Comparison of classical and flowcytometric osmotic fragility and flowcytometric eosin-5-maleimide binding tests in diagnosis of hereditary spherocytosis

Abstract Objectives Hereditary spherocytosis (HS) is the most common congenital hemolytic anemia in Northern Europe and North America. Damaged or deficient proteins in the erythrocyte membrane cause the condition, leading to a decrease in the surface area and volume of erythrocytes. Specialists traditionally use the osmotic fragility test (C-OF) for diagnosis. Researchers have developed new methods for flow cytometry-based tests that are the eosin-5-maleimide binding (EMA) and osmotic fragility (FC-OF) tests. In this study, we aimed to determine and compare the power of discrimination of FC-OF, EMA, and C-OF tests. Another purpose is to investigate the effect of incubation. Methods We performed both real-time and incubated C-OF, EMA, and FC-OF on 20 patients diagnosed with HS and 30 healthy controls. We diagnosed HS based on family history, spherocytes, and clinical and lab findings. Results We found that the success of all tests in the classification was statistically significant (p<0.001). The discriminatory power of C-OF was not different from that of EMA and FC-OF. FC-OF discriminated better than EMA. Incubation increased C-OF performance and decreased EMA and FC-OF performance. Conclusions We think FC-OF should be preferred. Because it has higher discrimination power, specificity, and sensitivity. It gives faster results, costs less, and needs less labor. The lack of flow cytometer devices in every center is the biggest handicap of FC-OF and EMA. But we think that the FC-OF method can be adapted to hemogram devices available in every center in the future.