Topical immunotherapy with diphenylcyclopropenone of patients with alopecia areata--a large retrospective study on 142 patients with a self-controlled design

BACKGROUND

Although diphenylcyclopropenone (DCP) is frequently used for the treatment of alopecia areata (AA), large studies with more than 100 patients are still scarce.

OBJECTIVE

To determine the efficacy of DCP immunotherapy in a large cohort of patients with AA who had been treated in our institute from January 2000 to December 2006.

METHODS

A total of 142 patients with AA undergoing topical DCP therapy in a self-controlled design were evaluated retrospectively.

RESULTS

Seven patients (4.9%) were anergic to DCP. Two of 135 patients (1.5%) discontinued DCP therapy because of adverse effects. Fifty-one patients (37.8%) had a complete response (CR: >90% re-growth of hair), 20 patients (14.8%) exhibited a partial response (PR: >50-90% re-growth), 26 patients (19.3%) experienced a minimal response (MR: 10-50% re-growth) and 38 patients (28.1%) had no response after DCP therapy (NR: <10% re-growth). Bivariate logistic analysis revealed that severity of hair loss at the beginning of DCP (P=0.001) is the only significant prognostic factor for therapeutic outcome. Twenty-three patients (45.1%) with CR had relapses upon discontinuation of the treatment or even during prolonged DCP therapy.

CONCLUSION

Topical immunotherapy with DCP of patients with AA is rather effective and mostly well tolerated. The extent of hair loss before therapy is the main predictor for the therapeutic success of DCP. However, DCP therapy is associated with a high degree of relapse of which patients should be well informed.

Expanding the keratin mutation database: novel and recurrent mutations and genotype-phenotype correlations in 28 patients with epidermolytic ichthyosis

BACKGROUND

Epidermolytic ichthyosis (EI) is a hereditary keratinization disorder caused by mutations in the keratin 1 (KRT1) or keratin 10 (KRT10) genes. In most cases of severe EI, heterozygous single point mutations are found at the highly conserved helix boundary motifs of KRT1 and KRT10 that play a critical role in filament formation. The presence of palmoplantar keratoderma suggests KRT1 mutations, whereas KRT10 mutations in most instances give rise to the nonpalmoplantar variants.

OBJECTIVES

To identify the underlying mutations in patients with EI and to correlate genotype and phenotype.

METHODS

Mutation analysis was performed in 28 patients with EI by direct sequencing of KRT1 and KRT10 genes.

RESULTS

We identified 14 different mutations, of which four have not been published previously.

CONCLUSIONS

Identification of novel mutations and genotype-phenotype correlations in EI allows improved understanding of disease pathogenesis as well as better patient management.

Loss of corneodesmosin leads to severe skin barrier defect, pruritus, and atopy: unraveling the peeling skin disease

Generalized peeling skin disease is an autosomal-recessive ichthyosiform erythroderma characterized by lifelong patchy peeling of the skin. After genome-wide linkage analysis, we have identified a homozygous nonsense mutation in CDSN in a large consanguineous family with generalized peeling skin, pruritus, and food allergies, which leads to a complete loss of corneodesmosin. In contrast to hypotrichosis simplex, which can be associated with specific dominant CDSN mutations, peeling skin disease is characterized by a complete loss of CDSN expression. The skin phenotype is consistent with a recent murine Cdsn knockout model. Using three-dimensional human skin models, we demonstrate that lack of corneodesmosin causes an epidermal barrier defect supposed to account for the predisposition to atopic diseases, and we confirm the role of corneodesmosin as a decisive epidermal adhesion molecule. Therefore, peeling skin disease will represent a new model disorder for atopic diseases, similarly to Netherton syndrome and ichthyosis vulgaris in the recent past.

Processing of procollagen III by meprins: new players in extracellular matrix assembly?

Meprins α and β, a subgroup of zinc metalloproteinases belonging to the astacin family, are known to cleave components of the extracellular matrix, either during physiological remodeling or in pathological situations. In this study we present a new role for meprins in matrix assembly, namely the proteolytic processing of procollagens. Both meprins α and β release the N- and C-propeptides from procollagen III, with such processing events being critical steps in collagen fibril formation. In addition, both meprins cleave procollagen III at exactly the same site as the procollagen C-proteinases, including bone morphogenetic protein-1 (BMP-1) and other members of the tolloid proteinase family. Indeed, cleavage of procollagen III by meprins is more efficient than by BMP-1. In addition, unlike BMP-1, whose activity is stimulated by procollagen C-proteinase enhancer proteins (PCPEs), the activity of meprins on procollagen III is diminished by PCPE-1. Finally, following our earlier observations of meprin expression by human epidermal keratinocytes, meprin α is also shown to be expressed by human dermal fibroblasts. In the dermis of fibrotic skin (keloids), expression of meprin α increases and meprin β begins to be detected. Our study suggests that meprins could be important players in several remodeling processes involving collagen fiber deposition.

