Significance of platelet indices in the diagnosis of immune thrombocytopenic purpura and aplastic anaemia

ABSTRACT

To compare the platelet indices in thrombocytopenia due to immune thrombocytopenic purpura and aplastic anaemia. This is observational study that was carried out from May 2006 to May 2007 at The Department of Haematology, Armed Forces Institute of Pathology [AFIP] and Armed Forces Bone Marrow Transplant Centre [AFBMTC], Rawalpindi. Seventy six [76] patients of thrombocytopenia were studied, of which 35 were patients of Immune thrombocytopenic purpura [ITP] and 41 patients of Aplastic anaemia [AA]. Platelet indices were measured on peripheral blood using automated haematology analyzer. Based on the bone marrow diagnosis, 35 patients of immune thrombocytopenic purpura and 41 patients of aplastic anaemia were studied. All indices were significantly higher in immune thrombocytopenic purpura than apiasiic anaemia. The mean MPV [Mean Platelet Volume] was 10.5fl in immune thrombocytopenic purpura and 8.6fl in aplastic anaemia [p <0.001], mean PDW [Platelet deviation width] was 15.6fl in immune thrombocytopenic purpura and 10.7fl in aplastic anaemia [p <0.001] and mean P-LCR [Platelet large cell ratio] was 31.2% in immune thrombocytopenic purpura and 17.7% in aplastic anaemia [p <0.001]. Our results suggest that these indices can provide reliable information to clinicians about the underlying etiology of thrombocytopenia and may help to avoid bone marrow examination, which is an invasive procedure, in some patients