A high mean platelet volume (MPV) count means that a person has a higher number of platelets than normal in his or her blood.
Doctors use the MPV count to diagnose or monitor numerous types of blood conditions. The MPV test is usually performed as part of a complete blood count (CBC) test, which evaluates many components of a person's blood in addition to platelets.
Platelets are the smallest of all blood cells. Their primary duty is to regulate blood clotting and prevent bleeding. When a person gets a scratch, for example, platelets gravitate to the scratch site to slow and eventually stop blood loss. Usually, people have a range of 150,000 to 450,000 platelets in each microliter of blood. A number of more than 450,000 means that a person has more than the average volume of platelets circulating in his or her body. This condition is called thrombocytosis. Thrombocytosis can be primary or secondary, and it can arise from several problems. Primary thrombocytosis means that the underlying problem originates from bone marrow. For unknown reasons, bone marrow is producing abnormal cells, which leads to an increased platelet level. Secondary thrombocytosis is similar to primary thrombocytosis, but the condition is attributed to an underlying disease or condition. Certain cancers and anemia can cause secondary thrombocytosis. Some infections and inflammation can also elevate platelet levels.
Why an MPV Test Is Ordered
Doctors sometimes discover abnormal MPV readings during a routine examination. They might also prescribe this test for patients who have signs and symptoms of bleeding problems. This includes unexplained or easy bruising, frequent nosebleeds, red or purple spots on the skin and wounds that take a longer than normal time to stop bleeding. Physicians might also order an MPV test for individuals who have unexplained blood clots, which usually develop in the arms and legs. When left untreated, blood clots can cause a heart attack or stroke.
The MPV test is relatively simple. To perform the MPV test, doctors take a sample of blood from the patient using a needle. The sample is then enclosed in a vial and sent to a laboratory for testing. Patients do not usually need to prepare in any special way for the test. However, they may need to fast for a period of time before the test if the doctor has also ordered other blood tests.
Causes of a High MPV Level
When the results return, doctors can diagnose a patient's condition and start proper treatment. High MPV readings can result from heart disease, diabetes, myeloproliferative disease (a type of cancer) and thrombocytopenia. Women who are pregnant may also have high MPV levels from preeclampsia, which is a complication that arises around the 20th week of pregnancy and causes high blood pressure.
As with other blood tests, certain factors can affect the outcome of an MPV test. Living in higher altitudes and engaging in strenuous activity can cause MPV readings to be higher than normal. Some drugs and medications can elevate MPV levels, including birth control pills. Individuals should let their physicians know before the test what medications they are taking. In addition to the MPV test, doctors might order additional follow-up tests to get a complete picture of their patients' blood health.