Myelodysplastic Syndromes (MDS)

Myelodysplastic Syndromes (MDS) are a group of bone marrow disorders in which the bone marrow (‘myelo’) does not produce enough healthy blood cells. The blood cells produced in patients with MDS are often of abnormal shape, appearance and function (‘dysplasia’). It is primarily a disease of the elderly but can affect younger patients. 

The bone marrow functions as a factory that manufactures three kinds of blood cells: red blood cells which carry oxygen, neutrophils (a type of white blood cell) which fights infection, and platelets that stop bruising and bleeding. Healthy bone marrow produces immature blood cells that normally develop into mature, fully functional red blood cells, white blood cells, and platelets. In MDS the bone marrow dysfunction results in fewer than normal mature blood cells being released into the circulation. Low blood cell counts, referred to as cytopenias, are the main feature of MDS and are responsible for the symptoms that MDS patients experience such as infection, anaemia, bruising and bleeding. In addition to reduced numbers of blood cells, the mature blood cells may not function properly and further increase the risk of infection and bruising/bleeding. In the early stages of MDS patients may experience no symptoms at all and the disease may have been diagnosed when a routine blood count revealed abnormalities such as anaemia, low white cell count and/or low platelet count.

Patients with MDS may develop:

Anaemia – resulting in fatigue, low energy levels, shortness of breath and palpitations (fast heart beat) on exertion.

Low neutrophils (neutropenia) - increases the risk of bacterial
infections, skin infections and respiratory tract (lung) infections.

Low platelets (thrombocytopenia) - increases the risk of bruising and bleeding either spontaneously or after minor trauma/injury. Failure of the bone marrow to produce mature healthy cells is usually a gradual process which develops over many years.

Patients may require blood transfusions, treatment for infection and platelet transfusions depending upon the clinical manifestations of their MDS. Approximately 30% of patients diagnosed with MDS progress to acute myeloid leukemia (AML).

In most cases the cause of MDS is unknown. Occasionally it can be secondary to previous radiotherapy or chemotherapy for a prior malignancy. Long term exposure to certain environmental or industrial chemicals, such as benzene, can also trigger MDS.  Smokers have an increased risk of developing MDS and AML. Treatment options for MDS include supportive care (e.g. blood transfusions, treatment of infection and platelet transfusions) or disease modifying therapies (e.g azacitidine).

Some therapies are available via participating in a clinical trial.

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