Evidence of defective fattyacidome and aminoacidome in sebaceous and non
sebaceous skin surface in atopic dermatitis.
Background Atopic dermatitis (AD) is a composite disease
characterized by derangement of the skin permeability barrier (SPB),
altered immune defence, and dysbiosis. Little is known on the role
played by the sebaceous gland (SG) activity in the SPB integrity and in
the AD pathomechanisms. Objectives To investigate profiles of
sebaceous and epidermal free fatty acids (FFAs), squalene, cholesterol,
triglycerides (TGs), and wax esters (WEs) in sebum and stratum corneum
(SC) from seborrheic and non-seborrheic areas, in healthy subjects and
patients with AD. To simultaneously acquire aminoacidome in SC.
Methods In healthy controls and patients with AD, sebum and SC
were sampled consecutively from facial areas (forehead, and cheeks). SC
was sampled also from non sebaceous areas (arm) in healthy controls and
from the non lesional and lesional areas on the arm in AD. Sampling was
preceded by assessments of skin biophysics, i.e. TEWL and corneometry.
Results Disruption of the SBP was associated with decreased
levels of lipids of both sebaceous and epidermal type. Extent of lipid
derangement in the SG and the SC was correlated with the AD severity.
Relative composition of natural moisturizing factors was altered in the
SC of patients with AD. Conclusions The SG activity is
compromised in adult AD. Aminoacidome is deranged in the facial areas in
AD. Lipid signatures in association with aminoacidome, and skin physical
properties may serve the definition of phenotype clusters that associate
with AD severity.