The area between the end of the rib cage and the beginning of the pelvic bone (hip). The major organs in this area are liver, spleen, stomach, pancreas, gallbladder, small intestine and colon.

Abdominal pain

Pain that is felt in the abdominal area.

Acute Myeloid Leukemia

A quickly progressive malignant disease in which there are too many immature blood-forming cells (red blood cells, white blood cells or platelets) in the blood and bone marrow.

Allogeneic Bone Marrow Transplant

A procedure in which new healthy stem cells are transferred from a donor’s bone marrow, or from a donor’s peripheral blood, to the recipient. The donors can be related or not related to the recipient.


Anagrelide helps to reduce platelet count only, and is only recommended if hydroxyurea therapy fails. Anagrelide does not help with splenomegaly and is not recommended for patients with heart conditions.


A medical condition in which the red blood cell count (hemoglobin) is lower than normal.

Aspirin therapy

Therapy in which low-dose Aspirin is used to keep the blood thin to prevent blood clots from forming.

Blood clot

Forms when the blood cells (red blood cells, white blood cells or platelets) begin to stick together and form a clot (thrombus). A blood clot becomes dangerous if it travels through the blood stream and blocks blood flow to an area of the body, or to an organ (such as brain, heart, liver, lungs, kidney).

Blood transfusion

The transfer of blood or blood products (red blood cells, platelets or plasma) from a donor to a recipient intravenously. Transfusion is used to replace blood loss due to accidents or illness.

Bone marrow

The spongy tissue found inside the long bones (femur in the thigh), sternum (middle of the rib cage) and pelvis (hip). Stem cells are formed in the marrow that produce red blood cells, white blood cells (infection fighting cells) and platelets


Busulphan is a chemotherapy drug which can reduce high red blood cell count in PV patients. Only used as a last line of therapy due to it’s potential to cause Leukemia.

Calreticulin (CALR)

A gene that has many responsibilities to ensure proteins function normally in different cells (such as muscle cells, nerve cells and brain cells). It is known to be mutated in some patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF), but it is not yet well understood.


Therapy for cancer using chemicals that stop the growth of cancer cells.


A disease or illness where symptoms continue for a long period of time. Myeloproliferative neoplasms are considered chronic conditions.

Complementary therapy

Alternative therapies such as acupuncture, yoga, homeopathy and naturopathy, which can be used alongside conventional therapies to provide symptom control.

Complete blood cell (CBC) count

A test that measures the level of hemoglobin (red blood cells), leukocytes (white blood cells), platelets, and a few other important values, which helps to determine a person’s health status. These may be abbreviated as: Hb (hemoglobin), WBC (white blood cells) and plts (platelets).


Proteins that help to regulate the immune system, stem cell production (hematopoeisis) and inflammation.

Cytokine production

Different cytokine proteins are released based on the cellular response (body’s need for regulation and maintenance).

Cytoreductive therapy

Therapy to reduce the number of malignant cells.

Early satiety

Feeling full after eating a small amount of food.


An increased red blood cell (hemoglobin) count.


A hormone produced by the kidneys that promotes the formation of red blood cells by the bone marrow.

Essential thrombocythemia

A rarely-acquired MPN characterized by a continued increase of platelets, which can lead to increased clots (thrombosis) and increased bleeding (hemorrhage).


A lack of energy and motivation. Fatigue can be acute and come on suddenly, or be chronic and persistent.


Increase in body temperature over 38 °C/ 100.4 °F

Heart attack

Damage to or death of the heart muscle due to loss of blood supply to the coronary artery.


The percentage of red blood cells in the total blood volume.


A doctor specially trained in hematology.


The diagnosis, treatment and prevention of diseases of the blood and bone marrow.


The process of forming new blood cells. All blood cells begin as hematopoietic stem cells before developing into more specialized types of blood cell (red blood cells, white blood cells or platelets).

Hematopoeitic stem cells

The stem cells in the bone marrow that form all new blood cells (red blood cells, white blood cells and platelets).

Heparin prophylaxis

Heparin is an anti-coagulant (blood thinner). Heparin prophylaxis is the use of heparin injections to keep the blood thin to prevent the formation of blood clots.


An enlarged liver.


An antimetabolite (interferes with cell reproduction) that can reduce blood counts.


Thickening of the blood.


A study drug currently being evaluated for the treatment of MPN.


A cytokine that is released by the immune system when the body has an infection or cancer cells are invading. Interferon can be given by injection to help stop the cancer cells from growing, and to signal other immune cells to attack cancer cells.

Janus Kinase (JAK 2)

JAK2 is a protein (called an enzyme) that exists in all people. It forms a communications pathway for messages travelling inside the cell.


An organ in the upper abdomen that aids in digestion and removes waste products and worn-out cells from the blood.


Also known as a JAK2 inhibitor, this study drug decreases spleen size and has the potential to improve anemia.

Marrow fibrosis

When the spongy tissue in the bone marrow forms scar tissue and is no longer able to produce hematopoeitic stem cells.


A gene that is involved in the growth of platelets.

Myelofibrosis (MF)

Fibrosis or spontaneous scarring of the bone marrow. It is characterized by significant anemia and an enlarged spleen.

Myeloproliferative neoplasms (MPNs)

Diseases of the blood and bone marrow, sometimes referred to as blood cancers. Four main types make up around 95% of MPNs: primary myelofibrosis, essential thrombocythemia, polycythemia vera and chronic myeloid leukemia (CML).


A condition in which the number of neutrophils (a type of white blood cell) in the bloodstream is decreased.

Night sweats

Severe hot flushes that occur at night and result in a drenching sweat.


A study drug that has the potential to be better tolerated for thrombocytopenic patients.


A treatment in which a set amount of blood is removed to decrease elevated hemoglobin or platelet levels.


An irregular, disc-shaped cell in the blood that assists in blood clotting.

Platelet count

The calculated number of platelets in a volume of blood. Normal range is 150-450 x 109 (150-450 billion) per litre.

Polycythemia vera (PV)

A myeloproliferative neoplasm that results from an overproduction of red blood cells.

Post-ET myelofibrosis

Transformation from essential thrombocythemia to myelofibrosis.

Post-PV myelofibrosis

Transformation from polycythemia vera to myelofibrosis.


Itching that can be caused by MF or PV.


A treatment in which high-energy rays are used to damage cancer cells and stop them from growing and dividing.

Red blood cell (erythrocyte)

The blood cell that carries oxygen.


A commercial drug that helps to decrease spleen size and symptoms associated with PV and MF. Also known as a JAK2 inhibitor. Also called Jakavi® or Jakafi®


An organ located in the upper left part of the abdomen near the stomach (usually the size of a fist). It acts as a reservoir for blood and filters old blood cells. In MPN patients, the spleen may try to assist in hematopoeisis when the marrow is unable to.


Surgical removal of the spleen.


An increased spleen size.

Stem cells

Cells that have the potential to develop into many different specialized cell types.

Stroke (cerebrovascular accident – CVA)

Lack of blood flow to the brain due to a blockage, resulting in brain cell damage or death.

Thrombocythemia (thrombosis)

An abnormally high number of platelets in the blood: greater than 450 x 109 (450 billion) per litre.


A lower than normal number of platelets in the blood: lower than 150 x 109 (150 billion) per litre.


The formation or presence of a blood clot in a blood vessel.

White blood cell (leukocyte)

One of the cell types the body makes to help fight infections. The two most common are lymphocytes and neutrophils.