Dermatologists can now use single cell technology to diagnose even hard-to-identify skin conditions.
Precision medicine has been used in fields such as oncology for over two decades but is yet to be widely used in dermatological settings.  A newly published proof-of-concept study has shown that single-cell sequencing can distinguish between two common inflammatory skin diseases: atopic dermatitis (AD) and plaque psoriasis.  With drug therapies for these diseases targeting dysregulated pathways specific to the disease, it is key to provide a correct diagnosis, which can be challenging through clinical observations and histology.
Along with healthy control tissue, the study utilized biopsies from patients diagnosed with plaque psoriasis (eight samples) and AD (seven samples), as well as biopsies from six patients with indeterminate rashes. Having isolated cutaneous immune cells, T cells and antigen-presenting cells (APCs) were profiled with single-cell RNA sequencing (scRNA-seq) using 10X Genomics technology.
Skin-resident memory T cells (Trm) are key to the findings, with many genes newly shown to be differentially dysregulated in psoriasis and AD. “By employing a very high-resolution single-cell discovery technology, we expanded the number of known psoriasis-specific genetic abnormalities in this cell population about 10-fold,” said Dr. Jeffrey B. Cheng, co-corresponding author, Department of Dermatology, University of California, San Francisco.
“Interestingly, many of the genes that have been reported as related to psoriatic disease are also abnormal in many other inflammatory skin diseases,” said Dr. Cheng. But now with the identification of these psoriasis-specific genetic abnormalities, the 10X Genomics scRNA-seq technology can be used to distinguish between psoriasis and AD, even in difficult to diagnose cases.