Usefulness of the lymphocyte positional parameters in the Sysmex XN haematology analyser in lymphoproliferative disorders and mononucleosis syndrome.

INTRODUCTION: The lymphocyte positional parameters included in Sysmex XN have been suggested as useful means to differentiate lymphoproliferative disorders (LPD), mononucleosis syndrome (MNS) and other lymphocytoses. METHODS: We evaluated Sysmex XN analysers, which supply 6 lymphocyte positional parameters that can be measured in the WDF scattergram: LY-X, LY-Y, LY-Z, LY-WX, LY-WY and LY-WZ. RESULTS: We collected 301 samples from normal controls, polyclonal lymphocytosis, MNS and LPD. MNS and monoclonal expansion of T granular lymphocyte (T-GL) diagnostic groups accumulated higher numbers of significant differences in the mean values in comparison with the other groups. We propose a new algorithm that can differentiate T-GL cases from other diagnostic groups with an SE of 67.5%, an SP of 98.2%, a PPV of 87.1% and an NPV of 94.3%. Another algorithm showed its efficiency to differentiate MNS cases from other diagnostic groups with an SE of 63.6%, an SP of 97.5%, a PPV of 70.0% and an NPV of 96.7%. In 38.5% of all cases, the analyser did not generate any morphologic flag. Abnormal results in lymphocyte positional parameters were useful to detect 72.5% of these samples. CONCLUSION: The lymphocyte positional parameters provided by Sysmex XN analysers are useful to differentiate expansions of T-GLs from other LPD and to differentiate MNS cases from other diagnostic groups. In addition, these parameters are very useful for detecting changes in the lymphocytes that make it necessary to review blood smears in samples without morphological flagging.

The utility of the Sysmex XE-2100 analyzer's NEUT-X and NEUT-Y parameters for detecting neutrophil dysplasia in myelodysplastic syndromes.

The diagnosis of myelodysplastic syndromes (MDS) is based on morphological changes in the blood and bone marrow. The parameters NEUT-X and NEUT-Y of the Sysmex XE-2100 analyzer could help detect neutrophil dysplasia. A control group of 50 patients, along with 50 postpartum patients, 50 anemias, 50 leukopenias, 50 patients with microscopically visible hypergranulated neutrophils and 50 MDS patients were assessed. The NEUT-X and NEUT-Y values (mean +/- SD) for the control group were 1346 +/- 28.2 and 420 +/- 19.3, respectively, with the anemia and leukopenia groups giving similar values. The postpartum and hypergranulated neutrophils groups presented higher values (P < 0.05), whereas the values in the MDS group were 1286 +/- 72.8 and 385 +/- 50.9 (P < 0.05), respectively. There were no differences between the morphological MDS types. The NEUT-X and NEUT-Y values in MDS patients with optical hypogranulation were significantly lower than for MDS patients without optical hypogranulation. NEUT-X and NEUT-Y values lower than 1298 and 398, respectively, would have a specificity for detecting MDS of 94% and 91% and would detect 60% and 56% of cases, respectively, whereas they would detect 75% and 74%, respectively, of MDS cases with optical hypogranulation. NEUT-X and NEUT-Y parameters can be used to detect neutrophil dysplasia arising from MDS and chronic myelomonocytic leukemia.