Ichthyosis: clinical manifestations and practical treatment options

Ichthyoses constitute a large group of cornification disorders that affect the entire integument. The skin is characterized by visible scaling and in many cases by inflammation, for example, in bullous/keratinopathic ichthyosis or Netherton syndrome. From the viewpoint of classification it is useful to distinguish non-syndromic from syndromic types of ichthyosis. Ichthyosis vulgaris and recessive X-linked ichthyosis are common disorders - often of delayed onset, in contrast to congenital ichthyoses, which belong to the group of rare diseases and present at birth with either the features of collodion membrane or congenital ichthyosiform erythroderma. The diagnostic steps are based on clinical data, analyses such as the steroid sulfatase activity test, skin biopsies, and genetic results. However, the dramatic increase in knowledge about the pathophysiology of these conditions has not led to a curative therapy so far. The therapeutic management is multidisciplinary and involves ichthyosis patient organizations in many countries. The mainstay of treatment remains with moisturizing creams containing, for example, urea, lactic acid and other humectants and keratolytics, regular bathing, and mechanical scale removal. Patients with lamellar ichthyosis or ichthyosiform erythroderma in particular profit from oral therapy with retinoids or retinoic acid metabolism-blocking agents.

Ichthyoses--Part 2: Congenital ichthyoses

Congenital ichthyoses are a group of genetic disorders with defective cornification, clinically characterized by scaling of the skin. Additionally, distinctive cutaneous inflammation can often be observed. For most of the patients these diseases lead to a significant restriction in quality of life. The diagnostic hallmarks are discussed. The diagnostic criteria include clinical and histological findings, often enhanced or confirmed by specialized tests. Because many of the congenital ichthyoses are extremely rare, their accurate diagnosis is often carried out in specialized centers. After discussing the vulgar ichthyoses as well as the diagnostic and therapeutic options in part one, in this second part we review congenital ichthyoses both with and without associated symptoms, focusing on the common genetic changes and their clinical phenotype. Specific therapies are still not available for most of these disorders. The use of different topical agents (e. g. urea, retinoids and salicylic acid) and baths followed by mechanical keratolysis (sometimes in combination with systemic retinoids) reduce skin symptoms. Patients with uncommon congenital ichthyoses often benefit from interdisciplinary management which involves specialized dermatological centers.

Ichthyoses - Part 1: Differential diagnosis of vulgar ichthyoses and therapeutic options

Ichthyoses are a group of genetic disorders with defective cornification, clinically characterized by scaling of the skin. Additionally, distinctive cutaneous inflammation can often be observed. For most of the patients these diseases lead to a significant restriction in quality of life. The diagnostic criteria include clinical and histological findings, often confirmed by specialized tests. Because many of the ichthyoses are extremely rare, their accurate diagnosis is often carried out in specialized centers. We summarize isolated vulgar and congenital ichthyoses both with and without associated symptoms and focus on the common genetic changes and their clinical phenotype. Specific therapies are still not available for most of these genetic disorders. The use of different topical agents (e. g. urea, retinoids and salicylic acid) and baths followed by mechanical keratolysis (sometimes in combination with systemic retinoids) reduce symptoms. Patients with uncommon congenital ichthyoses often benefit from interdisciplinary management which involves specialized dermatological centers. In this first part of the paper the vulgar ichthyoses as well as the diagnostic and therapeutic options are discussed. The second part focuses on the congenital ichthyoses and their differential diagnosis.

Characterisation of psoriasis susceptibility locus 6 (PSORS6) in patients with early onset psoriasis and evidence for interaction with PSORS1

BACKGROUND

Psoriasis is a genetically complex, chronic inflammatory skin disease. The authors have previously identified a susceptibility locus on chromosome 19p13 (PSORS6).

METHODS AND RESULTS

In a follow-up linkage disequilibrium (LD) study in an independent family based cohort, the authors found evidence for association to a newly discovered microsatellite at this locus (D19SPS21, p<5.3x10(-5)). An LD based association scan in 300 trios revealed association to several single, single nucleotide polymorphisms (SNPs) in one LD block. When the authors stratified this cohort for carrying the PSORS1 risk allele at the HLA-C locus, evidence for association became much stronger at single SNP and haplotype levels (p values between 1.0x10(-4) and 8.0x10(-4)). In a replication study of 1114 patients and 937 control individuals, evidence for association was also observed after stratification to the PSORS1 risk allele. In both study groups, logistic regression showed evidence for interaction between the risk alleles at PSORS1 and PSORS6. Best p values for rs12459358 in both study groups remained significant after correction for multiple testing. The associated LD block did not comprise any known genes. Interestingly, an adjacent gene, MUC16, coding for a large glycosylated protein expressed in epithelia and of unknown function, could be shown to be also expressed in tissues relevant for pathogenesis of psoriasis such as skin and thymus. Immunohistochemical analyses of skin revealed focal staining for MUC16 in suprabasal epidermal cells. Further functional studies are required to clarify its potential role in psoriasis and identify the causal variant(s) at this locus.

