About myelodysplastic syndrome (MDS)

The term myelodysplastic syndromes (MDS) describes a group of bone marrow disorders. In humans, various types of blood cells are made in the bone marrow. In MDS, the body’s bone marrow (the Greek prefix ‘myelo-’ in the name of the disease means ‘marrow’) produces unhealthy, abnormally shaped (‘dysplastic’) blood cells. As a result, not enough healthy blood cells are provided, leading to low blood cell counts (‘cytopenias’), a typical characteristic of MDS. The affected blood cells include:

• red blood cells (‘erythrocytes’) which are responsible for carrying oxygen to organs and body tissues
• white blood cells (‘leukocytes’) which collectively fight against infection
• blood platelets (‘thrombocytes’) which prevent the body from bruising and bleeding.

A decrease in the amount of red blood cells (‘anaemia’) is the most frequent symptom experienced by people diagnosed with MDS. Other symptoms include infection, spontaneous bleeding and easy bruising. The word ‘syndromes’ in the term MDS is used to describe a group of symptoms that occur together.

MDS is predominant in the elderly (people above 65 years of age), but it can also affect younger people. Failure of the bone marrow to produce healthy blood cells is a gradual process and there are different levels of severity (or ‘prognostic risk categories’) of MDS, including:

• very low-risk MDS
• low-risk MDS
• intermediate-risk MDS
• high-risk MDS
• very high-risk MDS.

These categories are based on the Revised International Prognostic Scoring System (IPSS-R) for MDS Risk Assessment. Roughly 30 percent of the patients diagnosed with MDS develop acute myeloid leukaemia (AML), a cancer of the white blood cells.

The exact cause of MDS is often unknown. There is an increased risk of developing MDS if you have been a smoker, have been heavily exposed to certain chemicals or have had chemotherapy or radiation treatments. There is no evidence suggesting that MDS is caused by a virus, which also means that MDS is not contagious. The symptoms and the course of MDS can vary from person to person. Many MDS patients suffer from chronic fatigue (a debilitating form of exhaustion) and weakness due to the low levels of red blood cells (anaemia).

MDS is a comparatively rare and complex disease and it is usually diagnosed with the help of blood and bone marrow tests. Different classification or scoring systems are used for determining the severity of the disease and the prognosis, as well as the course of treatment. The primary goal of MDS treatment is to increase the number of healthy blood cells in the body. Depending on the type of MDS, treatment options include:

• Watch and wait (when the blood counts are not too low)
• Supportive care (symptom management, often used for lower-risk MDS patients, including blood transfusions and treatment of ‘iron overload’)
• Immunosuppressive therapy (treatment to lower the body's immune response)
• Medicines specifically approved for MDS treatment (to stop abnormal cells from growing and to stimulate the growth of healthy bone marrow cells)
• Chemotherapy (drugs that help to kill abnormal cells)
• Bone marrow transplantation, also called stem cell transplantation (for replacing damaged stem cells in the bone marrow with healthy ones – ‘haematopoietic’ (blood-building) stem cells develop into mature blood cells)