One goal,different strategies – molecular and cellular approaches for the treatment of inherited skin fragility disorders

Epidermolysis bullosa (EB) is a heterogeneous group of inherited diseases characterized by the formation of blisters in the skin and mucosa. There is no cure or effective treatment for these potentially severe and fatal diseases. Over the past few years, several reports have proposed different molecular strategies as new therapeutic options for the management of EB. From classical vector‐based gene therapy to cell‐based strategies such as systemic application of bone marrow stem cells or local application of fibroblasts, a broad range of molecular approaches have been explored. This array also includes novel methods, such as protein replacement therapy, gene silencing and the use of induced pluripotent stem cells (iPCs). In this review, we summarize current concepts of how inherited blistering diseases might be treated in the future and discuss the opportunities, promises, concerns and risks of these innovative approaches.     

The use of tissue-engineered skin (Apligraf) to treat a newborn with epidermolysis bullosa.

BACKGROUND: Inherited epidermolysis bullosa (EB) is a mechanobullous disorder. The Dowling-Meara variant, a subtype of EB, is characterized by widespread blister formation that may include the oral cavity and nails. Many patients with the Dowling-Meara phenotype are at increased risk of sepsis and death during infancy. The treatment of EB is generally supportive. The tissue-engineered skin used (Apligraf) is a bilayered human skin equivalent developed from foreskin. It is the only Food and Drug Administration-approved skin equivalent of its kind. It is approved for the treatment of venous ulcers of the lower extremities. It has also been used to treat acute wounds, such as graft donor sites and cancer excision sites. OBSERVATION: To our knowledge, we describe the first case in which a newborn with EB, Dowling-Meara variant, was treated with bilayered tissue-engineered skin. The areas treated with the tissue-engineered skin healed faster than the areas treated with conventional therapy. Most of the areas treated with tissue-engineered skin have remained healed, without developing new blisters. These areas appear to be more resistant to trauma. CONCLUSIONS: Our early success with tissue-engineered skin in this patient may have a significant impact on the future treatment of neonates with EB simplex. Future studies are needed to determine if the beneficial effects of tissue-engineered skin are reproducible in other neonates with EB simplex and in patients of all ages with different subtypes of EB.     

遗传性大疱性表皮松解症致病基因研究进展

遗传性大疱性表皮松解症(EB)是由皮肤中各种结构蛋白的遗传基因突变导致的一组机械性大疱病，临床主要表现为机械性脆性皮肤、张力性大疱和结痂等。根据电子显微镜下水疱的位置，大疱性表皮松解症分为4类不同的临床亚型，分别是单纯型EB、交界型EB、营养不良型EB以及Kindler综合征。迄今为止，已发现19个导致大疱性表皮松解症发生的基因。本文对大疱性表皮松解症的致病基因以及各基因型和临床表型之间的关系进行了综述。     

Expression of integrins in junctional and dystrophic epidermolysis bullosa.

Recently, monoclonal antibodies (MoAb) have been raised against a family of adhesive membrane receptors (R) for extracellular matrix molecules known as integrins. In order to ascertain whether these adhesive proteins are normally expressed in inherited epidermolysis bullosa (EB) dermal epidermal junction, we studied the reactivity of MoAb recognizing receptors for VLA-1 (R for unknown ligand), VLA-2 (R for collagen), VLA-3 (R for collagen, laminin, fibronectin), VLA-4 (R for unknown ligand), VLA-5 (R for fibronectin), VLA-6 (R for laminin), VNR alpha, and VNR beta (R for vitronectin) on cryostat skin sections from EB patients and normal controls and on cytospins of normal epidermal cell suspensions with indirect immunohistochemical methods. Two cases of junctional EB (EBj) (lethal and non-lethal), three cases of dominant dystrophic EB (EBdd), two cases of recessive dystrophic EB (EBdr), and two normal controls skin sections and cell suspensions entered the study. No significant modification of the distribution of these adhesive receptors was observed in junctional and dystrophic EB skin. Both in normal and EB specimens MoAb against VLA-2, VLA-3, and VNR alpha determinants showed reactivity with the total cytoplasmic membrane of basal keratinocytes and basement membrane zone. Interestingly, anti-VLA-6 MoAb was characterized by an intense linear staining of the dermal-epidermal junction with the same localization on the roof of the blisters in EBj, EBdd, and EBdr as bullous pemphigoid (BP) serum. On the basis of these results we suggest that anti-VLA-6 MoAb could be used instead of BP serum for immunohistochemical detection of the cleavage of blisters in EB.     