CONCLUSION

The data establish PSORS6 as a confirmed psoriasis susceptibility locus showing interaction with PSORS1.

Deletion of LCE3C and LCE3B genes at PSORS4 does not contribute to susceptibility to psoriatic arthritis in German patients

Introduction

Psoriasis susceptibility locus 4 (PSORS4) is a susceptibility locus for psoriasis vulgaris (PsV), a common inflammatory, hyperproliferative skin disorder. Recently, a deletion of 2 late cornified envelope (LCE) genes within epidermal differentiation complex on chromosome 1 was shown to be enriched in 1426 patients with PsV, suggesting compromised barrier function in deletion carriers. This genetic association was subsequently confirmed in a German cohort.

Methods

In order to investigate whether this variant also predisposes to psoriatic arthritis (PsA), this deletion and 3 single nucleotide polymorphisms (SNPs) in strong linkage disequilibrium with it were genotyped in a case-control cohort of 650 patients and 937 control individuals of German origin.

Results

LCE deletion frequency did not significantly differ between patients with PsA and controls (65.0% vs 65.5%). Similarly, no evidence for association to the three SNPs was observed.

Discussion

This is the first non-human leucocyte antigen (HLA) risk factor predisposing only to skin type of psoriasis, supporting the concept of partially overlapping but different aetiological factors underlying skin and joint manifestations.

Ichthyosis vulgaris: novel FLG mutations in the German population and high presence of CD1a+ cells in the epidermis of the atopic subgroup

BACKGROUND

Ichthyosis vulgaris (IV) is a genetic disorder with a prevalence of 1:250-1000 caused by filaggrin (FLG) mutations, which also predispose to atopic diseases.

OBJECTIVES

To study the genotype/phenotype relationship in IV and to analyse whether the suggested skin barrier defect is associated with differences of epidermal dendritic cells.

PATIENTS/METHODS

We evaluated a cohort of 26 German patients with IV, established an IV severity score and analysed epidermal ultrastructure, histology, filaggrin and CD1a antigens. Mutations were screened by restriction enzyme analysis. Particular sequencing techniques allowed the complete FLG analysis to reveal novel mutations.

RESULTS

The combined null allele frequency of R501X and 2282del4 was 67.3%. Patients also showed the mutations S3247X and R2447X as well as five novel FLG mutations: 424del17 and 621del4 (profilaggrin S100 domain), 2974delGA (repeat 2), R3766X (repeat 10(1)) and E4265X (repeat 10(2)). Their combined allele frequency in controls was <0.7%. No mutation was found in one IV patient, all in all approximately 27% were heterozygous, and the majority (approximately 69%) showed two null alleles. The IV severity score and ultrastructure showed a significant correlation with genotypes. Interestingly, CD1a cell counts showed a significant difference between nonatopic and atopic IV patients both with eczema and without eczema.

CONCLUSIONS

We confirm that the mutations R501X and 2282del4 represent the most frequent genetic cause in German IV patients. The novel mutations are probably population and family specific. The observed differences of CD1a cells support the hypothesis that there is a barrier defect that predisposes to atopic manifestations, possibly independent of atopic eczema.

Genetic variants of the IL-23R pathway: association with psoriatic arthritis and psoriasis vulgaris, but no specific risk factor for arthritis

Variants in two genes of the IL-23 receptor (R) pathway have recently been shown to be associated with psoriasis vulgaris (PV). We were interested whether the risk conferred by these variants differs between psoriatic skin and joint disease. Four variants of the IL12B and IL23R genes were analyzed in 1,114 PV patients, 748 patients with psoriatic arthritis (PA) and 937 healthy controls before and after stratification for the major psoriasis risk allele at psoriasis susceptibility locus 1 (PSORS1). For both PA and PV, we detected the strongest association with two IL12B single-nucleotide polymorphisms and the corresponding haplotype as reflected by minimal P-values of 10(-7) and highest odds ratios of 1.50 (1.28-1.75) for rs6887695 in PA patients and 1.50 (1.27-1.76) for rs3212227 in the PV cohort, respectively. For IL23R, only rs11209026 showed an association. The results remained significant after correction for multiple testing. No difference was observed after stratification for the PSORS1 risk allele. While confirming recent reports on variants of the IL-23R pathway as susceptibility factors for PV, our study is the first to extend analysis of both genes to PA. However, our results indicate that these variants are not specific risk factors for arthritis, but relevant for susceptibility to psoriasis in general.

