Functional genotype-phenotype associations in recessive dystrophic epidermolysis bullosa.

BACKGROUND: Genotype-phenotype associations in recessive dystrophic epidermolysis bullosa (RDEB) have been difficult to elucidate. OBJECTIVE: To investigate RDEB genotype-phenotype associations and explore a functional approach to genotype classification. METHODS: Clinical examination and genetic testing of RDEB subjects, including assessment of clinical disease by RDEB subtype and extent of blistering. Genotypes were evaluated according to each variant's effect on type VII collagen function per updated literature and subsequently categorized by degree of impact on VII collagen function as low-impact (splice/missense, missense/missense), medium-impact (premature termination codon [PTC]/missense, splice/splice), and high-impact (PTC/PTC, PTC/splice). Genotype-phenotype associations were investigated using Kruskal-Wallis and Fisher's exact tests, and age-adjusted regressions. RESULTS: Eighty-three participants were included. High-impact variants were associated with worse RDEB subtype and clinical disease, including increased prevalence of generalized blistering (55.6% for low-impact vs 72.7% medium-impact vs 90.4% high-impact variants, P = .002). In age-adjusted regressions, participants with high-impact variants had 40.8-fold greater odds of squamous cell carcinoma compared to low-impact variants (P = .02), and 5.7-fold greater odds of death compared to medium-impact variants (P = .05). LIMITATIONS: Cross-sectional design. CONCLUSION: Functional genotype categories may stratify RDEB severity; high-impact variants correlated with worse clinical outcomes. Further validation in larger cohorts is needed.

Incidence of Nonkeratinocyte Skin Cancer After Breast Cancer Radiation Therapy.

Importance: Previous studies have suggested that radiation therapy may contribute to an increased risk of subsequent nonkeratinocyte (ie, not squamous and basal cell) skin cancers. Objective: To test the hypothesis that radiation therapy for breast cancer increases the risk of subsequent nonkeratinocyte skin cancers, particularly when these cancers are localized to the skin of the breast or trunk. Design, Setting, and Participants: This population-based cohort study used longitudinal data from the Surveillance, Epidemiology, and End Results (SEER) Program for January 1, 2000, to December 31, 2019. The SEER database includes population-based cohort data from 17 registries. Patients with newly diagnosed breast cancer were identified and were evaluated for subsequent nonkeratinocyte skin cancer development. Data analysis was performed from January to August 2023. Exposures: Radiation therapy, chemotherapy, or surgery for breast cancer. Main Outcomes and Measures: The primary outcomes were standardized incidence ratios (SIRs) for subsequent nonkeratinocyte skin cancer development from 2000 to 2019 based on treatment type (radiation therapy, chemotherapy, or surgery), skin cancer site on the body, and skin cancer subtype. Results: Among the 875 880 patients with newly diagnosed breast cancer included in this study, 99.3% were women, 51.6% were aged older than 60 years, and 50.3% received radiation therapy. A total of 11.2% patients identified as Hispanic, 10.1% identified as non-Hispanic Black, and 69.5% identified as non-Hispanic White. From 2000 to 2019, there were 3839 patients with nonkeratinocyte skin cancer, including melanoma (3419 [89.1%]), Merkel cell carcinoma (121 [3.2%]), hemangiosarcoma (104 [2.7%]), and 32 other nonkeratinocyte skin cancers (195 [5.1%]), documented to occur after breast cancer treatment. The risk of nonkeratinocyte skin cancer diagnosis after breast cancer treatment with radiation was 57% higher (SIR, 1.57 [95% CI, 1.45-1.7]) than that of the general population when considering the most relevant site: the skin of the breast or trunk. When risk at this site was stratified by skin cancer subtype, the SIRs for melanoma and hemangiosarcoma were both statistically significant at 1.37 (95% CI, 1.25-1.49) and 27.11 (95% CI, 21.6-33.61), respectively. Receipt of radiation therapy was associated with a greater risk of nonkeratinocyte skin cancer compared with chemotherapy and surgical interventions. Conclusions and Relevance: In this study of patients with breast cancer, an increased risk of melanoma and hemangiosarcoma after breast cancer treatment with radiation therapy was observed. Although occurrences of nonkeratinocyte skin cancers are rare, physicians should be aware of this elevated risk to help inform follow-up care.

Advances in cutaneous squamous cell carcinoma.

