Underreporting of basophil count by automated analyzer Sysmex XN 1000 in chronic myeloid leukemia: A diagnostic concern

Objectives: This study compared the basophil counts (BC) on the automated analyzer Sysmex XN1000 (XN 1000) with manual differential count (DC). Materials and Methods: The study was conducted over a period of 2 years and included 77 diagnosed chronic myeloid leukemia (CML) cases. We compared the basophil percentages provided by XN 1000 with those of manual DC on peripheral blood smear (PBS). Manual DC was done by two hematopathologists on 200 cells, and the mean values were taken. Manual DC was considered the gold standard for comparison. Statistical analysis: Statistical analysis was done on R statistical software, version 4.1. Results: Seventy-seven patients of CML were included in the study. Mean basophil percentage (%) by XN1000 was 3.96% while the mean basophil % by manual DC was 7.07%. Pearson correlation between the two values was 0.249 with a significant p value (0.03). It was evident that the basophil percentage by automated analyzer was significantly lower compared to that obtained by manual counts. There was a mean difference (bias) of −3.11, suggesting that Sysmex XN 1000 can underestimate by ~3.1% when compared with the manual method. Conclusions: Automated analyzers (Sysmex XN 1000) underestimate the percentage of basophils in CML. The BC should be done manually on PBS for all cases of suspected CML since BC has a significant role in deciding the clinical management in CML patients.