Performance Evaluation of Hematology Analyser Sysmex KX – 21 for Platelet and WBC Count

Objective: To evaluate the performance of Sysmex KX – 21 for the estimation of Platelet and WBC count in comparison with microscopy. Study Design: It is prospective cohort study. Place and Duration: It was conducted in the Pathology department, Allama Iqbal Medical College, from 7th Oct. 2009 to 6th Nov. 2009. Materials and Methods: Out of the total 1500 samples, 1458 (97%) samples after exclusions were finally evaluated for the study. On each sample, automated blood cell count was performed using Sysmex KX – 21 and the results were compared by peripheral smear examination for Platelet count, WBC count and its differential. The samples were from Medicine, Pediatrics and Oncology wards only. Results: Out of 1458 samples, WBC count of 1452 (99.5%) samples matched the total count on peripheral smear examination. 06 (0.5%) samples showed spurious WBC count due to the presence of nucleated RBCs and lyze resistant RBCs (indicated by respective flags on Sysmex KX – 21). 262 (17.9%) samples missed differential count on automated analyser, due to low count or high count with immature cells and normal count with immature cells. Differential of rest of the 1196 (82.1%) samples also matched the manually done differential count. Regarding platelets, 1435 (98.4%) samples matched the platelet count on peripheral smear. 23 (1.6%) samples didn’t correlate with the smear due to platelet clumps and fragmented RBCs (indicated by respective flags on Sysmex KX – 21). Conclusion: Sysmex KX – 21 is a reliable automated analyser for total WBC and platelet count while reevaluation by peripheral smear is only required for those samples where the automated analyser indicates with flagging.  Non-toxic, biodegradable reagents.  Reliable hardware and results.  Network capability via your LIS.