Human malignancies arise predominantly in tissues of epithelial origin, where the stepwise transformation from healthy epithelium to premalignant dysplasia to invasive neoplasia involves sequential dysregulation of biological networks that govern essential functions of epithelial homeostasis. Cutaneous squamous cell carcinoma (cSCC) is a prototype epithelial malignancy, often with a high tumour mutational burden. A plethora of risk genes, dominated by UV-induced sun damage, drive disease progression in conjunction with stromal interactions and local immunomodulation, enabling continuous tumour growth. Recent studies have identified subpopulations of SCC cells that specifically interact with the tumour microenvironment. These advances, along with increased knowledge of the impact of germline genetics and somatic mutations on cSCC development, have led to a greater appreciation of the complexity of skin cancer pathogenesis and have enabled progress in neoadjuvant immunotherapy, which has improved pathological complete response rates. Although measures for the prevention and therapeutic management of cSCC are associated with clinical benefit, the prognosis remains poor for advanced disease. Elucidating how the genetic mechanisms that drive cSCC interact with the tumour microenvironment is a current focus in efforts to understand, prevent and treat cSCC.

A scalable, GMP-compatible, autologous organotypic cell therapy for Dystrophic Epidermolysis Bullosa.

Background: Gene editing in induced pluripotent stem (iPS) cells has been hailed to enable new cell therapies for various monogenetic diseases including dystrophic epidermolysis bullosa (DEB). However, manufacturing, efficacy and safety roadblocks have limited the development of genetically corrected, autologous iPS cell-based therapies. Methods: We developed Dystrophic Epidermolysis Bullosa Cell Therapy (DEBCT), a new generation GMP-compatible (cGMP), reproducible, and scalable platform to produce autologous clinical-grade iPS cell-derived organotypic induced skin composite (iSC) grafts to treat incurable wounds of patients lacking type VII collagen (C7). DEBCT uses a combined high-efficiency reprogramming and CRISPR-based genetic correction single step to generate genome scar-free, COL7A1 corrected clonal iPS cells from primary patient fibroblasts. Validated iPS cells are converted into epidermal, dermal and melanocyte progenitors with a novel 2D organoid differentiation protocol, followed by CD49f enrichment and expansion to minimize maturation heterogeneity. iSC product characterization by single cell transcriptomics was followed by mouse xenografting for disease correcting activity at 1 month and toxicology analysis at 1-6 months. Culture-acquired mutations, potential CRISPR-off targets, and cancer-driver variants were evaluated by targeted and whole genome sequencing. Findings: iPS cell-derived iSC grafts were reproducibly generated from four recessive DEB patients with different pathogenic mutations. Organotypic iSC grafts onto immune-compromised mice developed into stable stratified skin with functional C7 restoration. Single cell transcriptomic characterization of iSCs revealed prominent holoclone stem cell signatures in keratinocytes and the recently described Gibbin-dependent signature in dermal fibroblasts. The latter correlated with enhanced graftability. Multiple orthogonal sequencing and subsequent computational approaches identified random and non-oncogenic mutations introduced by the manufacturing process. Toxicology revealed no detectable tumors after 3-6 months in DEBCT-treated mice. Interpretation: DEBCT successfully overcomes previous roadblocks and represents a robust, scalable, and safe cGMP manufacturing platform for production of a CRISPR-corrected autologous organotypic skin graft to heal DEB patient wounds.

LY6D marks pre-existing resistant basosquamous tumor subpopulations.

Improved response to canonical therapies requires a mechanistic understanding of dynamic tumor heterogeneity by identifying discrete cellular populations with enhanced cellular plasticity. We have previously demonstrated distinct resistance mechanisms in skin basal cell carcinomas, but a comprehensive understanding of the cellular states and markers associated with these populations remains poorly understood. Here we identify a pre-existing resistant cellular population in naive basal cell carcinoma tumors marked by the surface marker LY6D. LY6D+ tumor cells are spatially localized and possess basal cell carcinoma and squamous cell carcinoma-like features. Using computational tools, organoids, and spatial tools, we show that LY6D+ basosquamous cells represent a persister population lying on a central node along the skin lineage-associated spectrum of epithelial states with local environmental and applied therapies determining the kinetics of accumulation. Surprisingly, LY6D+ basosquamous populations exist in many epithelial tumors, such as pancreatic adenocarcinomas, which have poor outcomes. Overall, our results identify the resistant LY6D+ basosquamous population as an important clinical target and suggest strategies for future therapeutic approaches to target them.

