T cells plays important role in the pathogenesis of severe cutaneous adverse drug reactions (SCARs), such as DIHS/DRESS. Drug-specific T cells are found in both the peripheral blood and the affected skin. However, characteristics of T cell receptor (TCR) repertoire in DIHS/DRESS lesions remain unclear. Furthermore, involvement of resident memory T cells (TRMs) in the development of DIHS/DRESS has not been fully investigated. To address these issues, we analyzed T cell receptor (TCR) repertoire of the skin-infiltrating T cells in the skin lesions of DIHS/DRESS (n =7). For comparison, TCR repertoire in SJS/TEN lesions were analyzed (n = 8). Skin T cells were expanded in vitro using IL-2 and anti-CD3/CD28 mAbs, and the TCR Vbeta usage was assessed by flowcytometry. The diversity was analyzed by diversity index and relative abundance curve. We also investigated the characteristics of CD8+CD103+ TRMs in each lesion. In all the cases, skin-infiltrating T cells showed skewed TCR Vbeta usage with several prominent peaks. In DIHS/DRESS, CD4+ T cells showed highly skewed TCR usages and the diversity indexes of CD4+ T cells were lower than those of CD8+ T cells although not statistically significant. In the SJS/TEN, the TCR usages were skewed more in CD8+ T cells than in CD4+ T cells and the diversity indexes of CD8+ T cells were significantly lower than those of CD4+ T cells (P=0.018). Whereas, CD8+CD103+ T cell population was increased in DIHS/DRESS skin compared with SJS/TEN skin. CD8+CD103+ T cell population in DIHS/DRESS showed a lower diversity index of TCR Vbeta than that of conventional CD8+ T cells and produced Th2-shifted cytokines, suggesting that it was a unique population. Taken together, these results suggest that CD8+CD103+ TRMs and possibly CD4+ T cells in DIHS/DRESS show highly skewed TCR Vbeta usage, and may be involved in the development of DIHS/DRESS.

ESDR095 - CD8+CD103+ resident memory T cells with skewed TCR Vbeta usage infiltrate in the skin lesion of DIHS/DRESS

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.