Association of a promoter polymorphism of tumor necrosis factor-alpha with subacute cutaneous lupus erythematosus and distinct photoregulation of transcription

Analysis of clinical characteristics of terbinafine-induced subacute cutaneous lupus erythematosus

INTRODUCTION

Terbinafine may cause subacute cutaneous lupus erythematosus (SCLE), and we aimed to analyze its clinical characteristics.

METHODS

We collected literature on terbinafine-induced SCLE from 1997 to 2023 for retrospective analysis. Thirty-seven patients (33 females and 4 males) were included.

RESULTS

The patients have a median age of 49.5 years (range 18-79) and onset time of 5 weeks (range 1-12). SCLE is mainly manifested as annular erythematous (83.3%), scaly erythematous (44.4%), and maculopapular erythematous (13.9%). Mainly, histopathological manifestations are lymphocytic infiltrate (55.6%), hyperkeratosis (38.9%) and keratinocyte necrosis (38.9%). Positive immunological parameters mainly include antinuclear antibody (100.0%), anti-Ro/SSA antibody (94.1%), and anti-La/SSB antibody (72.2%). Past medical history usually includes photosensitivity (33.3%), inflammatory disease (33.33%), and lupus erythematosus (12.1%). Symptoms are completely resolved within a median time of 35 days (range 7-84) after discontinuation of terbinafine and treatment with topical corticosteroids, systemic corticosteroids, hydroxychloroquine, and immunosuppressant. No recurrence was observed within 12 months (range 1.5-48) of follow-up.

CONCLUSION

These results suggest that terbinafine-induced SCLE should be comprehensively diagnosed based on clinical symptoms, histopathological manifestations, immunological parameters, and past medical history. Terbinafine should be immediately discontinued when SCLE occurs, while systemic and topical corticosteroids combined with hydroxychloroquine may be an effective treatment.

Tumor Necrosis Factor-Alpha: Ally and Enemy in Protean Cutaneous Sceneries

Skin is the forestage for a series of many-sided functions of tumor necrosis factor-alpha (TNF-α), a proinflammatory cytokine with staggering versatility and sizable implications for tissue homeostasis, immune responses, angiogenesis, apoptosis, local and systemic inflammation. An aberrant TNF-α-mediated crosstalk has been linked to the pathogenesis of acute and chronic skin inflammatory diseases, and indeed, TNF-α dysregulation can contribute to the development and progression of psoriasis, vitiligo, local damage following exposition to ultraviolet light radiations, cutaneous lupus erythematosus, and acne vulgaris. Therapies that target TNF-α are conspicuously used in the treatment of different skin disorders, aiming to modulate the in vivo immune functions triggered by many cutaneous cells, including keratinocytes, mast cells, or Langerhans cells, and reduce inflammation taking place within the skin. Herein, we focus on the key relationships between TNF-α and distinct skin non-neoplastic inflammatory or physiologic conditions, showing that a natural induction of TNF-α may have a protective significance but that TNF-α overproduction may be harmful or even lethal. Many questions remain unraveled in the therapeutic practice, and caution should be exercised due to eventual backlashes exerted by TNF-α in maintaining skin health or in provoking skin disease.

Nano-encapsulated anandamide reduces inflammatory cytokines in vitro and lesion severity in a murine model of cutaneous lupus erythematosus

Cutaneous lupus erythematosus (CLE) is a heterogeneous autoimmune skin disease which occurs independently and in conjunction with systemic lupus erythematosus. Drug development for CLE is severely lacking. Anandamide (AEA) is a primary endocannabinoid which exhibits immunomodulatory effects through mixed cannabinoid receptor agonism. We evaluated AEA as topical treatment for CLE and assessed benefits of nanoparticle encapsulation (AEA-NP) on cutaneous drug penetration, delivery and biological activity. Compared to untreated controls, AEA-NP decreased IL-6 and MCP-1 in UVB-stimulated keratinocytes (p < 0.05) in vitro. In BALB/c mice, AEA-NP displayed improved cutaneous penetration, extended release and persistence of AEA in the follicular unit extending to the base after 24 h. Utilizing the MRL-lpr lupus murine model, twice weekly treatment of lesions with topical AEA-NP for 10 weeks led to decreased clinical and histologic lesion scores compared to unencapsulated AEA and untreated controls (p < 0.05). Prophylactic application of AEA-NP to commonly involved areas on MRL-lpr mice similarly resulted in decreased clinical and histologic scores when compared to controls (p < 0.05), and reduced C3 and IBA-1 in lesional tissue (p < 0.05). The demonstrated clinical and immunomodulatory effects of treatment with AEA support its potential as therapy for CLE. This work also suggests that encapsulation of AEA improves penetration and treatment efficacy. Future studies will be conducted to assess full therapeutic potential.

Differential genotypes of TNF-α and IL-10 for immunological diagnosis in discoid lupus erythematosus and oral lichen planus: A narrative review

Discoid lupus erythematosus and oral lichen planus are chronic systemic immune system-mediated diseases with unclear etiology and pathogenesis. The oral mucosa is the common primary site of pathogenesis in both, whereby innate and adaptive immunity and inflammation play crucial roles. The clinical manifestations of discoid lupus erythematosus on the oral mucosa are very similar to those of oral lichen planus; therefore, its oral lesion is classified under oral lichenoid lesions. In practice, the differential diagnosis of discoid lupus erythematosus and oral lichen planus has always relied on the clinical manifestations, with histopathological examination as an auxiliary diagnostic tool. However, the close resemblance of the clinical manifestations and histopathology proves challenging for accurate differential diagnosis and further treatment. In most cases, dentists and pathologists fail to distinguish between the conditions during the early stages of the lesions. It should be noted that both are considered to be precancerous conditions, highlighting the significance of early diagnosis and treatment. In the context of unknown etiology and pathogenesis, we suggest a serological and genetic diagnostic method based on TNF-α and IL-10. These are the two most common cytokines produced by the innate and adaptive immune systems and they play a fundamental role in maintaining immune homeostasis and modulating inflammation. The prominent variability in their expression levels and gene polymorphism typing in different lesions compensates for the low specificity of current conventional diagnostic protocols. This new diagnostic scheme, starting from the immunity and inflammation of the oral mucosa, enables simultaneous comparison of discoid lupus erythematosus and oral lichen planus. With relevant supportive evidence, this information can enhance physicians’ understanding of the two diseases, contribute to precision medicine, and aid in prevention of precancerous conditions.

