Platelet disorders are relatively common in the practice of medicine. In order clarify the cause of these orders and help with diagnosis and treatment, mean platelet volume is now reported on every complete blood count.
If you’ve recently had a complete blood count (CBC), you may have seen the letters MPV. This measurement is conducted in most health screening tests, as well as during monitoring for many health-related conditions. Complete blood counts assess white blood cells, red blood cells, and platelet cells.
Platelet volume and size depend on certain circumstances and their production in the marrow. MPV measures the relation of aging platelet within bloodstream circulation.
Overall, platelet parameters are stable in most patients. Serial measurements are therefore valued in determining patient risks associated with recovery from pancytopenia following chemotherapy or the development of pre-eclampsia.
Complete blood count (CBC)
A CBC is a blood test used to evaluate your overall health, as well as detect a wide range of medical disorders, including leukemia, infection, and anemia.
Your complete blood count will measure several different features and components of your blood, including:
- White blood cells, which work to fight off infections
- Red blood cells, which carry nutrients and oxygen
- Hematocrit, the proportion of red blood cells to plasma (fluid component) in the blood
- Hemoglobin, oxygen-carrying protein that is present in red blood cells
- Platelets, which assist in healthy and necessary blood clotting
Abnormal decreases and increases of any of the cell counts revealed in a CBC can indicate an underlying medical condition and will call for a further health evaluation.
What are platelets?
The mean platelet volume is the average platelet size in the bloodstream. Platelets are cells that are responsible for forming clots in the presence of bleeding or an injury.
Platelets are essential because they keep us from excessively bleeding out when we are cut, and they help to patch holes found in blood vessels within the body.
Cells located in bone marrow, called megakaryocytes, are what produce platelets. Platelets themselves are tiny pieces of these megakaryocytes that don’t contain nuclei.
These pieces are released throughout our bloodstream from our bone marrow. In general, younger platelets are found to be larger in size than platelets that are older.
High mean platelet volume (MPV)
The mean platelet volume is the average platelet size in the bloodstream. A higher MPV level is typically a sign that those young platelets are more prominent in your bloodstream.
This can happen if you have major surgery or other recent medical procedures. This is because your body is using platelets to repair cuts found in blood vessels.
In order to keep up with the body’s demand, your bone marrow will release more of the larger, younger platelets causing your levels of MPV to rise.
A higher MPV with a lower platelet count reveals that your bone marrow is producing platelets actively, but processes within your body are using them.
Your doctor will assess high MVP counts in light of the procedures and conditions you’ve recently had, conducting further tests if needed.
Other conditions, such as idiopathic thrombocytopenic purpura, could cause a heightened MPV level, which can lead to a system-mediated, immune destruction of platelets.
Elevated MPV is also present in blood cancers, including leukemia.
Following up on high MPV results
When your MPV values come back as higher than normal, the lab will typically follow up your results with a differential blood smear.
The tech working on your sample will create a slide of your blood and examine it under a microscope to review if you really have large platelets or if your platelets are clumping together.
A CBC typically requires anti-coagulated blood and is generally drawn with a purple top tube. Clumping platelets are generally due to blood clots in the sample.
This could require a repeat blood draw. Some people need their blood drawn with a different tube other than an anticoagulant tube in order to prevent their platelets from clumping together.
The being said, some people really do have larger than normal platelets, either from Bernard-Soulier disease or immune thrombocytopenic purpura.
Low mean platelet volume (MPV)
A low MPV paired with a lower platelet count can reflect the presence of a disorder that affects the bone marrow, decreasing or slowing down the production of platelets. This can happen in conditions such as aplastic anemia.
A low MPV can also be found with normal, low, and high, platelet counts in the presence of sepsis – a reaction to infection that is life-threatening to the body; chronic kidney failure; splenomegaly (enlarged spleen); or medications that suppress the production of blood.
MVP Clinical Significance
A low platelet count with a high MPV indicates platelet destruction such as:
- Various hereditary disorders such as Bernard Soulier Syndrome
A low platelet count low MPV indicates marrow under produces of platelets or hypersplenism, such as:
- Cytotoxic drug therapy
- Aplastic anemia
- Various hereditary disorders such as Wiskott Aldrich Syndrome
A high platelet count with low MPV can suggest secondary or reactive thrombocytosis seen in:
A high platelet count with high MPV can suggest more of a primary thrombocytosis, which is associated with myeloproliferative disorders.
Normal platelet count
- Low MPV – Chronic renal failure
- High MPV – Hyperthyroidism
- High MPV – Chronic myeloid leukemia
Possible MPV role in acute coronary syndrome
Platelet aggregation and activation have been to know to play a critical role in platelet adherence following coronary plaque formation or contribute to thrombus formation.
Since MPV correlates with the functional status of platelets in the body, it is an emerging marker for the presence of atherothrombosis.
Additionally, MPV may also act as a risk factor for myocardial infarction that is recurrent, independent of established risk factors, and is determined through an inexpensive and simple laboratory test paired with conventional cardiac biomarkers for the risk stratification of acute coronary syndrome patients who are admitted to the emergency room.