. After the transplant, all patients were given a dose of cyclophosphamide. The drug plays an important role in preventing a potentially fatal disease known as graft anti-host disease, which is particularly common in semi-matching transplants.
over the next 30, 60, 180 and 360 days, and every year there are years that follow, researchers test the amount of DNA in a patient's blood, the amount of DNA from the recipient, a sign of a successful transplant. They found that all but one of the patients with sickle cell disease showed successful transplants. Although five patients had transplant anti-host disease, their condition was alleviated.
as of the study's release, only three patients were still needed to take immunosuppressive drugs. Of all the patients shown to have successful transplants, some were in great relief, some were gone, and sickle cell disease patients were no longer suffering from pain. Similarly, people β with thalassemia no longer rely on blood transfusions.
" new findings add a wealth of strong evidence to the safety and effectiveness of semi-matched bone marrow transplants. Richard Jones, director of the bone marrow transplant program at Kimmel Cancer Center, said, "We've had more than 1,000 semi-matched bone marrow transplants, and our clinical studies have been successful, with the safety and toxicity comparable to exactly matched bone marrow transplants, so semi-matched bone marrow transplants should be used as a treatment to benefit more patients." Jones says that for patients with sickle cell disease and thalassemia, gene therapy means high-dose (clear-myelin) treatment, which is often unbearable, while transplants involve only mild, low-dose treatments with a higher safety factor. (Source: China Science Journal Zhao Xixi)
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