Bioinformatics analyses of gene expression profile identify key genes and functional pathways involved in cutaneous lupus erythematosus

BACKGROUND

Lupus erythematosus is an autoimmune disease that causes damage to multiple organs ranging from skin lesions to systemic manifestations. Cutaneous lupus erythematosus (CLE) is a common type of lupus erythematosus (LE), but its molecular mechanisms are currently unknown. The study aimed to explore changes in the gene expression profiles and identify key genes involved in CLE, hoping to uncover its molecular mechanism and identify new targets for CLE.

METHOD

We analyzed the microarray dataset (GSE109248) derived from the Gene Expression Omnibus (GEO) database, which was a transcriptome profiling of CLE cutaneous lesions. The differentially expressed genes (DEGs) were identified, and the functional annotation of DEGs was performed with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Protein-protein interaction (PPI) network was also constructed to identify hub genes involved in CLE.

RESULT

A total of 755 up-regulated DEGs and 405 down-regulated DEGs were identified. GO enrichment analysis showed that defense response to virus, immune response, and type I interferon signaling pathway were the most significant enrichment items in DEGs. The KEGG pathway analysis identified 51 significant enrichment pathways, which mainly included systemic lupus erythematosus, osteoclast differentiation, cytokine-cytokine receptor interaction, and primary immunodeficiency. Based on the PPI network, the study identified the top 10 hub genes involved in CLE, which were CXCL10, CCR7, FPR3, PPARGC1A, MMP9, IRF7, IL2RG, SOCS1, ISG15, and GSTM3. By comparison between subtypes, the results showed that ACLE had the least DEGs, while CCLE showed the most gene and functional changes.

CONCLUSION

The identified hub genes and functional pathways found in this study may expand our understanding on the underlying pathogenesis of CLE and provide new insights into potential biomarkers or targets for the diagnosis and treatment of CLE. Key Points • The bioinformatics analysis based on CLE patients and healthy controls was performed and 1160 DEGs were identified • The 1160 DEGs were mainly enriched in biological processes related to immune responses, including innate immune response, type I interferon signaling pathway, interferon-γ-mediated signaling pathway, positive regulation of T cell proliferation, regulation of immune response, antigen processing, and presentation via MHC class Ib and so on • KEGG pathway enrichment analysis indicated that DEGs were mainly enriched in several immune-related diseases and virus infection, including systemic lupus erythematosus, primary immunodeficiency, herpes simplex infection, measles, influenza A, and so on • The hub genes such as CXCL10, IRF7, MMP9, CCR7, and SOCS1 may become new markers or targets for the diagnosis and treatment of CLE.

NF-κB: At the Borders of Autoimmunity and Inflammation

The transcription factor NF-κB regulates multiple aspects of innate and adaptive immune functions and serves as a pivotal mediator of inflammatory response. In the first part of this review, we discuss the NF-κB inducers, signaling pathways, and regulators involved in immune homeostasis as well as detail the importance of post-translational regulation by ubiquitination in NF-κB function. We also indicate the stages of central and peripheral tolerance where NF-κB plays a fundamental role. With respect to central tolerance, we detail how NF-κB regulates medullary thymic epithelial cell (mTEC) development, homeostasis, and function. Moreover, we elaborate on its role in the migration of double-positive (DP) thymocytes from the thymic cortex to the medulla. With respect to peripheral tolerance, we outline how NF-κB contributes to the inactivation and destruction of autoreactive T and B lymphocytes as well as the differentiation of CD4⁺-T cell subsets that are implicated in immune tolerance. In the latter half of the review, we describe the contribution of NF-κB to the pathogenesis of autoimmunity and autoinflammation. The recent discovery of mutations involving components of the pathway has both deepened our understanding of autoimmune disease and informed new therapeutic approaches to treat these illnesses.

The effects of immunostimulatory herbal supplements on autoimmune skin diseases

The use of herbal supplements that promise to improve immune health has gained popularity among dermatology patients. However, there is little to no evidence that herbal supplements improve dermatologic conditions. Several in vitro and in vivo studies have shown that Spirulina platensis, Aphanizomenon flos-aqua, Chlorella, Echinacea, and alfalfa activate immune cells via certain cytokines and chemokines. Case reports suggest the association of ingesting immunostimulatory herbs and the clinical onset or flares of diseases characterized by an exaggerated immune response such as lupus erythematosus, dermatomyositis, and autoimmune blistering disorders. Therefore, it is imperative to investigate the prevalence of herbal supplement use in this patient population. In addition, in vitro studies should examine the underlying mechanisms by which herbs stimulate immune pathways that are already overactive in autoimmune patients.

Systematic Review: Monoclonal Antibody-Induced Subacute Cutaneous Lupus Erythematosus

Background

Subacute cutaneous lupus erythematosus (SCLE) lacks consensus diagnostic criteria and the pathogenesis is poorly understood. There are increasing reports of SCLE induced by monoclonal antibodies (mAbs), but there are limited data on the aetiology, clinical characteristics and natural course of this disease.

Methods

We devised a set of diagnostic criteria for SCLE in collaboration with a multinational, multispecialty panel. This systematic review employed a two-layered search strategy of five databases for cases of mAb-induced SCLE (PROSPERO registered protocol CRD42019116521). To explore the relationship between relative mAb use and the number of SCLE cases reported, the estimated number of mAb users was modelled from 2013 to 2018 global commercial data and estimated annual therapy costs.

Results

From 40 papers, we identified 52 cases of mAb-induced SCLE, occurring in a cohort that was 73% female and with a median age of 61 years. Fifty percent of cases were induced by anti-tumour necrosis factor (TNF)-ɑ agents. A median of three drug doses preceded SCLE onset and the lesions lasted a median of 7 weeks after drug cessation. Oral and topical corticosteroids were most frequently used. Of the licensed mAbs, adalimumab, denosumab, rituximab, etanercept and infliximab were calculated to have the highest relative number of yearly users based on global sales data. Comparing the number of mAb-induced SCLE cases with estimated yearly users, the checkpoint inhibitors pembrolizumab and nivolumab showed strikingly high rates of SCLE relative to their global use, but ipilimumab did not.

Conclusion

We present the first systematic review characterising mAb-induced SCLE with respect to triggers, clinical signs, laboratory findings, prognosis and treatment approaches. We identify elevated rates associated with the use of checkpoint inhibitors and anti-TNFɑ agents.

Electronic supplementary material

The online version of this article (10.1007/s40268-020-00320-5) contains supplementary material, which is available to authorized users.