Atopic dermatitis: therapeutic challenge in an infant with dystrophic epidermolysis bullosa

Inherited epidermolysis bullosa (EB) manifests as blisters that usually result from minor trauma. The severity of expression ranges from mild occasional blistering to severe extensive bullae. We report an infant with dystrophic EB worsened by atopic dermatitis (AD). This concomitant skin disease exacerbated EB, because scratching induced bullae and milia. Careful management of AD provided a marked improvement in cutaneous involvement. This report shows that it is important to document and treat inflammatory skin disorders coexisting with EB, because they may influence the overall prognosis of EB.     

Extensive acantholysis as the major histological feature of a severe case of Dowling Meara-epidermolysis bullosa simplex: a reappraisal of acantholysis in the newborn

Epidermolysis bullosa (EB) is a heterogeneous group of inherited skin disorders characterized by blistering and skin fragility secondary to mechanical trauma. Epidermolysis bullosa simplex (EBS) is the most frequent form of EB, with Dowling-Meara (DM-EBS) subtype being the most severe form in this group. Conventional histopathological evaluation is usually of low value in the diagnosis of EB, and significant histological features have rarely been reported in this group of diseases. We describe a case of severe DM-EBS in which acantholysis was observed in the histological examination. This finding led us to consider other diagnoses, such as neonatal pemphigus vulgaris or lethal acantholytic EB. Histological, immunological, ultrastructural and genetic tests were performed, leading to a final diagnosis of DM-EBS. Therefore, we believe that DM-EBS should be considered in the differential diagnosis of a newborn with blisters, where acantholysis is the main histological feature.     

Inherited epidermolysis bullosa: new diagnostic criteria and classification

Epidermolysis bullosa (EB) is a group of inherited, mechanobullous disorders caused by mutations in various structural proteins in the skin. There have been several advances in the classification of EB since it was first introduced in the late 19th century. We now recognize four major types of EB, depending on the location of the target proteins and level of the blisters: EB simplex (epidermolytic), junctional EB (lucidolytic), dystrophic EB (dermolytic), and Kindler syndrome (mixed levels of blistering). This contribution will summarize the most recent classification and discuss the molecular basis, target genes, and proteins involved. We have also included new subtypes, such as autosomal dominant junctional EB and autosomal recessive EB due to mutations in the dystonin (DST) gene, which encodes the epithelial isoform of bullouspemphigoid antigen 1. The main laboratory diagnostic techniques—immunofluorescence mapping, transmission electron microscopy, and mutation analysis—will also be discussed. Finally, the clinical characteristics of the different major EB types and subtypes will be reviewed.     

Abnormal binding of an anti-amnion antibody to epidermal basement membrane provides a novel diagnostic probe for junctional epidermolysis bullosa

AA3 is a novel antibody raised against human amnion, which reacts with the basement membrane of various epithelia of ectodermal origin. We used AA3 to examine the epidermal basement membrane zone in normal skin and different genetically determined types of epidermolysis bullosa (EB), by indirect immunofluorescence. AA3 staining was normal in dystrophic and simplex EB, but was markedly reduced in lesional and non-blistered skin in severe forms of junctional EB. In non-lethal junctional EB, the intensity of staining was variable and appeared to be inversely associated with disease severity, but did not correlate with demonstrable abnormalities of hemidesmosomes. AA3 binding was not reduced in pemphigoid lesions or normal suction blisters. It appeared to localize to the lamina lucida, but with different characteristics compared with antibodies to laminin and bullous pemphigoid antigen. These finding suggest that AA3 recognizes an antigen (or antigens) which may be involved in a primary biochemical defect in junctional EB. Moreover, this antibody may act as a new probe for this potentially lethal mechano-bullous disease.     