[The situation of rare skin diseases in Germany]

In Germany a disease is considered to be "rare" when its prevalence is less than 5:10,000. However, as far as genetic skin diseases are concerned, they are often much more uncommon with a prevalence in the range of 1:100,000. Currently considerable deficits prevail in both diagnosis and treatment of rare skin diseases. Driven by scientific research on rare skin diseases and benefiting from start-up grants of the Federal Ministry for Education and Research (BMBF), the following networks for rare skin diseases were formed: a) epidermolysis bullosa, b) ichthyosis and related keratinisation disorders, c) systemic scleroderma. From a scientific point of view these networks are very successful, they publish in high impact journals and at the same time developed into national centres of reference for the respective disease groups, although formally this status does not exist in Germany. Thus, the 5 year start-up grants considerably improved the clinical care for these three skin disease groups. However, now we are confronted with the threat that the newly formed structures will be difficult to maintain, due to lack of adequate financing. In contrast to France, Germany does not have a "national plan for rare diseases"--probably because the federal structure in Germany is difficult to reconcile with "national plans". In France the situation of clinical care for rare diseases is permanently restructured by the establishment of official national reference centres and by allocation of additional financial means to fulfill these national tasks. In our view, a similar approach is also necessary in Germany.

Deficiency of PORCN, a regulator of Wnt signaling, is associated with focal dermal hypoplasia

Focal dermal hypoplasia (FDH) is an X-linked dominant multisystem birth defect affecting tissues of ectodermal and mesodermal origin. Using a stepwise approach of (i) genetic mapping of FDH, (ii) high-resolution comparative genome hybridization to seek deletions in candidate chromosome areas and (iii) point mutation analysis in candidate genes, we identified PORCN, encoding a putative O-acyltransferase and potentially crucial for cellular export of Wnt signaling proteins, as the gene mutated in FDH. The findings implicate FDH as a developmental disorder caused by a deficiency in PORCN.

Lung Transplantation in the Fischer 344→Wistar Kyoto Rat Strain Combination is Not Suitable to Study Bronchiolitis Obliterans

BACKGROUND

To elucidate the pathogenesis of bronchiolitis obliterans (BO) a reliable animal model is needed. According to the literature, lung transplantation from Fischer 344 (F344) to Wistar Kyoto (WKY) rats is the only model that reliably results in BO without a further stimulus.

METHODS

We performed orthotopic left lung transplantation in F344 to WKY rats and in both isogeneic rat strain combinations. Suture and cuff techniques for anastomosis were compared. The time course of rejection and the morphology of the bronchial anastomoses were documented by repeated flat-panel volumetric computed tomography (fpVCT) in the living animal. Graft histopathology was analyzed 3 months post-transplant.

RESULTS

According to the graft outcome, as revealed by fpVCT, grafts were sub-divided into two groups: In Group 1, infiltrates due to acute rejection occurred early after transplantation and resolved thereafter. Graft histopathology showed minor changes but no BO. In Group 2, acute rejection caused total atelectasis that never resolved. After 3 months, grafts were shrunken and exhibited tissue remodeling with some similarities to BO. No correlation between graft outcome and anastomotic technique was apparent.

CONCLUSIONS

Modeling lung transplantation using the F344-to-WKY combination is without clinical relevance because BO does not develop in grafts with life-sustaining function. Consecutive fpVCT is useful to monitor pathologic changes in rat pulmonary grafts.

Loss-of-function variants of the filaggrin gene are not major susceptibility factors for psoriasis vulgaris or psoriatic arthritis in German patients

Psoriasis vulgaris and atopic dermatitis share a number of features such as chronic cutaneous inflammation and disturbed epidermal barrier function. Genome-wide scans have revealed a conspicuous overlap of susceptibility loci for both diseases involving chromosomal regions 1q21, 3q21, 17q25, and 20p12. Recently, two loss-of-function variants in the gene encoding filaggrin at 1q21 were shown to be strongly associated with atopic dermatitis. In view of a possible genetic overlap of the two skin diseases, we investigated 375 patients suffering from psoriasis vulgaris, 375 patients with psoriatic arthritis, and 376 control probands. Moreover we directly studied expression of filaggrin in 10 patients suffering from psoriasis vulgaris. Our immunohistochemical analysis revealed a checkered pattern with alternating positive broadened or almost absent filaggrin expression. However, no association was found for the two variants of filaggrin (FLG). We conclude that despite a markedly altered filaggrin expression in psoriatic skin, loss-of-function variants of the FLG gene are neither associated with psoriasis vulgaris nor with psoriatic arthritis. The abnormal staining might reflect the altered epidermal differentiation. Our findings imply that the genetic background underlying the epidermal barrier defect in psoriasis is distinct from that found in atopic dermatitis.

