Definition

Myelodysplastic syndromes include group of disorders that appear after improper function of the bone marrow where blood cells are made thus dysfunctional blood cells are formed. Sometimes the treatment solution for myelodysplastic syndromes is bone marrow transplantation. However, the focus of the treatments is usually on prevention and reduction of the complications of the disease and its treatments.

 

Symptoms

Generally, no symptoms or signs of the disease are noticed in the early stages. However, over time, the following symptoms may appear:

  • Exhaustion
  • Pale skin due to anemia
  • Shortness of breath
  • Bruising or bleeding easily
  • Petechiae – small red spots under the skin because of bleeding
  • Numerous infections

 

Causes

Myelodysplastic syndromes occur when something is disrupting the normal production of the blood cells. The blood cells are formed in the bone marrow. The bone marrow is a soft, fatty substance in the cavities of the bones. When something is interrupting the normal function of the bone marrow to produce healthy blood cells, poorly formed blood cells are formed. Therefore, immature and defective blood cells are formed in people with myelodysplastic syndromes. The cells die in the bone marrow or as they entered the bloodstream instead of developing normally. The number of defective cells accumulates with time and eventually surpass the number of healthy cells thus resulting in problematic medical conditions such as anemia, infections or bleeding.

Doctors differ two types of myelodysplastic syndrome according to whether the cause is known of not.

  • Myelodysplastic syndromes with no known cause or de novo myelodysplastic syndromes are sometimes treated more easily even though the cause is not known
  • Myelodysplastic syndromes caused by chemicals and radiation are called secondary myelodysplastic syndromes. They usually occur after chemotherapies or radiation as part of a cancer treatment or due to overexposure to chemicals. The secondary type of myelodysplastic syndromes are harder to treat.

 

Different subtypes according to the World Health Organization:

According to the WHO there are several subtypes of myelodysplastic syndromes depending on the type of blood cells (red, white and platelets):

  • Refractory cytopenia with unilineage dysplasia-only one type of blood cells appear abnormal and in lower number
  • Refractory anemia with ringed sideroblasts-lower number of red blood cells that contain excess amounts of iron
  • Refractory cytopenia with multilineage dysplasia-two types of blood cells are abnormal and less than 1% are immature cells
  • Refractory anemia with excess blasts-types 1 and 2-any of the types of cells can be low in number and appear abnormal and a lot of (blasts) of immature blood cells are found in the blood
  • Unclassified myelodysplastic syndrome-rare syndrome that occurs when the number of one of the three types of blood cells is reduced and the white blood cells or the platelets are abnormal
  • Myelodysplastic syndrome associated with isolated del(5q) chromosome abnormality-low number of red blood cells that have specific mutation in their DNA

 

Risk factors

Risk factors that increase the possibility of developing myelodysplastic syndromes are:

  • Age  (the affected people are usually adults over 60 years)
  • Chemotherapy
  • Radiation therapy
  • Chemicals such as tobacco smoke, pesticides and industrial chemicals like benzene
  • Heavy metals like lead and mercury

 

Complications

The complications that can result from these syndromes are:

  • Anemia (lack of blood cells that makes a person feel tired)
  • Frequent infections (lack of white blood cells)
  • Excess bleeding (lack of platelets to stop the bleeding)
  • Bigger risk of developing cancer of the blood cells (leukemia)

 

Treatment

The treatments for myelodysplastic syndromes usually focus on slowing down the progress of the disease and managing the symptoms like fatigue, bleeding and infections.

The treatments can be:

  • Blood transfusion-used to replace the three types of blood cells, the red blood cells, the white blood cells and platelets, in the bloodstream of the affected person
  • Medications-used to increase the production of healthy blood cells:

-medications that enlarge the number of blood cells the body produces called growth factors

-medicines that stimulate the blood cells to mature

-medications for suppressing the immune system

-drugs for people with certain genetic abnormality (with gene mutation called isolated del(5q))

  • Bone marrow stem cell transplantation-after the defective blood cells are damaged with chemotherapy drugs, the abnormal bone marrow stem cells are replaced with healthy ones that are donated

-as this procedure carries risk of side effects, only few people are candidates for bone marrow stem cell transplant

 

Tips to reduce possible infections

The white blood cells, leucocytes, protect the body from invaders and infectious diseases. People with specific myelodysplastic syndromes have low number of white blood cells and that is why they are at greater risk of frequent and serious infections. In order to reduce the risk a person should follow the advices listed below:

  • Wash the hands frequently with warm water and soap, especially before eating or preparing the food
  • Have a disinfectant by the hand
  • Be careful with the food: avoid raw foods or fruits and vegetables that cannot be peeled, such as lettuce, and wash the products really well, and cook meat and fish thoroughly
  • Avoid close contact with ill people