A study into growth and anaemia in children with epidermolysis bullosa

Severe subtypes of epidermolysis bullosa (EB) are devastating conditions that cause extremely fragile skin and mucosal membranes and lots of wounds. So far, no cure for EB exists. About 5,000 people in the U.K. and 500,000 people worldwide suffer from different EB types. Apart from skin problems, children with EB often have trouble gaining weight, and they develop anaemia (deficiency of iron). As wound healing works best when the body is strong, researchers needed to see how exactly children with EB grow and what factors may stop them from growing properly. To address this, a research group from the German EB reference centre, has looked back at weight, height and blood measurements of 200 children with EB. 157 had a type of EB called recessive dystrophic EB (RDEB) and 43 had junctional EB (JEB). The researchers calculated growth charts that allowed better comparison with growth of healthy children and can help to find EB-specific growth patterns. The researchers found that the growth of children with RDEB was impaired from the second year of life (age 18 months+). In JEB, growth resembled that of healthy children. Anaemia was present from the second year of life onwards in RDEB and JEB. Children with RDEB who suffered from anaemia and deficiency of proteins, vitamins and certain minerals in the blood had impaired growth compared to those who did not. A lot of inflammation in the body also compromised the growth of children with EB. The EB growth charts from this study will help doctors and families in making decisions on feeding, like giving extra vitamins or tube feeding. The results are also important now that therapies for EB are being developed, so that we can compare how growth will improve in line with such therapies. The direct results of this study are printable growth charts that can be used throughout the world immediately, to assess and counsel children with EB. This is a summary of the study: Natural history of growth and anaemia in children with epidermolysis bullosa: a retrospective cohort study     

先天性大疱性表皮松解症诊断及治疗进展

先天性大疱性表皮松解症是一组以皮肤脆性增加、轻微摩擦或外伤即可导致皮肤或黏膜水疱、糜烂为共同特点的遗传性皮肤病。目前该病可分为4型,即单纯型、交界型、营养不良型和Kindler综合征型。诊断方面,提倡“洋葱皮诊断方法”,即先进行免疫荧光定位,而后针对性进行基因检测明确致病基因位点。治疗上要加强护理,药物、手术对症治疗可缓解不适症状。细胞、蛋白、基因治疗等方面研究不断深入有望为患者带来希望,及时进行产前诊断,避免不良后果的发生。     

Multiple Facetten der genetisch bedingten Hautfragilität

The inherited skin fragility encompasses a heterogeneous group of disorders, collectively designated as epidermolysis bullosa, characterized by recurrent mechanically induced blisters, erosions or wounds. The spectrum of clinical manifestations is broad, as well as the molecular background. Besides the skin, mucosal membranes and other organs can be affected. In real-world practice, patients with mild genetic skin fragility usually do not require medical care and often remain underdiagnosed. In contrast, the well-defined severe EB subtypes are recognized based on typical clinical features. The molecular diagnostics is usually performed in order to allow genetic counselling and prenatal diagnosis. Besides wound care and careful management of the disease complications, new experimental targeted therapies are being developed. New very rare forms of inherited skin fragility have been identified with modern sequencing methods.     

Impact of inherited epidermolysis bullosa on parental interpersonal relationships, marital status and family size

BACKGROUND: The presence in a family of a child or children with epidermolysis bullosa (EB) may have profound psychological implications for other family members. OBJECTIVES: To assess the impact of the presence of EB in one or more children on the personal relationships between their parents. METHODS: Standardized questionnaires were used. RESULTS: In general, the presence of a child severely affected with EB had profound effects on many aspects of marriage. This included a lack of interest in participating in activities as couples [junctional EB (JEB), 45%; recessive dystrophic EB (RDEB), 25%], a lack of energy to invest in such pursuits (JEB, 82%; RDEB, 50%), limitations in opportunities for sharing nonintimate physical activities (reported by most parents having children with some type of generalized EB), and negatively altered parental sex life (JEB, 55%; RDEB, 39%). This is consistent with the fact that 10%, 64%, 25% and 36% of parents of an affected child with EB simplex (EBS), JEB, dominant dystrophic EB (DDEB) and RDEB, respectively, characterized their relationships as couples as revolving almost exclusively around the day-to-day care of their affected children. The severity of disease in an affected child clearly influenced parental decisions about having more children: 24% and 64% of parents of children with JEB and RDEB, respectively, chose not to have additional children, compared with 26% and 54% of parents with children having EBS or DDEB. This choice was most often pursued via tubal ligation; less often, alternative means of surgical sterilization were chosen. Divorce was common among parents of children with EB (range: 17% in EBS to 31% in JEB) and, with the exception of parents of children with EBS, was usually directly attributed by one or both parents to the profound impact that this disease had exerted on their marriage. CONCLUSIONS: Physicians caring for children with EB need to give more consideration to the many psychological factors that may contribute to their patients' well being. They may need to assist these children's parents in seeking support and counselling to prevent destruction of the family unit.     

