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.