Platelet Distribution Width (PDW) - A Rarely Studied Platelet Indice for Determining the Causes of Thrombocytopenia

Abstract

Background: Thrombocytopenia (TCP) is low platelets count, which is either due to defective platelet production or due to increased platelet breakdown. The platelet number alone does not give a complete picture of platelet maturity and function, therefore, the platelet indices have been the subject of intensive study in recent years, but they have not been firmly established. Mean platelet volume (MPV) and platelet distribution width (PDW) are useful parameters in evaluating disorders of platelets. This study was undertaken to evaluate the effectiveness of PDW in diagnosing causes of thrombocytopenia. Methods: 510 cases of thrombocytopenia and 500 cases of Control group with normal platelet count were included in the study. TCP was defined as platelet counts below 1.5 lacs/cumm. Hematological analysis was done on Mindray BC-3000 plus automated hematology analyzer. All cases were reevaluated by peripheral smear examination. Only those cases were included in the study, which showed platelet count and platelet volume parameters with graph both in cases and in control group. Results: Hyper-destructive group constituted majority of the cases 352 (69%), while hypo-productive group and abnormal pooling constituted 30% and 1.42% cases respectively. The mean PDW was significantly higher in hyper-destructive group when compared with hypo-productive group, Abnormal pooling and control group. The difference was statistically significant. Conclusion: PDW provides plenty of clinical information about the causes and patho-mechanisms of thrombocytopenia and could be helpful to distinguish hyper-destructive thrombocytopenia from hypo-productive thrombocytopenia. More attention should be paid to PDW along with other platelet indices to differentiate between hyper-destructive TCP from hypo-productive and abnormal pooling TCP. .

Predictive Value Of Platelet Indices For Differentiating Hyper Destructive Thrombocytopenia From Hypo Productive Thrombocytopenia In Patients Attending Teritiary Care Hospital

“…Males were predominantly affected in hypo productive and hyper destructive thrombocytopenia with 41.4% and 58.6%. Dengue (19) and malaria (11) Pearson correlation between the platelet count and platelet indices in hyper destructive TCP cases shows positive correlation for MPV 0.067 with a p value of 0.64 which is statistically not significant. There is a negative correlation between the platelet count and platelet indices PDW -0.001 and PLCR -0.113 with a p value of 0.99 and 0.44 which is statistically not significant (Fig.…”

“…5 Studies done by kharikar et al mentioned that Babu E and Basu D suggested that it is not always possible to record platelet indices in the presence of red cell fragmentation, in severe thrombocytopenia. 11 We also avoided this problem by discarding cases without indices and selected only those cases which had platelet indices and provided a histogram. In the present study we are used Sysmex XN1000 hematology fully automated analyzer which works on the principal of hydrodynamic focusing and flow cytometry.…”

“…i.e; 38.8% and 22.5% were the more prevalent aetiologies in hyper destructive thrombocytopenia category. While Erythroid hyperplasia (15) and acute myeloid leukemia(11) i.e; 42.8% and 31.4% were the most common causes for hypo productive thrombocytopenia (Table1. ).…”

A Study of Variation in Adult Thrombocytopenic Histograms A Graph Often Overlooked

“…[2,9,10] The analyzers also display a plateletogram along with numerical indices which are often overlooked. [4] Other than the routine platelet counts, which is the most commonly asked parameter, the other platelet indices like MPV [Mean platelet volume], PCT [plateletcrit] and PDW [platelet distribution width] are also available in the analyzer readings. [10,11] Majority of the thrombocytopenic cases in our study fell into the third decade of life, with the male to female ratio being 1.3:1, similar to the study done by Borkataky et al [12] This dominant age group could be attributed to the large load of viral infections in our area affecting young population working outdoors.…”

“…These analyzers routinely give platelet histogram in addition to platelet count and indices at no extra cost. [3,4,5] However, the histogram is often neglected, with the main emphasis being only on the platelet counts. [6] A good basic knowledge on the interpretation of histograms can be a useful adjunct tool along with platelet indices to determine the underlying mechanism of thrombocytopaenia.…”