Hereditäre Blasen bildende Hauterkrankungen

Epidermolysis bullosa (EB) is a group of genetic skin disorders whose common feature is the formation of blisters following minor trauma. They present with a wide clinical spectrum of manifestations because of a variety of molecular defects. In patients with mild phenotypes, only skin is affected. The most severe EB forms are multiorgan disorders with a poor prognosis. EB arises from abnormalities in proteins of the dermal-epidermal junction. These specialized protein components aggregate to form anchoring complexes, which attach the epidermis to the dermis. Three major EB-forms can be distinguished on the basis of ultrastructural blistering level: EB simplex—epidermolytic, junctional EB—in the lamina lucida and dystrophic EB—dermolytic. To establish a provisional diagnosis for an EB patient, clinical data, family history and morphologic examination of the skin, e.g. by antigen-mapping, are needed. Complete knowledge of the genetic defect provides the basis to a rational genetic counseling and prenatal testing. Treatment of EB is based on wound care; multidisciplinary management of cases with severe course is required.     

Management of severe epidermolysis bullosa by haematopoietic transplant: principles,perspectives and pitfalls

People with severe forms of epidermolysis bullosa (EB) develop widespread blistering and progressively debilitating multisystem complications that may result in a shortened lifespan. As some wounds in EB individuals are difficult or impossible to access with topical therapy, we examined the potential of systemic therapy with normal haematopoietic stem cells. In both animal models and children with EB, healthy donor cells from the haematopoietic graft migrated to the injured skin; simultaneously, there was an increase in the production of skin‐specific structural proteins deficient in EB, increased skin integrity and reduced tendency to blister formation. Even though the majority of evaluable individuals have had a positive response in skin healing, frequently changing their quality of life, the improvement in lifestyle has been varied and the overall clinical response incomplete. To change the current amelioration of disease into a full cure, we propose to (i) increase safety as well as efficacy of haematopoietic cell transplant (HCT) using co‐infusion of mesenchymal stromal/stem cells with haematopoietic stem cells and non‐myeloablative conditioning for transplant; (ii) optimize homing of donor cells into the skin erosions in animal models of EB; and (iii) discover and test new drugs for EB therapy using patient‐specific induced pluripotent stem cells. We conclude that although HCT has always been a risky treatment restricted to those with serious life‐threatening or debilitating diseases, by most benchmarks, the results of HCT in EB have shown that HCT has the potential of being a durable, systemic therapy for people with severe forms of EB.     

Epidermolysis bullosa simplex generalized severe induces a T helper 17 response and is improved by apremilast treatment

Epidermolysis bullosa (EB) is a group of genetic disorders in which the skin is abnormally fragile. In EB simplex, the skin cells tend to fall apart because their internal scaffolding of keratin fibres is defective, due to mutations in the genes encoding keratins type 5 or 14 (KRT5 and KRT14). But people with the generalised, severe type of EB simplex (EBS-GS) are sometimes more ill than would be expected just from a mechanical problem with the skin; some even die in infancy, usually from infection. This group from France and Scotland explored the possibility that EBS-GS patients also have a faulty immune system. They re-examined skin specimens taken previously for diagnostic purposes from 17 patients with EBS-GS and also tested fresh skin biopsies and blister fluid from a further 10 patients. They consistently found more inflammatory cells and higher levels of chemicals which promote inflammation (cytokines) than normal. The findings were the same regardless of whether the sample was from blistered or normal-looking skin and whether the fault was in KRT5 or KRT14. Markers for the cytokine Th17 were particularly high, encouraging them to treat three EBS-GS patients with the anti-Th17 drug Apremilast as used in psoriasis. All three reported a dramatic reduction in blisters within the first month, which lasted throughout treatment for up to 10 months, with minimal side-effects. One patient stopped the Apremilast after 7 months because of nausea and the blistering came back 2 days later. This appears to be a promising new approach to treating EBS-GS.     

