Myeloproliferative disorders, or MPD, are a group of hematologic (blood) diseases that affect production of blood cells in the bone marrow. MPDs are characterized by the over-production of certain types of cells, particularly red blood cells (which carry oxygen), platelets (which assist in blood clotting) and white blood cells (which fight disease).
MPD can strike at any age and have no known cause. Symptoms, prognosis and progression vary depending on the patient's age, health and type of disease. Some patients may have slowly progressing disease that may not require any treatment beyond careful monitoring, while others may progress to more advanced stages or acute myelogenous leukemia.
Types of MPD
Chronic Idiopathic Myelofibrosis (CIMF) affects the red blood cells and granulocytes, a type of white blood cell. The cells don't mature normally and are irregularly shaped. CIMF also causes thickening or scarring of the fibers inside bone marrow, which can decrease the production of red blood cells and cause anemia.
Polycythemia Vera (PV) is caused by the overproduction of red blood cells in the bone marrow, which then build up in the blood. Often, the spleen swells as extra blood cells collect there, causing pain or a full feeling on the left side. Itching all over the body is a common symptom of PV.
Essential Thrombocythemia (ET) means that the number of platelets in the blood is much higher than normal, while other blood cell types are normal. The extra platelets make the blood "sticky," which slows down blood flow.
Chronic Eosinophilic Leukemia/Hypereosinophilic Syndrome (HES) is characterized by a higher than normal number of the white blood cells responsible for fighting allergic reactions and some parasitic infections (eosonophils). Patients may experience itching, swelling around the eyes and lips or swollen hands and/or feet. In some patients, HES may quickly progress to acute myelogenous leukemia.
Systemic Mastocytosis (SM) affects mast cells, which are found in skin, connective tissue and in the lining of the stomach and intestines. Mast cells serve as a sort of alarm system by signaling disease-fighting blood cells to target areas of the body where they're needed. They may also play a role in wound healing. SM is caused by too many mast cells accumulating in the body's tissues, which can eventually affect the spleen, bone marrow, liver or small intestine.
Some symptoms of MPD are common to all hematologic diseases like the ones listed below, while some MPD types have specific symptoms. Not everyone with MPD will experience symptoms, especially in early stages, or they may indicate other health problems.
- Shortness of breath
- Easy bruising or bleeding
- Petechiae (tiny red spots under the skin)
- Unexplained weight loss
- Night sweats
Having one or more of the symptoms listed above does not necessarily mean you have MPD. However, it is important to discuss any symptoms with your doctor, since they may indicate other health problems.