Long-term safety and efficacy of gene-corrected autologous keratinocyte grafts for recessive dystrophic epidermolysis bullosa.

BACKGROUND: Recessive dystrophic epidermolysis bullosa (RDEB) is a rare, devastating blistering genodermatosis caused by mutations in the COL7A1 gene, which encodes for type VII collagen and is necessary for dermal-epidermal adhesion and integrity. Disease manifestations include severe and debilitating wounds, aggressive squamous cell carcinomas, and premature death; however, there are currently no approved therapies. This Phase 1/2a, open-label study evaluated the long-term efficacy and safety of gene-corrected autologous keratinocyte grafts (EB-101) for chronic RDEB wounds. METHODS: Autologous keratinocytes were harvested from participants with severe RDEB, transduced with a retrovirus containing the full-length COL7A1 gene, and grown into 5 × 7 cm (35 cm2) sheets. Gene-corrected keratinocyte sheets were then transplanted onto chronic RDEB wounds present for ≥ 12 weeks. RESULTS: Seven adult participants with severe RDEB were grafted with six sheets each (42 total sheets) onto wounds and followed for a mean of 5.9 years (range 4-8 years). Long-term improvements in wound healing and symptoms were observed. At year five, 70% (21/30) of treated sites demonstrated ≥ 50% wound healing compared to baseline by investigator global assessment. No sites with ≥ 50% wound healing were painful or pruritic, compared to 67% (6/9) of sites with < 50% wound healing (p < 0.001) at year five. Grafts were well-tolerated throughout long-term follow-up. No serious adverse events related to treatment were reported over a mean of 5.9 years of follow-up. No persistent systemic autoimmunity against type VII collagen or replication-competent retrovirus infections were identified, and no participants developed squamous cell carcinomas related to treatment during long-term follow-up. CONCLUSIONS: Treatment with EB-101 appears safe and efficacious, and produces long-term improvements in wound healing, pain, and itch for RDEB patients. Results from the Phase 3 randomized controlled trial are forthcoming. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01263379. Registered December 15, 2010. https://clinicaltrials.gov/ct2/show/NCT01263379.

A global, cross-sectional survey of patient-reported outcomes, disease burden, and quality of life in epidermolysis bullosa simplex.

BACKGROUND: Epidermolysis bullosa simplex (EBS) comprises a group of rare, blistering genodermatoses. Prior work has been limited by small sample sizes, and much remains unexplored about the disease burden and health-related quality of life (QOL) of patients with EBS. The aim of this study was to characterize the most common patient-reported clinical manifestations and the health-related impact of QOL in EBS, and to examine differences in disease burden by age. METHODS: Patients with a diagnosis of epidermolysis bullosa (EB) or their caregivers completed a one-time online survey administered by EBCare, an international online EB registry. Survey data from respondents self-reporting a diagnosis of EBS were analyzed for clinical and wound manifestations, medication use, and QOL (using Quality of Life in Epidermolysis Bullosa [QOLEB] scores). Differences across age groups were assessed using Kruskal-Wallis and Fisher's exact tests. RESULTS: There were 214 survey respondents with EBS. The mean age was 32.8 years (standard deviation = 19.2). Many respondents reported blisters (93%), recurrent wounds (89%), pain (74%), chronic wounds (59%), itch (55%), and difficulty walking (44%). Mean QOLEB score was 14.7 (standard deviation = 7.5) indicating a "moderate" impact on QOL, and 12% of respondents required regular use of opiates. Findings were consistent in subgroup analyses restricted to respondents with diagnostic confirmation via genetic testing or skin biopsy (n = 63 of 214). Age-stratified analyses revealed differences in disease burden: younger respondents were more likely to self-report severe disease (24% vs. 19% vs. 5% for respondents aged 0-9 vs. 10-17 vs. 18 + , p = 0.001), failure to thrive (9% vs. 15% vs. 3%, p = 0.02), and use of gastrostomy tubes (15% vs. 12% vs. 1%, p < 0.001) and topical antibiotics (67% vs. 69% vs. 34%, p < 0.001), while older respondents were more likely to be overweight or obese (6% vs. 0% vs. 51%, p < 0.001) and have difficulty walking (24% vs. 46% vs. 48%, p = 0.04). CONCLUSIONS: In the largest international cross-sectional survey of EBS patients conducted, respondents reported extensive disease burden including significant wounding, pain, itch, difficulty walking, and impact on QOL. Age stratified disease manifestations. These findings suggest significant unmet need, and treatment and counseling for EBS patients should consider age-specific differences.

