IL-6 levels dominate the serum cytokine signature of severe epidermolysis bullosa: A prospective cohort study.

BACKGROUND: Systemic inflammation is considered a major player in the pathogenesis of epidermolysis bullosa (EB), but its pattern has only been described in small heterogeneous cohorts. There is controversy if and how systemic inflammation should be therapeutically targeted. METHODS: We examined serum proinflammatory, anti-inflammatory, and itch related cytokines in a paediatric cohort of 29 patients with junctional and dystrophic EB. The cytokine that emerged as the most relevant was measured in a validation cohort of 42 patients during follow-up visits over 2 years. RESULTS: IL-6 showed the most consistent and highest aberration dominating systemic inflammation. IL-6 correlated with wound body surface area (BSA) in both, finding and validation cohorts. Patients with less than 3% wound BSA had normal IL-6, while IL-6 levels significantly increased at more than 5% and 10% of wound BSA. TGF-ß was only marginally elevated in patients with severe recessive dystrophic EB, while TNF-α, IFN-γ and IL-1ß varied inconsistently. Patients reporting itch showed elevations in type 2 immunity (IgE, TSLP, IL4 and/or IL-31, respectively). CONCLUSIONS: Our data suggest a dominant skin barrier and wound healing inflammatory pattern in junctional and dystrophic EB that depends on the wound area and not on the EB type. In EB, itch mediators may be similar to other pruritic disorders.

Integrin α3 negative podocytes: A gene expression study.

Integrin α3ß1 is a cell adhesion receptor widely expressed in epithelial cells. Pathogenic variants in the gene encoding the integrin α3 subunit ITGA3 lead to a syndrome including interstitial lung disease, nephrotic syndrome, and epidermolysis bullosa (ILNEB). Renal involvement mainly consists of glomerular disease caused by loss of adhesion between podocytes and the glomerular basement membrane. The aim of this study was to characterize the impact of loss of integrin α3 on human podocytes. ITGA3 was stably knocked-out in the human podocyte cell line AB8/13, designated as PodoA3-, and in human proximal tubule epithelial cell line HK2 using the targeted genome editing technique CRISPR/Cas9. Cell clones were characterized by Sanger sequencing, quantitative PCR, Western Blot and immunofluorescence staining. RNASeq of integrin α3 negative cells and controls was performed to identify differential gene expression patterns. Differentiated PodoA3- did not substantially change morphology and adhesion under standard culture conditions, but displayed significantly reduced spreading and adhesion when seed on laminin 511 in serum free medium. Gene expression studies demonstrated a distinct dysregulation of the adhesion network with downregulation of most integrin α3 interaction partners. In agreement with this, biological processes such as "extracellular matrix organization" and "cell differentiation" as well as KEGG pathways such as "ECM-receptor interaction", "focal adhesion" and the "PI3K-Akt signaling pathway" were significantly downregulated in human podocytes lacking the integrin α3 subunit.

Proposal for a 6-step approach for differential diagnosis of neonatal erythroderma.

The broad differential diagnosis of neonatal erythroderma often poses a diagnostic challenge. Mortality of neonatal erythroderma is high due to complications of the erythroderma itself and the occasionally severe and life-threatening underlying disease. Early correct recognition of the underlying cause leads to better treatment and prognosis. Currently, neonatal erythroderma is approached on a case-by-case basis. The purpose of this scoping review was to develop a diagnostic approach in neonatal erythroderma. After a systematic literature search in Embase (January 1990 - May 2020, 74 cases of neonatal erythroderma were identified, and 50+ diagnoses could be extracted. Main causes were the ichthyoses (40%) and primary immunodeficiencies (35%). Congenital erythroderma was present in 64% (47/74) of the cases, predominantly with congenital ichthyosis (11/11; 100%), Netherton syndrome (12/14, 86%) and Omenn syndrome (11/23, 48%). Time until diagnosis ranged from 102 days to 116 days for cases of non-congenital erythroderma and congenital erythroderma respectively. Among the 74 identified cases a total of 17 patients (23%) died within a mean of 158 days and were related to Omenn syndrome (35%), graft-versus-host disease (67%) and Netherton syndrome (18%). Disease history and physical examination are summarized in this paper. Age of onset and a collodion membrane can help to narrow the differential diagnoses. Investigations of blood, histology, hair analysis, genetic analysis and clinical imaging are summarized and discussed. A standard blood investigation is proposed, and the need for skin biopsies with lympho-epithelial Kazal-type related Inhibitor staining is highlighted. Overall, this review shows that diagnostic procedures narrow the differential diagnosis in neonatal erythroderma. A 6-step flowchart for the diagnostic approach for neonatal erythroderma during the first month of life is proposed. The approach was made with the support of expert leaders from international multidisciplinary collaborations in the European Reference Network Skin-subthematic group Ichthyosis.

