Evidence for cutaneous dysbiosis in dystrophic epidermolysis bullosa

Modulations of the skin microbiome in skin disorders: A narrative review from a wound care perspective

The cutaneous microbiome represents a highly dynamic community of bacteria, fungi and viruses. Scientific evidence, particularly from the last two decades, has revealed that these organisms are far from being inconsequential microscopic hitchhikers on the human body, nor are they all opportunistic pathogens waiting for the chance to penetrate the skin barrier and cause infection. In this review, we will describe how dermatological diseases have been found to be associated with disruptions and imbalances in the skin microbiome and how this new evidence had shaped the diagnosis and clinical practice relating to these disorders. We will identify the microbial agents which have been found to directly exacerbate skin diseases, as well as those which can ameliorate many of the symptoms associated with dermatological disorders. Furthermore, we will discuss the studies which suggest that bacteriotherapy, either by topical use of probiotics or by bacteria-derived compounds, can rectify skin microbial imbalances, thereby offering a promising alternative to antibiotic treatment and reducing the risks of antibiotic resistance.

Skin Microbial Composition and Genetic Mutation Analysis in Precision Medicine for Epidermolysis Bullosa

Epidermolysis bullosa (EB) is an inherited skin disease representing a spectrum of rare genetic disorders. These conditions share the common trait that causes fragile skin, resulting in the development of blisters and erosions. The inheritance follows an autosomal pattern, and the array of clinical presentations leads to significant physical suffering, considerable morbidity, and mortality. Despite EB having no cure, effectively managing EB remains an exceptional challenge due to its rarity and complexity, occasionally casting a profound impact on the lives of affected individuals. Considering that EB management requires a multidisciplinary approach, this sometimes worsens the condition of patients with EB due to inappropriate handling. Thus, more appropriate and precise treatment management of EB is essentially needed. Advanced technology in medicine and health comes into the bioinformatics era. Including treatment for skin diseases, omics-based approaches aim to evaluate and handle better disease management and treatment. In this work, we review several approaches regarding the implementation of omics-based technology, including genetics, pathogenic mutation, skin microbiomics, and metagenomics analysis for EB. In addition, we highlight recent updates on the potential of metagenomics analysis in precision medicine for EB.

Gluten-sensitive enteropathy in recessive dystrophic epidermolysis bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a blistering genodermatosis due to biallelic loss-of-function variants in the type VII collagen (C7) gene (COL7A1). We report the impact of inflammation/autoimmunity on the gut (and other organs) in the nine children with RDEB recruited to an early-phase clinical trial of systemic cell therapy (NCT04153630). This pilot study provides evidence that autoimmunity may play an important role in sustaining chronic inflammation and the coexistence of coeliac disease, which, in turn, could exacerbate anaemia/malnutrition and progression in RDEB. Testing this hypothesis in a larger cohort including children and adults with RDEB and other epidermolysis bullosa (EB) subtypes is warranted so that targeted interventions may improve outcomes.

Type VII Collagen Deficiency in the Oncogenesis of Cutaneous Squamous Cell Carcinoma in Dystrophic Epidermolysis Bullosa

Dystrophic epidermolysis bullosa is a rare genetic skin disorder caused by COL7A1 sequence variations that result in type VII collagen deficits and cutaneous and extracutaneous manifestations. One serious complication of dystrophic epidermolysis bullosa is cutaneous squamous cell carcinoma, a leading driver of morbidity and mortality, especially among patients with recessive dystrophic epidermolysis bullosa. Type VII collagen deficits alter TGFβ signaling and evoke multiple other cutaneous squamous cell carcinoma progression-promoting activities within epidermal microenvironments. This review examines cutaneous squamous cell carcinoma pathophysiology in dystrophic epidermolysis bullosa with a focus on known oncogenesis pathways at play and explores the idea that therapeutic type VII collagen replacement may reduce cutaneous squamous cell carcinoma risk.

Temporal Changes in the Skin Microbiome of Epidermolysis Bullosa Patients following the Application of Wound Dressings

OBJECTIVE

Epidermolysis bullosa (EB) is a group of rare hereditary skin disorders characterized by the formation of painful blisters, erosions, and ulcers. In addition, the wounds can easily become infected with different pathogens. Therefore, the dynamics in the microbial populations across the various stages of EB can shed light on pathophysiology, the effect of treatment, and the factors involved in its recovery, but they are understudied. We thus sought to characterize the skin microbiome among patients with EB over time.

METHODS

A prospective study conducted in the pediatric dermatology clinic at Soroka Medical Center, Beer-Sheva, Israel. Children (0-18) with simplex and recessive dystrophic EB were sampled at two different time points: before a therapeutic regimen and 90 days (±14 days) later. Samples were obtained from lesional skin (wound), healthy, non-lesional skin, and seborrheic skin (forehead). Samples were subject to 16S rRNA amplicon sequencing. Analyses performed included comparisons of relative abundance at the phyla and genera taxonomic levels, alpha and beta diversity comparisons, and differential abundance.

