Scientists from Brazil and France create a consortium to research sickle cell anemia

Initiative intends to promote collaboration in research to improve the diagnosis and treatment of blood-borne diseases.

By Karina Toledo

Agência FAPESP – Scientists from Universidade de São Paulo (USP) and Paris Diderot University have created an International Network in Hematology with the objective of promoting collaboration in research focused on improving the diagnosis and treatment of sickle cell anemia and other blood diseases.

According to Belinda Simões, professor of medicine at Universidade de São Paulo’s Ribeirão Preto School of Medicine (FMRP-USP) and one of the coordinators of the group, the intention is to promote an exchange between researchers and students of the institution in addition to facilitating the process of securing funding for joint research.

“Sickle cell anemia is the most prevalent hereditary disease in Brazil, and it is estimated that there are more than 50,000 cases. It is a question of public health in the country, and for this reason, we will focus on this topic initially. The consortium will also work with bone marrow failures, such as aplastic anemia, and autoimmune diseases, such as diabetes and scleroderma,” explained Simões, a researcher at the Cellular Therapy Center (CTC), one of FAPESP’s Research, Innovation and Dissemination Centers.

More common in populations of African descent, sickle cell anemia is caused by a genetic alteration in hemoglobin, the protein that gives blood its red coloring and helps in the transportation of oxygen through the circulatory system.

This alteration makes erythrocytes – red blood cells – take the shape of a sickle or a crescent moon after oxygen is released. The deformed cells harden and become more likely to aggregate, i.e., to form groups that adhere to the endothelium and impede blood circulation.

In addition to constant inflammation, this vascular occlusive process can cause necrosis in several tissues and intense pain crises. Ulcers on legs, detachment of the retina, priapism (painful and prolonged erections), cerebral vascular accidents, heart attacks, kidney failure and lung failure are not uncommon. This disease also compromises bones and joints and tends to worsen over time, reducing life expectancy to 25 to 30 years.

“We are trying to identify centers of excellence around the world to establish common research protocols and, based on the results, create guidelines for the disease. The CTC in Ribeirão Preto is one of these centers. We are officializing a long-standing partnership,” affirmed Eliane Gluckman, a professor of medicine at Paris-Diderot who was responsible for the world’s first transplant of stem cells from an umbilical cord.

The objective of the collaboration, according to Gluckman, is not only to search out good methods for the diagnosis and treatment of sickle cell anemia but also to adapt them to developing countries. “The majority of patients are in Africa and India and do not have access to basic care. However, this will not be easy because not in even in our countries [Brazil and France] are we diagnosing and treating in an adequate manner,” she affirmed.

According to Gluckman, the only treatment capable of curing sickle cell anemia is a transplant of hematopoietic stem cells, which can be obtained from the bone marrow of a compatible donor or from public umbilical cord blood banks.

“In Brazil, this procedure is still not recognized. For example, in the United States, although more than 600 patients have received transplants, the treatment has been recommended for approximately 100,000. In Europe, another 600 had transplants,” affirmed Gluckman.

Brazilian outlook

According to Simões, 21 sickle cell anemia patients had hematopoietic stem cell transplants – 14 of which were performed at the CTC. “Only three of these patients died (one in Ribeirão Preto) and not because of the transplant, but because of health complications caused by the advanced stages of the disease,” he affirmed.

However, the procedure is still considered experimental by the Ministry of Health and is therefore not reimbursed by the National Health System (SUS). “We have been waiting a long time for revision of this statute. They argue that sufficient evidence is not available to approve the treatment, although there have been more than 1,200 transplants worldwide, and the survival rate is 94%. These patients are completely cured. Not even leukemia or any other disease for which this type of procedure is recommended has such a high success rate,” said Simões.

The researcher believes that approval for the transplant to treat sickle cell anemia will be a cheaper option for the public health system than treatment of the disease’s complications throughout a patient’s lifetime. According to Simões, one of the consortium’s aims will precisely be to make this comparison of costs.

“In the case of patients using exchange transfusion (slow and successive transfusion of small fractions of blood), for example, a month and a half of treatment would cover the cost of the transplant. We have a case of a 38-year-old patient who underwent this procedure every 15 days, who couldn’t work and didn’t pay taxes. After a transplant, he managed to study, and today he has a job and has not cost the government another cent,” noted the doctor.

Furthermore, added Simões, according to the protocol used in Brazilian research, the procedure is recommended for only 20% of sickle cell anemia patients. The protocol also requires that the donor be a compatible sibling. “With this pre-requisite alone, the number of eligible patients drops significantly. There are countries that allow the mother to be a donor and use blood from their umbilical cord. However, as in Brazil, there is a funding problem ; we prefer to begin with siblings and then expand,” he said.

When asked for comment, the Health Ministry stated that “recommendation of the allogeneic bone marrow transplant has been included in current discussions regarding revision of the technical regulations for transplants in Brazil, which is slated for publication in the second half of this year.”