Recessive Dystrophic Epidermolysis Bullosa Wounds Research Articles

ABCB5+ mesenchymal stromal cells facilitate complete and durable wound closure in recessive dystrophic epidermolysis bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a hereditary, rare, devastating and life-threatening skin fragility disorder with a high unmet medical need. In a recent international, single-arm clinical trial, treatment of 16patients (aged 6-36years) with three intravenous infusions of 2×106immunomodulatory ABCB5+ dermal mesenchymal stromal cells (MSCs)/kg on days0, 17 and 35 reduced disease activity, itch and pain. A post-hoc analysis was undertaken to assess the potential effects of treatment with ABCB5+ MSCs on the overall skin wound healing in patients suffering from RDEB. Documentary photographs of the affected body regions taken on days0, 17, 35 and at 12weeks were evaluated regarding proportion, temporal course and durability of wound closure as well as development of new wounds. Of 168baseline wounds in 14patients, 109 (64.9%) wounds had closed at week12, of which 63.3% (69wounds) had closed already by day35 or day17. Conversely, 74.2% of the baseline wounds that had closed by day17 or day35 remained closed until week12. First-closure ratio within 12weeks was 75.6%. The median rate of newly developing wounds decreased significantly (P=0.001) by 79.3%. Comparison of the findings with published data from placebo arms and vehicle-treated wounds in controlled clinical trials suggests potential capability of ABCB5+ MSCs to facilitate wound closure, prolongate wound recurrence and decelerate formation of new wounds in RDEB. Beyond suggesting therapeutic efficacy for ABCB5+ MSCs, the analysis might stimulate researchers who develop therapies for RDEB and other skin fragility disorders to not only assess closure of preselected target wounds but pay attention to the patients' dynamic and diverse overall wound presentation as well as to the durability of achieved wound closure and the development of new wounds. Clinicaltrials.gov NCT03529877; EudraCT 2018-001009-98.

758 Assessing the natural history of recessive dystrophic epidermolysis bullosa wounds using a home photography app

Recessive dystrophic epidermolysis bullosa (RDEB) is a devastating, genetic, blistering condition caused by the absence of type VII collagen (C7) resulting in wounding. One major barrier to clinical trial development is the lack of understanding of the natural history of RDEB wounds, as the measurement of wound change has not been studied prospectively or validated. We conducted a longitudinal observational study of 13 participants with RDEB, that were not currently participating in interventional clinical trials.

273 Long-term efficacy and safety of investigational autologous gene-corrected skin sheets (EB-101) for recessive dystrophic epidermolysis bullosa (RDEB)

RDEB is a rare, severe dermatosis caused by mutations in type VII collagen (C7), a major component of structural attachments between the basement membrane and dermis. Manifestations include large, chronic wounds and blisters, increased squamous cell carcinoma (SCC) and early death. Currently, there are no approved therapies. We report long-term outcomes of a Phase 1/2a trial to treat large, chronic RDEB wounds with 35cm2 autologous skin sheets (EB-101) gene-corrected with a retroviral vector (RV).

T-cell activation and bacterial infection in skin wounds of recessive dystrophic epidermolysis bullosa patients.

Recessive dystrophic epidermolysis bullosa (RDEB) patients develop poorly healing skin wounds that are frequently colonized with microbiota. Because T cells play an important role in clearing such pathogens, we aimed to define the status of adaptive T cell‐mediated immunity in RDEB wounds. Using a non‐invasive approach for sampling of wound‐associated constituents, we evaluated microbial contaminants in cellular fraction and exudates obtained from RDED wounds. Infectivity and intracellular trafficking of inactivated Staphylococcus aureus was accessed in RDEB keratinocytes. S. aureus and microbial antigen‐specific activation of RDEB wound‐derived T cells were investigated by fluorescence‐activated cell sorting‐based immune‐phenotyping and T‐cell functional assays. We found that RDEB wounds and epithelial cells are most frequently infected with Staphylococcus sp. and Pseudomonas sp. and that S. aureus essentially infects more RDEB keratinocytes and RDEB‐derived squamous cell carcinoma cells than keratinocytes from healthy donors. The RDEB wound‐associated T cells contain populations of CD4+ and CD8+ peripheral memory T cells that respond to soluble microbial antigens by proliferating and secreting interferon gamma (IFNγ). Moreover, CD8+ cytotoxic T lymphocytes recognize S. aureus‐infected RDEB keratinocytes and respond by producing interleukin‐2 (IL‐2) and IFNγ and degranulating and cytotoxically killing infected cells. Prolonged exposure of RDEB‐derived T cells to microbial antigens in vitro does not trigger PD‐1‐mediated T‐cell exhaustion but induces differentiation of the CD4high population into CD4highCD25+FoxP3+ regulatory T cells. Our data demonstrated that adaptive T cell‐mediated immunity could clear infected cells from wound sites, but these effects might be inhibited by PD‐1/Treg‐mediated immuno‐suppression in RDEB.

