Increased FADS2-derived n-6 PUFAs and reduced n-3 PUFAs in plasma of atopic dermatitis patients.

Fatty acid concentrations, in particular n-3 and n-6 polyunsaturated fatty acids (PUFAs), have been described to be dysregulated in atopic dermatitis (AD) patients. The role of genetic polymorphisms of fatty acid enzymes in AD is controversial. We determined in a Hungarian cohort of healthy volunteers (n = 20) and AD patients (n = 20) triglyceride-, sterol- and phospholipid-bound fatty acids in the plasma, mRNA expression of fatty acid desaturase 2 (FADS2) and stearoyl-coenzyme A desaturase 1 in peripheral blood mononuclear cells (PBMCs) and FADS2 concentrations in plasma. We observed higher levels of monounsaturated fatty acids, 16:1 versus 16:0 ratios in phospholipids, triglycerides and sterol esters in patients compared to healthy subjects. In addition higher levels of the FADS2-derived n-6 PUFAs γ-linolenic acid and dihomo-γ-linolenic acid were observed in PBMCs of patients as well as lower levels of n-3 PUFAs. We conclude that the increased expression of FADS2 in PBMCs, as a representative tissue accessible from human blood of AD patients, might be responsible for higher levels of FADS2-derived n-6 PUFAs and lower n-3 PUFA levels in patients.