Hereditary blistering disorders

Epidermolysis bullosa (EB) is a group of genetic skin disorders whose common feature is the formation of blisters following minor trauma. They present with a wide clinical spectrum of manifestations because of a variety of molecular defects. In patients with mild phenotypes, only skin is affected. The most severe EB forms are multiorgan disorders with a poor prognosis. EB arises from abnormalities in proteins of the dermal-epidermal junction. These specialized protein components aggregate to form anchoring complexes, which attach the epidermis to the dermis. Three major EB-forms can be distinguished on the basis of ultrastructural blistering level: EB simplex--epidermolytic, junctional EB--in the lamina lucida and dystrophic EB--dermolytic. To establish a provisional diagnosis for an EB patient, clinical data, family history and morphologic examination of the skin, e.g. by antigen-mapping, are needed. Complete knowledge of the genetic defect provides the basis to a rational genetic counseling and prenatal testing. Treatment of EB is based on wound care; multidisciplinary management of cases with severe course is required.     

Hand Function and Quality of Life in Children with Epidermolysis Bullosa

Patient‐reported outcomes are becoming increasingly important to clinical care. Epidermolysis bullosa (EB), a rare genetic skin disorder, can result in severe hand impairment, but parent and patient perceptions of hand function have never been assessed. This study aimed to quantify parent‐ and patient‐reported hand function and assess its relationship with quality of life (QOL) in children with EB. This cross‐sectional study included children with EB treated at an interdisciplinary EB center. Hospital records were searched for demographic characteristics and medical history. Eligible families were invited to complete two surveys by mail or telephone. The ABILHAND‐Kids questionnaire assessed manual hand ability for 21 functions. The Quality of Life in Epidermolysis Bullosa questionnaire assessed EB‐related QOL. Hand function and QOL of various subtypes were compared using Mann–Whitney tests. Seventy‐one parents and patients ages 2 to 18 years with EB from 20 states in the United States completed questionnaires. Children with recessive dystrophic EB reported the worst hand function and QOL. Bimanual functions involving finger mobility were the most challenging for all EB subtypes. QOL was highly related to the degree of hand function, being correlated with 20 of the 21 individual hand functions and most associated with the ability to perform unimanual functions. Parent‐ and patient‐reported hand function can be measured in children with EB using the ABILHAND‐Kids questionnaire. Hand impairment is strongly associated with worse QOL, probably due to difficulty performing daily activities. The effect of interventions such as hand surgery could be prospectively evaluated using this questionnaire.     

Graftskin therapy in epidermolysis bullosa

BACKGROUND: Epidermolysis bullosa (EB) is a family of 23 genetic skin disorders for which treatments are mainly supportive. Graftskin is a bilayered living human skin construct characterized by a normal expression profile of all the genes reported as mutant in EB. OBJECTIVE: The objective of this study was to evaluate the efficiency and durability of graftskin in the treatment of EB. METHODS: A total of 9 children with EB were treated with graftskin. These include EB simplex: Dowling-Meara type (n = 2); Weber-Cockayne type (n = 1); junctional EB-Herlitz type (n = 1); and recessive dystrophic EB (n = 5). Lesions were debrided of epidermis and crusts followed by application of fenestrated graftskin under sterile conditions. Syndactyly hand release for "mitten deformity" was performed after removal of all epidermis under general anesthesia. All treatment sites were dressed with a nonadherent contact layer followed by absorbent foam dressing, roll gauze, and a compression wrap covering and were left intact for 1 week. Graft take was assessed clinically at weeks 1, 2, 4, 12, and 20 to 28. Graft persistence was assessed by electron microscopy and polymerase chain reaction analysis at weeks 4 and 12, and between weeks 20 and 28 on selected cases. RESULTS: A total of 96 sites were treated with 90% to 100% healing observed by 5 to 7 days, and many sites appearing as normal skin by 10 to 14 days. Finger and hand lesions showed 50% to 90% improvement in range of motion over baseline. Two children learned to walk after graftskin treatment of chronic plantar lesions. Two children had improvement in their chronic anemia after graftskin treatment. All patients and/or parents reported rapid pain resolution. Immunologic and genetic studies of graft persistence revealed evidence of donor DNA up to 28 weeks after graftskin application. None of the samples from female patients demonstrated Y chromosome-specific sequence when analyzed by the method of short tandem repeat. CONCLUSION: The encouraging results reported herein support the hypothesis that graftskin is more than a simple bandage or a source of growth factors to stimulate autologous closure of EB wounds. The improved quality of life and rapid achievement of growth/development milestones we have observed makes this an exciting step forward in the care of the patient with EB.