Bone Marrow Basophil Evaluation in Myeloproliferative Neoplasms Using Flow Cytometry

The aim of this study was to evaluate the characteristics of bone marrow (BM) basophils in myeloproliferative neoplasm (MPN) using flow cytometry (FCM). Basophils have been known to be elevated in chronic myeloid leukemia (CML) through blood analyzers or microscopes, but these methods are not reliable for identifying BM basophils, and the changes in BM basophils in non-CML MPN were unclear.

BM basophils of 101 MPN were evaluated by FCM, assessing indices related to basophil levels and CD63/CD203c expression. PB basophils were counted by blood analyzer. The basophil characteristics of MPN were compared to that of 95 individuals without hematopoietic disorders and 30 newly diagnosed myelodysplastic neoplasms (MDS).

MPN patients showed increased levels of BM basophils and basophils with CD203c expression compared to normal or reactive group. Although weak correlation was observed, BM basophil levels were statistically different from those in PB. Comparing basophil characteristics between non-CML MPN and normal or reactive group, BM basophil indices demonstrated higher elevated counts than PB basophil indices in MPN. BM baso/lym ratio and basophil percentage were most effective in distinguishing non-CML MPN from non-hematopoietic disorders, while PB basophil indices demonstrated limited discriminative value. Most of the basophil indices of CML were different from those of normal group, reactive basophilia, non-CML MPN and MDS. CML could be discriminated from non-hematopoietic disorders by all basophil indices, with BM baso/lym ratio, PB basophil count and PB baso/lym ratio demonstrating superior capacity of discrimination.

BM basophil indices, particularly the baso/lym ratio, enhance MPN identification and outperform PB basophil indices in discriminating non-CML MPN from non-hematopoietic disorders. These findings indicate BM basophil analysis by FCM could serve as a potential tool for MPN screening.