Sensitivity and specificity of the high fluorescent lymphocyte count-gate on the Sysmex XE-5000 hematology analyzer for detection of peripheral plasma cells.

BACKGROUND: Plasma cells are one of the end products of the B-lymphocyte mediated immune response. These cells normally reside in the bone marrow or some peripheral lymphoid tissues. Increased numbers of plasma cells in the blood, usually indicates pathology such as infection, auto-immunity or haematological malignancy. Therefore, the ability to measure plasma cells (PCs) on an automated cell analyzer might be advantageous.

METHODS: The performance of the Sysmex XE-5000 leukocyte differential channel [high fluorescent lymphocyte count (HFLC) area] was evaluated for the ability to detect plasma cells in peripheral blood and compared to the detection of plasma cells by flow cytometric analyses.

RESULTS: Our results show that the HFL count from the XE-5000 correlates (R(2)=0.8) with the number of PCs in peripheral blood, but detects PCs with moderate to good sensitivity (88.9%) and specificity (87.8%).

CONCLUSIONS: The Sysmex XE-5000 is suitable for screening blood samples for the presence of elevated number of plasma cells in peripheral blood, but the actual quantification needs to be confirmed by flow cytometry.