RESULTS

32 children with EB were enrolled, for whom 192 skin microbiome samples were obtained. Lesional skin samples harbored significantly less Bacteroidota and Fusobacteriota before the initiation of treatment. Following topical dressing, we observed more Firmicutes and less Proteobacteria in lesional skin samples than healthy and seborrheic skin samples. In addition, Staphylococcus was significantly more abundant in lesional samples than in non-lesional and seborrheic samples following treatment.

CONCLUSIONS

Our study recaptured the reduced bacterial diversity and increased staphylococcal carriage in EB patients, showing a potential effect of topical dressing either directly on the wound microbiome or indirectly through the contribution towards skin healing. The detection of Firmicutes in general, and S. aureus specifically, commensurate with the application of a wound dressing may warrant the use of additional treatment methods to facilitate wound healing. Future studies in these patients should prospectively correlate the temporal changes in the microbiome associated with various treatment modalities in order to optimize the care of EB patients.

IgA nephropathy in adults with epidermolysis bullosa

Epidermolysis bullosa (EB) is a devastating genetic condition caused by mutations in genes that give rise to aberrant proteins. There are 16 different such proteins implicated in EB that are important in maintaining the integrity of the dermoepidermal junction. It is classified into four major subtypes: (i) EB simplex; (ii) junctional EB (JEB); (iii) dystrophic EB (DEB); and (iv) Kindler EB. Renal disease is a recognized complication of EB and the aetiology is complex. We describe our experience of managing five patients with EB and IgA nephropathy. We recommend that patients with recessive DEB and JEB routinely have the following monitored: renal function, urinary albumin/creatinine ratio, urine analysis, serum albumin levels and immunoglobulins; specifically serum IgA. Management of IgA nephropathy in the context of EB should be tailored to the individual and be carried out within a specialist multidisciplinary team. Our case series provides important insights into the treatment of IgA nephropathy in patients with EB and will help inform treatment in this rare genetic disease. Case series and reports like ours are key in gaining real-life data to quantify the actual risk of morbidity and mortality from each of the treatment modalities discussed.

Longitudinal study of wound healing status and bacterial colonisation of Staphylococcus aureus and Corynebacterium diphtheriae in epidermolysis bullosa patients

Epidermolysis bullosa (EB) is an inherited disorder characterised by skin fragility and the appearance of blisters and wounds. Patient wounds are often colonised or infected with bacteria, leading to impaired healing, pain and high risk of death by sepsis. Little is known about the impact of bacterial composition and susceptibility in wound resolution, and there is a need for longitudinal studies to understand healing outcomes with different types of bacterial colonisation. A prospective longitudinal study of 70 wounds from 15 severe EB patients (Junctional and Recessive Dystrophic EB) from Chile. Wounds were selected independently of their infected status. Wound cultures, including bacterial species identification, composition and Staphylococcus aureus (SA) antibiotic susceptibility were registered. Wounds were separated into categories according to their healing capacity, recognising chronic, and healing wounds. Hundred-one of the 102 wound cultures were positive for bacterial growth. From these, 100 were SA-positive; 31 were resistant to Ciprofloxacin (31%) and only seven were methicillin-resistant SA (7%). Ciprofloxacin-resistant SA was found significantly predominant in chronic wounds (**P < .01). Interestingly, atoxigenic Corynebacterium diphtheriae (CD) was identified and found to be the second most abundant recovered bacteria (31/101), present almost always in combination with SA (30/31). CD was only found in Recessive Dystrophic EB patients and not related to wound chronicity. Other less frequent bacterial species found included Pseudomonas aeruginosa, Streptococus spp. and Proteus spp. Infection was negatively associated with the healing status of wounds.

The impact of using a multistrain probiotic supplement on gastrointestinal function in children and adolescents with severe recessive dystrophic epidermolysis bullosa

BACKGROUND

Children and adolescents with severe recessive dystrophic epidermolysis bullosa (RDEB-S) often have severe constipation in addition to gastrointestinal dysbiosis, due to frequent antibiotic use and reduced oral diet. Constipation is treated with long-term use of high daily doses of macrogol gel (Movicol Paediatric PlainTM or LaxidoTM). Constipation is refractory to increases in fibre and fluids, and impacts severely on quality of life.

AIM

To study the initial impact and efficacy of using a multistrain probiotic supplement daily for 12 weeks in patients with RDEB-S. The authors sought to determine the impact of such a supplement on  gastrointestinal symptoms, stool consistency and the use of macrogol gel to treat constipation, as well as understanding patient reaction, palability and ease of use.

