LIPID AND FATTY-ACID COMPOSITION IS ALTERED IN PLAQUE TISSUE FROM MULTIPLE-SCLEROSIS BRAIN COMPARED WITH NORMAL BRAIN WHITE MATTER

Plaques and white matter from brains of multiple sclerosis (MS) patients were analyzed for lipid content, class composition, and fatty acid composition of total lipid, together with the fatty acid composition of plaque glycerophospholipids, and the results were compared with white matter from normal brain. Plaques contained less than 30% of the lipid present in normal white matter. Plaque lipid was characterized by significantly increased proportions of glycerophospholipids and decreased cerebrosides and sulfatides. In addition, a subacute plaque contained approximately 10 times the proportion of steryl esters observed in chronic plaques or normal white matter. Total lipid from all the MS plaques showed significantly increased percentages of saturated fatty acids, n-6, n-3 and total polyunsaturated fatty acids and decreased percentages of monoenes and alk-1-enyl ethers in comparison with normal brains. These results were consistent with increased cellularity and astrogliosis associated with MS plaques. However, analysis of plaque glycerophospholipids showed that the fatty acid changes observed in total lipid were not simply due to the increased proportion of glycerophospholipids and decreased myelin lipids, but that the fatty acid composition of the individual glycerophospholipids was different.