The pathogenesis of cutaneous lupus erythematosus: The aberrant distribution and function of different cell types in skin lesions

Cutaneous lupus erythematosus (CLE) is an autoimmune disease with a broad range of cutaneous manifestations. In skin lesions of CLE, keratinocytes primarily undergo apoptosis. Interferon-κ(IFN-κ) is belonged to type I interferons (type I IFNs) and is selectively produced by keratinocytes. Recently, keratinocytes selectively produced IFN-κ is identified to be a key to trigger type I interferon responses in CLE. Other immune cells such as plasmacytoid dendritic cells (pDCs) are identified to be relevant origin of type I interferons (type I IFNs) which are central to the development of CLE lesions and responsible for mediating Th1 cell activity. Other types of cells such as neutrophils, B cells and Th17 cells also are involved in the development of this disease. The close interaction of those cells composes a comprehensive and complicated network in CLE. In this review, we discussed the aberrant distribution and function of different cells types involved in this disease and will offer a new direction for research and therapy in the near future.

An Update on the Pathogenesis of Cutaneous Lupus Erythematosus and Its Role in Clinical Practice

PURPOSE OF REVIEW

Understanding the pathogenesis of cutaneous lupus erythematosus (CLE) is an important step in developing new medications and providing effective treatment to patients. This review focuses on novel research within CLE pathogenesis, as well as some of the medications being developed based on this knowledge.

RECENT FINDINGS

The subtle differences between systemic lupus erythematosus (SLE) and CLE pathogenesis are highlighted by differences in the circulating immune cells found in each disease, as well as the specific pathways activated by ultraviolet light. Plasmacytoid dendritic cells and the related type I interferon pathway are major components of CLE pathogenesis, and as such, therapies targeting components of this pathway have been successful in recent clinical trials. B cell-depleting therapies have shown success in SLE; however, their role in CLE is less clear. Understanding the differences between these manifestations of lupus allows for the development of therapies that are more effective in skin-specific disease. Discovering key pathways in CLE pathogenesis is critical for understanding the clinical features of the disease and ultimately developing new and effective therapies.

[Lupus erythematosus-a clinico-pathological heterogeneous disease]

Lupus erythematosus (LE) is an autoimmune disorder where immune tolerance towards nucleic acids is lost and a hyperactivated type I interferon system drives chronic immune activation. Typically, signs, symptoms, and clinical disease course are very variable between patients. Cutaneous LE can be associated with or precede systemic involvement or be limited to the skin, necessitating careful examination and follow-up of patients. LE skin disease includes a wide range of manifestations and precise classification for clinical studies is challenging. In this review article we discuss common and rare manifestations of cutaneous lupus with its clinical presentation and histopathological characteristics.

An Update on the Pathogenesis of Skin Damage in Lupus

PURPOSE OF REVIEW

Lupus erythematosus (LE) is characterized by broad and varied clinical forms ranging from a localized skin lesion to a life-threatening form with severe systemic manifestations. The overlapping between cutaneous LE (CLE) and systemic LE (SLE) brings difficulties to physicians for early accurate diagnosis and sometimes may lead to delayed treatment for patients. We comprehensively review recent progress about the similarities and differences of the main three subsets of LE in pathogenesis and immunological mechanisms, with a particular focus on the skin damage.

RECENT FINDINGS

Recent studies on the mechanisms contributing to the skin damage in lupus have shown a close association of abnormal circulating inflammatory cells and abundant production of IgG autoantibodies with the skin damage of SLE, whereas few evidences if serum autoantibodies and circulating inflammatory cells are involved in the pathogenesis of CLE, especially for the discoid LE (DLE). Till now, the pathogenesis and molecular/cellular mechanism for the progress from CLE to SLE are far from clear. But more and more factors correlated with the differences among the subsets of LE and progression from CLE to SLE have been found, such as the mutation of IRF5, IFN regulatory factors and abnormalities of plasmacytoid dendritic cells (PDCs), Th1 cells, and B cells, which could be the potential biomarkers for the interventions in the development of LE. A further understanding in pathogenesis and immunological mechanisms for skin damage in different subsets of LE makes us think more about the differences and cross-links in the pathogenic mechanism of CLE and SLE, which will shed a light in predictive biomarkers and therapies in LE.

Cutaneous Lupus Erythematosus: Progress and Challenges

PURPOSE OF REVIEW

The review provides an update on the diagnosis, pathogenesis, and treatment of cutaneous lupus erythematosus (CLE).

RECENT FINDINGS

Diagnostic challenges exist in better defining CLE as an independent disease distinct from systemic lupus erythematosus with cutaneous features and further classifying CLE based on clinical, histological, and laboratory features. Recent mechanistic studies revealed more genetic variations, environmental triggers, and immunologic dysfunctions that are associated with CLE. Drug induction specifically has emerged as one of the most important triggers for CLE. Treatment options include topical agents and systemic therapies, including newer biologics such as belimumab, rituximab, ustekinumab, anifrolumab, and BIIB059 that have shown good clinical efficacy in trials. CLE is a group of complex and heterogenous diseases. Future studies are warranted to better define CLE within the spectrum of lupus erythematosus. Better insight into the pathogenesis of CLE could facilitate the design of more targeted therapies.

Cutaneous lupus erythematosus: updates on pathogenesis and associations with systemic lupus

PURPOSE OF REVIEW

Cutaneous lupus erythematosus (CLE) is a common manifestation among systemic lupus patients. There are no U.S. Food and Drug Administration approved therapies for CLE, and these lesions are frequently disfiguring and refractory to treatment. The present review will cover the recent inroads made into understanding the mechanisms behind CLE lesions and discuss promising therapeutic developments.

RECENT FINDINGS

The definition of cutaneous lupus is being refined to facilitate diagnostic and research protocols. Research into the pathogenesis of CLE is accelerating, and discoveries are now identifying genetic and epigenetic changes which may predispose to particular disease manifestations. Furthermore, unique features of disease subtypes are being defined. Murine work supports a connection between cutaneous inflammation and systemic lupus disease activity. Importantly, human trials of type I interferon blockade hold promise for improving our treatment armamentarium for refractory CLE lesions.

SUMMARY

Continued research to understand the mechanisms driving CLE will provide new methods for prevention and treatment of cutaneous lesions. These improvements may also have important effects on systemic disease activity, and thus, efforts to understand this link should be supported.

