Understanding Mean Platelet Volume
One of the primary components of the blood clotting system within our body is platelets. Platelet function estimates are often taken as a routine in patients who are admitted with any illness in the hospital. One such estimate or test that is conducted is called mean platelet volume. Here we shall take a look at this in a bit more detail.
Defining Mean Platelet Volume
Mean platelet volume is an average measure of the total number of platelets in the blood. Its value is calculated using specific laboratory equipment.
Calculation
Mean platelet volume is calculated from a regular blood sample obtained from patients vein. It is a parameter that can be calculated along with complete blood count i.e. CBC. The sample is run through a specific machine that calculates the platelet volume based on the values derived from a platelet histogram.
Applications
Typically, the mean platelet volume ranges between 7.2 to 11.7 fL. This is roughly equivalent to tiny spheres that range in size from 2.65 to 2.8 micrometer in diameter. Any value of the mean platelet volume outside this range is indicative of an underlying clinical process.
Platelets whose mean platelet volume is above the normal range are called macro-thrombocytes while those below the normal range are micro-thrombocytes. The table below lists the different conditions where mean platelet volume may vary.
Increased Mean Platelet Volume
• Idiopathic thrombocytopenia purpura – characterized by a low platelet count and low platelet volume and extensive bruising all over the body.
• Bernard-Soulier syndrome – Also called giant platelet syndrome.
Decreased Mean Platelet Volume
• Aplastic anemia – Characterized by failure of bone marrow to produce blood cells.
• Wiskott Aldrich syndrome – A rare clinical disorder characterized by numerous clinical features that includes a low platelet count and small platelet size.
• Platelet storage pool deficiency – Another rare clinical condition where the platelets are small and immature.
More recently, studies have been conducted that have assessed the value of mean platelet volume estimation in clinical conditions such as ischemic bowel disease and stroke. In fact, it is now being used as a prognostic marker in determining whether or not outcomes will be favorable in patients who have suffered from an acute stroke. Patients who have a mean platelet volume of >9.4 fL have a higher prevalence of previous stroke. A high mean platelet volume is associated with a poor outcome in patients with stroke.
Conclusion
Mean platelet volume is an important blood marker and can indicate the presence of an underlying illness. The test is simple to perform and provides valuable information.