Comparison of basophil count by Beckman Coulter UniCel DxH 800, Sysmex XN-1000, and manual microscopy in cases of suspected chronic myeloid leukemia

INTRODUCTION: Basophilia can help stratify cases of chronic myeloid leukemia (CML) into different phases and monitor response to therapy and has a significant prognostic value. It helps differentiate patients of CML from those with leukemoid reaction. Basophil counts (BCs) given by automated hematology analyzers are often not reliable. Analysis of peripheral blood picture therefore holds its importance in these cases. In this study, we aim to compare the BC in patients with suspected CML using two automated analyzers with manual microscopy. MATERIALS AND METHODS: Two hundred and sixty-nine ethylenediaminetetraacetic acid samples identified as suspected CML run on Beckman Coulter UniCel DxH 800 and Sysmex XN-1000 were analyzed for BC microscopically on Giemsa-stained peripheral smear slides by two pathologists. The mean of basophil counts obtained microscopically was considered to be standard. They were compared with BC given by automated counters using correlation analysis and Bland Altman plots. RESULTS: The age of the patients ranged from 4 to 89 years, with a male-to-female ratio of 1.2:1 (148 males; 121 females). BC obtained among both analyzers did not correlate (r2 = 0.14). Results of microscopically counted basophils correlated well among two pathologists (r2 = 0.92). Bland–Altman plots showed a mean bias of 2.2% and 2.4% by XN-1000 and DxH 800, respectively, when compared with manual counts. In the frequency distribution analysis, XN-1000 missed all 10 cases with BC >20% whereas DxH 800 missed 3/10 cases with BC >20%. In addition, in the 10%–20% range of BC, XN-1000 identified 6/22 cases whereas DxH 800 identified 12/22 cases. In the 5%–10% range of BC, XN-1000 identified 59/78 cases whereas DxH 800 identified only 43/78 cases. CONCLUSION: With lower BC, Sysmex XN-1000 and, at higher BC, Beckman Coulter DxH 800 showed better performance. However, BC from none of the analyzers can be used alone without consideration of the microscopic results. All smears should be manually counted for basophils in cases of suspected CML because of its importance in clinical management.