METHODS

Patients were identified through the epidermolysis bullosa tertiary multidisciplinary team clinic in July 2021. Patients were included if they had a diagnosis of RDEB-S, prescribed at least one sachet of macrogol gel and provided written consent to take part. Patients were provided, proprietary liquid multistrain probiotic supplement (Symprove™) with a high bacterial count, at a dose of 1 mL kg-1 once a day. Each patient completed an anonymous, nine-question, electronic survey to document symptoms and report overall findings at the start and end of a 12-week trial period.

RESULTS

Four patients with RDEB-S (two boys and two girls; age range 7-14 years) who met the inclusion criteria were approached to take part. All patients had chronic constipation requiring daily macrogol gel use (range 2-5 sachets per day). Three out of four (75%) completed the 12-week course. At baseline (before supplementation commenced), all three (100%) patients reported poor oral appetite, constipation, flatulence, abdominal bloating and pain, and frequent skin infections requiring oral antibiotics, with two of the three (66%) patients also having nausea. After 12 weeks of supplementation, all three patients (100%) reported a significant improvement in abdominal pain and bloating, nausea, stool consistency, stool frequency, flatulence and increased appetite. Two of the three patients (66%) were able to reduce their macrogol gel usage and the third patient (33%) was able to stop macrogol gel usage altogether during the study period. All three patients said they would choose to continue using the supplement if it was available.

CONCLUSION

We have shown in this case series that giving a multistrain probiotic supplement in patients with RDEB-S has the potential to improve stool consistency and reduce or prevent the need for chronic macrogol gel use. Future larger-scale, placebo-controlled trials are needed to confirm these results.

Chronic wounds

Chronic wounds are characterized by their inability to heal within an expected time frame and have emerged as an increasingly important clinical problem over the past several decades, owing to their increasing incidence and greater recognition of associated morbidity and socio-economic burden. Even up to a few years ago, the management of chronic wounds relied on standards of care that were outdated. However, the approach to these chronic conditions has improved, with better prevention, diagnosis and treatment. Such improvements are due to major advances in understanding of cellular and molecular aspects of basic science, in innovative and technological breakthroughs in treatment modalities from biomedical engineering, and in our ability to conduct well-controlled and reliable clinical research. The evidence-based approaches resulting from these advances have become the new standard of care. At the same time, these improvements are tempered by the recognition that persistent gaps exist in scientific knowledge of impaired healing and the ability of clinicians to reduce morbidity, loss of limb and mortality. Therefore, taking stock of what is known and what is needed to improve understanding of chronic wounds and their associated failure to heal is crucial to ensuring better treatments and outcomes.

Predominance of Staphylococcus correlates with wound burden and disease activity in dystrophic epidermolysis bullosa: a prospective case-control study

Recessive dystrophic epidermolysis bullosa (RDEB) is characterized by skin blistering and wounds. To uncover changes in skin and mucosal microbiome related to age and disease progression, and microbiome impact on clinical and inflammatory laboratory parameters, swabs from wounded and unwounded skin, oral mucosa and stool samples of 28 children with RDEB and 28 healthy controls were subjected to 16S-rRNA gene sequencing. Skin microbiome of RDEB patients showed significantly reduced alpha diversity compared to healthy controls and early, age-dependent predominance of Staphylococcus aureus first in wounds, then in unwounded skin. These findings were more pronounced in severe disease with higher abundances of Staphylococcus aureus compared to intermediate disease. Staphylococcus aureus abundance correlated significantly with both acute and chronic wound burden. Changes in oral mucosal and gut microbiome were discrete with no significant differences in alpha diversity. Our findings show that children with RDEB experience skin microbiome changes early in life. Longitudinal studies should confirm that dysbiosis starts in wounds and later extends to unwounded skin. The predominance of Staphylococcus aureus significantly correlates with wound burden and disease activity, and to some extent with systemic inflammation.

Dystrophic Epidermolysis Bullosa: Secondary Disease Mechanisms and Disease Modifiers

The phenotypic presentation of monogenetic diseases is determined not only by the nature of the causative mutations but also is influenced by manifold cellular, microenvironmental, and external factors. Here, heritable extracellular matrix diseases, including dystrophic epidermolysis bullosa (DEB), are no exceptions. Dystrophic epidermolysis bullosa is caused by mutations in the COL7A1 gene encoding collagen VII. Deficiency of collagen VII leads to skin and mucosal fragility, which progresses from skin blistering to severe fibrosis and cancer. Clinical and pre-clinical studies suggest that targeting of secondary disease mechanisms or employment of natural disease modifiers can alleviate DEB severity and progression. However, since many of these mechanisms are needed for tissue homeostasis, informed, selective targeting is essential for safe and efficacious treatment. Here, we discuss a selection of key disease modifiers and modifying processes active in DEB, summarize the still scattered knowledge of them, and reflect on ways forward toward their utilization for symptom-relief or enhancement of curative therapies.