Diagnostic Pitfalls in Newborns and Babies with Blisters and Erosions

Establishing the correct diagnosis in newborns presenting with blisters and erosions is not always a straightforward process. Many different disease entities including acquired (i.e., infectious, immunobullous, traumatic) and inherited disorders have to be taken into consideration. Similarities in clinical appearance, colonization and/or superinfections of preexisting skin lesions, as well as the absence of late changes in the neonate often pose significant diagnostic challenges. In this paper we discuss by giving examples the process of making an accurate diagnosis of blistering skin diseases in the neonatal period on the basis of a diagnostic algorithm. In addition, we provide an overview of the rational use and the limitations of laboratory procedures such as microbial testing, routine light microscopy, immunofluorescence antigen mapping, transmission electron microscopy, and molecular genetic analysis

Functional Correction of Type VII Collagen Expression in Dystrophic Epidermolysis Bullosa

Functional defects in type VII collagen, caused by premature termination codons on both alleles of the COL7A1 gene, are responsible for the severe autosomal recessive types of the skin blistering disease, recessive dystrophic epidermolysis bullosa (RDEB). The full-length COL7A1 complementary DNA (cDNA) is about 9kb, a size that is hardly accommodated by therapeutically used retroviral vectors. Although there have been successful attempts to produce functional type VII collagen protein in model systems of RDEB, the risk of genetic rearrangements of the large repetitive cDNA sequence may hamper the clinical application of full-length COL7A1 cDNA in the human system. Therefore, we used trans-splicing to reduce the size of the COL7A1 transcript. Retroviral transduction of RDEB keratinocytes with a 3′ pre-trans-splicing molecule resulted in correction of full-length type VII collagen expression. Unlike parental RDEB keratinocytes, transduced cells displayed normal morphology and reduced invasive capacity. Moreover, transduced cells showed normal localization of type VII collagen at the basement membrane zone in skin equivalents, where it assembled into anchoring fibril-like structures. Thus, using trans-splicing we achieved correction of an RDEB phenotype in vitro, which marks an important step toward its application in gene therapy in vivo.JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://www.nature.com/jid/journalclu

Cells from discarded dressings differentiate chronic from acute wounds in patients with Epidermolysis Bullosa

Impaired wound healing complicates a wide range of diseases and represents a major cost to healthcare systems. Here we describe the use of discarded wound dressings as a novel, cost effective, accessible, and non-invasive method of isolating viable human cells present at the site of skin wounds. By analyzing 133 discarded wound dressings from 51 patients with the inherited skin-blistering disease epidermolysis bullosa (EB), we show that large numbers of cells, often in excess of 100 million per day, continually infiltrate wound dressings. We show, that the method is able to differentiate chronic from acute wounds, identifying significant increases in granulocytes in chronic wounds, and we show that patients with the junctional form of EB have significantly more cells infiltrating their wounds compared with patients with recessive dystrophic EB. Finally, we identify subsets of granulocytes and T lymphocytes present in all wounds paving the way for single cell profiling of innate and adaptive immune cells with relevance to wound pathologies. In summary, our study delineates findings in EB that have potential relevance for all chronic wounds, and presents a method of cellular isolation that has wide reaching clinical application

MMP-9 and CXCL8/IL-8 are potential therapeutic targets in epidermolysis bullosa simplex.

Epidermolysis bullosa refers to a group of genodermatoses that affects the integrity of epithelial layers, phenotypically resulting in severe skin blistering. Dowling-Meara, the major subtype of epidermolysis bullosa simplex, is inherited in an autosomal dominant manner and can be caused by mutations in either the keratin-5 (K5) or the keratin-14 (K14) gene. Currently, no therapeutic approach is known, and the main objective of this study was to identify novel therapeutic targets. We used microarray analysis, semi-quantitative real-time PCR, western blot and ELISA to identify differentially regulated genes in two K14 mutant cell lines carrying the mutations K14 R125P and K14 R125H, respectively. We found kallikrein-related peptidases and matrix metalloproteinases to be upregulated. We also found elevated expression of chemokines, and we observed deregulation of the Cdc42 pathway as well as aberrant expression of cytokeratins and junction proteins. We further demonstrated, that expression of these genes is dependent on interleukin-1 β signaling. To evaluate these data in vivo we analysed the blister fluids of epidermolysis bullosa simplex patients vs. healthy controls and identified matrix metalloproteinase-9 and the chemokine CXCL8/IL-8 as potential therapeutic targets

Summarized patient data.

*<p>P, phenotype: mi, mild; me, medium; se, severe.</p>**<p>Age at time of sample collection.</p>***<p>Two or more blisters collected from different locations and pooled. Abbr.: BB, burn blister; CD, clinical diagnosis; del, deletion; dup, duplication; EBS-DM, EBS Dowling-Meara; EBS-K, EBS Koebner (EBS generalized other); EBS-MD, EBS with muscular dystrophy; EBS-WC, EBS Weber-Cockayne (EBS localized); ex, exon; ins, insertion; MB, mechanical blister.</p

Microarray analysis of C-X-C chemokines.

<p>Microarray analysis of C-X-C chemokines.</p

Expression of chemokines.

<p><b>A.</b> SQRT-PCR of chemokine mRNA expression in NEB-1, KEB-7 and EBDM-1 (n = 3 to n = 5). <i>CXCL1</i>, <i>CXCL8/IL-8</i> and <i>CXCL14</i> expression was increased in KEB-7. Only <i>CXCL11</i> and <i>CXCL14</i> were increased in EBDM-1. <b>B.</b> CXCL8/IL-8 ELISA of 48-h-conditioned cell culture supernatant showed 2-fold upregulation at the protein level in KEB-7 but not in EBDM-1, which correlates with the SQRT-PCR results (n = 4). <b>C.</b> CXCL8/IL-8 concentrations were highly increased in EBS patients blister fluids. In blister fluids of healthy controls no CXCL8/IL-8 was detectable (n = 3 to n = 4). The numbers correlate with <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070123#pone-0070123-t001" target="_blank">Table 1</a>. Student’s <i>t</i>-test was performed with p values: * ≤0.05, *** ≤0.005, Δ≤0.001, ‡ = no significant difference between investigated cell lines. (In 6C, the Student’s <i>t</i>-test compared the entire patient group to the entire control group).</p