Bone marrow failure occurs when the bone marrow – the soft, spongy center of the bones – fails to produce enough healthy blood cells to keep up with the body’s needs. Bone marrow is the site where all blood cells are produced. These include red blood cells, which carry oxygen throughout the body via the protein hemoglobin, white blood cells, which fight infection, and platelets, which help blood to clot.
Depending on the types of blood cells that are comprised, bone marrow failure manifests in different ways. Many conditions may cause bone marrow failure, but in about 30 percent of cases, no specific cause is identified. Bone marrow failure can be inherited or acquired after birth.
The most common cause of acquired bone marrow failure in children and adults is acquired aplastic anemia. When the bone marrow’s hematopoietic stem cells are damaged, the body cannot make enough red, white, or platelet blood cells. Acquired aplastic anemia differs from another disorder similar to bone marrow failure, called myelodysplastic syndromes (MDS), because even though the marrow fails to make enough blood cells, the few that are produced appear normal. With MDS, the bone marrow manufactures abnormal (dysplastic) cells that often have acquired chromosomal abnormalities. Both disorders are rare.
Some of the common inherited bone marrow failure syndromes are Fanconi anemia, dyskeratosis congenital, Diamond Blackfan anemia, and Shwachman Diamond syndrome, GATA2-related disorders, and SAMD9/SAMD9L-related disorders. It is particularly important to think about inherited bone marrow failure in younger patients, as the major complications of these tend to develop with age. For example, it has been shown that Fanconi anemia can lead to aplastic anemia. Additionally, these disorders are associated with an increased risk of cancer, such as leukemia and solid tumor cancers.
How is bone marrow failure treated?
Depending on the type, there are many ways to treat bone marrow failure. Doctors sometimes provide supportive care, with treatments such as blood transfusions , to temporarily relieve symptoms. For example, a patient with thrombocytopenia, a condition characterized by abnormally low levels of platelets, can receive injections of platelets intravenously to control bleeding.
Bone marrow failure can also be treated with stem cell transplant. Otherwise known as a bone marrow transplant, a stem cell transplant involves is the infusion of healthy blood stem cells into the body to stimulate new bone marrow growth and restore production of healthy blood cells. In one type of transplant, an allogeneic transplant, cells are collected from a tissue-matched donor, usually a brother or sister or an unrelated donor, whose human leukocyte antigens (HLA) are a compatible match.
Before receiving the transplant, patients undergo conditioning therapy, which includes chemotherapy and/or radiation, to prepare the body for the transplant. The goal of the conditioning therapy is to remove the diseased bone marrow cells to make space for the new healthy ones to grow. The conditioning therapy also suppresses the immune system so that the body doesn’t reject the donor’s foreign stem cells. The transplant stem cells are infused into the blood through an IV. It takes about two to four weeks for the new blood cells to grow – during this period, the immune system is still weak and the patient is highly susceptible to viral, bacterial, and fungal infections. Bone marrow failure disorders are often complicated to transplant, so patients, both old and young, benefit from care at a center highly experienced treating these disorders.