EVALUATION OF PLATELET INDICES IN HYPOPRODUCTIVE AND HYPERDESTRUCTIVE TYPE OF THROMBOCYTOPENIA

Thrombocytopenia, defined as a platelet count below 150×10⁹/L, may result from either hypoproliferation or peripheral hyperdestruction of platelets. Differentiation between these causes traditionally requires bone marrow examination. However, advances in automated blood cell analyzers have enabled measurement of platelet indices such as Mean Platelet Volume (MPV), Platelet Distribution Width (PDW), and Plateletcrit (PCT), which may assist in evaluating thrombocytopenia.

Aim: To assess the utility of platelet indices in distinguishing between hypoproductive and hyperdestructive thrombocytopenia.

Materials and Methods: This cross-sectional study included 240 cases of thrombocytopenia, examination between January 2024 and March 2024. Patients were classified into hypoproductive (n=41) and hyperdestructive (n=199) groups. Platelet indices (MPV, PDW, PCT) and platelet counts were compared across the study groups using Student’s t-test.

Results: The mean age was 38.81 years in the hypoproductive group and 39.79 years in the hyperdestructive group, with a male-to-female ratio of 1.05:1 and 1.45:1 respectively. When comparing the hypoproductive and hyperdestructive groups, only MPV showed statistically significant differences (p ≤ 0.05). Of the platelet indices, only MPV demonstrated significant discrimination (p = 0.02) between the two groups.

Conclusion: MPV may serve as a useful preliminary test for distinguishing between hypoproductive and hyperdestructive thrombocytopenia, potentially reducing the need for invasive bone marrow aspiration and avoiding unnecessary platelet transfusions in patients with hyperdestructive thrombocytopenia

INTRODUCTION:

Platelets are the first line of defense that restrict blood loss caused by micro- and macrovascular damage because they aggregate and adhere to each other, preserving endothelial integrity. A platelet count of less than 150 × 109/L indicates thrombocytopenia. Thus, bleeding is a common complication of low platelet count because platelets play an important role in primary hemostasis, and it can be fatal in thrombocytopenic patients.[1,2] Thrombocytopenia is be caused by marrow hypoplasia, accelerated platelet breakdown, or splenic sequestration. The gold standard procedure for determining the reasons of thrombocytopenia is bone marrow examination, however it is invasive and costly. As a result, an alternative method should be developed as the first-line diagnostic procedure. The automated blood cell analyzer has recently enabled the assessment of the cause of thrombocytopenia using various machine-derived parameters known as platelet indices, which include the mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT), which are provided as part of a routine complete blood count.

Platelet indices are also bio-markers of platelet activation, which give diagnostic and prognostic clues in many clinical settings. MPV is a method of measuring platelet volume that determines the progenitor cells (megakaryocytes) in the bone marrow. When platelet synthesis is reduced, immature platelets become bigger and more active, and the MPV level rises, indicating greater platelet diameter, which can be utilized as a metric of platelet rate and activity. MPV, like mean corpuscular volume, measures average platelet size. [3,4,5].

PDW directly measures the variability in platelet size and reflects the heterogeneity in platelet morphology and has shown usefulness in establishing the differential diagnosis between reactive thrombocytosis and thrombocytosis associated with the myeloproliferative disease. Therefore, it helps in establishing a differential diagnosis of thrombocytopenia because of decreased production or platelet destruction.[3,4,6,7,8]PCT measures total platelet mass and is an excellent screening technique for detecting platelet quantitative abnormalities. The platelet-large cell ratio (P-LCR) is a measure of circulating bigger platelets and is used to track platelet activity. It is the ratio of bigger platelets to total platelet count, which is inversely related to platelet count but directly connected to MPV and PDW. Thus, platelet indices play an important role in distinguishing between hypo-productive and hyper-destructive thrombocytopenia. [9,10] Studies have indicated that MPV, PDW, and PCT have a good diagnostic association, which can be compared to findings from bone marrow studies. The current study seeks to determine the utility of these platelet indices (MPV, PDW, and PCT) derived from hematology analyser based on the impedance principle in distinguishing between hyper-destructive or hypoproductive causes of thrombocytopenia, for avoiding or delaying a request for bone marrow examination.