International Journal of Hematology and Oncology 2023, Vol 33, Num 4 Page(s): 071-076
ETIOLOGY OF THROMBOCYTOSIS AND THE USE OF PLATELET PARAMETERS TO DISTINGUISH BETWEEN CLONAL AND REACTIVE THROMBOCYTOSIS

Mehri TAFAZZOLİ1, Mohammad R. KERAMATİ1, Rahim VAKİLİ2

1Mashhad University Medical Science, Imam Reza Hospital, Department of Laboratory Hematology, IRAN
2Mashhad University Medical Science, Imam Reza Hospital, Department of Pediatrics, IRAN

Keywords: Thrombocytosis, Primary, Secondary, Mean platelet volume (MPV), Platelet distribution width (PDW)
We aimed to determine the etiology and changes of platelet parameters of elevated platelet counts. A prospective study was performed to evaluate all patients,who had at least one platelet count more than 450 x 109 L. 146 patients with thrombocytosiswere studied.


Out of146 patients,16 (10.9%) had primary and 130 (89.1%) had secondary thrombocytosis. Among 16 patients with primary thrombocytosis: 6 (37.5%) patients with essential thrombocythaemia, 5 (31.25%) patients with chronic myeloid leukemia, 4 (25%) patients with polycythemia vera and 1 (6.25%) patient with myelofibrosis and myeloid metaplasia.


The most frequent causes of secondary thrombocytosis were infection (50.7%), burn (20%), malignancy (11.5%), bleeding (6.9%) and chronic inflammation (6.1%) . Primary thrombocytosis was significantly associated with a higher platelet count, mean platelet volume (MPV) and platelet distribution width (PDW).


Compared with secondry thrombocytosis, primary thrombocytosis was significantly associated with platelet counts of more than 1000 x 109/L (1.5% compared to 50%)


When a patient has an unexplained high platelet count, the combined interpretation platelet count, MPV and PDW appears to be highly useful in the differential diagnosis of thrombocytosis. Most cases of thrombocytosis are reactive and only a small percentage of patients has primary thrombocytosis.