Morphometric evaluation of megakaryocytes in bone marrow aspirates of immune-mediated thrombocytopenic purpura.

Immune-mediated thrombocytopenic purpura (ITP), one of the common causes of thrombocytopenia, is characterized by morphologic alterations in megakaryocytes in the bone marrow. Few studies have explored morphometric measurements of megakaryocytes in bone marrow trephine biopsies. Quantitative morphometric analysis of megakaryocytes in bone marrow aspirate smears is lacking in the available literature. This study was aimed at evaluating the morphometric alterations in megakaryocytes in cases of ITP on bone marrow aspirate smears vis-á-vis non-ITP cases. In this study, 35 cases of ITP and 15 non-ITP aspirates were included. The bone marrow aspirate smears were reviewed for diagnosis. Computer-aided image analysis was performed in all aspirate smears for megakaryocytic morphometric measurements, including cytoplasmic and nuclear features. Appropriate statistical tests were applied for comparison. Megakaryocytes in cases of ITP showed a higher nuclear/cytoplasmic ratio (p = 0.021), lower nuclear roundness factor (p = 0.04) and lower nuclear contour ratio (p = 0.027). Cellular circularity and compactness were significantly different in ITP as compared to non-ITP cases, indicating that the megakaryocytes were less round in ITP subjects. Discriminant analysis and cross-validation studies found that 65.5% of megakaryocytes could be correctly classified as ITP or non-ITP. This study shows that significant alterations occur in megakaryocytes in cases of ITP. These changes can potentially be utilized in the development of algorithms for computer-assisted diagnosis of such cases on bone marrow aspirates.