Usefulness of Eosin-5’-Maleimide (EMA) Dye for the Diagnosis of Hereditary Spherocytosis

Abstract

Abstract Background the normal biconcave discoid shape of the red blood cell (RBC) is maintained by cytoskeletal proteins underneath the membrane. This protein network and its link with the lipid bilayer are essential for RBCs to remain flexible and carry out their physiological functions. A number of disorders including hereditary spherocytosis (HS) and hereditary elliptocytosis (HE) are caused by decreased expression or mutation of cytoskeletal proteins. Aim of the Work to evaluate the usefulness eosin-5-maleamide (EMA) dye binding flow cytometric test in the diagnosis of HS and assess the sensitivity and specificity of this test to distinguish HS patients from patients having anemia due to other causes. Subjects and Methods this study was conducted on 52 patients with chronic anemia, 21 diagnosed as HS (group I) and 31 patients with anemia due to other causes (group II). The patients were 28 males and 23 females with a male to female ratio 1.2:1, their ages ranged between 3 to 12.5 years old attending at the Pediatric Hematology Clinics, Ain Shams University Hospitals. Normal control group (group III) was included in the study. Results median fluorescence intensity (MFI) had shown significantly lower values in HS patients (group I) (3.78±0.48) than (iron deficiency anemia) IDA patients (group IIa) (5.56±0.35), auto immune hemolytic anemia (AIHA) patients (group IIb) (5.7±0.27), beta thalassemia intermedia (BTI) patients (group IIc) (6.01±0.63) and control group (group III) (5.3±0.43). The % reduction in EMA fluorescence proved to be significantly higher in HS patient (group I) (29.88±8.27) than in IDA patients (group IIa) (1.13±6.18), AIHA patients (-6.14±10.44) and BTI patients (group IIc) (-5.1±10.07). Multi regression analysis had been used to check the most sensitive predictors for diagnosis of HS, both EMA MFI and the % reduction in EMA fluorescence proved to be the best sensitive predictive values for discriminating HS patients, however the higher F-ratio in EMA MFI (F = 25.222) than in % reduction in EMA fluorescence intensity (F = 19.866) showed that the MFI is even better than % reduction in fluorescence in diagnosis of HS. Conclusion the present study highlighted the role of flow cytometric EMA binding test in differentiating HS patients from patients having anemia due to other causes.