Topical drug-induced subacute cutaneous lupus erythematosus isolated to the hands

Subacute cutaneous lupus erythematosus (SCLE) is a well-defined subtype of lupus erythematosus, characterised by photosensitivity, annular and/or psoriasiform lesions, variable systemic involvement and presence of circulating SSA/anti-Ro antibodies. SCLE may be idiopathic or drug-induced. Both the idiopathic and drug-induced forms of SCLE are analogous in their clinical, serological and histological features. Drug-induced SCLE has been reported with various oral agents, but to our knowledge this is the first reported case due to a topical medication. A 34-year-old female foot masseuse presented with a 2-month history of scaly, erythematous lesions isolated to the dorsal hands and interdigital spaces. She had used topical terbinafine, a topical antifungal cream, to her clients’ feet for a number of years. ANA and anti-SSA/Ro antibodies were positive. Physical examination, serology and histopathology were consistent with SCLE. We propose that our patient's unique presentation of SCLE may be explained by a prolonged occupational exposure to topical terbinafine as a foot masseuse. While oral terbinafine is a drug known to cause drug-induced SCLE, to our knowledge, this is the first topically induced form of the disease.

Use of Infliximab, an Anti-Tumor Necrosis Alpha Antibody, for Inflammatory Dermatoses

Background:

Infliximab is a monoclonal antibody against tumor necrosis factor alpha currently approved by the U.S. FDA for the treatment of Crohn's disease and rheumatoid arthritis. Recently, a controlled trial reported its effectiveness for psoriasis.

Objective:

The object of our study was to evaluate the efficacy and safety of infliximab for inflammatory or autoimmune cutaneous disorders.

Methods:

A retrospective chart review was performed for patients who received infliximab at the University of Miami, Cedars Medical Center.

Results:

Patients with various disease, including panniculitis, pityriasis rubra pilaris, eosinophilic fasciitis, discoid lupus erythematosus, and necrobiosis lipoidica diabeticorum, received infliximab infusion at a dose of 5 mg/kg. All patients had refractory disease or adverse effects to previous therapy, which included cyclosporine, systemic steroids, azathioprin, clofazimine, mycophenolate mofetil, acitretin, UVB, and thalidomide. Six out of the seven patients improved after treatment.

Conclusions:

Infliximab was well tolerated in most patients and the majority benefited from the use of infliximab.

Pathophysiology of cutaneous lupus erythematosus

The pathophysiology of cutaneous lupus erythematosus (CLE) encompasses the complex interactions between genetics, the environment, and cells and their products. Recent data have provided enhanced understanding of these interactions and the mechanism by which they cause disease. A number of candidate genes have been identified which increase the risk of developing CLE. Ultraviolet radiation, the predominant environmental exposure associated with CLE, appears to initiate CLE lesion formation by inducing apoptosis, precipitating autoantigen presentation, and promoting cellular production of specific cytokines. Autoantibodies are a well-known entity in CLE, but their exact role remains unclear. Finally, cells ranging from native skin cells to innate and adaptive immune cells produce cytokines and other molecules and play specific roles in lesion formation and perpetuation. Native skin cells implicated in CLE include keratinocytes and endothelial cells. Innate immune cells crucial to CLE pathophysiology include dendritic cells and neutrophils. The primary adaptive immune cells thought to be involved include Th1 cells, Th17 cells, cytotoxic T cells, and invariant natural killer T cells. Though the pathophysiology of CLE has yet to be fully characterized, current research provides direction for future research and therapies.

The immunopathology of cutaneous lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that is characterized by the development of autoantibodies and immunologic attack of different organ systems, including the skin. This review aims to provide an overview of some of the pathogenic processes that may be important in the development of SLE, specifically cutaneous lupus erythematosus, and then illustrates how therapies might be tailored to modify these processes and treat disease.

Photoaggravated disorders

Photoaggravated skin disorders are diseases that occur without UV radiation but are sometimes or frequently exacerbated by UV radiation. In conditions, such as lupus erythematosus, photoaggravation occurs in a majority of patients, whereas in conditions, such as psoriasis and atopic dermatitis, only a subset of patients demonstrate photoaggravation. Polymorphous light eruption is a common photodermatosis in all skin types, making it important to differentiate photoaggravation of an underlying disorder, such as lupus erythematosus, from superimposed polymorphous light eruption. Disease-specific treatments should be instituted where possible. A key component of management of photoaggravated conditions is photoprotection with behavioral change, UV-protective clothing, and broad-spectrum sunscreen.

Immunologic and genetic considerations of cutaneous lupus erythematosus: a comprehensive review

Cutaneous lupus erythematosus (CLE) refers to those subtypes of lupus erythematosus (LE) that have predominantly skin manifestations. Discoid lupus erythematosus (DLE), subacute cutaneous lupus erythematosus (SCLE), LE panniculitis (LEP) and lupus erythematosus tumidus (LET) all fall into the category of CLE. The pathogenesis of CLE is likely multifactorial. UV irradiation has been shown to induce keratinocyte apoptosis. Impaired clearance of apoptotic cells is a potential mechanism for the development of CLE. UV irradiation can also induce externalization of autoantigens such as Ro/SSA, exposing them to circulating autoantibodies. Some drugs have been associated with CLE. Possible mechanisms include stimulation of an immune response through disruption of central tolerance and altered T cell function. T17 cells may also play a role in the pathogenesis of CLE as they have been detected in skin lesions of LE. Treg cells have been found to be decreased in LE lesions, which may contribute to the breakdown of self-tolerance. Epidermal Langerhans cells are reduced in CLE while plasmacytoid DCs are increased in the lesions of CLE, suggesting that DCs may also play an important role in the pathogenesis of CLE. Type I IFN- and TNF-α are both upregulated in lesions of CLE. Other cytokines such as IL-6 and IL-17 are also implicated in the pathogenesis of CLE. Cellular and cytokine networks can be impacted by environmental factors and genetic variations and this can result in an increased risk of developing autoimmune diseases such as CLE.

Preferential transmission of genetic risk variants of candidate loci at 6p21 from asymptomatic grandparents to mothers of children with neonatal lupus

OBJECTIVE

Neonatal lupus (NL) occurs in fetuses exposed to maternal anti-SSA/Ro and/or anti-SSB/La antibodies, although the mothers themselves may not manifest any clinical disease. A focus on transmission of risk factors for NL from maternal grandparents to mothers of children with NL may yield dividends toward understanding the aggregation of autoantibodies and genetic factors in affected families. This study was perforned to determine the role of maternal grandparents in the development of the autoimmune phenotype of mothers of children with NL.

METHODS

Fifty-one mothers of children with cardiac and/or cutaneous NL, 48 maternal grandmothers, and 35 maternal grandfathers in the Research Registry for Neonatal Lupus were interrogated for clinical symptoms by questionnaire and underwent laboratory assessments, including determination of anti-SSA/Ro and anti-SSB/La antibody status (by enzyme-linked immunosorbent assay) and genotype at rs1800629 (TNFα) and rs7775397 (C6orf10) (allelic discrimination). The transmission disequilibrium test (TDT) was computed to test for nonrandom transmission from maternal grandparents to mothers of children with NL.

