Establishing a Reference Interval for Flow Cytometric Analysis of Red Blood Cell Osmotic Fragility in a Healthy Korean Population.

OBJECTIVE

The flow cytometric osmotic fragility test (OFT) screens for hereditary spherocytosis (HS) and other red blood cell (RBC) membrane disorders. It has been suggested that the proportion of residual RBCs at the midpoint region of the time/forward scatter plot would be just as informative for HS diagnosis as that at the terminal region. We established reference intervals for both regions in healthy Korean adults using one of the most recently available flow cytometry systems.

METHODS

This cross-sectional study included 249 adults (129 men and 120 women) with normal complete blood cell counts. The proportions of residual RBCs after exposure to hypotonic solution were measured at defined intervals using the BD FACSLyric system. Sex-specific differences were determined.

RESULTS

The reference intervals for the midpoint region for men and women were 16.49-19.61% (median: 18.24%) and 16.27-19.22% (18.18%), respectively, while those for the endpoint region were 7.00-15.21% (11.20%) and 5.58-15.16% (10.87%), respectively. The differences between the sexes and age groups were not statistically significant at either time point.

CONCLUSION

We established reference intervals for the flow cytometric OFT at the midpoint and endpoint time/forward scatter plot regions in a Korean population for the first time.