Fatty acid composition of lymphocyte membrane phospholipids in children with acute leukemia

The composition of phospholipid fatty acids (PLFA) of separated mononuclear blood cells (MNC) from patients with leukemia was established by high-reso lution gas chromatography. Abnormal fatty acid concentrations are detected in the MNC membrane phospholipids in patients with acute lymphoblastic leuk emia (ALL) without a deficiency of essential fatty acids (EFA). Significant ly reduced relative levels of linoleic acid (4.35 vs. 7.82%; P < 0.001) are found in the MNC-PL in patients with ALL as compared to a healthy control group. Moreover, the Delta (6)-desaturated fatty acids are increased: gamma -linoleic acid (3.56 vs. 0.17%; P < 0.001), arachidonic acid (21.82 vs. 16. 27%; P < 0.05), docosatetraenoic acid (3.52 vs. 1.56%; P < 0.001), docosape ntaenoic acid (0.34 vs. 0.04% P < 0.001), octadecatetraenoic acid (0.53 vs. 0.23%; P < 0.05), eicosatetraenoic acid (1.83 vs. 0.08%; P < 0.001) and do cosahexaenoic acid (2.77 vs. 1.54%; P < 0.001). A increased Delta (6)-desat urase activity is postulated as the cause for the increased level of desatu rate products or the increased Delta (6)-activity index (Ratio of gamma-lin oleic acid + dihomogamma-linolenic acid to linoleic acid) (1.21 vs. 0.27; P < 0.001). The Delta (6)-enzyme activities measured using linoleic acid and alpha -linoleic acid as substrate underscore these findings (Delta (6) (n- 6); 2.49 vs. 0.65 and Delta (6)(n-3); 2.75 vs. 1.12 nmol X h(-1)/10(8) MNC) . In contrast, patients with acute myeloid leukemia (AML) do not show any s ignificant differences in the lymphocyte membrane PLFA and no Delta (6)-des aturase abnormalities. (C) 2001 Elsevier Science Ireland Ltd. All rights re served.