Practical management of epidermolysis bullosa: consensus clinical position statement from the European Reference Network for Rare Skin Diseases.

Inherited epidermolysis bullosa (EB) comprises rare disorders that manifest with fragility and blistering of the skin and mucous membranes, with variable clinical severity. Management of EB is challenging due to disease rarity and complexity, the wide range of extracutaneous manifestations and a profound impact on daily life for the patient and family members. Although reference centres providing multidisciplinary care for EB exist in each European country, it is common for healthcare professionals that are not specialized in this rare disorder to treat EB patients. Here, experts of the European Reference Network for Rare and Undiagnosed Skin Diseases (ERN-Skin, https://ern-skin.eu) propose practical recommendations for the diagnosis and management of the commonest clinical issues, skin blisters and wounds, oral manifestations, pain and itch.

High rate of self-improving phenotypes in children with non-syndromic congenital ichthyosis: case series from south-western Germany.

BACKGROUND: Non-syndromic congenital ichthyosis describes a heterogeneous group of hereditary skin disorders associated with erythroderma and scaling at birth. Although both severe and mild courses are known, the prediction of the natural history in clinical practice may be challenging. OBJECTIVES: To determine clinical course and genotype-phenotype correlations in children affected by non-syndromic congenital ichthyosis in a case series from south-western Germany. METHODS: We performed a retrospective observational study of 32 children affected by non-syndromic congenital ichthyoses seen in our genodermatosis clinic between 2011 and 2020. Follow-ups included assessment of weight and severity of skin involvement utilizing a modified Ichthyosis Area Severity Index (mIASI). mIASI was calculated as a sum comprising the previously published IASI score and an additional novel score to evaluate palmoplantar involvement. Linear regression was assessed using Pearson correlation, and statistical analysis was performed using the Wilcoxon-Mann-Whitney test. RESULTS: This study included 23 patients with autosomal recessive congenital ichthyosis, seven with keratinopathic ichthyosis and two with harlequin ichthyosis. Cutaneous manifestations improved in more than 70% of the children during the follow-up. Especially in patients with mutations in ALOXE3 and ALOX12B, mIASI scores dropped significantly. The most common phenotype observed in this study was designated 'mild fine scaling ichthyosis'. Severe palmoplantar involvement occurred in patients with KRT1 and ABCA12 mutations; most patients demonstrated hyperlinearity as a sign of dryness and scaling. Weight was mainly in the normal range and negatively correlated with the severity of skin involvement. CONCLUSIONS: Congenital ichthyosis that self-improves and evolves with mild fine scaling ichthyosis was the most common phenotype observed in our patients. This type might be underdiagnosed if the genetic diagnosis is not performed in the first year of life. mIASI is an easy and fast instrument for scoring disease severity and adding additional points for palmoplantar involvement might be valuable.

Prognostic assessment and management of a patient with Carmi syndrome. A case report.

Carmi syndrome is a rare and severe disease defined by pyloric atresia and junctional epidermolysis bullosa. There are no clear recommendations when to consider a curative therapy, including surgical repair of pyloric atresia and when to transition to palliative care. We report the case of a female preterm infant suffering from Carmi syndrome. After definitive diagnosis and appropriate ethical counselling, we decided for surgical repair of the pyloric atresia. Nonetheless, there was no clinical improvement and our patient died after 35 days. Reviewing the literature, we found immunofluorescence microscopy to be most decisive examination to determine the prognosis of this severe disease.

Plantar involvement correlates with obesity, pain and impaired mobility in epidermolysis bullosa simplex: a retrospective cohort study.

BACKGROUND: Epidermolysis bullosa simplex (EBS) is the most common type of EB, a group of rare genodermatoses. Affected individuals suffer from skin blistering and report a high disease burden. In some EBS subtypes, plantar keratoderma (PK) has been described. OBJECTIVES: This study investigated the presence and correlation of PK with body mass index, pain and mobility in EBS. METHODS: Individuals (n = 157) with genetically characterized EBS were included in this retrospective cohort study, and clinical data were collected over 16 years (referral patients to the largest German EB centre). Descriptive statistics and mixed linear models were used to assess correlations. RESULTS: PK was found in 75.8% of patients beginning at a mean age of 4.3 years. Both focal and diffuse PK were observed, and 60% of adults with localized and severe EBS were preobese or obese, with ˜30% of patients reporting severely reduced mobility. The presence of PK, especially diffuse PK, correlated significantly with local infections, obesity, pain and requirement of a wheelchair. CONCLUSION: Along with treating skin fragility and blistering, PK should be considered a potential marker of increased morbidity and may represent a target of EBS therapy development.

