title: Using the eosin-5-maleimide binding test in the differential diagnosis of hereditary spherocytosis and hereditary pyropoikilocytosis.
abstract: BACKGROUND
  Flow cytometric analysis of eosin-5-maleimide (EMA)-labeled red blood cells (RBCs) has been used as a screening test for the diagnosis of patients with hereditary spherocytosis (HS). We assessed the fluorescence profiles for patients having HS and hereditary pyropoikilocytosis (HPP) together with their red cell indices.
  
  
  METHODS
  Flow cytometry was used to analyze EMA-labeled RBCs. Membrane protein defects and spectrin variants were identified by SDS-polyacrylamide gel electrophoresis.
  
  
  RESULTS
  An overlay of single fluorescence peaks for normal individuals, and those with HS and HPP revealed a graded fluorescence intensity (normal > HS > HPP). The area under each peak defined a specific RBC subpopulation; namely, normal RBCs, spherocytes, and microspherocytes. HS RBCs having a gross reduction in band 3 or spectrin content gave fluorescence readings almost as low as those for HPP. Complex fluorescence profiles were obtained for isolated HS and HPP cases.
  
  
  CONCLUSIONS
  The mean cell volume is a useful discriminator for HS and HPP. We presented evidence that a mixed RBC population could occur in some HS and HPP patients, either in a transient manner or for a long-term period. A differential diagnostic scheme for detecting HPP and HS by flow cytometry is proposed.
authors.affiliation: Membrane Biochemistry, International Blood Group Reference Laboratory, Bristol, United Kingdom. may-jean.king@nbs.nhs.uk
authors.forename: May-Jean
authors.initials: MJ
authors.lastname: King
authors.forename: Paul
authors.initials: P
authors.lastname: Telfer
authors.forename: Heather
authors.initials: H
authors.lastname: MacKinnon
authors.forename: Lisa
authors.initials: L
authors.lastname: Langabeer
authors.forename: Corrina
authors.initials: C
authors.lastname: McMahon
authors.forename: Philip
authors.initials: P
authors.lastname: Darbyshire
authors.forename: Didier
authors.initials: D
authors.lastname: Dhermy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000745:Anemia, Hemolytic, Congenital / Q000097:blood / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004801:Eosine Yellowish-(YS) / Q000031:analogs & derivatives* / Q000378:metabolism; D004910:Erythrocyte Membrane / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D004913:Erythrocytes, Abnormal; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D013049:Spectrin / Q000235:genetics / Q000378:metabolism; D013103:Spherocytosis, Hereditary / Q000097:blood / Q000175:diagnosis*
chemical_list: D013049:Spectrin; C033531:eosin maleimide; D004801:Eosine Yellowish-(YS)