Evaluation of the immature myeloid information (IMI) by Sysmex XE 2100® hematology analyzer in the identification of blasts of myeloid lineage

Abstract

The immature myeloid information (IMI) provided by the Sysmex XE 2100 hematology analyzer has demonstrated that it is possible to differentiate granulocytes of immature cells in daily practice. A specific reagent lyses mature white blood cells, allowing that immature myeloid cells remain intact and consequently detectable. It is known that lymphoblasts cannot be detected in this channel. This channel does not entail additional costs, since it is provided by the traditional hematology analyzers used in blood tests and is widely useful in differentiating cell lines. This study has aimed to assess the consonance between IMI results and subtypes of acute leukemias and other hematologic malignancies in order to use it as screening test in the definition of cell lineage. A total of 141 cases of hematologic malignancies have been evaluated. Results of the IMI channel were compared using the Sudan Black cytochemical and flow cytometry. The Cohen's Kappa coefficient of agreement between IMI and flow cytometry results was 0.8%. IMI had sensibility and specificity levels of 90.7% and 90.8%, respectively; VP: 68 (91.9%); FP: 6 (8.1%); VN: 59 (89.4%) and FN: 7 (10.6%); PPV 91.9% and NPV 89.4%. The Sysmex XE 2100 analyzer showed a good analytical performance for the detection of immature myeloid cells. These results indicate that the IMI channel has sensitivity and specificity levels, consistent with previous studies. Given this situation, one may conclude that IMI was able to be used as a screening test to complement cytochemistry for identify blasts of myeloid lineage.