Genotype-Phenotype Correlation in Junctional Epidermolysis Bullosa: Signposts to Severity.

Junctional epidermolysis bullosa (JEB) is a rare autosomal recessive genodermatosis with a broad spectrum of phenotypes. Current genotype-phenotype paradigms are insufficient to accurately predict JEB subtype and characteristics from genotype, particularly for splice site variants, which account for over a fifth of disease-causing variants in JEB. This study evaluated the genetic and clinical findings from a JEB cohort, investigating genotype-phenotype correlations through bioinformatic analyses and comparison with previously reported variants. Eighteen unique variants in LAMB3, LAMA3, LAMC2, or COL17A1 were identified from 17 individuals. Seven had severe JEB, 9 had intermediate JEB, and 1 had laryngo-onycho-cutaneous syndrome. Seven variants were previously unreported. Deep phenotyping was completed for all intermediate JEB cases and demonstrated substantial variation between individuals. Splice site variants underwent analysis with SpliceAI, a state-of-the-art artificial intelligence tool, to predict resultant transcripts. Predicted functional effects included exon skipping and cryptic splice site activation, which provided potential explanations for disease severity and in most cases correlated with laminin-332 immunofluorescence. RT-PCR was performed for 1 case to investigate resultant transcripts produced from the splice site variant. This study expands the JEB genomic and phenotypic landscape. Artificial intelligence tools show potential for predicting the functional effects of splice site variants and may identify candidates for confirmatory laboratory investigation. Investigation of RNA transcripts will help to further elucidate genotype-phenotype correlations for novel variants.

Epidermolysis bullosa.

Epidermolysis bullosa (EB) is an inherited, heterogeneous group of rare genetic dermatoses characterized by mucocutaneous fragility and blister formation, inducible by often minimal trauma. A broad phenotypic spectrum has been described, with potentially severe extracutaneous manifestations, morbidity and mortality. Over 30 subtypes are recognized, grouped into four major categories, based predominantly on the plane of cleavage within the skin and reflecting the underlying molecular abnormality: EB simplex, junctional EB, dystrophic EB and Kindler EB. The study of EB has led to seminal advances in our understanding of cutaneous biology. To date, pathogenetic mutations in 16 distinct genes have been implicated in EB, encoding proteins influencing cellular integrity and adhesion. Precise diagnosis is reliant on correlating clinical, electron microscopic and immunohistological features with mutational analyses. In the absence of curative treatment, multidisciplinary care is targeted towards minimizing the risk of blister formation, wound care, symptom relief and specific complications, the most feared of which - and also the leading cause of mortality - is squamous cell carcinoma. Preclinical advances in cell-based, protein replacement and gene therapies are paving the way for clinical successes with gene correction, raising hopes amongst patients and clinicians worldwide.

In utero development of epidermolysis bullosa acquisita.

We report the case of an infant born with perioral vesicles that rapidly spread to involve his mouth and the majority of his body. Histopathology, immunofluorescence, and enzyme-linked immunohistochemistry assays confirmed a diagnosis of epidermolysis bullosa acquisita (EBA). His mother had no history of EBA, and serum indirect immunofluorescence was negative. The patient improved rapidly with local wound care and oral dapsone.

Drug-induced linear IgA bullous dermatosis in a patient with a vancomycin-impregnated cement spacer.

Linear IgA bullous dermatosis (LABD) is an autoimmune blistering rash caused by IgA autoantibodies against the epidermal basement membrane zone. It commonly is drug induced, often in association with systemic vancomycin. We report a case of a previously healthy 77-year-old man who developed a diffuse macular rash and hemorrhagic bullae on the left leg 10 days after placement of a vancomycin-impregnated cement spacer (VICS) during a revision knee arthroplasty and initiation of postoperative treatment with intravenous (IV) vancomycin. The lesions initially were limited to the leg in which the hardware was placed, but the patient later developed painful palmoplantar and oropharyngeal blisters as well as edematous, erythematous plaques on the back and buttocks. A punch biopsy from a lesion on the left thigh revealed neutrophil-rich subepidermal bullae, and immunofluorescence revealed linear IgA and C3 deposition along the dermoepidermal junction, confirming a diagnosis of LABD. This report illustrates the importance of considering antibiotic-impregnated cement spacers, which frequently are used to manage prosthetic joint infections, as potential culprits in patients with cutaneous eruptions.

