BLOOD POLYUNSATURATED FATTY-ACIDS IN PATIENTS WITH PEROXISOMAL DISORDERS - A MULTICENTER STUDY

The purpose of the study was to compare the polyunsaturated fatty acid (PUFA) status in patients with X-linked adrenoleukodystrophy or adren omyeloneuropathy (X-ALD/AMN) with that in disorders of peroxisome biog enesis (PB). Total fatty acids and plasmalogens were quantified in pla sma and red cells from 28 patients with X-ALD/AMN, 26 patients with ge neralized peroxisomal disorders, and 37 controls. Total fatty acid met hyl esters and plasmalogen dimethyl acetals were obtained by direct tr ansmethylation and separated by capillary column gas chromatography. T he results confirm previous findings in that docosahexaenoic acid (DHA , 22:6n-3) was greatly decreased in both plasma and erythrocytes from patients with PB disorders. When nutritional conditions were adequate, patients with X-ALD/AMN had normal levels of DHA, A highly significan t positive correlation was found between the levels of DHA and those o f plasmalogens in peroxisomal patients. As in other tissues, the paren t n-6 fatty acid, linoleic acid (LA, 18:2n-6) was significantly increa sed in red cells from PB patients, whereas arachidonic acid (20:4n-6) was virtually within normal limits. in clear contrast to red cells and other tissues, arachidonate was significantly lower in plasma from PB patients. The decrease in plasma arachidonate and the high tissue lev els of LA suggest a defect of Delta 6 desaturase and/or Delta 5 desatu rase in PB patients. The n-6 fatty acids were normal in X-ALD/AMN pati ents. The present data show that X-ALD/AMN patients do not have the pr ofound PUFA alterations that PB patients have, at least in blood.