Using tape-stripping researchers from Mount Sinai School of Medicine, New York, have identified a single gene biomarker that accurately distinguishes atopic eczema from psoriasis.
The team evaluated the tape strips from both normal and lesional skin in 20 adults with either moderate to severe eczema and psoriasis or healthy controls and subjected the samples to RNA sequencing for analysis. The results showed huge differences in the genes expressed in lesional compared to normal skin for both diseases. For instance, in eczema patients, there were 4123 differentially expressed genes (DEGs) in lesional skin compared to 1498 DEGs in normal skin. Similarly, there were 5390 DEGs in lesional skin compared to 1135 in normal skin. There were also importance differences related to expression of immune system T cells with eczema patient samples showing a skewing towards T-2 helper cells and psoriasis samples, T-17 helper cells. In addition, there were differences in gene expression related to epidermal barrier function which also allowed for a distinction between the two skin conditions.
However, more relevant was the finding that nitric oxide synthetase2 was a single gene biomarker that distinguished between the conditions. The gene produces nitrous oxide subsequent to stimulation by pro-inflammatory cytokines and was only present in psoriasis.
They concluded that as a minimally invasive approach, tape-stripping can be used to monitor biomarkers of disease activity in clinical trials.
He H et al. Tape strips detect distinct immune and barrier profiles in atopic dermatitis and psoriasis. J Allergy Clin Immunol 2020; doi.org/10.1016/j.jaci.2020.05.048.