Abnormalities of erythrocyte membranes in biliary atresia: ultrastructure and lipid composition

Biochemical and ultrastructural studies of red blood cell membranes from seven patients with congenital biliary atresia have been performed. Scanning electron microscopic observations revealed that more than half of these cells were of abnormal shapes, such as target, spur and cup-formed cells. By freeze-fracture electron microscopy, membrane particle-free smooth areas were noted in the fracture faces. In addition, the number of membrane-associated particles was 20% less than those in control subjects. The lipid analysis of red blood cells showed a significant increase in phospholipid and a marked increase in cholesterol content. The increase of phospholipid content was primarily caused by the increase of lecithin. The acyl chain analysis of erythrocyte lecithin demonstrated an increase in palmitic, palmitoleic and oleic acid, and a decrease in stearic and linoleic acid. These observations are similar to those of acquired biliary obstruction. The fluidity of erythrocyte membrane lipid, studied by a fluorescence technique using fluorescent probe 1,6-diphenyl-1,3,5-hexatriene (DPH), was found to be less in an individual with congenital biliary atresia than in the control subject.