Myelofibrosis (MF) | Aplastic Anemia and MDS International Foundation

Myelofibrosis (MF)

Myelofibrosis is a bone marrow disorder where the marrow is replaced with fibrous scar tissue. It can lead to low blood cell counts and an enlarged spleen. It is considered a myeloproliferative neoplasm (MPN).

Myelofibrosis (MF)

The Basics

Researchers believe that myelofibrosis is caused by abnormal stem cells in the bone marrow. These abnormal cells grow quickly and cause scaring in the bone marrow and chronic inflammation. If the marrow is scarred, it can’t produce blood cells correctly or perform its normal functions. As a result, the liver and spleen try to make these cells, which in turn causes swelling and malfunction of these organs.

Relation to bone marrow failure diseases:

Myelofibrosis can develop without having had any other condition. This is called primary myelofibrosis or chronic idiopathic myelofibrosis.

It can also develop in people who have polycythemia vera or essential thrombocytosis. This is called secondary myelofibrosis. Patients with MDS, leukemia or even lymphoma can also have fibrosis in their bone marrows.

Causes

The exact cause of myelofibrosis in any given patient is not known. There are, however, known risk factors that increase the chances of getting myelofibrosis:

  • People in their 50s, 60s or older are more likely to get myelofibrosis than younger people.
  • Having another blood cell disorder, like essential thrombocythemia or polycythemia vera, as these disorders can evolve to myelofibrosis over time
  • The presence of the JAK2 mutation
  • Exposure to certain industrial chemicals, such as toluene and benzene
  • Exposure to high levels of radiation

Symptoms

Common symptoms include:

  • Abdominal fullness, pain or feeling full before finishing a meal (because of an enlarged spleen)
  • Bone pain
  • Fatigue
  • Itching
  • Night sweats
  • Bruising
  • Easy bleeding
  • Increased likelihood of getting an infection
  • Pale skin
  • Shortness of breath with exercise
  • Weight loss without trying

Diagnosis

There are a number of tests and tools doctors use to diagnose and confirm myelofibrosis. They may include:

  • Physical exam and history
  • Blood tests:
    • A complete blood count with a differential that looks at the total number and type of blood cells in your blood
    • A blood smear that allows your doctor to look at your blood under a microscope
  • Bone marrow examination, including aspiration and biopsy to see how your bone marrow looks (required for diagnosis)
  • Gene testing to look at abnormalities in your cell DNA

Treatment

Many patients don’t need treatment at first. As the disease progresses and symptoms get worse, a number of treatments may be used:

  • Supportive care with blood transfusions, blood cell growth factors, androgens (male hormones) and antibiotics to increase blood counts and stop infections
  • Ruxolitinib to decrease enlarged spleen size and reduce other symptoms such as fatigue
  • Immune modulating drugs such as thalidomide and the related drugs lenalidomide and pomalidomide, which in some patients may improve blood cell counts and relieve enlarged spleens
  • Interferon, another type of immune modulating drug
  • Stem cell transplants, which replace blood-forming stem cells in bone marrow with healthy stem cells from a donor
  • Surgical removal of the spleen which may be needed in rare cases

Clinical trials, also called research studies. These may offer good treatment options for some patients. These studies also help researchers better understand the value of promising new treatments or procedures.