RESULTS

The common phenotypic feature in mothers of children with NL was the autoantibody and not the clinical profile; 7 had lupus, 14 had Sjögren's syndrome, 7 had both, and 23 were asymptomatic. Mothers of children with NL were significantly enriched for the risk alleles at both TNFα and C6orf10. The grandparents of children with NL carried minimal burden for autoimmune disease or abnormal antibody production and were not enriched in the genetic risk factors. However, the TDT analysis showed significant excess transmission of the risk alleles at both TNFα (odds ratio [OR] 6.67, P = 3.93 × 10(-4) ) and C6orf10 (OR 35.0, P = 3.74 × 10(-5) ) to mothers of children with NL.

CONCLUSION

Mothers of children with NL are enriched for the TNFα and C6orf10 risk alleles, which are preferentially inherited from the asymptomatic maternal grandparents. These findings support the hypothesis that the development of NL and genetic etiology are multigenerational.

Recent advances in cytokines in cutaneous and systemic lupus erythematosus

Lupus erythematosus (LE) includes a broad spectrum of diseases from a cutaneous-limited type to a systemic type. Systemic lupus erythematosus (SLE) is a systemic autoimmune disease which affects multiple organs. Cutaneous lupus erythematosus (CLE) includes skin symptoms seen in SLE and cutaneous-limited LE. Although immune abnormalities, as well as heritable, hormonal and environmental factors, are involved in the pathology of LE, the actual pathogenesis is still unclear. Recently, the involvement of various cytokines has been shown in the pathogenesis of LE. Moreover, some trials with biological agents targeted specific cytokines are also ongoing for SLE. In this article, we review the contributions of major cytokines such as interferon, tumor necrosis factor-α and interleukin-18 to LE, especially SLE and CLE.

Pregnancy outcomes in patients with autoimmune diseases and anti-Ro/SSA antibodies

Anti-Ro/SSA antibodies are associated with neonatal lupus (congenital heart block (CHB), neonatal transient skin rash, hematological and hepatic abnormalities), but do not negatively affects other gestational outcomes, and the general outcome of these pregnancies is now good, when followed by experienced multidisciplinary teams. The prevalence of CHB, defined as an atrioventricular block diagnosed in utero, at birth, or within the neonatal period (0-27 days after birth), in the offspring of an anti-Ro/SSA-positive women is 1-2%, of neonatal lupus rash around 10-20%, while laboratory abnormalities in asymptomatic babies can be detected in up to 27% of cases. The risk of recurrence of CHB is ten times higher. Most of the mothers are asymptomatic at delivery and are identified only by the birth of an affected child. Half of these asymptomatic women develop symptoms of a rheumatic disease, most commonly arthralgias and xerophtalmia, but few develop lupus nephritis. A standard therapy for CHB is still matter of investigation, although fluorinated corticosteroids have been reported to be effective for associated cardiomyopathy. Serial echocardiograms and obstetric sonograms, performed at least every 1-2 weeks starting from the 16th week of gestational age, are recommended in anti-Ro/SSA-positive pregnant women to detect early fetal abnormalities that might be a target of preventive therapy.

Polymorphisms in the TNF-α and IL10 gene promoters and risk of arsenic-induced skin lesions and other nondermatological health effects

In West Bengal, India, at present, more than 26 million people are exposed to arsenic through drinking water. Among them, only 15-20% manifest arsenic-induced noncancerous, precancerous, and cancerous skin lesions, indicating that genetic variants play important role in arsenic susceptibility. Chronic arsenic exposure has been associated with impairment of immune systems in the exposed individuals. Because cytokines are important immune mediators, alteration in expression of these gene products may lead to arsenic-specific disease manifestations. The aim of the present work was to investigate the association between the TNF-α-308G>A (rs1800629) and IL10 -3575T>A (rs1800890) polymorphisms and arsenic-induced dermatological and nondermatological health outcomes. A case-control study was conducted in West Bengal, India, involving 207 cases with arsenic-induced skin lesions and 190 controls without skin lesions having similar arsenic exposure. The polymorphisms were determined using conventional PCR-sequencing method. ELISA was done to determine the serum levels of the two cytokines tumor necrosis factor α (TNF-α) and interleukin 10 (IL10). Associations between the polymorphisms studied and nondermatological health effects in the study subjects were determined from our epidemiological survey data. Individuals with GA/AA (-308 TNF-α) and TA/AA (-3575 IL10) genotypes were at higher risk of developing arsenic-induced skin lesions, ocular, and respiratory diseases. Also the -308 TNF A allele corresponded to a higher production of TNF-α, and -3575 IL10 A allele corresponded to a lower production of IL10. Thus, the polymorphisms studied impart significant risk toward development of arsenic-induced dermatological and nondermatological health effects in the chronically exposed population of West Bengal, India.

Polymorphisms of the ITGAM gene confer higher risk of discoid cutaneous than of systemic lupus erythematosus

Background

Lupus erythematosus (LE) is a heterogeneous disease ranging from mainly skin-restricted manifestations (discoid LE [DLE] and subacute cutaneous LE) to a progressive multisystem disease (systemic LE [SLE]). Genetic association studies have recently identified several strong susceptibility genes for SLE, including integrin alpha M (ITGAM), also known as CD11b, whereas the genetic background of DLE is less clear.

Principal Findings

To specifically investigate whether ITGAM is a susceptibility gene not only for SLE, but also for cutaneous DLE, we genotyped 177 patients with DLE, 85 patients with sporadic SLE, 190 index cases from SLE families and 395 population control individuals from Finland for nine genetic markers at the ITGAM locus. SLE patients were further subdivided by the presence or absence of discoid rash and renal involvement. In addition, 235 Finnish and Swedish patients positive for Ro/SSA-autoantibodies were included in a subphenotype analysis. Analysis of the ITGAM coding variant rs1143679 showed highly significant association to DLE in patients without signs of systemic disease (P-value  = 4.73×10⁻¹¹, OR  = 3.20, 95% CI  = 2.23–4.57). Significant association was also detected to SLE patients (P-value  = 8.29×10⁻⁶, OR  = 2.14, 95% CI  = 1.52–3.00), and even stronger association was found when stratifying SLE patients by presence of discoid rash (P-value  = 3.59×10⁻⁸, OR  = 3.76, 95% CI  = 2.29–6.18).

Significance

We propose ITGAM as a novel susceptibility gene for cutaneous DLE. The risk effect is independent of systemic involvement and has an even stronger genetic influence on the risk of DLE than of SLE.

