Evaluation of fragmented red cell (FRC) counting using Sysmex XE‐5000 – Does hypochromia play a role?

Abstract

Despite the agreement between FRC count and the manual method, the overvaluation of FRC was high, leading to false-positive results. Microcytosis appeared to have no impact on FRC count, whereas mild hypochromia seemed to be related with FRC count. Particular attention is required to assess automated FRCs in samples with mild hypochromia.

Comparison between optical microscopy and the Sysmex XN‐3000 for schistocyte determination in patients suspected of having schistocytosis

“…Jiang et al reported that the FRC count by the Sysmex XE‐2100 was spuriously high in samples taken from patients with iron deficiency anaemia. In contrast, previous studies using the Sysmex XE‐5000 and XN‐9000 devices have reported that an increased number of microcytic RBCs did not interfere with the FRC count, which is similar to the result we observed in our thalassaemia group. The reason for this difference between studies may be improvement in the function of subsequent generations of automated analysers.…”

“…This study is the first to compare schistocyte detection and quantification by the Sysmex XN series with that of the gold standard microscopy method in blood samples taken from patients suspected of having schistocytosis. Previous studies either researched FRC count by the Sysmex XE series (XE‐2100 and XE‐5000) in heterogeneous groups of patients, or studied the FRC reference range using an XN‐9000 in healthy patients . We found that when using the analyser in the samples derived from the group of patients suspected of having schistocytosis, it could discriminate between presence and absence of schistocytosis reasonably well, as evidenced by the AUC of the ROC curve being more than or equal to 0.8 (AUC = 0.803; 95% CI, 0.689‐0.917) .…”

“…Therefore, events which have less ribosomal RNA content than PLT and that are smaller than mature RBCs, are counted as FRCs . About 30 000 RBCs can be analysed simultaneously, and the FRCs are automatically presented as a percentage appearing below the RBC area . The Sysmex XN‐3000 used in this study was validated daily by internal quality control procedures, consistent with the manufacturer's instructions.…”

“…For the present study, the automated Sysmex XN‐3000 (Sysmex Corporation, Kobe, Japan) was selected for comparison with microscopy because it includes a function for the detection of schistocytes, and it is already used at our centre for routine laboratory tests, including complete blood count, nucleated red blood cell count, and reticulocyte count. Furthermore, the Sysmex XN‐3000 can count an average of 30 000 RBCs simultaneously, whereas only about 1000 RBCs can be examined microscopically in one peripheral blood smear, and with reported poor reproducibility …”

Automated Quantification of Fragmented Red Blood Cells: Neonatal Reference Intervals and Clinical Disorders of Neonatal Intensive Care Unit Patients with High Values

“…Certainly the FRC count does not represent an automated count of schistocytes only, and if a precise schistocyte evaluation is needed, a film review is needed. However, in studies of adults, automated and manual values tended to correlate well [5,[23][24][25]. Also, we had relatively few very premature neonates in our database.…”