Comparative study of erythrocyte sedimentation rate measurement between Celltac Alpha+ (MEK-1305) ESR Analyzer and standard Westergren method

Abstract

Background: The Westergren method, a gold standard method for erythrocyte sedimentation rate (ESR) measurement, is one of the screening tests for routine clinical hematology that can be used as an inflammation marker. Since the results can be altered by numerous factors, new methodologies have been established to manage the possible pitfalls. Objective: This study compared erythrocyte sedimentation rate measurements obtained by the Celltac Alpha+ (MEK-1305) Automated Hematology and ESR analyzer with those obtained by the standard Westergren method. Materials and methods: The Celltac Alpha+ (MEK-1305) Automated Hematology and ESR analyzer was used to assess the performance of ESR measurement compared to the standard Westergren method. A total of 220 random EDTA whole blood samples from patients were included and analyzed in parallel using the automated analyzer and the standard Westergren method. Results: Spearman’s rank correlation coefficient (ρ = 0.916) obtained a good correlation between the two methods. In addition, the precision was good and acceptable according to the criteria, with a %CV of less than 10% in both intra-run and inter-run precision. There was no contamination between blood samples from using a single capillary probe. Moreover, Bland-Altman mean difference plot also indicated a good agreement, with a mean bias of -1.4 (95% CI: -0.8 to 2.1), an upper LOA of 7.6 (95% CI: 6.6 to 8.7) and a lower LOA = -10.5 (95% CI: -11.6 to -9.5). Conclusion: This comparative study indicated that the Celltac Alpha+ (MEK-1305) Automated Hematology and ESR analyzer is applicable within clinical routine practice along with proper measurement regulation. Even though the principles between these two methods are completely different, an acceptable interrelation was obtained due to the calibration process by Nihon Kohden corporation.