Counting of highly fluorescent ymphocytes (HFLC) as antibody-producing plasma cells on XE-5000

Fluorescence flow cytometry enhances analytical possibilities beyond the normal 5-part differential by providing excellent cluster resolution and separation of abnormal blood cells. A nucleated red blood cell count (NRBC) and an immature granulocyte count (IG) are part of an extended differential on the xe systems with the potential to improve the diagnostic usefulness of the routine 5-part differential, which can be reported directly for all analysed samples. Besides the IG there is a distinct separation of an abnormal cell population with high fluorescence intensity above the monocyte and lymphocyte region. Highly fluorescent lymphocyte cells (HFLC) are observed in the DIFF channel of the Sysmex xe series haematology analysers in an area of high fluorescence which is used for flagging of ‘Atypical Lymphocytes’. They are detected by their characteristically high fluorescence intensity reflecting a high RNA content. The recently introduced xe-5000 analyser with improved gating and flagging excludes those samples in which the analyser cannot discriminate a distinct HFLC population (mostly in cases of systemic diseases or malaria infections).