European Journal of Cardiovascular Medicine

Thrombocytosis, characterized by an elevated platelet count, is a common hematological abnormality encountered in clinical practice. It is broadly classified into two categories: reactive (secondary) thrombocytosis, which is driven by underlying conditions such as infection, inflammation, or malignancy, and clonal (primary) thrombocytosis, which includes myeloproliferative disorders like essential thrombocythemia.¹ The differentiation between these subtypes is crucial for appropriate management, as clonal thrombocytosis carries a higher risk of thromboembolic complications.²

Platelet indices, including mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT), have emerged as valuable biomarkers in hematology. MPV reflects the average size of platelets, while PDW indicates the variability in platelet size, and PCT represents the total platelet mass.³ These indices provide insights into platelet production and activation, which can vary significantly between reactive and clonal thrombocytosis.⁴

Reactive thrombocytosis is often associated with conditions such as chronic inflammatory diseases, iron deficiency anemia, and infections. In contrast, clonal thrombocytosis is typically linked to myeloproliferative neoplasms (MPNs), such as essential thrombocythemia, polycythemia vera, and primary myelofibrosis.⁵ The distinction between these two categories is critical, as clonal thrombocytosis requires specific therapeutic interventions, including cytoreductive therapy and aspirin, to prevent thrombotic events.⁶

Despite their potential utility, platelet indices are underutilized in routine clinical practice. This study aims to bridge this gap by evaluating the correlation between thrombocytosis and platelet indices in a tertiary care hospital. By analyzing a cohort of 200 patients, we seek to establish the diagnostic and prognostic significance of these indices in differentiating thrombocytosis subtypes.

Study Design and Population: This retrospective study included 200 patients diagnosed with thrombocytosis (platelet count >450,000/µL) over two years. Patients were recruited from the hematology outpatient department of a tertiary care hospital.

Inclusion Criteria:

• Age >18 years.
• Persistent thrombocytosis (confirmed on two consecutive tests).
• Availability of complete clinical and laboratory data.

Exclusion Criteria:

• Recent trauma or surgery within the past three months.
• Pregnancy or postpartum status.
• Patients on medications known to affect platelet counts (e.g., chemotherapy, steroids).
• Patients with a history of splenectomy.

Data Collection:

Demographic details, clinical history, laboratory parameters (including platelet count, MPV, PDW, and PCT), and etiological classification were recorded. Platelet indices were measured using an automated hematology analyzer. Statistical analysis was performed using SPSS version 25.0. Continuous variables were expressed as mean ± standard deviation (SD), and categorical variables were expressed as percentages. The Student’s t-test and chi-square test were used for comparisons, and p<0.05 was considered statistically significant.

The findings are summarized in five tables:

Table 1: Demographic Distribution of Patients

Table 2: Etiological Classification of Thrombocytosis

Table 3: Comparison of Platelet Indices Between Reactive and Clonal Thrombocytosis

Table 4: Correlation of Platelet Indices with Clinical Outcomes

Table 5: Diagnostic Accuracy of Platelet Indices in Differentiating Thrombocytosis Subtypes

This study highlights the clinical utility of platelet indices in the evaluation of thrombocytosis. The significantly higher MPV and PDW in clonal thrombocytosis suggest increased platelet activation and heterogeneity, consistent with the pathophysiology of myeloproliferative disorders.⁸ These findings align with previous studies, which have reported similar trends in platelet indices among patients with essential thrombocythemia. ^9-13

Reactive thrombocytosis, on the other hand, is associated with normal or slightly elevated platelet indices, reflecting the physiological response to underlying conditions such as infection or inflammation. ¹⁴ The diagnostic accuracy of platelet indices, though moderate, highlights their potential as adjunctive tools in differentiating thrombocytosis subtypes. However, their utility should be interpreted in conjunction with clinical and laboratory findings, as overlapping values can occur. ¹⁵

The correlation between high MPV and PDW with thrombotic events underscores the prognostic significance of these indices. Patients with clonal thrombocytosis and elevated platelet indices may benefit from early intervention to prevent complications. ¹⁶ Future studies with larger cohorts and longitudinal follow-up are needed to validate these findings and explore the prognostic implications of platelet indices in thrombocytosis.

Platelet indices, particularly MPV and PDW, are valuable in differentiating reactive from clonal thrombocytosis. Their integration into routine clinical practice can enhance diagnostic accuracy and guide therapeutic decisions. Further research is warranted to establish their prognostic significance and optimize their use in patient management

1. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms: The 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia. 2008;22(1):14-22.
2. Gasparyan AY, Ayvazyan L, Mikhailidis DP, Kitas GD. Mean platelet volume: A link between thrombosis and inflammation? Curr Pharm Des. 2011;17(1):47-58.
3. Kaushansky K. The molecular mechanisms that control thrombopoiesis. J Clin Invest. 2005;115(12):3339-3347.
4. Harrison CN, Bareford D, Butt N, et al. Guideline for investigation and management of adults and children presenting with a thrombocytosis. Br J Haematol. 2010;149(3):352-375.
5. Budak YU, Polat M, Huysal K. The use of platelet indices, plateletcrit, mean platelet volume and platelet distribution width in emergency non-traumatic abdominal surgery: A systematic review. Biochem Med (Zagreb). 2016;26(2):178-193.
6. Kaito K, Otsubo H, Usui N, et al. Platelet size deviation width, platelet large cell ratio, and mean platelet volume have sufficient sensitivity and specificity in the diagnosis of immune thrombocytopenia. Br J Haematol. 2005;128(5):698-702.
7. Noris P, Melazzini F, Balduini CL. New roles for mean platelet volume measurement in the clinical practice? Platelets. 2016;27(7):607-612.
8. Vizioli L, Muscari S, Muscari A. The relationship of mean platelet volume with the risk and prognosis of cardiovascular diseases. Int J Clin Pract. 2009;63(10):1509-1515.
9. Tefferi A, Barbui T. Polycythemia vera and essential thrombocythemia: 2021 update on diagnosis, risk-stratification, and management. Am J Hematol. 2021;96(3):379-394.
10. Kaser A, Brandacher G, Steurer W, et al. Interleukin-6 stimulates thrombopoiesis through thrombopoietin: Role in inflammatory thrombocytosis. Blood. 2001;98(9):2720-2725.
11. Colwell JA, Nesto RW. The platelet in diabetes: Focus on prevention of ischemic events. Diabetes Care. 2003;26(7):2181-2188.
12. Slavka G, Perkmann T, Haslacher H, et al. Mean platelet volume may represent a predictive parameter for overall vascular mortality and ischemic heart disease. Arterioscler Thromb Vasc Biol. 2011;31(5):1215-1218.
13. Gunes Y, Guntekin U, Tuncer M, Sahin M, Simsek H. Association between preoperative platelet indices and postoperative atrial fibrillation after coronary artery bypass grafting. Platelets. 2013;24(5):354-358.
14. Korniluk A, Koper-Lenkiewicz OM, Kamińska J, Kemona H, Dymicka-Piekarska V. Mean platelet volume (MPV): New perspectives for an old marker in the course and prognosis of inflammatory conditions. Mediators Inflamm. 2019;2019:9213074.