Identification of candidate loci at 6p21 and 21q22 in a genome-wide association study of cardiac manifestations of neonatal lupus

OBJECTIVE

Cardiac manifestations of neonatal lupus, comprising atrioventricular conduction defects and cardiomyopathy, occur in fetuses exposed to anti-Ro/SSA antibodies, and carry substantial mortality. There is strong evidence of a genetic contribution to the risk. This study was undertaken to evaluate single-nucleotide polymorphisms (SNPs) for associations with cardiac neonatal lupus.

METHODS

Children of European ancestry with cardiac neonatal lupus (n = 116) were genotyped using the Illumina 370K SNP platform and merged with 3,351 controls. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for association with cardiac neonatal lupus were determined.

RESULTS

The 17 most significant associations with cardiac neonatal lupus were found in the HLA region. The region near the MICB gene showed the strongest variant (rs3099844; P(dom) = 4.52 × 10(-10) , OR 3.34 [95% CI 2.29-4.89]), followed by a missense variant within C6orf10 (rs7775397; P(dom) = 1.35 × 10(-9) , OR 3.30), which lies between NOTCH4 and BTNL2, and several SNPs near the tumor necrosis factor α gene, including rs2857595 (P(add) = 1.96 × 10(-9) , OR 2.37), rs2230365 (P(add) = 1.00 × 10(-3) , OR 0.46), and rs3128982 (P(add) = 6.40 × 10(-6) , OR 1.86). Outside the HLA region, an association was detected at 21q22, upstream of the transcription regulator ets-related isoform 1 (rs743446; P = 5.45 × 10(-6) , OR 2.40). HLA notwithstanding, no individual locus previously implicated in autoimmune diseases achieved genome-wide significance.

CONCLUSION

These results suggest that variation near genes related to inflammatory and apoptotic responses may promote cardiac injury initiated by passively acquired autoantibodies.

Overview of common, rare and atypical manifestations of cutaneous lupus erythematosus and histopathological correlates

The skin is the second most frequently affected organ system in lupus erythematosus. Although only very rarely life threatening--an example is lupus erythematosus-associated toxic epidermal necrolysis--skin disease contributes disproportionally to disease burden in terms of personal and psychosocial wellbeing, vocational disability, and hence in medical and social costs. Since several manifestations are closely associated with the presence and activity of systemic lupus erythematosus, prompt and accurate diagnosis of cutaneous lupus erythematosus is essential. This review aims to cover common, rare, and atypical manifestations of lupus erythematosus-associated skin disease with a detailed discussion of histopathological correlates. Cutaneous lupus erythematosus covers a wide morphological spectrum well beyond acute, subacute and chronic cutaneous lupus erythematosus, which are commonly classified as lupus-specific skin disease. Other uncommon or less well-known manifestations include lupus erythematosus tumidus, lupus profundus, chilblain lupus, mucosal lupus erythematosus, and bullous lupus erythematosus. Vascular manifestations include leukocytoclastic and urticarial vasculitis, livedoid vasculopathy and livedo reticularis/ racemosa. Finally, we discuss rare presentations such as lupus erythematosus-related erythema exsudativum multiforme (Rowell syndrome), Kikuchi-Fujimoto disease, extravascular necrotizing palisaded granulomatous dermatitis (Winkelmann granuloma), and neutrophilic urticarial dermatosis.

Pathogenesis of cutaneous lupus erythematosus: common and different features in distinct subsets

The term 'cutaneous lupus erythematosus' (CLE) comprises several related autoimmune skin disorders, defined as 'specific' skin manifestations of lupus erythematosus (LE). The spectrum of clinical presentation of CLE is wide, reaching from mild erythema to disseminated scarring skin lesions. There is increasing knowledge concerning the pathogenesis of LE skin lesions and it has been shown that a complex network of cutaneous cytokines, chemokines and adhesion molecules orchestrate and promote tissue injury observed in LE skin lesions. However, a complete understanding of the diverse pathophysiological mechanisms in the different CLE subsets does not exist. Here we review the main pathological features described in CLE patients against the background of the clinical diversity of different CLE subtypes.

IL-10 and TNFalpha genotypes in SLE

The production of two regulators of the inflammatory response, interleukin 10 (IL-10) and tumor necrosis factor α (TNFα), has been found to be deeply deregulated in SLE patients, suggesting that these cytokines may be involved in the pathogenesis of the disease. Genetic polymorphisms at the promoter regions of IL-10 and TNFα genes have been associated with different constitutive and induced cytokine production. Given that individual steady-state levels of these molecules may deviate an initial immune response towards different forms of lymphocyte activation, functional genetic variants in their promoters could influence the development of SLE. The present review summarizes the information previously reported about the involvement of IL-10 and TNFα genetic variants on SLE appearance, clinical phenotype, and outcome. We show that, in spite of the heterogeneity of the populations studied, the existing knowledge points towards a relevant role of IL-10 and TNFα genotypes in SLE.

Dermatomyositis and polymyositis: Clinical presentation, autoantibodies, and pathogenesis

Dermatomyositis (DM) and polymyositis (PM) are autoimmune myopathies characterized clinically by proximal muscle weakness, muscle inflammation, extramuscular manifestations, and frequently, the presence of autoantibodies. Although there is some overlap, DM and PM are separate diseases with different pathophysiological mechanisms. Furthermore, unique clinical phenotypes are associated with each of the myositis-specific autoantibodies (MSAs) associated with these disorders. This review will focus on the clinical features, pathology, and immunogenetics of PM and DM with an emphasis on the importance of autoantibodies in defining unique phenotypes and, perhaps, as clues to help elucidate the mechanisms of disease.

Light, including ultraviolet

Ultraviolet (UV) light is intricately linked to the functional status of the cutaneous immune system. In susceptible individuals, UV radiation can ignite pathogenic inflammatory pathways leading to allergy or autoimmunity. In others, this same UV radiation can be used as a phototherapy to suppress pathogenic cutaneous immune responses. These vastly different properties are a direct result of UV light's ability to ionize molecules in the skin and thereby chemically alter them. Sometimes these UV-induced chemical reactions are essential, the formation of pre-vitamin D(3) from 7-dehydrocholesterol, for example. In other instances they can be potentially detrimental. UV radiation can ionize a cell's DNA causing adjacent pyrimidine bases to chemically bond to each other. To prevent malignant transformation, a cell may respond to this UV-induced DNA damage by undergoing apoptosis. Although this pathway prevents skin cancer it also has the potential of inducing or exacerbating autoreactive immune responses by exposing the cell's nuclear antigens. Ultraviolet-induced chemical reactions can activate the immune system by a variety of other mechanisms as well. In response to UV irradiation keratinocytes secrete cytokines and chemokines, which activate and recruit leukocytes to the skin. In some individuals UV-induced chemical reactions can synthesize novel antigens resulting in a photoallergy. Alternatively, photosensitizing molecules can damage cells by initiating sunburn-like phototoxic reactions. Herein we review all types of UV-induced skin reactions, especially those involving the immune system.