The alpha and beta subunits of the metalloprotease meprin are expressed in separate layers of human epidermis, revealing different functions in keratinocyte proliferation and differentiation

The zinc endopeptidase meprin (EC 3.4.24.18) is expressed in brush border membranes of intestine and kidney tubules, intestinal leukocytes, and certain cancer cells, suggesting a role in epithelial differentiation and cell migration. Here we show by RT-PCR and immunoblotting that meprin is also expressed in human skin. As visualized by immunohistochemistry, the two meprin subunits are localized in separate cell layers of the human epidermis. Meprin alpha is expressed in the stratum basale, whereas meprin beta is found in cells of the stratum granulosum just beneath the stratum corneum. In hyperproliferative epidermis such as in psoriasis vulgaris, meprin alpha showed a marked shift of expression from the basal to the uppermost layers of the epidermis. The expression patterns suggest distinct functions for the two subunits in skin. This assumption is supported by diverse effects of recombinant meprin alpha and beta on human adult low-calcium high-temperature keratinocytes. Here, beta induced a dramatic change in cell morphology and reduced the cell number, indicating a function in terminal differentiation, whereas meprin alpha did not affect cell viability, and may play a role in basal keratinocyte proliferation.

TNF polymorphisms in psoriasis: Association of psoriatic arthritis with the promoter polymorphismTNF*-857 independent of thePSORS1 risk allele

OBJECTIVE

Single-nucleotide polymorphisms (SNPs) of the tumor necrosis factor gene TNF at positions -238 and -308 have been associated with psoriasis vulgaris and psoriatic arthritis (PsA). The strong linkage disequilibrium (LD) at chromosome region 6p21, a region known to harbor risk factors for psoriasis susceptibility (PSORS1) other than just SNPs of the TNF gene, renders the interpretation of these findings difficult. The aim of this study was to analyze several SNPs of the TNF gene and its neighboring LTA gene for independent and dependent carriage of the PSORS1 risk allele.

METHODS

SNPs in the promoter of the TNF (-238G/A, -308G/A, -857C/T, and -1031T/C), LTA (+252A/G), TNLFRSF1A (+36A/G), and TNLFRSF1B (+676T/G) genes were genotyped in 375 psoriasis patients, 375 PsA patients, and 376 controls. The Trp- Trp-Cys-Cys haplotype of the CCHCR1 gene (CCHCR1*WWCC) was used as an estimate of the risk allele PSORS1.

RESULTS

Whereas we were able to confirm the previously described strong association of allele TNF*-238A with psoriasis, our study revealed that this association was completely dependent on carriage of the PSORS1 risk allele. For PsA, but not psoriasis vulgaris without joint involvement, a strong association with the allele TNF*-857T (odds ratio 1.956 [95% confidence interval 1.334-2.881]; corrected P = 0.0025) was also detected in patients negative for the PSORS1 risk allele.

CONCLUSION

Our results indicate that there are genetic differences between psoriasis vulgaris patients with and without joint manifestations. While the previously reported association between TNF*-238A and psoriasis seems to primarily reflect LD with PSORS1, TNF*-857T may represent a risk factor for PsA that is independent of the PSORS1 allele.

Bathing suit ichthyosis is caused by transglutaminase-1 deficiency: evidence for a temperature-sensitive phenotype

Bathing suit ichthyosis (BSI) is a striking and unique clinical form of autosomal recessive congenital ichthyosis characterized by pronounced scaling on the bathing suit areas but sparing of the extremities and the central face. Here we report on a series of 10 BSI patients. Our genetic, ultrastructural and biochemical investigations show that BSI is caused by transglutaminase-1 (TGase-1) deficiency. Altogether, we identified 13 mutations in TGM1-among them seven novel missense mutations and one novel nonsense mutation. Structural modeling for the Tyr276Asn mutation reveals that the residue is buried in the hydrophobic interior of the enzyme and that the hydroxyl side chain of Tyr276 is exposed to solvent in a cavity of the enzyme. Cryosections of healthy skin areas demonstrated an almost normal TGase activity, in contrast to the affected BSI skin, which only showed a cytoplasmic and clearly reduced TGase-1 activity. The distribution of TGase-1 substrates in the epidermis of affected skin corresponded to the situation in TGase-1 deficiency. Interestingly, the expression of TGase-3 and cathepsin D was reduced. Digital thermography validated a striking correlation between warmer body areas and presence of scaling in patients suggesting a decisive influence of the skin temperature. In situ TGase testing in skin of BSI patients demonstrated a marked decrease of enzyme activity when the temperature was increased from 25 to 37 degrees C. We conclude that BSI is caused by TGase-1 deficiency and suggest that it is a temperature-sensitive phenotype.

