A high resolution spatial transcriptomic atlas of korean atopic dermatitis

Summary: Abstract Body: Atopic dermatitis (AD) is a chronic skin disorder linked to a Th2-dominant immune response. Recent studies have identified Asian-specific AD phenotypes, but their findings are limited by small sample sizes and bulk RNA or single-cell sequencing. This underscores the need for atlas-scale immune phenotyping combining single-cell RNA sequencing and spatial transcriptomics. This study explores immune pathways in AD at single-cell resolution, focusing on fibroblasts in lesional and non-lesional skin, and analyzing blood samples to capture local and systemic immune changes. Standardized protocols were followed for skin biopsy and blood sample collection from pediatric, adult, and elderly patients, and healthy controls. A total of 41 skin and 46 blood samples, containing 210,000 and 380,000 cells, respectively, were analyzed. Single-cell RNA sequencing identified immune signatures linked to Asian AD endotypes, disease severity, and age-related differences. The baseline immune profile of the Asian AD phenotype shows a decrease in the Th1 axis and upregulation of the Th17 axis, with Th17 abundance increasing with age. This atlas will expand our understanding by unraveling new immunophenotypes of AD, contribute to precision medicine, and enable cross-disease comparisons. The atlas, incorporating datasets from Singapore and Japan, will be released in late 2025. Una Choi⁵, Hyunsung Nam⁴, Soyoung Jeong¹, Jung Ho Lee¹, Seung Min Cha¹, Hyun Jun Rha⁶, Jay W. Shin³, Hyun Je Kim^{2, 1} 1. Department of Microbiology and Immunology, Seoul National University, Seoul, Korea (the Republic of). 2. Department of Dermatology, Seoul National University Hospital, Jongno-gu, Seoul, Korea (the Republic of). 3. Genome Institute of Singapore, Singapore, Singapore. 4. Genomic Medicine Institute, Seoul National University, Seoul, Seoul, Korea (the Republic of). 5. College of Medicine, Inha University, Incheon, Korea (the Republic of). 6. Seoul National University College of Medicine, Seoul, Seoul, Korea (the Republic of). Bioinformatics, Computational Biology, and Imaging