Dominant dystrophic epidermolysis bullosa is associated with glycolytically active GATA3+ Th2 cells which may contribute to pruritus in lesional skin.

BACKGROUND: Dominant dystrophic epidermolysis bullosa (DDEB) is characterized by trauma-induced blisters and, in some individuals, intense pruritus. Precisely what causes itch in DDEB and optimal ways to reduce it have not been fully determined. OBJECTIVE: To characterize DDEB skin transcriptomes to identify therapeutic targets to reduce pruritus in patients. METHODS: We evaluated affected and unaffected skin biopsy samples from 6 DDEB subjects (all with the very itchy pruriginosa subtype), and 4 healthy individuals using bulk RNA-seq. Single-cell transcriptomes of affected (n=2) and unaffected (n=1) DDEB and healthy skin (n=2) were obtained. Dupilumab treatment was provided for three patients. RESULTS: The skin bulk transcriptome showed significant enrichment of Th1/2 and Th17 pathways in affected DDEB skin compared with non-lesional DDEB and healthy skin. Single-cell transcriptomics showed an association of glycolytically active GATA3+ Th2 cells in affected DDEB skin. Treatment with dupilumab in three people with DDEB led to significantly reduced VAS itch scores after 12 weeks (mean VAS=3.83) compared to pre-treatment (mean VAS=7.83). Bulk RNA-seq and qPCR showed that healthy skin and dupilumab-treated epidermolysis bullosa (EB) pruriginosa skin show very similar transcriptomic profiles, and reduced Th1/2 and Th17 pathway enrichment. CONCLUSIONS: Single-cell RNA-seq helps define an enhanced DDEB-associated Th2 profile and rationalizes drug repurposing of anti-Th2 drugs in treating DDEB pruritus.

Itch in recessive dystrophic epidermolysis bullosa: findings of PEBLES, a prospective register study.

BACKGROUND: Itch is common and distressing in epidermolysis bullosa (EB) but has not previously been studied in depth in different recessive dystrophic EB (RDEB) subtypes. OBJECTIVES: As part of a prospective register study of the natural history of RDEB we explored features of itch, medications used, and correlation with disease severity and quality of life. METHODS: Fifty individuals with RDEB aged 8 years and above completed the Leuven Itch Scale (LIS) (total 243 reviews over a 7-year period). Data included itch frequency, severity, duration, distress, circumstances, consequences, itch surface area and medications for itch. The iscorEB disease severity score and the validated EB quality of life tool, QOLEB, were compared to LIS domains and analysed by RDEB subtype. RESULTS: Itch was frequent, present in the preceding month in 93% of reviews. Itch severity and distress were significantly greater in severe (RDEB-S) and pruriginosa (RDEB-Pru) subtypes compared to intermediate RDEB (RDEB-I). Itch medications were reported in just over half of reviews including emollients, topical corticosteroids and antihistamines; the proportion of participants not using medication despite frequent pruritus suggests limited efficacy. In inversa RDEB (RDEB-Inv) and RDEB-I, LIS domains correlated with iscorEB and QOLEB. In contrast to previous studies, correlations were lacking in RDEB-S suggesting that global disease burden relatively reduces the contribution of itch. CONCLUSIONS: This comprehensive study of RDEB-associated itch highlights differences between RDEB subtypes, suggests an unmet need for effective treatments and could serve as control data for future clinical trials incorporating itch as an endpoint.