Ichthyoses: differential diagnosis and molecular genetics

Ichthyoses are a heterogeneous group of cornification disorders characterized by a generalized scaling of the skin. Common types such as ichthyosis vulgaris and X-linked recessive ichthyosis manifest after birth. In contrast, rare congenital ichthyoses are inherited diseases, which at birth typically present collodion membranes or ichthyosiform erythroderma. Syndromic ichthyoses display a variety of outstanding associated non-cutaneous symptoms. Because of their rarity these disorders often pose a diagnostic challenge for the clinician. This review discusses a broad spectrum of 13 isolated types of ichthyoses, 11 different syndromes with associated ichthyosis and four related cornification disorders. The clinical, ultrastructural and biochemical characteristics are described along with the different molecular causes of ichthyosis. Special attention is given to lamellar ichthyosis and non-bullous congenital ichthyosiform erythroderma. The different pathomechanisms causing ichthyosis provide a fascinating insight into the role of various proteins, enzymes, lipids and metabolic pathways involved in terminal epidermal differentiation/keratinisation.

Mutation spectrum and functional analysis of epidermis-type lipoxygenases in patients with autosomal recessive congenital ichthyosis

Autosomal-recessive congenital ichthyosis (ARCI) is a clinically and genetically heterogeneous group of severe hereditary keratinization disorders characterized by intense scaling of the whole integument, and differences in color and shape. It is often associated with erythema. To date, six loci for ARCI have been mapped. Mutations in ALOXE3 and ALOX12B on chromosome 17p13, which code for two different epidermal lipoxygenases, were recently found in patients with ichthyosiform erythroderma from Turkey, France, and North Africa. Here we describe molecular and clinical findings in 17 families with ARCI originating from Central Europe, Turkey, and the Indian subcontinent, with mutations in ALOXE3 or ALOX12B. We identified 11 novel point mutations in ALOX12B (one nonsense mutation and 10 missense mutations) and four different inactivating mutations in ALOXE3. The gene products of ALOX12B and ALOXE3, the epidermal lipoxygenases 12R-LOX and eLOX3, respectively, are preferentially synthesized in the skin. They act in sequence to convert arachidonic acid via 12(R)-HPETE to the corresponding epoxyalcohol, 8(R)-hydroxy-11(R),12(R)-epoxyeicosatrienoic acid. To assess the impairment of enzyme activity, we expressed the mutated genes in vitro and determined the activity of the recombinant proteins toward their genuine substrates. All but one of the recombinant mutants were enzymatically inactive. The characterization of disease-causing mutations in ALOXE3 and ALOX12B and the resulting ARCI phenotypes did not result in clear diagnostic criteria; however, we found a first correlation between the genetic findings and the clinical presentation of ichthyosis.

Towards characterization of palmoplantar keratoderma caused by gain-of-function mutation in loricrin: analysis of a family and review of the literature

Loricrin keratoderma is an autosomal dominant palmoplantar keratoderma heterogeneous in clinical appearance. We report a family with diffuse ichthyosis and honeycomb palmoplantar keratoderma but no occurrence of pseudoainhums or autoamputations. All patients were born as collodion babies and displayed prominent knuckle pads. We identified the previously reported mutation 730insG in LOR, which elongates loricrin by 22 amino acids because of delayed termination. As pseudoainhums are missing in all patients of the family reported, we propose two compulsory features of loricrin keratoderma: (i) honeycomb palmoplantar keratoderma and (ii) diffuse ichthyosiform dermatosis. Therefore we suggest that the condition should be described clinically as 'honeycomb palmoplantar keratoderma with ichthyosis'. Furthermore, we have assessed the amounts of transcript of LOR using pyrosequencing. This revealed an equal expression of mutant and wild-type alleles of LOR in an affected individual. These findings further underline the gain-of-function theory for mutant LOR in loricrin keratoderma.

Plasminogen activator inhibitor-2 is expressed in different types of congenital ichthyosis:in vivoevidence for its cross-linking into the cornified cell envelope by transglutaminase-1

BACKGROUND

Plasminogen activator inhibitor-2 (PAI-2), a regulatory serpin of the plasminogen activator (PA) system, has been described as a potential component of the cornified cell envelope (CE). Protease inhibitors are essential for skin homeostasis and in particular for the regulation of the desquamation process. Therefore, an aberrant expression of PAI-2 could be involved in the pathogenesis of certain cornification disorders.

OBJECTIVES

Evaluation of the expression of PAI-2 in different types of congenital ichthyosis, especially in lamellar ichthyosis/nonbullous congenital ichthyosiform erythroderma (LI/NCIE) and in Netherton syndrome (NTS). Demonstration of the functional relationship between PAI-2 and transglutaminase (TGase)-1.

PATIENTS AND METHODS

Using immunohistochemistry we evaluated cryosections from individuals suffering from LI/NCIE (n=67), NTS (n=6), ichthyosis-follicularis-atrichia-photophobia syndrome (n=2) and Harlequin ichthyosis (n=1) in comparison with psoriasis vulgaris and healthy skin. Moreover, we assessed the respective TGase-1 activity and the presence of TGase-1 protein. A functional assay was developed to elucidate whether PAI-2 is a substrate for TGase-1.

