GNPS Local and systemic changes in lipid profile as potential biomarkers for canine atopic dermatitis.

Lipids play a critical role in the skin as components of the epidermal barrier and as sig-naling molecules. Atopic dermatitis in dogs is associated with changes in the lipid composition of the skin, but whether these precede the onset of dermatitis or occur secondary to the dermatitis is unclear. We applied rapid lipid profiling mass spectrometry methods to skin and blood samples of dogs and determined changes following systemic treatment. Thirty control dogs and 30 atopic dogs with mild to moderate dermatitis were enrolled. Marked differences in lipid profiles were observed between control, nonlesional and lesional skin of dogs. Additionally, there were significant altera-tions in the lipid composition of the blood samples indicating systemic changes in lipid metabolism. Treatment with oclacitinib or lokivetmab resulted in a significant decrease of the disease clinical severity associated with changes in skin and blood lipids. A set of lipid features of the skin were selected as biomarkers that classified samples as control or atopic dermatitis with 95% accuracy, whereas blood lipids discriminated between control and atopic dogs with 82% accuracy. These data suggest that atopic dermatitis is a systemic disease and support the use of rapid lipid profiling to identify novel biomarkers.