Screening for Myelodysplastic Syndromes on Peripheral Blood Using the NEUT-X Parameter on the New Sysmex XE-5000 Analyzer
Dick G Hwang, David M Dorfman, Debra A Briggs, Ricardo Silverio, Olga Pozdnyakova. Brigham and Women's Hospital, Boston, MA; Dana Farber Cancer Institute, Boston, MA; Harvard Medical School, Boston, MA
Background: Myelodysplastic syndromes (MDS) are clonal hematopoietic disorders that present with cytopenia(s) as a result of ineffective hematopoiesis. The diagnosis of MDS is made from a combination of clinical, morphologic, and genetic findings. However, in the absence of dysplasia and/or cytogenetic abnormalities, diagnosis can be challenging. NEUT-X is a new neutrophil parameter available on the Sysmex XE-5000 hematology analyzer that is not currently used for routine CBC analysis. It is a measurement of side scatter diffraction that reflects neutrophil structure. We hypothesize that NEUT-X may reflect granulocytic dysplasia and may be useful in assisting MDS diagnosis in patients with persistent cytopenia.
Design: We compared the NEUT-X parameter on peripheral blood samples of 32 patients with MDS-related neoplasms confirmed on bone marrow biopsy (MDS group) with 196 patients without known hematologic disorders (control group). The MDS group included cases of RCUD (n=1), RAEB-1/2 (n=14), MDS/MPN (n=5), and AML with MDS-related changes (n=12). Statistical significance was computed using the two-tailed Welch's t test, which allows for unequal variance. 95% confidence intervals (CI) were computed for the means.
Results: Mean NEUT-X for the MDS group was 132.7 (CI: 129.3 to 136.0) with a standard deviation (SD) of 9.2. Within the control group, the mean NEUT-X was 139.4 (CI: 138.9 to 139.9) with SD=3.4. NEUT-X was significantly lower in the MDS group (p=0.00027). The distribution of NEUT-X values in each group is shown in the histogram.
Conclusions: A substantial fraction of the MDS group have NEUT-X values below the range observed in control patients. A cutoff of 132 allowed for detection of 44% of MDS-related neoplasm while excluding 99.5% of control cases. Using NEUT-X in combination with other CBC parameters may further increase detection of MDS without a substantial increase in false positivies. Our study suggests that NEUT-X, a new CBC parameter, may be valuable in screening for MDS in patients with persistent cytopenia. It may also prove useful in monitoring a patient's response to MDS therapy.
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 239, Wednesday Afternoon