PDW is an indicator of platelet anisocytosis in blood count results. This parameter is certainly less important than the total number of platelets, but it should not be completely underestimated. Analysis of PDW (when assessed together with other platelet parameters) may lead to the suspicion that the patient suffers, for example, from anemia or cancer.
What is PDW?
PDW(short for English wordsPlatelet Distribution Width ) in Polishindicator of platelet anisocytosis, i.e. thrombocytes.
What does PDW mean?
PDW is directly related to the platelet volume, or more precisely, this indicator tells you what the volume variation is between the platelets present in the patient's blood sample.
The mean platelet volume (MPV - Mean Platelet Volume) is about 7.5-10.5 fl and PDW shows the percentage of the patient's thrombocytes deviating from the average platelet volume.
PDW: norm
Typically the PDW standard is between 40 and 60%. This means that 4 to 6 out of 10 of the patient's platelets differ in volume from the volume of typical platelets.
Decreasing or increasing PDW alone is of essentially no clinical significance. A conclusion about the existence of any platelet-related disorders in a patient can be made only when the platelet anisocytosis index, but also at least the number of platelets and the average volume of platelets are analyzed.
When deviations of PDW values are accompanied by abnormal results of the above-mentioned tests, then only then should the reasons for such a state be sought.
PDW: blood count
PDW belongs to one of the standard parameters that are tested during blood counts. It is worth mentioning here, however, that basically no physician planning to assess aspects related to platelets will order a patient only to test platelet anisocytosis - in order to be able to say anything about the platelet system, PDW must be assessed together with other platelet parameters. Among them, the above-mentioned MPV should be mentioned, but also the more important indicator, which is PLT (Platelet, i.e. the number of platelets).
There are some situations, however, inwhere doctors may be particularly interested in analyzing a patient's platelets. These include, first of all, the occurrence of various symptoms in the patient that make him suspect some blood clotting disorders, such as a tendency to bruise easily, the occurrence of prolonged bleeding (e.g. as a result of an injury or after tooth extraction) or the appearance of spontaneous bleeding from the mucous membranes occurs in the patient.
Increased PDW: Causes
If the PDW is higher than the established norm, it means that the volume of the thrombocytes is more than normal than the typical volume of platelets.
High PDW
Increased PDW should always be assessed in conjunction with the MPV. If the increase in platelet anisocytosis is accompanied by an increase in MPV, it may be due to:
- bacterial infection
- thrombocytopenic purpura
- with some type of leukemia.
The reverse situation, i.e. the state where increased PDW occurs in conjunction with decreased MPV, is due to completely different reasons. Such blood count results may lead to, for example, anemia (aplastic anemia or megaloblastic anemia), and they may also result from the fact that the patient is undergoing chemotherapy treatment for cancer.
Reduced PDW: reasons
The lower-than-normal PDW value has no clinical significance - demonstrating in the study that the patient's platelet anisocytosis index is reduced (especially in a situation where it is not accompanied by any other abnormalities in blood count) is definitely not a reason for any anxiety.
About the authorBow. Tomasz NęckiA graduate of medicine at the Medical University of Poznań. An admirer of the Polish sea (most willingly strolling along its shores with headphones in his ears), cats and books. In working with patients, he focuses on always listening to them and spending as much time as they need.