I would like information on myelodysplasia. My 72-year-old uncle has been diagnosed with it. No one seems able to tell us anything about this condition, except that it means the white blood cells are taking over. In one month he went from weighing 134 pounds down to 101 pounds. He is so weak and needs help to get around.
Myelodysplasia is a diagnosis that includes several subcategories with very different findings and different prognoses. The derivation of the term is myelo, meaning bone marrow; and dysplasia, meaning disordered cell growth. The common element in all of the myelodysplasias is anemia, usually refractory, meaning that treatments other than blood transfusions are often not helpful.
The different categories of myelodysplasia are difficult to describe, but they all represent a disorder of the bone marrow stem cell, the primitive cell type from which all other bone marrow cells are derived. Failure of the stem cell to produce adequate numbers of the cells that produce red blood cells, called erythroblasts, produces severe anemia. Failure to produce megakaryocytes, the cells that make platelets in the blood, leads to a reduced platelet count, and so on for all of the blood cells produced in the bone marrow.
Myelodysplasia is generally a disease of the elderly, and may also be seen after chemotherapy for cancer. It is thought to be due to a mutation in one of the genes of the stem cell, leading to an overgrowth of one type of cell and suppression of the other cells that normally derive from the stem cell. As one might expect, the overgrowth of one type of cell often develops into leukemia, which is a cancer of a bone marrow cell type. The rate of transition to leukemia in myelodysplasia varies according to the subcategory, but ranges from a low of 5 percent to as high as 50 percent.
Because the anemia in myelodysplasia cannot usually be treated, it is often necessary to give people with this condition repeated blood transfusions. As with other anemias requiring frequent transfusions, this can occasionally lead to hemosiderosis, a condition where too much iron builds up in the body. Treatments using various growth factors that have been developed during the past ten years or so are under investigation, and these may be promising. Bone marrow transplantation has cured the condition in many cases.
People with myelodysplasia often develop infections due to inadequate production of functional white blood cells, or severe bleeding due to inadequate production of platelets. These are the most common causes of death in this disease. The uncle of our writer today has too many white cells, which are described as “taking over.” This may mean that he has one of the subcategories of the disease characterized by excessive white cell precursors, which have a higher likelihood of developing into leukemia. The large numbers of white blood cells produced in this subcategory of the disease do not function well to fight infection, so infection remains a serious complication. Certainly, the amount of weight loss and weakness that are described would make me think that he has a serious form of the condition. Today’s writer might want to discuss the possibility of bone marrow transplantation with her uncle’s doctors.