Erythematous plaques and papules on a premature infant.

A 2240 gram boy was born at 33.2 weeks gestation with nonblanching, deeply erythematous plaques and papules on the back, flanks, and scalp (Figure 1). His mother was GBS positive and on antibiotic suppression for prior cutaneous MRSA and urinary tract infections. Intrapartum intravenous Penicillin G was administered, and the amniotic sac was artificially ruptured 4 hours prior to delivery to facilitate labor. The delivery was uncomplicated without concern for chorioamnionitis, but the patient initially required CPAP for respiratory distress with 1-minute and 5-minute Apgar scores of 7 and 8, respectively. A skin punch biopsy is shown (Figure 2).

Epidemiology of Inherited Epidermolysis Bullosa Based on Incidence and Prevalence Estimates From the National Epidermolysis Bullosa Registry.

Importance: Accurate estimation of the incidence and prevalence of each subtype of epidermolysis bullosa (EB) is essential before clinical trials can be designed and sufficient funding allocated by government agencies and third-party insurers for the care of these individuals. Objective: To determine the incidence and prevalence of inherited EB stratified by subtype in the United States during a 16-year period. Design, Setting, and Participants: Prospective cross-sectional and longitudinal study. Data were obtained from 3271 patients consecutively enrolled in the National Epidermolysis Bullosa Registry from January 1, 1986, through December 31, 2002, using a detailed instrument created with the assistance of the National Institutes of Health. Analyses were performed in January 1999 and April 2015. Participants were patients of all ages with EB. Main Outcomes and Measures: Extensive clinical and laboratory data were collected on patients who were subclassified and serially revalidated based on published diagnostic recommendations by an international panel of experts. Pertinent to this report, estimates were made of the incidence and prevalence during 2 time frames. Results: During the first 5 years of funding of the registry, the overall incidence and prevalence of inherited EB were 19.60 and 8.22 per 1 million live births, respectively. When reassessed over the entire 16 years of the study, the prevalence rose to 11.07, whereas the overall incidence remained unchanged at 19.57 cases. Changes were also observed within some disease subsets as increased numbers of patients were identified, recruited, followed up longitudinally, and resubclassified as needed over time. For example, in 2002, the prevalence of EBS overall and localized EBS had increased considerably by 30.4% and 25.5%, respectively, whereas the prevalence of generalized intermediate EBS declined by 76.7% as a result of later subclassification of some of those patients into other subtypes. In contrast, no significant change was noted in the overall prevalence of JEB or generalized severe JEB, although there was a 73.0% decline in the prevalence of generalized intermediate JEB. Conclusions and Relevance: Precise estimates of the incidence and prevalence of each major subtype of inherited EB in the United States are now available that should assist investigators in choosing which subtypes are amenable to properly designed, large-scale, clinical trials.

Autoimmune bullous diseases with skin and eye involvement: Cicatricial pemphigoid, pemphigus vulgaris, and pemphigus paraneoplastica.

Autoimmune blistering diseases are a heterogeneous group of disorders that mostly affect the skin and mucous membranes. Occasionally, other organ systems may be involved, depending on the unique pathophysiology of each disease. Cicatricial pemphigoid, pemphigus vulgaris, and paraneoplastic pemphigus are distinct entities, but all have the potential to have cutaneous and ocular involvement. Awareness and early recognition of ocular involvement in these diseases is important given the increased risk for vision loss and blindness with delay in management. Several skin diseases may be associated with involvement of the external eye. The most common autoimmune diseases are cicatricial pemphigoid, pemphigus vulgaris, and paraneoplastic pemphigus.

Systemic granulocyte colony-stimulating factor (G-CSF) enhances wound healing in dystrophic epidermolysis bullosa (DEB): Results of a pilot trial.

