IMAGE DNA ANALYSIS OF BONE MARROW MEGAKARYOCYTES IN DIFFERENTIAL DIAGNOSIS OF THROMBOCYTOSIS

Background. Megakaryocyte (Mk) nuclear DNA content was measured by image analysis using new S-Form software. Feulgen-stained bone marrow aspirates from 11 patients with reactive thrombocytosis and 12 patients with clonal thrombocytosis of chronic myeloproliferative disorders (CMPDs) were analysed. Ploidy of 100 Mk was calculated for each patient and the fractions of hyperploid cells were compared. The presence of more than 5% of Mk with nuclear ploidy > 96N or ≥ 2% of Mk with nuclear ploidy > 128N in patients with thrombocytosis strongly suggests CMPD. On the other hand, the absence of hyperploid cells > 128N or the presence of a small fraction (less than 5%) of moderately hyperploid cells (96–128 N) indicates reactive thrombocytosis. Image cytometry analysis therefore appears to add valuable information to conventional cytological examination in the diagnostic assesment of thrombocytosis.Conclusions. S-Form software image analysis is much faster and more reliable than microdensitometric DNA analysis, which we previously used for cytometric studies. We believe the method of image DNA analysis has the potential for widespread clinical use in the differential diagnosis of megakaryocyte disorders.