Role of Mean Platelet Volume (MPV), Platelet Distribution Width (PDW) and Platelet Large Cell Ratio (P-LCR) Value in the Diagnosis of Immune Thrombocytopenic Purpura

Abstract

A cross-sectional retrospective study was carried out at the Bangabandhu Sheikh Mujib Medical University, Dhaka to determine the diagnostic significance of platelet indices in ITP. Total 60 cases were included in this study. Complete history was taken either from patient or accompanying attendants. Thorough clinical examination was done. Mean age of the study population of aplastic anaemia (AA) was 36.66(±17.04) years and immune thrombocytopenic purpura (ITP) was 29.70(±13.99) years. Mean platelet count was 38.73(±15.99) x109/L and 30.46(±14.17) x109/L in AA and ITP respectively and that was not statistically significant. In AA mean platelet volume was 9.75(±1.15) fl and in ITP mean platelet volume was 12.01(±1.23) fl. In AA mean platelet distribution width was 11.75(±2.13) fl and in ITP mean platelet distribution width was 18.07(±2.52) fl. In AA mean platelet large cell ratio was 21.07(±5.51) % and in ITP mean platelet large cell ratio was 36.68(±7.91) % and that was statistically significant. Sensitivity and specificity of platelet indices to make a diagnosis of ITP was calculated under various cut-off ranges. MPV cut of value >11fl sensitivity was 73.33% and Specificity was 80.0%, MPV cut of value >12 fl sensitivity was 53.3% and Specificity was 96.7%, MPV cut of value >13 fl sensitivity was 26.7% and Specificity was 100%. PDW cut of value >14 fl sensitivity was 86.67% and Specificity was 93.3%. PDW cut of value >15 fl sensitivity was 100% and Specificity was 83.0%. P-LCR cut of value >40% sensitivity was 100% and Specificity was 63.0%. These indices could help to distinguish hyper-destructive thrombocytopenia and hypo-productive thrombocytopenia very easily and it is also cost effective. Platelet indices, if reported, provide a lot of clinical information about the underlying conditions of thrombocytopenia.