Abnormal phospholipid molecular species of erythrocytes in sickle cell anemia

h the lipid composition of cell membranes has sig- nificant effects upon cellular function, we hypothesized that the membranes of sickle cells might have a distorted lipid composition. Accordingly, we analyzed the molecular species of the choline and ethanolamine glycerophospholipids, the fatty acid composition of the total phospholipids and of the five major individual phospholipids of erythrocytes from 8 pa- tients with sickle cell anemia and from 14 normal suhjects. Of the 31 molecular species identified for each subclass of the glycerophospholipids, 12 were found to be distinctly abnoi-- mal. Sickle cells contained more molecular species with satu- rated and monounsaturated fatty acid at the sn-2 position and fewer molecular species with polyunsaturated Fatty acids at the sn-2 position. The values ranged from 20 to 60% above or below normal values. In diacyl choline glycerophospholipids (outer membrane leaflet), sickle erythrocytes containrd lower amounts of the l6:O-18:2 species and higher 16:0-18:1 and 16:0-16:0 species. In diacyl ethanolamine glycerophos- pholipid (inner membrane leaflet), sickle erythrocytes had lower amounts of 18:0-'22:6; 16:O-22:4; 18:O-18:2; 18: 1-18:2; and 18:l-203. In phosphatidylcholine and phosphatidyletha- nolamine, sickle erythrocytes contained less linoleic acid, less docosahexaenoic acid (30-40%) and more oleic and palmitic acids (20-30%) compared to normal erythrocytes. These same differences were seen also in the total phospho1ipids.l Our data demonstrated distinct abnormalities of the phos- pholipid molecular species composition in the menibraiie lip- ids of sickle erythrocytes. These defects might have a role in one or more known metabolic abnormalities of sickle cell dis- ease including cation imbalance, dehydration, disturbed membrane phospholipid asymmetry, and hypercoagulability. Furthermore, detailed information of the phospholipid mo- lecular species composition of normal erythrocytes was pro- vided.-Connor, w. E., D. s. Lin, G. Thomas, E Ey, T. De- Loughery, and N. Zhu. Abnormal phospholipid molecular species of erythrocytes in sickle cell anemia. ,J Z.ipid Re.\. 1997. 38: 2516-2528.