RESULTS

PAI-2 is expressed in different types of congenital ichthyosis and there is a strong correlation between TGase-1 activity and PAI-2 protein signal. Double staining revealed a strong colocalization of TGase-1 activity and PAI-2 protein. The epidermal incorporation of the specific PAI-2 peptide containing a TGase binding site revealed a strong pericellular staining in the stratum granulosum in healthy skin. In contrast, TGase-1-deficient skin showed only a lamellar staining in the stratum corneum.

CONCLUSIONS

We provide in vivo evidence that PAI-2 is a substrate of TGase-1. The normal expression of PAI-2 in a large group of TGase-1-proficient LI/NCIE patients makes it rather unlikely that PAI-2 alone is a primary molecular cause of LI/NCIE.

Evidence for susceptibility determinant(s) to psoriasis vulgaris in or near PTPN22 in German patients

INTRODUCTION

Variant R620W of protein tyrosine phosphatase non-receptor type 22 (PTPN22) has consistently been reported as a susceptibility factor for several autoimmune diseases. We investigated its role in susceptibility to psoriasis, the relevance of possibly other disease-causing variants, and interdependency of the major risk factor for psoriasis at PSORS1.

METHODS

R620W was tested in a case-control study initially with 375 German patients and then with an enlarged sample of an additional 418 patients. Analyses were extended to linkage disequilibrium (LD) based haplotypes. Potential interaction between risk haplotypes of PTPN22 and the PSORS1 associated risk allele was tested by regression analysis. PTPN22 coding sequence was determined in 20 patients carrying the risk haplotype. Association and regression analysis were also performed in the extended case-control study.

RESULTS

R620W was not associated in either case-control study, while significant association (corrected for multiple testing) with one haplotype (C-4) of the LD block encompassing PTPN22 as well with another haplotype (B-3) within an adjacent telomeric LD block was detected. No evidence for interaction between risk haplotype C-4 and the PSORS1 associated risk allele was found. Sequencing excluded other coding variants within PTPN22 as a basis for association findings. Analysis of the extended study group confirmed association for haplotypes B-3 and C-4 and independence of risk haplotypes C-4 and PSORS1.

DISCUSSION

We exclude a major role of *620W in German psoriasis patients but suggest that other susceptibility determinant(s) within non-coding regions of PTPN22 or its proximity might exist acting independently of the major PSORS1 risk factor.

[Subcutaneous fat necrosis of the newborn]

Subcutaneous fat necrosis presents as red-to-bluish, indolent, well-circumscribed, subcutaneous nodules and plaques, unusually in healthy infants. Histologically, a lobular panniculitis with a mixed inflammatory infiltrate is seen. Characteristic crystalloid structures can be found within some of the lipocytes and, most prominently, within macrophages. This rarely diagnosed skin disease is harmless and self-limited, yet the associated hypercalcaemia has a high complication rate.

Systematic Linkage Disequilibrium Analysis of SLC12A8 at PSORS5 Confirms a Role in Susceptibility to Psoriasis Vulgaris

The gene for solute carrier family 12 member A8 has recently been proposed as a candidate gene for psoriasis susceptibility (PSORS5) on chromosome 3q based on association of five single nucleotide polymorphisms (SNP) in Swedish patients. To investigate whether this locus is relevant for German psoriasis vulgaris (PsV) patients, we analyzed a group of 210 trios and a case-control group including 375 patients. Based on our investigation of the linkage disequilibrium (LD) structure of SLC12A8, we assayed 35 haplotype tag SNP and grouped them into nine LD-blocks. In the case-control study, we detected an association for six SNP and three LD-based haplotypes. Association was strongest for ss35527511 (chi2 = 11.224, p = 0.0008) and haplotype E-2 (chi2 = 11.788, p = 0.00059) and independent of the presence of an HLA-associated PSORS1 risk allele. Through extended haplotype analysis, we could show that two independent association signals exist in SLC12A8, suggesting allelic heterogeneity. None of the SNP showed association in trios, apart from a weak association of rs2228674 (transmission disequilibrium test statistics p = 0.048), probably due to insufficient power. We conclude that SLC12A8 is a susceptibility locus for PsV. In order to establish the exact nature of this association, efforts to identify the disease-causing variants are ongoing.

The expression of the 27-kd heat shock protein in keratinization disorders: an immunohistological study

