RESUMO
BACKGROUND: Red cell membrane is a lipid bilayer laminated by the membrane cytoskeleton at the surface of inner monolayer. A class of hemolytic anemia, such as hereditary spherocytosis (HS) or hereditary elliptocytosis (HE) is mainly caused by the abnormalities of the protein components in the cytoskeleton, which is useful to diagnosis each disorder. We investigated red cell membrane protein defects in HS and HE using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). METHODS: We studied 10 normal healthy volunteers, 27 HS cases and 5 HE cases. Erythrocyte membrane proteins were prepared by hypotonic lysis, and fractionated by SDS-PAGE using both the Fairbanks system (3.5~17% exponential gradient gel), and the Laemmli system (4~17% linear gradient gel). Fractionated proteins were stained with Coomassie brilliant blue and scanned to quantitate each protein using a densitometer. RESULTS: We detected nine peaks in Fairbanks' gel and eight peaks in Laemmli's. We identified red cell membrane abnormalities in 18 of 27 HS patients (66.7%) : Spectrin deficiency alone was in 7.4% of HS cases (2/27), ankyrin deficiency alone in 29.6% (8/27), combined spectrin and ankyrin deficiency in 3.7% (1/27), band 3 deficiency in 11.1% (3/27) and protein 4.2 deficiency in 14.8% (4/27). In HE, three of five cases showed protein 4.1 deficiency. RBC membrane protein deficiencies were not observed in nine HS cases and two HE case. CONCLUSION: In HS, Ankyrin deficiency is the most common RBC membrane protein abnor mality, and protein 4.2 deficiency is more frequently found in Korean HS patients than in Caucasians. In HE patients, protein 4.1 deficiencies is the main red cell membrane protein defect, which is rarely reported in Caucasians.