Gorlin Syndrome: Assessing Genotype-Phenotype Correlations and Analysis of Early Clinical Characteristics as Risk Factors for Disease Severity.

PURPOSE: Gorlin syndrome (GS) is a rare genetic disorder characterized by lifetime risk of basal cell carcinomas (BCCs), skeletal anomalies (SAs), and other extracutaneous neoplasms. There is great variation in disease severity, and a genotype-phenotype correlation has not been well established. Here, we investigate whether patients' clinical characteristics predict disease severity to inform clinical decision making. METHODS: Data of 248 patients with GS were collected between 2014 and 2021 from three institutions. Multivariable regression analyses were performed to investigate whether clinical characteristics predicted disease burden. Genotype-phenotype correlations were investigated in 40 patients. RESULTS: Patients with SAs had a mean increase of 120 lifetime BCCs (95% CI, 27.1 to 213) relative to patients without SAs. Those with ≥ 2 SAs had 2.45 increased odds (95% CI, 1.01 to 5.91) of advanced or metastatic BCCs. Moreover, the presence of multiple SAs was associated with 5.00 increased odds of having a keratocystic odontogenic tumor (95% CI, 2.22 to 11.3) and 2.79 increased odds of an ovarian fibroma (95% CI, 1.05 to 7.40). Genotype-phenotype analyses showed that missense/in-frame mutations were more likely to be hereditary compared with severe deleterious mutation types (100% v 27%; P = .004). In addition, heat map visualization illustrated that those with more deleterious variants, like large deletions, trended toward increased burden of SAs and BCCs per year. CONCLUSION: GS patients with SAs may be at greater risk for developing more numerous and severe BCCs and other neoplastic growths including keratocystic odontogenic tumors and ovarian fibromas. Current clinical guidelines suggest yearly follow-up in individuals with GS. Since SAs are usually recognized at the time of diagnosis, our results suggest that more vigilant lifetime multidisciplinary surveillance should be considered for these patients starting in childhood.

A retrospective analysis of diagnostic testing in a large North American cohort of patients with epidermolysis bullosa.

BACKGROUND: Accurate diagnosis of epidermolysis bullosa (EB) has significant implications for prognosis, management, and genetic counseling. OBJECTIVE: To describe diagnostic testing patterns and assess diagnostic concordance of transmission electron microscopy (TEM), immunofluorescence mapping (IFM), and genetic analysis for EB. METHODS: A retrospective cohort included patients enrolled in the Epidermolysis Bullosa Clinical Characterization and Outcomes Database from January 1, 2004, to July 8, 2019. Tests concluding the same EB type (EB simplex, junctional EB, dominant dystrophic EB, and recessive dystrophic EB) were considered concordant; those concluding different EB types were considered discordant; and those with nonspecific/nondefinitive results were equivocal. RESULTS: A total of 970 diagnostic tests were conducted from 1984 to 2018 in 771 patients. Genetic analyses were performed chronologically later than IFM or TEM (P < .001). The likelihood of undergoing genetic analysis was greater for junctional EB and recessive dystrophic EB, and the same for dominant dystrophic EB as compared with EB simplex. TEM results in 163 patients were equivocal (55%), concordant (42%), and discordant (3%). IFM results in 185 patients were equivocal (54%), concordant (42%), and discordant (4%). LIMITATIONS: Retrospective design. CONCLUSIONS: Diagnostic testing has shifted in favor of genetic analysis. TEM and IFM frequently offer equivocal findings when compared to the specificity afforded by genetic analysis.

Patient-reported outcomes and quality of life in dominant dystrophic epidermolysis bullosa: A global cross-sectional survey.

INTRODUCTION: Dystrophic epidermolysis bullosa is a debilitating skin condition, without curative treatment. Previous research has focused on the recessive variant, which is known to cause severe disease. Limited work focusing on the clinical manifestations and outcomes of dominant dystrophic epidermolysis bullosa is found (DDEB). METHODS: Analysis of an online survey of 42 DDEB patients. RESULTS: Self-reported severity of disease did not correlate with size of the wound or number of dressing changes, but did correlate with severity of pain reported in the last 12 months (3.4 mild vs 6.8 severe disease, P = 0.0002). Patients with severe DDEB also reported more severe internal disease symptoms, such as difficulty swallowing (62.5%, P = 0.01) and greater analgesic use during dressing changes (4.4% mild vs 81.3% severe, P = <0.001). DISCUSSION: Patient perception of disease severity in DDEB appears to be most impacted by pain, presence of chronic open wounds, difficulty swallowing, difficulty walking, and anal strictures. As research on DDEB increases, future studies focused on these symptoms might be the most impactful for DDEB patients. However, distinguishing DDEB from other subtypes remains a challenge.

