From the Research
The discrepancy between the automated platelet count and microscopic examination in this 65-year-old male patient is most likely due to platelet clumping or satellitism, as supported by the elevated MPV of 12.9, which is a common cause of undercounting by automated analyzers 1. The phenomenon of platelet clumping is often caused by EDTA, the anticoagulant used in blood collection tubes, which can induce platelet aggregation in some individuals. To confirm this diagnosis, the laboratory should collect a new blood sample using an alternative anticoagulant such as sodium citrate or heparin, as suggested by 2. If platelet clumping is the cause, these alternative samples should show normal platelet counts on automated analysis. This condition is generally a laboratory artifact rather than a true clinical problem, which explains why the patient has no clinical abnormalities despite the apparently low platelet count, as discussed in 3 and 4. No treatment is necessary for the patient, but proper identification of this phenomenon is important to avoid unnecessary diagnostic procedures or treatments for presumed thrombocytopenia, as emphasized by 5. Key points to consider in this case include:
- The use of alternative anticoagulants to confirm the diagnosis
- The importance of microscopic examination in identifying platelet clumping
- The need to avoid unnecessary diagnostic procedures or treatments for presumed thrombocytopenia
- The role of MPV in supporting the diagnosis of platelet clumping, as discussed in 1.