Monohydroxylated fatty acid content in peripheral blood mononuclear cells and immune status of people at long times after the Chernobyl accident

The monohydroxylated fatty acid content of peripheral blood mononuclear cel ls from 23 cleanup workers and 16 unexposed individuals was studied in rela tion to their immune status after the Chernobyl accident. Men with absorbed doses below 0.32 Gy showed higher levels of free and esterified 12-hydroxy eicosatetraenoic acid (12-HETE) than unexposed men, whereas 15-HETE and the 17-hydroxy derivative of C22 fatty acid (17-OH 22), either free or esterif ied in phospholipids, were increased in a dose-dependent manner. The percen tage of CD4-positive cells was also increased significantly in heavily irra diated men, whereas the percentage of CD8-positive cells tended to decrease with dose. Furthermore, the absolute count of CD4-positive cells was corre lated positively with the amount of esterified 15-HETE in the phospholipid fraction of the mononuclear cells and with the total 15-HETE. These results show for the first time that the accumulation of autoxidized/lipoxygenase products of polyunsaturated fatty acids in the mononuclear cells of irradia ted individuals was associated with immune imbalance. This may be the basis for certain late effects of radiation such as autoimmune disorders, somati c and neoplastic diseases, and early aging. (C) 2001 by Radiation Research Society.