Race differences in immunogenetic features and photosensitivity of cutaneous lupus erythematosus from the aspect of Japanese studies

Skin lesions of collagen diseases are influenced by environmental triggers, such as UV light, and are variable in cutaneous lupus erythematosus (LE), such as systemic LE (SLE), chronic discoid LE (CDLE), subacute cutaneous LE (SCLE), and LE tumidus (LET). Although there are a few conflicting reports on photosensitivity in collagen diseases, many Japanese dermatologists feel there are photosensitivity differences in LE between Asians and Caucasians with SCLE and LET. To address this issue, we have carried out genetic studies of Japanese SLE and CDLE patients and reviewed the race differences in photosensitivity of cutaneous LE from Japanese studies. Human leukocyte antigen (HLA) studies in Japanese patients revealed that HLA-DRB1*1501 association was with CDLE and SLE. The association between HLA-Cw6 and CDLE was first reported in a Japanese population, and a HLA-A33-B44-DRB1*1302 haplotype showed a positive association in CDLE. However, these results are not compatible with those from Caucasian subjects. There are no significant associations among HLA studies, photosensitivity, and anti-Ro/SS-A antibodies in Japanese CLE patients. Photosensitivity will be a key factor to dissolve multifactorial complexes of LE etiopathogenesis. An axis of photosensitivity, anti-Ro/SS-A antibodies, and apoptosis via tumor necrosis factor-alpha is the best marker to verify the contribution of genetics in CLE patients. The incidence and degree of photosensitivity of SCLE and LET are much lower in Japanese than in Caucasians. This discrepancy may lead to investigations of CLE pathogenesis through global collaborations.

Epidermal platelet-activating factor receptor activation and ultraviolet B radiation result in synergistic tumor necrosis factor-alpha production

Ultraviolet B radiation (UVB) is a potent stimulator of epidermal cytokine production which has been implicated in photoaggravated dermatoses. In addition to cytokines such as tumor necrosis factor-alpha (TNF-alpha), UVB generates bioactive lipids including platelet-activating factor (PAF). Our previous studies have demonstrated that UVB-mediated production of keratinocyte TNF-alpha is in part due to PAF. The current studies use a human PAF-receptor (PAF-R) negative epithelial cell line transduced with PAF-Rs and PAF-R-deficient mice to demonstrate that activation of the epidermal PAF-R along with UVB irradiation results in a synergistic production of TNF-alpha. It should be noted that PAF-R effects are mimicked by the protein kinase C (PKC) agonist phorbol myristic acetate, and are inhibited by pharmacological antagonists of the PKC gamma isoenzyme. These studies suggest that concomitant PAF-R activation and UVB irradiation results in a synergistic production of the cytokine TNF-alpha which is mediated in part via PKC. These studies provide a novel potential mechanism for photosensitivity responses.

Tyrosine kinase 2 and interferon regulatory factor 5 polymorphisms are associated with discoid and subacute cutaneous lupus erythematosus

Lupus erythematosus (LE) is a heterogeneous disease ranging from skin-restricted manifestations to a progressive multisystem disease. The specific skin lesions include chronic cutaneous, subacute cutaneous and acute cutaneous LE. Both genetic and environmental factors are involved in the development of LE. However, reports on the genetic background of cutaneous lupus erythematosus (CLE) forms, namely discoid (DLE) and subacute cutaneous lupus erythematosus (SCLE), are sparse. We investigated whether the known systemic LE (SLE) susceptibility genes also predispose to CLE. Altogether, 219 Finnish patients with DLE or SCLE and 356 healthy controls were recruited. Single nucleotide polymorphisms tagging reported risk genes were genotyped. Tyrosine kinase 2 (TYK2) rs2304256 was associated with increased risk of DLE (P = 0.012, OR = 1.47, 95% CI = 1.01-1.98). Expression of TYK2 was demonstrated by immunohistochemistry in macrophage-like cells and neutrophils and interferon regulatory factor 5 (IRF5) in macrophage- and fibroblast-like cells of DLE, SCLE and SLE skin. IRF5 rs10954213 showed association with DLE (P = 0.017, OR = 1.40, 95% CI = 1.06-1.86) and SCLE (P = 0.022, OR = 1.87, 95% CI = 1.09-3.21). A haplotype of cytotoxic T-lymphocyte-associated protein 4 (CTLA4) showed association with DLE (P = 0.0065, OR = 2.51, 95% CI = 1.25-5.04). Our results show that the TYK2, IRF5 and CTLA4 genes previously associated with SLE also confer risk for DLE and SCLE, suggesting that different LE subphenotypes may share pathogenetic pathways.

[Photosensitivity in lupus erythematosus]

Photosensitivity is one of the ARA diagnostic criteria of systemic lupus erythematosus. Sun exposure can also induce extracutaneous manifestations of the disease. Photosensitivity may be difficult to prove by history taking in lupus patients, as the delay between sun exposure and the onset of specific skin lesions is rather long. Photo-induction of lupus can occur by ultraviolet A (UVA) radiation in the shadow or behind window glass, so that the relationship between radiation exposure and exacerbation of the disease may not seem obvious to the patient. Phototesting procedures for lupus erythematosus have been described, but they are not used in routine practice. Both UVB and UVA play a role in the pathogenesis of lupus erythematosus: in the epidermis they induce DNA damage, they expose nuclear antigens and photo-induced neo-antigens at the cell surface, they lead to an accumulation of apoptotic material, and they induce several pro-inflammatory cytokines. In the dermis, UV radiation triggers skin infiltration by inflammatory cells by modulation of microvascular flow rates and by upregulation of white blood cell migration from dermal capillaries to the skin. Photodistribution of skin lesions and a delay of their onset of more than 48 hours after sun exposure are clinical hallmarks of cutaneous lupus erythematosus that are usually completed by histological confirmation. Photoprotection is essential in the treatment of lupus patients: it comprises sun avoidance suitable for both UVB and UVA radiation, protective clothing, and topical broad-spectrum filters.

Cytokine gene polymorphisms as risk and severity factors for juvenile dermatomyositis

OBJECTIVE

To study tumor necrosis factor alpha (TNFalpha) and interleukin-1 (IL-1) cytokine polymorphisms as possible risk and protective factors, define their relative importance, and examine these as severity factors in patients with juvenile dermatomyositis (DM).

