Traveling for Care?
Whether you're crossing the country or the globe, we make it easy to access world-class care at Johns Hopkins.
Essential thrombocytosis (ET), or primary thrombocythemia, is a rare disorder in which the body produces too many platelets for unknown reasons. This can cause abnormal blood clotting or bleeding. The condition usually affects people in middle age, although it can be seen in younger patients, especially in women less than 40 years old. Patients with ET have an excellent chance of living a normal life span if they are properly monitored and treated as necessary. A small number of patients may develop acute leukemia or a bone marrow disorder called myelofibrosis.
The causes of ET are still unknown. About half of ET patients have a mutation called JAK2V617F within their blood-forming cells, which leads to many characteristic features of the disease.
Some risk factors associated with ET include:
Many patients do not have any symptoms, and are diagnosed after blood counts as part of a routine check-up reveal a high platelet count. Symptoms, if present, include fatigue, or blood vessel disturbances or bleeding.
Blood vessel disturbances or bleeding can result in:
Blood clots can be quite serious, leading to strokes or heart attacks.
ET is often detected on blood tests done for other reasons, before there are any symptoms. Additional tests may include:
Treatments for ET can vary depending on a patient's symptoms. Some patients may not need active treatment but should still be monitored by a physician expert. Treatments include:
The Johns Hopkins Center for Myeloproliferative Disorders coordinates the care of patients with ET and other related disorders and conducts research in these areas.
Johns Hopkins researchers led by Michael McDevitt, M.D., are participating in a Phase II clinical trial of the anti-cancer drug imetelstat in patients with ET or polycythemia vera (PV) who have failed or are intolerant to at least one prior therapy. For more information, contact Lori Tony, RN, BSN, at email@example.com, orvisit the clinical trials web site.
For more information, see the website for the MPN Research Foundation