BACKGROUND: Chronic nonhealing wounds are the norm in patients with inherited epidermolysis bullosa (EB), especially those with dystrophic EB (DEB). A possible benefit in wound healing after subcutaneous treatment with granulocyte colony-stimulating factor (G-CSF) was suggested from an anecdotal report of a patient given this during stem cell mobilization before bone-marrow transplantation. OBJECTIVE: We sought to determine whether benefit in wound healing in DEB skin might result after 6 daily doses of G-CSF and to confirm its safety. METHODS: Patients were assessed for changes in total body blister and erosion counts, surface areas of selected wounds, and specific symptomatology after treatment. RESULTS: Seven patients with DEB (recessive, 6; dominant, 1) were treated daily with subcutaneous G-CSF (10 µg/kg/dose) and reevaluated on day 7. For all patients combined, median reductions of 75.5% in lesional size and 36.6% in blister/erosion counts were observed. When only the 6 responders were considered, there were median reductions of 77.4% and 38.8% of each of these measured parameters, respectively. No adverse side effects were noted. LIMITATIONS: Limitations include small patient number, more than 1 DEB subtype included, and lack of untreated age-matched control subjects. CONCLUSIONS: Subcutaneous G-CSF may be beneficial in promoting wound healing in some patients with DEB when conventional therapies fail.

Inherited epidermolysis bullosa: updated recommendations on diagnosis and classification.

BACKGROUND: Several new targeted genes and clinical subtypes have been identified since publication in 2008 of the report of the last international consensus meeting on diagnosis and classification of epidermolysis bullosa (EB). As a correlate, new clinical manifestations have been seen in several subtypes previously described. OBJECTIVE: We sought to arrive at an updated consensus on the classification of EB subtypes, based on newer data, both clinical and molecular. RESULTS: In this latest consensus report, we introduce a new approach to classification ("onion skinning") that takes into account sequentially the major EB type present (based on identification of the level of skin cleavage), phenotypic characteristics (distribution and severity of disease activity; specific extracutaneous features; other), mode of inheritance, targeted protein and its relative expression in skin, gene involved and type(s) of mutation present, and--when possible--specific mutation(s) and their location(s). LIMITATIONS: This classification scheme critically takes into account all published data through June 2013. Further modifications are likely in the future, as more is learned about this group of diseases. CONCLUSION: The proposed classification scheme should be of value both to clinicians and researchers, emphasizing both clinical and molecular features of each EB subtype, and has sufficient flexibility incorporated in its structure to permit further modifications in the future.

Cumulative life course impairment by epidermolysis bullosa.

Inherited epidermolysis bullosa, which encompasses at least 30 distinctive genetic diseases, may be associated with marked functional impairment, the result of the presence of severe cutaneous and extracutaneous manifestations or complications in some of its subtypes.

Fibroblast-derived dermal matrix drives development of aggressive cutaneous squamous cell carcinoma in patients with recessive dystrophic epidermolysis bullosa.

Patients with the genetic skin blistering disease recessive dystrophic epidermolysis bullosa (RDEB) develop aggressive cutaneous squamous cell carcinoma (cSCC). Metastasis leading to mortality is greater in RDEB than in other patient groups with cSCC. Here we investigate the dermal component in RDEB using mRNA expression profiling to compare cultured fibroblasts isolated from individuals without cSCC and directly from tumor matrix in RDEB and non-RDEB samples. Although gene expression of RDEB normal skin fibroblasts resembled that of cancer-associated fibroblasts, RDEB cancer-associated fibroblasts exhibited a distinct and divergent gene expression profile, with a large proportion of the differentially expressed genes involved in matrix and cell adhesion. RDEB cancer-associated fibroblasts conferred increased adhesion and invasion to tumor and nontumor keratinocytes. Reduction of COL7A1, the defective gene in RDEB, in normal dermal fibroblasts led to increased type XII collagen, thrombospondin-1, and Wnt-5A, while reexpression of wild type COL7A1 in RDEB fibroblasts decreased type XII collagen, thrombospondin-1, and Wnt-5A expression, reduced tumor cell invasion in organotypic culture, and restricted tumor growth in vivo. Overall, our findings show that matrix composition in patients with RDEB is a permissive environment for tumor development, and type VII collagen directly regulates the composition of matrix proteins secreted by dermal and cancer-associated fibroblasts.