In human skin, the 27-kd heat shock protein (hsp27), a member of the small hsp family, is expressed mainly in the upper epidermal layers. Hsp27 functions as a molecular chaperone and is involved in the regulation of cell growth and differentiation. According to experimental evidence, epidermal hsp27, through its chaperone function, might play a role in the assembly of keratin filaments and the cornified cell envelope. This study was conducted to assess the expression pattern of hsp27 in a panel of different ichthyoses. Twelve hereditary and acquired skin diseases associated with an ichthyotic phenotype and 2 corresponding mouse models were investigated by immunohistochemistry on formalin-fixed paraffin-embedded tissue, using a monoclonal antibody specific for hsp27. In ichthyosis vulgaris, lamellar ichthyosis, Sjögren-Larsson syndrome, Netherton syndrome, and acquired ichthyosiform skin condition, the pattern of hsp27 expression resembles healthy human skin. Hsp27 expression was reduced in bullous ichthyosiform erythroderma and annular epidermolytic ichthyosis, and absent in X-linked recessive ichthyosis (1/3 patients) and congenital hemidysplasia with ichthyosiform nevus and limb defects syndrome (1/1). In X-linked dominant chondrodysplasia, 3 small samples are completely negative and 2 larger samples show a pattern resembling random X inactivation. In the mouse models, tattered and bare patches, representing the murine analogues to X-linked dominant chondrodysplasia and congenital hemidysplasia with ichthyosiform nevus and limb defects syndrome, expression of hsp25 (the murine homologue of hsp27) also showed lyonization, demonstrating a clear-cut link between hsp27 expression and underlying molecular pathology. Our results show that loss of hsp27 is a rare event in human epidermis that is associated with specific genetic defects. Among the cases described here, these defects are either in suprabasal keratins or in enzymes involved in cholesterol biosynthesis. The expression and chaperone function of hsp27 might be modified by low/absent epidermal cholesterol and aberrant substrates (ie, keratins) resulting in protein misfolding, dyskeratosis, and thus contribute to the ichthyotic phenotype.

Erythrokeratodermia variabilis (EKV) - eine Storung der epidermalen Expression von Gap-Junction-Proteinen. Erythrokeratodermia variabilis (EKV) - a disorder due to altered epidermal expression of gap junction proteins

Erythrokeratodermia variabilis (EKV) is a rare autosomal dominant genodermatosis with disturbed epidermal differentiation. Its clinical picture varies from transient, fast moving erythema to persistent brown hyperkeratoses. The gene defect in EKV was recently located on the short arm of chromosome 1 encoding the gap junction protein connexin 31. We report on a 48-year-old patient with sharply circumscribed, scaling erythema on the extremities, buttocks and trunk starting since 30 years of age. Histological investigation showed orthokeratotic hyperkeratosis with focal parakeratosis overlying an acanthotic epidermis. Immunohistochemistry revealed a decreased expression of the gap junction protein connexin 31 as well as increased expression of connexin 43. At the ultrastructural level, widened intercellular spaces in the upper epidermis were present with regular desmosomes, adherens junctions and gap junctions. Epidermal cell proliferation and differentiation are regulated by gap junctions. The mutation in connexin 31 is regarded therefore as causal for the clinical picture of the EKV. The unique upregulation of connexin 43 may occur as a consequence of the Cx31 mutation and temporarily compensate for this defect.

Lack of evidence for genetic association to RUNX1 binding site at PSORS2 in different German psoriasis cohorts

A DNA variant, rs734232, altering a RUNX1 binding site was recently reported as susceptibility allele at PSORS2 (17q25) in cohorts of psoriasis patients from the US. A testing of this variant in psoriasis patients from Germany did not confirm this association in 300 trios nor in two case-control studies with 281 patients with psoriasis vulgaris and 375 patients with psoriatic arthritis, respectively. These results fail to support rs734232 as a psoriasis susceptibility factor in German psoriasis patients.

Upper cranial nerve palsy resulting from spontaneous carotid dissection

INTRODUCTION

Upper cranial nerve palsy has a variety of causes such as cerebral and nerve ischemia, diabetes, infectious and non-infectious meningitis, subarachnoid hemorrhage and intracranial aneurysm. CASE 1 : A 45-year-old man suffered from holocephalic headaches and a right-sided neck pain for two weeks. He presented to our emergency department because of a sudden ptosis of the right eye. On admission neurological examination revealed a right sided Horner's syndrome and hypesthesia of the right side of the face. Magnetic resonance angiography identified a circumscribed dissection of the right extracranial internal carotid artery originating from the carotid bifurcation. Conventional angiography 2 weeks later showed a nearly recanalized artery. CASE 2 : A 55-year-old previously healthy man without cardiovascular risk factors developed right sided neck pain when loading a seeder with several sacks of crop. A few hours later he noticed a left-sided weakness. On admission a severe left sided hemiparesis and a mild neglect were present. Duplex sonography revealed a right-sided distal internal carotid artery (ICA) occlusion. The next morning the patient complained of double vision; he had a right-sided pupil-sparing oculomotor palsy. The diagnosis of ICA dissection was confirmed by conventional angiography, at that time showing a partially recanalized ICA without involvement of the cavernous region by the dissection.

CONCLUSION

ICA dissection must be included in the differential diagnosis of upper cranial nerve palsy and should be assessed by duplex ultrasound and magnetic resonance imaging. A possible explanation is nerve ischemia due to a transient or permanent interruption of the blood supply by compression of the vasa nervorum originating from the intracranial carotid artery.