Rothmund-Thomson syndrome type 1 caused by biallelic ANAPC1 gene mutations.

Background: Rare syndromic skin disorders may represent a diagnostic challenge. Aims: We report a unique case associating cutaneous manifestations and developmental delay. Materials & Methods: The affected 14 months old boy had poikiloderma, facial dysmorphism with deep-set eyes, atrichia, as well as nail dysplasia and non-descended testes. In addition, his psychomotor development was delayed. Exome sequencing and molecular karyotyping via array-CGH (oligo-array, 180k Agilent, design 22060) were performed. Results: Mutations in RECQL4 (found in patients with RTS2) were first excluded. In the ANAPC1 gene, a novel combination of a recurrent intronic mutation (c.2705-198C>T) and a deletion of the second ANAPC1 allele was detected, thus confirming the clinical diagnosis of RTS1. The deletion on chromosome 2q13 comprised further genes and spanned 1,7 megabases. Heterozygous deletions in this region are known as 2q13 microdeletion syndrome and are associated with developmental delay, autism and facial dysmorphism. Discussion: The genetic findings most probably explain both, the RTS1 features and the developmental delay. Genetic diagnosis in RTS is indispensable to confirm the specific subtype and its associated risks: juvenile cataracts are features of RTS1 (ANAPC1 gene), whereas a high risk of osteosarcoma is part of RTS2 (RECQL4 gene). Thus, the patient described here is at high risk for the development of juvenile cataracts and requires regular ophthalmologic examination. Conclusion: This case report underlines the necessity of thorough clinical diagnosis prior to genetic diagnosis of RTS1, since the recurrent intronic ANAPC1 mutation is otherwise missed.

Aberrant splicing as potential modifier of the phenotype of junctional epidermolysis bullosa.

BACKGROUND: A lack or dysfunction of the anchoring protein laminin-332 in the basement membrane leads to the skin blistering disorder junctional epidermolysis bullosa (JEB). The mutation c.628G>A in the gene LAMB3 encoding the laminin ß3-chain is associated with generalized intermediate JEB; it may introduce an amino acid substitution (p.Glu210Lys) or disrupt splicing. OBJECTIVE: This retrospective study aimed at determining the effects of aberrant splicing on the JEB phenotype. METHODS: LAMB3 transcription was analysed in two siblings compound heterozygous for the LAMB3 mutations p.Glu210Lys and p.Arg635* with a diverging JEB phenotype from late childhood on. Laminin-332 levels in skin sections and in cultured keratinocytes were investigated by immunofluorescence staining. Real-time PCR was used to quantify LAMB3 expression in keratinocytes. RNA splice variants were identified by subcloning of a LAMB3 cDNA fraction and subsequent DNA sequencing. Structural models of laminin-332 helped to assess the impact of certain mutations on laminin-332 folding. RESULTS: Both siblings showed diminished LAMB3 expression. Laminin-332 was equally reduced in skin sections obtained during infancy but differed in keratinocytes isolated during adolescence. Although aberrant LAMB3 splicing with 26 variants was detected in both patients, splicing differed significantly: the full-length LAMB3 transcript harbouring the p.Glu210Lys mutation was found more often in the patient affected less severely (14/108 vs. 5/106 clones; P = 0.03). Structural modelling predicted that several deletions in LAMB3, but not the point mutation p.Glu210Lys, have an effect on laminin-332 folding and secretion. CONCLUSIONS: Differential LAMB3 mRNA splicing in the patients may explain the disparate JEB phenotype. By elucidating the regulation of laminin-332 gene expression, these findings may contribute to the development of therapeutic strategies for JEB and might help to understand phenotype modification by splice-site mutations in other hereditary diseases.

Consensus reclassification of inherited epidermolysis bullosa and other disorders with skin fragility.

