Myeloproliferative Dimyeloproliferative disorders

Myeloproliferative disease or MPD deals with  a group of diseases of the bone marrow in which excess cells are produced. Myeloproliferative disorders is the name for a group of conditions that cause blood cells -- platelets, white blood cells, and red blood cells -- to grow abnormally in the bone marrow. Though myeloproliferative disorders are serious, and may pose certain health risks, people with these conditions often live for many years after diagnosis. The prognosis largely depends on the type of disorder.

Myeloproliferative disorders include:

• Polycythemia vera -- occurs when the bone marrow produces too many blood cells, especially red blood cells. More than 95% of people with polycythemia vera carry the blood mutation JAK2V617F.


• Essential thrombocytosis -- occurs when the body produces too many platelet cells, which help blood to clot. Clots can block blood vessels leading to heart attack or stroke.


• Primary or idiopathic myelofibrosis, also known as myelosclerosis -- occurs when the bone marrow produces too much collagen or fibrous tissue in the bone marrow. This reduces bone marrow's ability to produce blood cells.


• Chronic myelogenous leukemia (CML) -- cancer of the bone marrow that produces abnormal granulocytes, a type of white blood cell, in the bone marrow.

Signs and Symptoms:

Many people with myeloproliferative disorders have no symptoms when their doctors first make the diagnosis. One symptom shared by all myeloproliferative disorders, with the exception of essential thrombocytosis, is an enlarged spleen. An enlarged spleen can cause abdominal pain and a feeling of fullness.

Many times, especially in the early stages, myeloproliferative disease does not have symptoms. When it does have signs, they vary from person to person. If you have symptoms, they may include:

• Headache


• Fatigue


• Shortness of breath


• Easy bruising or bleeding


• Petechiae (tiny red spots under the skin)


• Unexplained weight loss


• Night sweats


• Fever

Specific disorders in which the bone marrow produces too many cells have similar and yet different symptoms.

Some signs and symptoms of the different types of myeloproliferative disorders include:

Polycythemia vera

• Fatigue, general malaise


• Trouble breathing


• Intense itching after bathing in warm water


• Stomachaches


• Purple spots or patches on the skin


• Nosebleeds, gum or stomach bleeding, or blood in the urine


• Throbbing and burning pain in the skin, often with darkened, blotchy areas


• Headache and problems with vision


• High blood pressure


• Blockage of blood vessels. This may cause heart disease, stroke, or gangrene (tissue death) of the arms and legs.

Essential thrombocytosis

• Heart attack or stoke


• Headache


• Burning or throbbing pain, redness, and swelling of the hands and feet


• Bruising


• Gastrointestinal bleeding or blood in the urine

Primary myelofibrosis

• Fatigue, general malaise


• Trouble breathing


• Anemia


• Weight loss


• Fever and night sweats


• Abnormal bleeding

Chronic myelogenous leukemia (CML)

• Fatigue, general malaise


• Weight loss or loss of appetite


• Fever and night sweats


• Bone or joint pain


• Heart attack or stroke


• Trouble breathing


• Gastrointestinal bleeding


• Infection

Complete blood count (CBC) and differential CBCs and differentials are the most frequently ordered tests used to help diagnose and monitor MPDs. Often ordered as part of a yearly physical exam, they are routine tests that count the number and relative proportion of each of the different types of cells in your blood stream. They give your doctor information about the size, shape, and relative maturity of the blood cells present in your blood at that moment. CBCs and differentials can be used to detect WBC, RBC, and platelet increases, decreases, and abnormalities. They can help determine their severity, diagnose their cause, monitor the course of a disease, and monitor the response to treatment.

With polycythemia vera, increased RBCs, platelets, and sometimes WBCs, may be seen. With myelofibrosis, mmature granulocytes and misshapen immature teardrop-shaped red blood cells are often seen, and WBC and RBC numbers are often decreased. With thrombocythemia, greatly increased numbers of platelets are seen along with abnormally large platelets, platelet clumps, and fragments of . Irregularities in cell counts may be due to MPDs, but they may also be due to a variety of other temporary or conditions. Other testing is usually done to confirm or rule out the diagnosis of an MPD.

Bone marrow aspiration/biopsyIf a doctor suspects a bone marrow disorder, he may order a bone marrow spiration or biopsy to collect a small sample of marrow. When a specialist (a , oncologist, or hematologist) examines the bone and fluid from the bone marrow sample under the microscope, he can see the number, size, and shape of precursor cells (), red and white blood cells, and megakaryocytes (platelet ). He can determine the proportions of mature and immature cells, see any overgrowth of fibrous tissue, and detect any cancer cells from cancers that may have spread to the marrow. Most bone marrow disorders can be diagnosed during this examination.

ABGs (Arterial blood gases) - This test measures the amount of gases in your arterial blood and may be done when polycythemia vera is suspected. Low levels of oxygen are associated with secondary polycythemia. Erythropoietin is a hormone that stimulates the bone marrow to produce RBCs. With primary polycythemia, erythropoietin levels will be very low or absent, but with secondary polycythemia they will be normal or high. Genetic testing is sometimes used in suspected chronic myelogenous leukemia to check for the presence or absence of a Philadelphia (Ph') or a bcr-abl (see BCR ABL) and in suspected polycythemia vera, myelofibrosis, and essential thrombocythemia for the presence or absence of JAK2 mutations, a gene associated with marrow cell production.

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