Cannabinoid use and effects in patients with epidermolysis bullosa: an international cross-sectional survey study.

BACKGROUND: Epidermolysis bullosa (EB) patient anecdotes and case reports indicate that cannabinoid-based medicines (CBMs) may alleviate pain and pruritus and improve wound healing. CBM use has not been characterized in the EB patient population. OBJECTIVES: To evaluate CBM use among EB patients, including CBM types, effects on symptoms (e.g., pain and pruritus), disease process (e.g., blistering, wounds, and inflammation), well-being (e.g., sleep, appetite) and concomitant medications. METHODS: English-speaking EB patients or caregivers completed an online international, anonymous, cross-sectional survey regarding CBM use. Respondents reported the types of CBMs, subsequent effects including perceived EB symptom alteration, changes in medication use, and side effects. RESULTS: Seventy-one EB patients from five continents reported using or having used CBMs to treat their EB. Missing question responses ranged between 0 (0%) and 33 (46%). Most used more than one CBM preparation (mean: 2.4 ± 1.5) and route of administration (mean: 2.1 ± 1.1). Topical and ingested were the most common routes. Pain and pruritus were reported retrospectively to decrease by 3 points (scale: 0-10; p < 0.001 for both) after CBM use. Most reported that CBM use improved their overall EB symptoms (95%), pain (94%), pruritus (91%) and wound healing (81%). Most participants (79%) reported decreased use of pain medications. The most common side-effect was dry mouth (44%). CONCLUSIONS: CBMs improve the perception of pain, pruritus, wound healing, and well-being in EB patients and reduced concomitant medication use. Nevertheless, a direct relation between the use of CBMs and reduction of the above-mentioned symptoms cannot be proven by these data. Therefore, future controlled studies using pharmaceutically standardised CBM preparations in EB are warranted to delineate the risks and benefits of CBMs.

Clinical characteristics associated with increased wound size in patients with recessive dystrophic epidermolysis bullosa.

As more therapeutic clinical trials focus on treatment of individual wounds in patients with recessive dystrophic epidermolysis bullosa, it has become crucial to understand the baseline clinical characteristics of these wounds. To investigate these features, we administered an RDEB-specific wound survey. Forty participants reported on location, size, pain, infection frequency, wound type, and duration of 189 wounds; a subset of 22 participants reported on pruritus in 63 wounds. Increased wound size was significantly associated with increased pain, increased pruritus, longer wound duration, increased infection frequency, and patients with mutations resulting in truncated type VII collagen.

Patient-reported outcomes and quality of life in recessive dystrophic epidermolysis bullosa: A global cross-sectional survey.

BACKGROUND: A spectrum of skin disease severity exists in patients with recessive dystrophic epidermolysis bullosa (RDEB). OBJECTIVE: To characterize the patient-reported outcomes and quality of life (QOL) in patients with RDEB. METHODS: A cross-sectional study of patients with RDEB surveyed through the global EBCare Registry. Patient-reported outcomes included skin disease severity, wound characteristics, pain, itch, extracutaneous symptoms, and medications. QOL was measured by using the validated Quality of Life in Epidermolysis Bullosa instrument. RESULTS: A total of 85 patients with RDEB reported 1226 wounds (937 recurrent wounds and 289 chronic open wounds). Overall skin disease severity was self-reported as mild (26%; 22/83), moderate (48%; 40/83), or severe (25%; 21/83). Worsening skin disease severity was significantly associated with larger wounds, increased opiate use, anemia, gastrostomy tube use, infections, osteoporosis, and squamous cell carcinoma. Larger wound size was associated with worse quality of life scores. LIMITATIONS: All data were self-reported from an online epidermolysis bullosa patient registry. CONCLUSIONS: This study shows a significant correlation between larger wound size with worsening skin disease severity and quality of life in participants with RDEB. Worsening skin disease severity significantly correlated with key clinical manifestations. These results show that patients with RDEB are able to self-report their skin disease severity and wounds.