Transcriptomic profiling of recessive dystrophic epidermolysis bullosa wounded skin highlights drug repurposing opportunities to improve wound healing.

Chronic wounds present a major disease burden in people with recessive dystrophic epidermolysis bullosa (RDEB), an inherited blistering skin disorder caused by mutations in COL7A1 encoding type VII collagen, the major component of anchoring fibrils at the dermal-epidermal junction. Treatment of RDEB wounds is mostly symptomatic, and there is considerable unmet need in trying to improve and accelerate wound healing. In this study, we defined transcriptomic profiles and gene pathways in RDEB wounds and compared these to intact skin in RDEB and healthy control subjects. We then used a reverse transcriptomics approach to discover drugs or compounds, which might restore RDEB wound profiles towards intact skin. Differential expression analysis identified >2000 differences between RDEB wounds and intact skin, with RDEB wounds displaying aberrant cytokine-cytokine interactions, Toll-like receptor signalling, and JAK-STAT signalling pathways. In-silico prediction for compounds that reverse gene expression signatures highlighted methotrexate as a leading candidate. Overall, this study provides insight into the molecular profiles of RDEB wounds and underscores the possible clinical value of reverse transcriptomics data analysis in RDEB, and the potential of this approach in discovering or repurposing drugs for other diseases.

LB812 Natural history of recessive dystrophic Epidermolysis Bullosa wounds using a home photography app

Recessive dystrophic epidermolysis bullosa (RDEB) is a devastating, genetic blistering condition caused by the absence of type VII collagen (C7), affecting the mucosa and skin. Patients often have recurrent and chronic open wounds, but one of the major barriers to the development of clinical trials is the lack of understanding of the natural history of RDEB wounds, as the measurement of target wound change has not been studied prospectively or validated. We conducted a longitudinal, clinical observational study of 10 patients with RDEB who used a mobile phone photography application, with built-in machine learning, to outline and track RDEB wounds autonomously.

Aberrant recruitment of leukocytes defines poor wound healing in patients with recessive dystrophic epidermolysis bullosa

BackgroundPoorly healing wounds are one of the major complications in patients suffering from recessive dystrophic epidermolysis bullosa (RDEB). At present, there are no effective means to analyze changes in cellular and molecular networks occurring during RDEB wound progression to predict wound outcome and design betted wound management approaches. ObjectivesTo better define mechanisms influencing RDEB wound progression by evaluating changes in molecular and cellular networks. MethodsWe developed a non-invasive approach for sampling and analysis of wound-associated constituents using wound-covering bandages. Cellular and molecular components from seventy-six samples collected from early, established and chronic RDEB wounds were evaluated by FACS-based immuno-phenotyping and ELISA. ResultsOur cross-sectional analysis determined that progression of RDEB wounds to chronic state is associated with the accumulation (up to 90 %) of CD16+CD66b+ mature neutrophils, loss of CD11b+CD68+ macrophages, and a significant increase (up to 50 %) in a number of CD11c+CD80+CD86+ activated professional antigen presenting cells (APC). It was also marked by changes in activated T cells populations including a reduction of CD45RO+ peripheral memory T cells from 80 % to 30 % and an increase (up to 70 %) in CD45RA+ effector T cells. Significantly higher levels of MMP9, VEGF-A and cathepsin G were also associated with advancing of wounds to poorly healing state. ConclusionsOur data demonstrated that wound-covering bandages are useful for a non-invasive sampling and analysis of wound-associated constituents and that transition to poorly healing wounds in RDEB patients as associated with distinct changes in leukocytic infiltrates, matrix-remodeling enzymes and pro-angiogenic factors at wound sites.

