Unravelling morphoea aetiopathogenesis by next-generation sequencing of paired skin biopsies

BACKGROUND

Morphoea can have a significant disease burden. Aetiopathogenesis remains poorly understood, with very limited existing genetic studies. Linear morphoea (LM) may follow Blascho's lines of epidermal development, providing potential pathogenic clues.

OBJECTIVE

The first objective of this study was to identify the presence of primary somatic epidermal mosaicism in LM. The second objective was tTo explore differential gene expression in morphoea epidermis and dermis to identify potential pathogenic molecular pathways and tissue layer cross-talk.

METHODOLOGY

Skin biopsies from paired affected and contralateral unaffected skin were taken from 16 patients with LM. Epidermis and dermis were isolated using a 2-step chemical-physical separation protocol. Whole Genome Sequencing (WGS; n = 4 epidermal) and RNA-seq (n = 5-epidermal, n = 5-dermal) with gene expression analysis via GSEA-MSigDBv6.3 and PANTHER-v14.1 pathway analyses, were performed. RTqPCR and immunohistochemistry were used to replicate key results.

RESULTS

Sixteen participants (93.8% female, mean age 27.7 yrs disease-onset) were included. Epidermal WGS identified no single affected gene or SNV. However, many potential disease-relevant pathogenic variants were present, including ADAMTSL1 and ADAMTS16. A highly proliferative, inflammatory and profibrotic epidermis was seen, with significantly-overexpressed TNFα-via-NFkB, TGFβ, IL6/JAKSTAT and IFN-signaling, apoptosis, p53 and KRAS-responses. Upregulated IFI27 and downregulated LAMA4 potentially represent initiating epidermal 'damage' signals and enhanced epidermal-dermal communication. Morphoea dermis exhibited significant profibrotic, B-cell and IFN-signatures, and upregulated morphogenic patterning pathways such as Wnt.

CONCLUSION

This study supports the absence of somatic epidermal mosaicism in LM, and identifies potential disease-driving epidermal mechanisms, epidermal-dermal interactions and disease-specific dermal differential-gene-expression in morphoea. We propose a potential molecular narrative for morphoea aetiopathogenesis which could help guide future targeted studies and therapies.

Social/economic costs and health-related quality of life in patients with scleroderma in Europe

OBJECTIVE

The aim of this study was to determine the economic burden from a societal perspective and the health-related quality of life (HRQOL) of patients with systemic sclerosis (SSc; scleroderma) in Europe.

METHODS

We conducted a cross-sectional study of patients with SSc (involving both localised and systemic sclerosis) from Germany, Italy, Spain, France, the UK, Hungary and Sweden. Data on demographic characteristics, healthcare resource utilisation, informal care, labour productivity losses and HRQOL were collected from the questionnaires completed by patients or their caregivers. HRQOL was measured with the EuroQol 5-domain (EQ-5D) questionnaire.

RESULTS

A total of 589 patients completed the questionnaire. The rate of patients with localised scleroderma, limited cutan and diffuse cutan SSc were 28, 68 and 4 %, respectively. Average annual costs varied from country to country and ranged from € 4607 to € 30,797 (reference year: 2012). Estimated direct healthcare costs ranged from € 1413 to € 17,300; direct non-healthcare costs ranged from € 1875 to € 4684 and labour productivity losses ranged from € 1701 to € 14,444. The mean EQ-5D index score for adult SSc patients varied from 0.49 to 0.75 and the mean EQ-5D visual analogue scale score was between 58.72 and 65.86.

CONCLUSION

The main strengths of this study lie in our bottom-up approach to costing and our evaluation of SSs patients from a broad societal perspective. This type of analysis is very unusual in the international literature on rare diseases in comparison with other illnesses. We concluded that SSc patients incur considerable societal costs and experience substantial deterioration in HRQOL.