Myelodysplastic Syndromes (MDS) are a collective of diverse bone marrow disorders in which the bone marrow does not produce adequate amounts of healthy blood cells. MDS is often referred to as a “bone marrow failure disorder”. MDS is primarily a disease that affects the elderly (most patients are older than age 65), but MDS can appear in younger patients as well.
The bone marrow functions as a factory that manufactures three kinds of blood cells: red blood cells, white blood cells, and platelets. Healthy bone marrow produces immature blood cells — called stem cells, progenitor cells, or blasts — that normally develop into mature, healthy and fully functional red blood cells, white blood cells, and platelets. In MDS however, these stem cells may not mature and may accumulate in the bone marrow. They may also have a shortened life span, resulting in fewer than normal mature blood cells in circulation.
SYMPTOMS OF MYELODYSPLASTIC SYNDROME
For most people, symptoms are mild at first but slowly get worse over time. At first you may experience:
- Weakness, tiredness and occasional breathlessness: This is due to the low number of red blood cells.
- Fequent infections: This is due to a low number of white blood cells.
- Bruising and easy bleeding such as nosebleeds: This is due to low numbers of platelets.
Some types of MDS develop more rapidly than others. Some people with MDS don’t display any symptoms, and their condition is picked up only after they have blood tests for something else.
Symptoms will depend on the type of MDS you have – for example, some people just have a problem with their red blood cells and have symptoms of anaemia, while others may lack all types of healthy blood cells.
TREATMENT OPTIONS AVAILABLE FOR MYELODYSPLASTIC SYNDROME
Treatment for myelodysplastic syndromes most often involves slowing down the progression of the disease as well as providing supportive care to help manage symptoms such as fatigue and to prevent bleeding and infections.
Blood transfusions can be used to replace red blood cells, white blood cells or platelets in people with myelodysplastic syndromes.
Medications used to increase the number of healthy blood cells your body produces include:
- Medications that increase the number of blood cells your body makes: Called growth factors, these medications are essentially artificial versions of naturally occurring substances found in your bone marrow.
Some growth factors, such as epoetin alfa or darbepoetin alfa, help reduce the need for blood transfusions by increasing your red blood cell count. Others may help prevent infections by increasing white blood cells in people with certain myelodysplastic syndromes.
- Medications that stimulate blood cells to mature, rather than remain immature: Medications such as azacitidine and decitabine may improve the quality of life of people with certain myelodysplastic syndromes whilst reducing the risk of developing acute myelogenous leukaemia.
- Medications that suppress your immune system: Medications used to suppress the immune system (immunosuppressants) may be used in certain myelodysplastic syndromes.
- Medication for people with a certain genetic abnormality: If your myelodysplastic syndrome is associated with a specific gene mutation called isolated del(5q), your doctor may recommend lenalidomide. Lenalidomide can reduce the need for blood transfusions in people who have this gene mutation.
BONE MARROW STEM CELL TRANSPLANT
During a bone marrow stem cell transplant, your defective blood cells are first destroyed using chemotherapy and then the abnormal bone marrow stem cells are replaced with healthy cells from a doner (allogeneic transplant).
Most bone marrow stem cell transplants used to treat myelodysplastic syndromes are lower-intensity or “mini” transplants. This means the chemotherapy drugs used before the transplant are less powerful than those used in standard transplants and are likely to cause considerably less side effects.
DIAGNOSING MYELODYSPLASTIC SYNDROME
The complete blood count (CBC) is a test that measures your red blood cells, white blood cells, and platelets. The CBC is often done with a differential count (or “diff”), which is a count of the different types of white blood cells in the blood sample. In a blood smear, some of the blood is placed on a slide and examined under a microscope. If any blood abnormalities are found, this may suggest MDS, but the doctor cannot make an exact diagnosis without examining a sample of bone marrow cells. The doctor may also order tests to check for other possible causes of low blood counts, such as low levels of vitamin B12 and folate.
Bone marrow test
During a bone marrow aspiration, you first lie on a table (either on your side or on your belly). After cleaning the area, the skin over the hip and the surface of the bone is numbed, using local anaesthetic, which may cause a brief stinging or burning sensation. A thin, hollow needle is then inserted into the bone and a syringe is used to suck out a small portion of liquid bone marrow (about 1 teaspoon). Even with the anaesthetic, most patients still experience some brief pain when the marrow is being removed.A bone marrow biopsy is usually done just after the aspiration and may also cause some pain.
During a biopsy, a small piece of bone and marrow (about 1/16 inch in diameter and 1/2 inch long) is removed with a needle that is twisted as it is pushed down into the bone. Once the biopsy is done, pressure will be applied to the site to help prevent bleeding.A pathologist (a doctor specializing in the diagnosis of diseases using laboratory tests) examines the bone marrow samples under a microscope. A hematologist (a doctor specializing in medical treatment of diseases of the blood and blood-forming tissues) or an oncologist (a doctor specializing in medical treatment of cancer) will usually review these samples as welBone marrow samples are obtained from a bone marrow aspiration and biopsy.
These samples are usually taken from the back of the pelvic (hip) bone. These tests are initially used for diagnosis and classification and may be repeated later to tell whether the MDS is responding to treatment or is transforming into an acute leukaemia.