251 Natural history of wounds in patients with recessive dystrophic epidermolysis bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) patients suffer from recalcitrant, painful blistering and open wounds, however, a systematic natural history of RDEB wounds with patient reported outcomes such as pain and itch has not been conducted. We hypothesized that RDEB patients have 2 major types of wounds, chronic wounds, defined as those that stay open for ≥ 12 weeks, and recurrent wounds, which heal but reblister easily, and that these wounds differ in size, pain, and itch. Recruited from Stanford's EB clinic, 40 patients completed a questionnaire to evaluate the size, duration, and associated symptoms of chronic and recurrent wounds. To validate the accuracy of patients’ self-assessment, we also serially photographed, classified, and measured target wounds on 25 patients. In comparison, patients' self-assessments of wound type and size were moderately reliable (chronic/recurrent: 0.54, 95% CI 0.30-0.77; size: 0.52, 95% CI 0.27-0.70). Based on photographs taken over a mean of 37 weeks (2 – 153), we classified 24% of wounds as chronic and 76% as recurrent. Patients’ survey results indicated that 100% of patients’ recurrent wounds routinely close and reopen, closing within an average of 7 weeks and opening within an average of 5 weeks. Both survey results (N=40 patients) and photographs (N=25 patients) confirmed that chronic wounds were significantly larger than recurrent wounds (66.3 vs. 44.7 cm2, p=0.005). Chronic wounds were more painful than recurrent wounds (4.31 vs. 3.59, 0-10 Wong Baker FACES™ Pain Rating Scale, p=0.05). Chronic wounds were also itchier than recurrent ones (2.36 vs. 1.65, 0-4 Itch Man Scale, p=0.11). Within each wound type, larger size correlated with more pain and itch. These results confirm that there are 2 types of RDEB wounds with different size, pain, and itch traits, and that patients reliably assess wound type and size. Results from this natural history study further demonstrate that chronic and recurrent RDEB wounds have distinct clinical outcomes and clinical trial endpoints.

577 Successful allogeneic epidermal grafting of chronic recessive dystrophic epidermolysis bullosa wounds from hematopoietic cell donors in the outpatient setting

Chronic wounds, or non-healing epidermal erosions present >6 weeks, are common, contribute to morbidity, and lack definitive therapy in recessive dystrophic epidermolysis bullosa (RDEB). The immune tolerance established by allogeneic hematopoietic cell transplantation (HCT) permits adoptive transfer of donor epidermal grafts and establishment of induced mosaicism. In a prospective, open label clinical trial for post-HCT RDEB patients with stable peripheral blood donor chimerism of ≥5%, up to 3 chronic wounds were grafted. Epidermal skin grafts measuring 5 cm2 were obtained from related HCT donors in the outpatient setting using the CelluTomeTM Epidermal Harvesting System. Wound size was measured at baseline, 6, 12, and 52 weeks. Nine patients received a total of 23 epidermal grafts at a median of 1207 days (range 267-3111) post-HCT. The mean (±SD) percent reduction in wound surface area achieved was 61.8% (±31.3), 85.1% (±20.3), and 90.9% (±16.8), at 6, 12, and 52 weeks, respectively, each significantly reduced compared to baseline (p < 0.0001). Donor harvest sites healed quickly with no scarring, though mild hypopigmentation was noted in 5 of 9. Recipient reported benefits include absence of blistering, touch sensation equivalent to native skin, and normal temperature regulation at donor sites. Evaluation of one graft following completion of the study at 1 year revealed wild-type type VII collagen staining by immunofluorescence, normal ultrastructure including intact anchoring fibrils at the dermal-epidermal junction by electron microscopy, and full thickness skin whole DNA donor chimerism of 42% (compared to 16% in concurrently biopsied native skin). Persistence of the donor graft beyond 1 year and observed migration of donor-grafted cells into adjacent wound suggest the epidermal grafts include non-terminally differentiated cells.

