Multicenter evaluation of the cobas m 511 integrated hematology analyzer

Introduction: The cobas m 511 integrated hematology analyzer conducts a complete blood count (CBC), white blood cell (WBC) differential, reticulocyte count, and nucleated red blood cell count using automated digital microscopy. This multicenter study validated the analytical performance of the cobas m 511 system. Methods: Repeatability, reproducibility, carryover, mode-to-mode comparison, cytomorphology, WBC clinical sensitivity, and method comparison were analyzed at four clinical sites using residual whole blood clinical samples (n = 2546) and fresh whole blood from healthy volunteers (n = 480). For WBC clinical sensitivity, the cobas m 511 system automated CBC and WBC differential, system flags, cobas m 511 images, and stained cobas m 511 slides were compared with manual microscopy. Sysmex® XN analyzers were used for interinstrument method comparison. Results: Repeatability and reproducibility results showed low variability. There was no significant sample carryover and no difference between open/closed modes. The overall percentage agreement of morphology assessments with manual microscopy (n = 163 samples) was 95.6% for cobas m 511 images and 95.7% for cobas m 511 slides. The sensitivity and specificity for detecting distributional and/or morphological abnormalities were 94.4% and 74.6% for cobas m 511 automated differential, and 95.9% and 73.3% for cobas m 511 image assessment, compared with a manual 400-cell reference differential (n = 439 samples). Some discordance was seen for monocytes and basophils. Correlations between cobas m 511 and Sysmex XN system data were very good (Pearson's R ≥ 0.95 for most CBC parameters). Conclusion: The cobas m 511 system performs robustly in the clinical laboratory and is suitable for routine clinical use.

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