Different illnesses may make it necessary, at any given moment, to make use of a bone marrow donation for an allograft (or allogeneic transplant : the donor and recipient are two different individuals).
This type of blood cancer (malignant haemopathy) is the most common reason for carrying out a bone marrow transplant. There are two types of leukaemia : acute and chronic.
This type affects approximately 5,000 people a year in France (particularly children and the elderly). It is characterised by an abnormally high number of white blood cells.
Acute leukaemia may be lymphoblastic (ALL) or myeloblastic (MAL) :
- acute lymphoblastic leukaemia (ALL) : 18.1% of indications for allografts
75% of all cases of leukaemia in children. This is the most common cancer among children. The peak of incidence is between 2 and 5 years old. The prognosis nowadays is good. In many cases, treatment is sufficient to cure the patient, without any need for a bone marrow transplant.
- acute myeloblastic leukaemia (AML) : 34% of indications for allografts
Chemotherapy is the primary treatment for acute leukaemias, and the indication for a marrow transplant varies according to the results of the chemotherapy.
Chronic myeloid leukaemia (CML)
2.6% of indications for allografts
CML is the most common myeloproliferative disorder, accounting for 15-20% of all cases of leukaemia. Its annual incidence has been estimated at 1-1.5 cases for every 100,000 people. Targeted drug treatments (imatinib, dasatinib) have recently been developed that give good results. If the disease does not respond to these treatments, a bone marrow transplant may then be indicated.
Medullary aplasia is a rare disease (1 in 500,000 people each year), affecting children and young adults in particular. It is characterised by a cessation of the functioning of the bone marrow. It may be caused by a viral infection (hepatitis) or chemical poisoning, or it may have no known cause. The results of transplantation are generally good.
Another indication, also rare (1 in 350,000 births), is Fanconi’s anaemia : a genetic disease belonging to the inherited medullary insufficiency disorders, involving a progressive and severe failure of the bone marrow.
Congenital immunideficiencies in children
Severe infant immunodeficiency : characterised by severe and recurring infections beginning in the first months of life. The incidence is in the order of 1 in 200,000 births. Bone marrow transplantation is the only treatment for the time being.
Drepanocytosis (or falciform anaemia)
This is an inherited disorder of red blood cell production, which particularly affects people originating from Africa and the West Indies. In metropolitan France, Ile-de-France is the region in which it occurs most frequently, affecting 1 out of 700 newborn babies (migrant population). The indications for transplantation are relatively rare.
An inherited form of anaemia associated with an haemoglobin deficiency disorder. Its incidence is 100,000 births a year for the severe forms found in Asia and around the Mediterranean. France registers 350-400 patients. For the disease also, the indications for transplantation are relatively rare.
The number of pathologies for which HSC transplantation is a therapeutic option is increasing. Other indications are currently being evaluated in clinical trials: high-grade malignant lymphoma, myeloma, chronic lymphoid leukaemia, Hodgkin’s lymphoma.
Sources : Orphanet