Haematopoietic stem cell transplantation from an unrelated donor works as a curative therapy for children with non-oncological blood disorders

Children with blood diseases have traditionally been cured by transplantation from an HLA-identical sibling donor. In the absence of such a compatible donor, patients are subjected to long and even chronic treatments that do not guarantee a good quality of life.

The annual meeting of the EBMT (European Society of Blood and Marrow Transplantation), a European meeting on haematopoietic stem cell transplantation (HSCT), was held on 14th April, where professionals from the Paediatric Oncology and Haematology Service of the Vall d'Hebron University Hospital and the Childhood Cancer and Haematological Diseases Group of the Vall d'Hebron Research Institute (VHIR) presented the results of two paediatric studies using a non-familial HLA-identical sibling donor.

Dr Maribel Benitez presented the excellent results of HSCT in children with transfusion-dependent thalassaemia, a chronic inherited red blood cell disorder that causes severe anaemia. Until now, patients have received lifelong transfusions every 3 to 5 weeks. This treatment carries the risk of side effects from excess iron and alloimmunisation, where the patient's immune system produces antibodies against the transfused red blood cells. It also means being dependent on the hospital for transfusions.

"The possibility of receiving a haematopoietic progenitor transplant not only from a sibling but also from a non-familial HLA-identical donor allows these patients to be cured and become transfusion independent," says Dr Maribel Benítez, assistant at the Paediatric Oncology and Haematology Service of Vall d'Hebron and researcher in the Childhood Cancer and Haematological Diseases Group at the VHIR.

Dr Luz Uría presented the cure of children with severe bone marrow aplasia, also by transplantation of haematopoietic precursors from an HLA-identical unrelated donor. This disease is characterised by the total or partial disappearance of haematopoietic precursors in the bone marrow and, as a result, patients suffer from severe infections, anaemia and thrombocytopenia. Until recently, if a child did not have an HLA-identical sibling donor for a transplant, he or she had to undergo a long course of immunosuppressive treatment. Such treatment rarely cures patients and they are at risk of developing myelodysplastic syndrome or leukaemia.

In addition, Dr Luz Uría, assistant at the Paediatric Oncology and Haematology Unit at Vall d'Hebron and researcher at the Paediatric Cancer and Haematological Diseases Group at the VHIR, confirms that "the results of this study have allowed all patients to be cured, opening up the possibility of a first-line unrelated donor transplant for many patients who do not have an HLA-identical sibling donor". To achieve this, the team emphasises that a thorough donor and patient evaluation will be required to try to reduce the risks associated with transplantation.