METHODS

TNFalpha and IL-1 cytokine polymorphism and HLA typing were performed in 221 Caucasian patients with juvenile DM, and the results were compared with those in 203 ethnically matched healthy volunteers.

RESULTS

The genotypes TNFalpha -308AG (odds ratio [OR] 3.6), TNFalpha -238GG (OR 3.5), and IL-1alpha +4845TT (OR 2.2) were risk factors, and TNFalpha -308GG (OR 0.26) as well as TNFalpha -238AG (OR 0.22) were protective, for the development of juvenile DM. Carriage of a single copy of the TNFalpha -308A (OR 3.8) or IL-1beta +3953T (OR 1.7) allele was a risk factor, and the TNFalpha -238A (OR 0.29) and IL-1alpha +4845G (OR 0.46) alleles were protective, for juvenile DM. Random Forests classification analysis showed HLA-DRB1*03 and TNFalpha -308A to have the highest relative importance as risk factors for juvenile DM compared with the other alleles (Gini scores 100% and 90.7%, respectively). TNFalpha -308AA (OR 7.3) was a risk factor, and carriage of the TNFalpha -308G (OR 0.14) and IL-1alpha -889T (OR 0.41) alleles was protective, for the development of calcinosis. TNFalpha -308AA (OR 7.0) was a possible risk factor, and carriage of the TNFalpha -308G allele (OR 0.14) was protective, for the development of ulcerations. None of the studied TNFalpha, IL-1alpha, and IL-1beta polymorphisms were associated with the disease course, disease severity at the time of diagnosis, or the patient's sex.

CONCLUSION

TNFalpha and IL-1 genetic polymorphisms contribute to the development of juvenile DM and may also be indicators of disease severity.

Evidence for a pathogenetic role of interleukin-18 in cutaneous lupus erythematosus

OBJECTIVE

Cutaneous manifestations are the most common clinical features of lupus erythematosus (LE). The aim of this study was to analyze differences in the inflammatory response of keratinocytes from patients with cutaneous LE (CLE) compared with healthy controls.

METHODS

Keratinocytes from LE patients and controls were cultured from epidermal stem cells of the hair follicle of anagen head hairs. Functional responses of keratinocytes to cytokine stimulation were determined by flow cytometry and enzyme-linked immunosorbent assay. Biopsy samples of lesional skin were analyzed by immunohistochemistry.

RESULTS

Keratinocytes from CLE patients expressed higher levels of IL-18 receptor on their cell surface in response to tumor necrosis factor alpha (TNFalpha) or interferon-gamma stimulation. In response to IL-18 stimulation, these cells produced large amounts of TNFalpha. Of note, in the presence of IL-18, CLE keratinocytes failed to express IL-12. IL-12 has previously been shown to protect keratinocytes from ultraviolet irradiation-induced apoptosis. Keratinocytes from LE patients were more prone to die upon exposure to IL-18, and this increased apoptosis was abrogated by blockade of endogenously produced TNFalpha as well as by the addition of exogenous IL-12. IL-18 was highly expressed in biopsy samples of lesional skin from CLE patients.

CONCLUSION

Our results demonstrate an intrinsic difference in the inflammatory response of keratinocytes and indicate an autocrine feedback loop involving TNFalpha, IL-18, and IL-12 family members. Our results suggest that IL-18 may occupy an important position in the cytokine hierarchy in CLE, indicating the potential benefit of a local agent that blocks IL-18 activity in the treatment of the manifestations of CLE.

Dermatomyositis

Dermatomyositis (DM) is a chronic inflammatory disorder of the skin and muscles. Although thought to be autoimmune in origin, many questions remain as to the etiopathogenesis of this disease. DM has classically been considered a humorally mediated disease. Current evidence, however, seems to increasingly support alternative (though not mutually exclusive) mechanisms of pathogenesis, including cell-mediated and innate immune system dysfunction. Pathologic findings of DM in muscle include infarcts, perifascicular atrophy, endothelial cell swelling and necrosis, vessel wall membrane attack complex deposition, and myocyte-specific MHC I upregulation. As for the skin, histopathologic findings include hyperkeratosis, epidermal basal cell vacuolar degeneration and apoptosis, increased dermal mucin deposition, and a cell-poor interface dermatitis. Autoantibodies, particularly those that bind nuclear or cytoplasmic ribonucleoprotein antigens, are also commonly found in DM, although their importance in pathogenesis remains unclear. Defective cellular clearance, genetic predilection and environmental exposures, such as viral infection, may also play an important role in the pathogenesis of DM. The seminal work regarding the pathogenesis of DM is reviewed and an update on the recent basic and molecular advances in the field is provided.

Conserved non-coding sequences and transcriptional regulation

Genes coding for transcription factors and developmental regulators have a high likelihood to harbour cis-regulatory regions that are structurally conserved among orthologous genes in the vertebrate lineage. These regions can span up to several hundred basepairs with 70 and more percent sequence identity between fish and mammals. Even though this conservation is an efficient tool to discover cis-regulatory regions, we know little about why these specific genes maintain such highly conserved regulatory sequences. Here, we summarise work of the past few years on the regulatory modules of the sonic hedgehog and neurogenin1 genes. We will discuss the high sequence conservation of the regulatory elements in the context of models of enhancer evolution. Our data suggest that conservation of sequence does not necessarily imply a conserved function in other vertebrates.

Sun-induced life-threatening lupus nephritis

Photosensitivity is a widely known characteristic of both cutaneous and systemic lupus erythematosus (LE). However, sun-induced organ involvement is rarely reported in LE. We describe a 34-year-old woman who had been in complete remission of systemic LE for more than 8 years without treatment. After sunbathing, she developed acute sunburn followed by cutaneous LE in sun-exposed areas. Six weeks later, a lupus nephritis was diagnosed and high serum levels of antidouble-stranded (ds) DNA and anti-Ro/SSA antibodies were detected. Treatment with systemic cyclophosphamide and prednisolone led to septicemia requiring assisted ventilation for more than 2 weeks and repeated hemodialysis. Clinical remission was achieved 3 months later by the use of prednisolone and mycophenolate mofetile. Meanwhile, mild proteinuria persisted, anti-dsDNA antibodies normalized. We hypothesize that the sunburn-induced keratinocyte necrosis/apoptosis exposed intracellular antigens as trigger for the generation of autoantibodies that finally mediated immune-complex nephritis. The patient highlights the impact of UV light not only on skin but also on internal organ involvement in LE.

Neonatal lupus syndromes

Neonatal lupus has become an important model of passively acquired autoimmunity since the seminal observation in the late 1970s that sera from nearly all mothers of children with isolated congenital heart block (CHB) contain specific autoantibodies.