Ternary Composite Nanofibers Containing Chondroitin Sulfate Scavenge Inflammatory Chemokines from Solution and Prohibit Squamous Cell Carcinoma Migration.

Recessive dystrophic epidermolysis bullosa (RDEB), an inherited disease featuring blistering wounds, causes constant inflammation that leads to the eventual development of an aggressive form of squamous cell carcinoma (RDEB SCC). The persistence of inflammatory chemokines such as MCP-1 and Il-8 in RDEB wounds may foster RDEB SCC carcinogenesis. We report the production of ternary composite nanofibers containing pullulan, chondroitin sulfate, and tannic acid as RDEB wound dressings. The swellable fibers are stable to hydration and absorb ∼500% their weight in water. The fibers remove ∼99% of MCP-1 from solution in <2 h. Scavenged media did not promote RDEB SCC migration.

Cultured allogeneic fibroblast injection vs. fibroblasts cultured on amniotic membrane scaffold for dystrophic epidermolysis bullosa treatment

Different methods of fibroblast application have been examined to treat recessive dystrophic epidermolysis bullosa (RDEB). To compare the effects of intradermal injection of cultured allogeneic fibroblasts in healing RDEB wounds with those of fibroblasts seeded on amniotic membrane scaffolds (FAMS) or standard wound care (SWC) with Vaseline® gauze as controls. Seven patients were recruited, and seven wounds were assessed in each patient: three wounds were treated with injection of intradermal fibroblasts, three were treated with FAMS and one was dressed with SWC. Changes in wound size were assessed after 2 and 12 weeks of treatment. Qualitative wound scores (QWS) were used to assess wound severity. Additionally, biopsies and antigen mapping were performed to detect type VII collagen in the dermoepidermal junction. In both treated areas, the QWS and wound size were significantly decreased (P < 0·001), whereas there were no changes in the control group (P = 0·29). After 2 and 12 weeks of treatment, the wound size was significantly decreased in wounds that were treated with fibroblast injection compared with those treated with FAMS (P < 0·001); but no significant changes were found in the control group. Fibroblast injection has been shown to promote healing of RDEB wounds and is superior to FAMS or the control treatment.

741 Reduced microbial diversity is a feature of recessive dystrophic epidermolysis bullosa wounds

741 Reduced microbial diversity is a feature of recessive dystrophic epidermolysis bullosa wounds

Fibroblast cell therapy enhances initial healing in recessive dystrophic epidermolysis bullosa wounds: results of a randomized, vehicle-controlled trial

Fibroblast cell therapy can modify disease biology in recessive dystrophic epidermolysis bullosa (RDEB) although whether it improves wound healing is not clear. To assess the effects of injecting of allogeneic fibroblasts into the margins of chronic erosions in individuals with RDEB in a prospective, double-blind, randomized, vehicle-controlled phase II trial. Erosions were randomized 1:1, to either a single treatment of 5 × 10(6) fibroblasts per linear cm of erosion margin or vehicle. All subjects continued standard wound care. The trial sponsor, participants and study outcome assessor were masked to treatment allocation. A hierarchy of endpoints germane to erosion closure was assessed. Twenty-six erosions in 11 subjects with RDEB were injected; 14 erosions received fibroblasts and 12 vehicle alone. A single series of injections was given at day 0 and all follow-up visits were completed. Treatment difference between fibroblasts and vehicle was -23.5% [95% confidence interval (CI) -3.5 to -43.5, P = 0.025] at day 7, -19.15% (95% CI 3.36 to -41.66, P = 0.089) at day 14 and -28.83% (95% CI 7.97 to -65.63, P = 0.11) at day 28. Beyond day 28, however, changes in mean erosion area did not differ significantly between the two groups. A single intradermal injection of allogeneic fibroblasts increases the initial rate of erosion healing in subjects with RDEB within the first 28 days but not thereafter. Further studies are needed to address the potential benefits of retreatment as well as optimal cell delivery.