BACKGROUND: Several new genes and clinical subtypes have been identified since the publication in 2014 of the report of the last International Consensus Meeting on Epidermolysis Bullosa (EB). OBJECTIVES: We sought to reclassify disorders with skin fragility, with a focus on EB, based on new clinical and molecular data. METHODS: This was a consensus expert review. RESULTS: In this latest consensus report, we introduce the concept of genetic disorders with skin fragility, of which classical EB represents the prototype. Other disorders with skin fragility, where blisters are a minor part of the clinical picture or are not seen because skin cleavage is very superficial, are classified as separate categories. These include peeling skin disorders, erosive disorders, hyperkeratotic disorders, and connective tissue disorders with skin fragility. Because of the common manifestation of skin fragility, these 'EB-related' disorders should be considered under the EB umbrella in terms of medical and socioeconomic provision of care. CONCLUSIONS: The proposed classification scheme should be of value both to clinicians and researchers, emphasizing both clinical and genetic features of EB. What is already known about this topic? Epidermolysis bullosa (EB) is a group of genetic disorders with skin blistering. The last updated recommendations on diagnosis and classification were published in 2014. What does this study add? We introduce the concept of genetic disorders with skin fragility, of which classical EB represents the prototype. Clinical and genetic aspects, genotype-phenotype correlations, disease-modifying factors and natural history of EB are reviewed. Other disorders with skin fragility, e.g. peeling skin disorders, erosive disorders, hyperkeratotic disorders, and connective tissue disorders with skin fragility are classified as separate categories; these 'EB-related' disorders should be considered under the EB umbrella in terms of medical and socioeconomic provision of care. Linked Comment: Pope. Br J Dermatol 2020; 183:603.

Skin fragility caused by biallelic KRT10 mutations: an intriguing form of self-improving epidermolytic ichthyosis.

Autosomal recessive epidermolytic ichthyosis is a rare skin condition associated with KRT10 loss-of-function mutations. It presents with severe life-threatening clinical manifestations. Here we describe a case of autosomal recessive epidermolytic ichthyosis with an unusually mild, spontaneously improving phenotype. Erythroderma and superficial blistering were present at birth, but the skin recovered and remained almost intact at the age of 1 year. Mild scaling on the neck and skin fragility manifesting as superficial erosions after scratching were the only clinical features as the child grew. As a cause, previously unreported compound heterozygous KRT10 pathogenic variants were found: a nonsense mutation leads to mRNA decay, while the other synonymous variant induces a leaky splice site, explaining the residual keratin 10 expression and mild clinical phenotype. What's already known about this topic? Autosomal recessive epidermolytic ichthyosis is a rare skin condition caused by loss-of-function KRT10 mutations. The clinical phenotype is severe with superficial skin blistering, scaling and hyperkeratosis. What does this study add? Here we extend the mutational and phenotypic spectrum of autosomal recessive epidermolytic ichthyosis. Our case presented with erythroderma and superficial blistering at birth, but the skin recovered and was almost intact at the age of 1 year. The only disease manifestations were mild scaling on the neck and skin fragility appearing as superficial erosions after scratching. The causative factors were found to be one nonsense mutation in KRT10 that leads to mRNA decay, and one synonymous variant that affects the donor splice site of exon 3. We hypothesize that this leaky splice site explains the residual keratin 10 expression and self-improving clinical phenotype.

Natural history of growth and anaemia in children with epidermolysis bullosa: a retrospective cohort study.

BACKGROUND: Impaired growth and anaemia are major extracutaneous complications of epidermolysis bullosa (EB), but data on their development are lacking. OBJECTIVES: To determine the clinical course of growth and anaemia in children with EB and clarify the impact of nutritional compromise, inflammation and genetic factors. METHODS: A retrospective study was conducted of 200 children, 157 with recessive dystrophic EB (RDEB) and 43 with junctional EB (JEB)-generalized intermediate, followed at the main referral centre in Germany. Growth charts were calculated using the modified LMS method and were correlated with parameters of anaemia, nutrition, inflammation and the molecular defect in a linear model. RESULTS: In our cohort of patients with RDEB, weight impairment started at 12-18 months old; by the age of 10 years, 50% showed wasting. The predicted median weight at age 20 years was 35·2 kg for men and 40·1 kg for women. In JEB, growth resembled that of healthy children. Anaemia was present from the second year of life onwards in RDEB and JEB. Low levels of haemoglobin, iron, vitamin D, zinc and albumin, high levels of C-reactive protein, and absence of collagen VII correlated significantly with low weight in RDEB. No correlation was observed in JEB. CONCLUSIONS: The results highlight that nutritional compromise occurs early in children with RDEB and therefore may require interventions as of the first year or two of life. What's already known about this topic? Children with epidermolysis bullosa (EB) suffer from failure to thrive and anaemia as major extracutaneous complications. The course of growth and the development of anaemia in EB are poorly characterized. What does this study add? A molecularly well characterized cohort of 200 children with EB was followed with regard to anthropometrics, anaemia and inflammation. We demonstrate early onset of growth failure and anaemia, most pronounced in the subset of recessive dystrophic EB. Awareness of early growth delay and nutritional deficiencies will improve EB care in daily practice.