A new breakthrough in the treatment of sickle-cell anemia with stem cells

Researchers at the Hospital of the University of Illinois at Chicago, USA cured 12 adult patients with sickle cell disease. They used a unique process of transplantation of stem cells from healthy tissue from brothers and sisters who have become a compatible donor. The new technique eliminates the need to chemotherapy for the preparation of the patient for transplantation and offers the prospect of cure tens of thousands of adults suffering from sickle cell anemia. The results are published in the September issue of the journal Biology of Blood and Marrow Transplantation.

First grafts were created in the National Institutes of Health campus in Maryland, where this method has been developed. Physicians there have treated 30 patients, with an 87 percent success rate. As a result on the Phase I/II of the study was cured 92% of patients.

The new technique eliminates the need to chemotherapy for the preparation of the patient for transplantation of allogeneic cells and opens up the prospect of cure tens of thousands of adults suffering from sickle-cell anemia.

Of about 450 patients to whom transplanted stem cells for the treatment of sickle-cell anemia, about 90% were children. This is because the use of chemotherapy for adults is associated with larger risk because mature body more weakened to disease than a child.

“Adults with sickle cell disease live average up to 50 years. They are constantly in need of blood transfusions and receiving painkillers, which makes their quality of life rather low,” – says Dr. Damiano Rondelli, lead author of the study.

“Now with the transplant without chemotherapy for the treatment of adults with sickle cell disease, we found that within a month after the procedure, the quality of life of patients significantly improved,” – said Rondelli. “They can go back to school, to work and are able to live without pain.”

Sickle cell anemia is inherited. It affects primarily people of African descent, including one of 500 African Americans born in the United States. The disease is characterized by sickle-shaped form of red blood cells that carry oxygen. These modified cells deliver less oxygen to the body’s tissues, causing severe pain and resulting in a stroke or malfunction of organs.

It is known that bone marrow transplantation from a compatible healthy donor can cure sickle cell anemia. However, this procedure is rarely carried out due with the need to use high doses of radiation for the destruction their own hematopoietic cells and the patient’s immune system in order to prevent rejection of foreign cells. The patient becomes vulnerable to any infections.

According to the new procedure, patients receive immunosuppressive drugs just before transplantation, along with a very low dose of total irradiation. Such therapy is much less stiff and characterized by a smaller number of potentially serious side effects than in the case of chemotherapy.

Then, stem cells from tissue-compatible sibling donor (brother or sister) is transplanted to a patient, whereupon they create a population of healthy blood cells in an amount sufficient to eliminate the symptoms of the disease. In many cases, sickle cells are no longer detectable. Then, during the year the patient should continue to take immunosuppressants.

In their study, the researchers transplanted to 13 patients from 17 to 40 years old, stem cells derived from the blood of a tissue-compatible siblings. Were conducted tests for compliance of leukocyte antigens in patients and their siblings. It is possible to obtain a set of markers for the cells in their bodies. Ten of these markers HLA were selected as having the greatest correspondence between the patients and healthy relatives to obtain the best results of transplantation.

Scientists from the University of Illinois stepped farther than colleagues from the National Institutes of Health in Maryland. They have successfully transplanted stem cells from patients with identical siblings markers HLA, but different blood groups.

All of the 13 patients, the transplanted cells successfully taken root in the bone marrow, producing healthy red blood cells. One of the patients who did not adhere to treatment regimen following transplantation, again developed symptoms of the disease. In all cases there was no rejection of the donor cells by the immune system of the patient.

One year after transplantation, 12 patients had normal levels of hemoglobin in the blood and improve the activity of the heart. At them reduced pain and improved health status.

Four patients discontinued immunotherapy without graft rejection or other complications.

“Adults with sickle cell disease can be cured without chemotherapy – the main barrier standing in the way for so long,” – said Rondelli. “Our results show that this therapy is a safe and effective and allows patients to live longer without pain and complications.”