Mean Platelet Volume (MPV) is a measurement included in standard blood tests, specifically as part of a complete blood count (CBC). It indicates the average size of platelets circulating in the bloodstream. While not a diagnosis on its own, MPV provides insight into platelet characteristics and can guide further medical evaluation.
What Mean Platelet Volume Represents
Platelets, also known as thrombocytes, are small, colorless cell fragments produced in the bone marrow. Their primary function is to help stop bleeding, a process called hemostasis. When a blood vessel is injured, platelets gather at the site, forming a plug to seal the damage and prevent blood loss.
MPV is typically expressed in femtoliters (fL), with a common normal range usually falling between 7.2 and 11.7 fL. Unlike a platelet count, which indicates the total number of platelets, MPV provides information about their physical characteristics.
Newer platelets tend to be larger than older ones, reflecting recent release from the bone marrow. MPV can therefore offer clues about the rate of platelet production and destruction. A low MPV suggests smaller average platelet size, indicating the bone marrow may not be producing enough new, larger platelets, or that existing platelets are predominantly older and smaller.
Reasons for Low Mean Platelet Volume
Issues with platelet production within the bone marrow are a common cause of low MPV. Conditions like aplastic anemia, where the bone marrow’s ability to produce blood cells is impaired, can result in smaller, fewer platelets. Marrow hypoplasia, a reduction in active bone marrow tissue, also contributes to decreased production of new platelets, leading to a lower average size.
Certain medical treatments, including chemotherapy drugs, can suppress bone marrow activity and consequently reduce new platelet formation, resulting in a low MPV. Some types of cancer, such as renal cell carcinoma, cervical cancer, lung cancer, or other blood cancers, may also be associated with a low MPV. Chronic conditions like kidney failure and excessive alcohol consumption can also negatively affect platelet production and lead to smaller platelets.
Beyond production issues, a low MPV can be observed in various other medical conditions. Viral infections, for instance, can temporarily impact platelet size and number. Certain autoimmune disorders, where the body’s immune system attacks its own tissues, have also been linked to low MPV values, including lupus, rheumatoid arthritis, ulcerative colitis, Crohn’s disease, and polymyositis. Additionally, conditions like hypersplenism, where the spleen removes blood cells too rapidly, and nutritional deficiencies such as iron deficiency anemia or vitamin B12 deficiency, can contribute to a lower mean platelet volume.
Interpreting and Addressing Low Mean Platelet Volume
A low Mean Platelet Volume is rarely a standalone diagnostic finding. Healthcare providers interpret MPV results with other complete blood count parameters, especially the platelet count, for a comprehensive understanding of platelet health and bone marrow function. This integrated approach helps distinguish between various potential causes of an abnormal MPV.
When a low MPV is identified, additional diagnostic tests are often necessary to pinpoint the underlying reason. These may include more specific blood tests to evaluate factors like inflammation markers, nutrient levels, or autoimmune indicators. In some cases, a bone marrow examination might be recommended to directly assess the health and activity of the bone marrow.
The general approach to managing a low MPV involves addressing the root cause rather than treating the MPV value itself. For example, if a medication is identified as the cause, adjustments might be considered. If an underlying condition like an infection or autoimmune disease is diagnosed, treatment will focus on managing that specific illness. Consulting a healthcare professional is important to accurately interpret results and determine appropriate next steps for evaluation and care.