Sysmex XR-Series (XR-20) Automated Hematology Analyzer

The Sysmex XR-Series (XR-20) is a quantitative multi-parameter automated hematology analyzer for in vitro diagnostic screening of patient populations in clinical laboratories. It measures and classifies parameters in whole blood (WBC, RBC, hemoglobin, hematocrit, platelets, differentials, reticulocytes, and immature granulocytes) and body fluids (CSF, peritoneal, pleural, synovial) using RF/DC detection, sheath flow methods, and flow cytometry.

The XR-20 uses the same measurement principles (RF/DC detection, flow cytometry with semiconductor laser and SLS-hemoglobin method) and measures the same parameters as the predicate XN-20. Key differences are: the XR-20 has an additional white progenitor cell (WPC) measuring channel providing separate flags for blasts and abnormal lymphocytes; uses Lysercell WDF II instead of Lysercell WDF as lyse reagent; and achieves throughput of 110 samples/hour in whole blood mode versus 100 samples/hour for the predicate.

Testing conducted per CLSI EP05-A3 (precision/repeatability), CLSI EP06-ED2:2020 (linearity), CLSI H26-A2 (carry-over), CLSI EP09-A3 (matrix and bridging studies), and referenced pediatric reference intervals from Wong et al. (2021). Standard hematology analytical performance testing protocols were applied.

The XR-20 is substantially equivalent to the XN-20 predicate because both devices share identical indications for use, fundamental technology (RF/DC detection and flow cytometry), measurement principles, specimen types, reagents (same diluents, lyses, stains, calibrators, controls), analysis modes, and software specifications. Comprehensive analytical testing (precision, linearity, interference studies, stability, detection limits, carryover, and method comparison across 865 whole blood and 397 body fluid samples) demonstrated performance meeting predefined acceptance criteria with correlation coefficients ≥0.93 and acceptable bias limits. Clinical sensitivity/specificity studies showed flagging performance comparable to the predicate. The additional WPC channel, reagent variation, and higher throughput do not impact safety or effectiveness as demonstrated through full validation.