Bone Marrow Diseases
Bone marrow is a soft fatty tissue found in the inside of the body's bones - such as the sternum (middle of the chest), pelvis (hip bone), and femur (thigh bone). Fibrous tissue in the marrow supports stem cells, which are large "primitive" undifferentiated cells. As needed, the stem cells differentiate to become a particular kind of cell - a white blood cell (WBC), red blood cell (RBC), or platelet. Only mature cells are normally released from the marrow into the blood stream. Any disease or condition that causes an abnormality in the production of any of the mature blood cells or their precursors (immature forms) can cause a bone marrow disorder. A variety of things can go wrong, including:
- The overproduction of one type of cell. This crowds out and decreases the production of the other cell types.
- Production of abnormal cells that don't mature or function properly
- Cell compression caused by an overgrowth of the supporting fibrous tissue network, resulting in abnormally shaped cells and decreased numbers of cells
- One cell line becomes predominant because the cells don't die at a normal rate
- The underproduction of cells , or the rapid loss of cells because they are fragile
- Not enough iron is available to create normal red blood cells (they may be microcytic - smaller than normal)
- Lymphomas and other cancers that may spread to the bone marrow, affecting cell production and maturation
Bone marrow disorder symptoms may be severe and life threatening or very subtle. Some chronic conditions may be discovered during yearly physical examinations, while other acute conditions cause symptoms related to too many or too few functioning blood cells. These symptoms include:
- Fever
- Weakness, fatigue, and pallor due to anemia
- Weight loss
- Swollen lymph nodes, liver, spleen, kidneys, and testicles
- Bleeding and bruising
- Night sweats
- Bone and joint pain
- Frequent infections
- Headaches, vomiting, confusion, and seizures (when excess cells collect in the brain or central nervous system
Treatments
There is usually no way to prevent bone marrow disorder. Some are a result of exposure to chemicals, due to previous radiation treatments, or due to rare genetic conditions but for most cases the cause is unknown. Treatment depends on the type of bone marrow disorder, its severity and the symptoms it is causing.
While acute leukemia is sometimes curable, most other bone marrow disorders are not. Leukemias are frequently treated with chemotherapy, or radiation. The goal of treatment is to drive the disease into remission and, if possible, to kill all of the abnormal blood cells, allowing norma
l cells to reproduce and restore blood cell function.
If the condition is severe and not responding to other therapies a bone marrow transplant may be necessary.
Bone marrow may be taken from the patient, "cleaned" of abnormal cells, and frozen to be reintroduced into the patient following treatment or it may come from a suitable donor (most frequently a relative).
Treatment for bone marrow disorders includes therapies for symptom relief. This may involve blood transfusions if anemia is present or blood removal (therapeutic phlebotomy) if the body is making too many RBCs. Platelet transfusions may be necessary to control excess bleeding, while platelet removal (plateletpheresis to filter out platelets) may be required with excess platelet production. Frequent infections may necessitate frequent antibiotic therapy, while iron deficiencies may respond to supplementation. If the spleen is too swollen, it may need to be surgically removed.