Identifying Myelodysplastic Syndrome Among Patients with Anemia: Neutrophil Characteristics Computed by a Cell Counter (Beckman Coulter LH750), An Effective Screening Tool

The inherent limitations of manual cellular analysis of peripheral blood include the small number of cellular elements counted and subjectivity associated with morphological examination of a smear. Significant advances in haematology cell counters over the last two decades have resulted in a more discriminatory leukocyte analysis. The Beckman Coulter LH750 (Beckman Coulter, Hialeah, FL, USA) uses the single platform VCS (Volume, Conductivity and Scatter) technology to characterize leucocytes and plot data on a 3 dimensional scatterplot, where size (Volume) is plotted on the Y-axis, measure of cellular contents including nuclear complexity and nucleo-cytoplasmic proportion (Conductivity) on the Z-axis and granularity (Scatter) on the X-axis. It gives statistical information of the parameters being measured for each subset of leukocyte population called positional parameters. Besides, evaluating more than 8000 leukocytes reduces bias and error as compared to manual techniques. Myelodysplastic syndromes (MDS) are diagnosed based on morphological criteria applied to bone marrow aspirate smears. Other than cytopenia, patients with MDS present with morphological changes in neutrophils such as the pseudo pelger-huet anomaly, variation in size and hypogranularity. The latter is more subjective and dependent on the staining method used.

To evaluate the role of positional parameters obtained by VCS technology of Beckman Coulter LH 750 cell counter in identifying abnormal neutrophils as a potential screening tool for diagnosis of myelodysplastic syndrome.

We have studied retrospectively 39 cases where myelodysplastic syndrome was diagnosed on bone marrow examination and categorized based on the World Health Organisation (WHO) classification, in our laboratory between June 2010 and June 2011[Table 1]. Cases with a large proportion of immature myeloid cells (left shift) and blasts were excluded because the presence of these cells may result in confounding positional parameters as they are included along with neutrophils during peripheral blood analysis. Cases with severe neutropenia (Absolute Neutrophil count of less than 500) were also excluded. We selected 21 patients with anaemia due to other causes as controls. The Neutrophil VCS parameters of these cases of MDS were compared with those of the controls after analysis on the Beckman Coulter LH 750 cell counter. The reference range for neutrophil VCS data and positional parameters was obtained from a group of 300 healthy volunteer blood donors. Statistical analysis was done using SPSS v16.0.0 (IBM Corporation USA).

The mean cell scatter of neutrophils among patients with MDS was significantly lower as compared to the control group (p<0.0001) [Table 2]. Distributions of cell volume, conductivity as well as cell scatter of neutrophils in the MDS group were significantly higher than that of cases with anaemia and correlated well with morphological features. In MDS patients, even when cytoplasmic hypogranularity and abnormal nuclear lobularity of neutrophils were not conspicuous on smears, these changes were observed. ROC analysis was used to assign cut-offs for these parameters, the results of which are tabulated. [Table 3]

Use of white cell positional parameters computed by the Coulter LH750 cell counter can flag abnormal neutrophils. This can be a tool for detection of MDS more so in cases where morphological changes are not conspicuous.

No relevant conflicts of interest to declare.