Inherited epidermolysis bullosa: recent basic and clinical advances.

PURPOSE OF REVIEW: This review highlights key findings, both clinical and basic, that have been published in the field of inherited epidermolysis bullosa within the past few years. RECENT FINDINGS: New epidermolysis bullosa phenotypes, genotypes and modes of transmission have been identified, resulting in a revised classification system. Detailed evidence-based data are now available on the risk of extracutaneous complications in each of the major epidermolysis bullosa subtypes. Studies are now underway to try to better explain the biological aggressiveness of squamous cell carcinomas arising in epidermolysis bullosa skin. Cell and animal models have been refined and used to ascertain the feasibility of gene replacement therapy, stem cell transplantation, and treatment with injected allogeneic fibroblasts or recombinant type VII collagen. As a result, clinical trials are now being pursued to test each of these in humans. SUMMARY: Epidermolysis bullosa is caused by mutations in at least 14 genes, leading to a broad spectrum of entities, each of which has its own relative risk for the development of specific extracutaneous complications and/or premature death. Intensive research, both basic and clinical, is bringing us closer to more effective treatments and possibly even a cure.

Inherited epidermolysis bullosa: past, present, and future.

Inherited epidermolysis bullosa encompasses dozens of diseases characterized by mechanical fragility of the skin, blister formation, and abnormal wound healing. Most of the more severe subtypes are associated with clinically significant extracutaneous complications. Some subtypes may lead to death, even in early infancy. Over the past two decades substantial advances have been made to our understanding of the underlying molecular basis for each member of this protean group of diseases. Research has now shifted toward the identification of therapeutic interventions, to include gene therapy, recombinant protein infusions, intradermal injection of allogeneic fibroblasts, and stem cell transplantation, that might eventually lead to a definitive cure for this disease. Other developing therapies being explored are directed toward the enhancement of wound healing and the prevention of potentially life-threatening skin cancers in these patients.

Inherited epidermolysis bullosa.

Inherited epidermolysis bullosa (EB) encompasses a number of disorders characterized by recurrent blister formation as the result of structural fragility within the skin and selected other tissues. All types and subtypes of EB are rare; the overall incidence and prevalence of the disease within the United States is approximately 19 per one million live births and 8 per one million population, respectively. Clinical manifestations range widely, from localized blistering of the hands and feet to generalized blistering of the skin and oral cavity, and injury to many internal organs. Each EB subtype is known to arise from mutations within the genes encoding for several different proteins, each of which is intimately involved in the maintenance of keratinocyte structural stability or adhesion of the keratinocyte to the underlying dermis. EB is best diagnosed and subclassified by the collective findings obtained via detailed personal and family history, in concert with the results of immunofluorescence antigenic mapping, transmission electron microscopy, and in some cases, by DNA analysis. Optimal patient management requires a multidisciplinary approach, and revolves around the protection of susceptible tissues against trauma, use of sophisticated wound care dressings, aggressive nutritional support, and early medical or surgical interventions to correct whenever possible the extracutaneous complications. Prognosis varies considerably and is based on both EB subtype and the overall health of the patient.

A mouse model of generalized non-Herlitz junctional epidermolysis bullosa.

Epidermolysis bullosa (EB) is a class of intractable, rare, genetic disorders characterized by fragile skin and blister formation as a result of dermal-epidermal mechanical instability. EB presents with considerable clinical and molecular heterogeneity. Viable animal models of junctional EB (JEB), that both mimic the human disease and survive beyond the neonatal period, are needed. We identified a spontaneous, autosomal recessive mutation (Lamc2(jeb)) due to a murine leukemia virus long terminal repeat insertion in Lamc2 (laminin gamma2 gene) that results in a hypomorphic allele with reduced levels of LAMC2 protein. These mutant mice develop a progressive blistering disease validated at the gross and microscopic levels to closely resemble generalized non-Herlitz JEB. The Lamc2(jeb) mice display additional extracutaneous features such as loss of bone mineralization and abnormal teeth, as well as a respiratory phenotype that is recognized but not as well characterized in humans. This model faithfully recapitulates human JEB and provides an important preclinical tool to test therapeutic approaches.