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

Sunscreen use associated with elevated prevalence of anti-nuclear antibodies in U.S. adults

BACKGROUND

Antinuclear antibody (ANA) prevalence in the U.S. population increased from 1988 to 2012, especially in white and more educated individuals. In adults ages 20-39 years from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and 2011-2012, ANA prevalence was previously associated with urinary concentrations of a common sunscreen ingredient, benzophenone 3, measured in winter. Spot urines may not capture relevant chronic exposures, thus we examined whether ANA was related to sunscreen use.

METHODS

In a cross-sectional study of adults ages 20-59 (N = 416 ANA positive, 2656 ANA negative, by Hep-2 immunofluorescence, 1:80 dilution), we examined associations of ANA with reported sunscreen use when in the sun for 1 h or more. Logistic regression was used to calculate covariate-adjusted prevalence odds ratios (POR) and 95 % Confidence Intervals (CI), overall and stratified by demographic factors, season, and vitamin D. We explored associations and joint effects with other sun protective behaviors and sunburn in the past 12 months.

RESULTS

The association of ANA with sunscreen differed by age (interaction p = 0.004): for ages 20-39, we saw an exposure response (POR 2.61, 95 % CI 1.50, 4.24 for using sunscreen always or most of the time, and POR 1.85; 1.12, 3.05 for less frequent versus never-use; trend p < 0.001). These associations were more apparent in females (interaction p = 0.082), non-Hispanic white and black participants (vs. other race/ethnicity, interaction p = 0.023), and those with sufficient serum vitamin D (≥50 vs. <50 nmol/L, interaction p = 0.001). ANA was not associated with other protective behaviors and not confounded or modified by these behaviors or recent sunburn.

CONCLUSIONS

These cross-sectional findings showed frequent sunscreen was associated with ANA in younger adults, supporting the need for replication, and longitudinal studies with detailed exposure histories.

Systemic lupus erythematosus: pathogenesis and targeted therapy

Systemic lupus erythematosus (SLE) is a multifaceted autoimmune disorder characterized by dysregulated immune responses and autoantibody production, which affects multiple organs and varies in clinical presentation and disease severity. The development of SLE is intricate, encompassing dysregulation within the immune system, a collapse of immunological tolerance, genetic susceptibilities to the disease, and a variety of environmental factors that can act as triggers. This review provides a comprehensive discussion of the pathogenesis and treatment strategies of SLE and focuses on the progress and status of traditional and emerging treatment strategies for SLE. Traditional treatment strategies for SLE have mainly employed non-specific approaches, including cytotoxic and immunosuppressive drugs, antimalarials, glucocorticoids, and NSAIDs. These strategies are effective in mitigating the effects of the disease, but they are not a complete cure and are often accompanied by adverse reactions. Emerging targeted therapeutic drugs, on the other hand, aim to control and treat SLE by targeting B and T cells, inhibiting their activation and function, as well as the abnormal activation of the immune system. A deeper understanding of the pathogenesis of SLE and the exploration of new targeted treatment strategies are essential to advance the treatment of this complex autoimmune disease.

Hepatitis E Virus Infection in Patients with Systemic and Cutaneous Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a multifactorial etiology in which genetic and environmental factors interplay. An exclusively cutaneous condition has been described and defined as cutaneous lupus erythematosus (CLE). In Italy, a nationwide blood donor survey found an overall HEV prevalence of 8.7%, with an interregional variation from 2.2% to 22.8%. In this study, we aimed to estimate HEV seroprevalence in a cohort of patients affected by SLE and CLE attending the Lupus Clinic, Sapienza University of Rome. Serum samples were tested for anti-HEV immunoglobulin Ig G and M antibodies using commercial enzyme-linked immunosorbent assay (ELISA) kits. Statistical analysis was performed. In total, 138 patients were enrolled, 92 (67%) affected by SLE and 46 by CLE. The prevalence of HEV infection was 23.9% in the CLE group and 7.6% in the SLE group. The anti-HEV+ prevalence was significantly more frequent in CLE. Some mechanisms may be linked to increased susceptibility to HEV such as a molecular mimicry associated with the CLE condition or with the skin compartment/skin self-antigens, as well as the involvement of the genetic background. Regarding the possible risk factors, no association was found, although, of note, the odds of HEV+ relative to contact with animals and to eating raw seafood were strongly higher than the unit in the CLE group.

Tumid Lupus Erythematosus (TLE): A Review of a Rare Variant of Chronic Cutaneous Lupus Erythematosus (cCLE) with Emphasis on Differential Diagnosis

Tumid lupus erythematosus (TLE) has been the subject of heated debate regarding its correct nosographic classification. The definition of TLE has changed over time, varying according to the different studies performed. In this review, we address the initial definition of TLE, the changes that have taken place in the understanding of TLE, and its placement within the classification of cutaneous lupus erythematosus (CLE), with a focus on clinical, histopathological, immunophenotypical, and differential diagnosis aspects.

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.

Thalidomide and Lenalidomide for Refractory Systemic/Cutaneous Lupus Erythematosus Treatment: A Narrative Review of Literature for Clinical Practice

BACKGROUND

Thalidomide has shown exceptional results in systemic/cutaneous lupus erythematosus(SLE/CLE). Recently, lenalidomide has been also prescribed for SLE/CLE treatment. Literature regarding efficacy/adverse events for these drugs is scarce with a single systematic review and meta-analysis focused solely on thalidomide for refractory cutaneous lupus subtypes.

OBJECTIVE

We, therefore, addressed in this narrative review the efficacy/adverse effects of thalidomide and lenalidomide for SLE and CLE. In addition, we provide a specialist approach for clinical practice based on the available evidence.

RESULTS

Efficacy of thalidomide for refractory cutaneous lupus treatment was demonstrated by several studies, mostly retrospective with small sample size(≤20). The frequency of peripheral polyneuropathy is controversial varying from 15-80% with no consistent data regarding cumulative dose and length of use. Drug withdrawn results in clinical partial/complete reversibility for most cases (70%). For lenalidomide, seven studies (small sample sizes) reported its efficacy for SLE/CLE with complete/partial response in all patients with a mean time to response of 3 months. Flare rate varied from 25-75% occurring 0.5-10 months after drug withdrawn. There were no reports of polyneuropathy/worsening of previous thalidomide-induced neuropathy, but most of them did not perform nerve conduction studies. Teratogenicity risk exist for both drugs and strict precautions are required.

CONCLUSIONS

Thalidomide is very efficacious as an induction therapy for patients with severe/refractory cutaneous lupus with high risk of scarring, but its longstanding use should be avoided due to neurotoxicity. Lenalidomide is a promising drug for skin lupus treatment, particularly regarding the apparent lower frequency of nerve side effects.

Immunopathogenesis of skin injury in systemic lupus erythematosus

PURPOSE OF REVIEW

Skin injury is the most common clinical manifestation of SLE and is disfiguring, difficult to treat, and incompletely understood. We provide an overview of recently published articles covering the immunopathogenesis of skin injury in SLE.

RECENT FINDINGS

Skin of SLE has an inherent susceptibility to apoptosis, the cause of which may be multifactorial. Chronic IFN overexpression leads to barrier disruption, infiltration of inflammatory cells, cytokine production, and release of autoantigens and autoantibody production that result in skin injury. Ultraviolet light is the most important CLE trigger and amplifies this process leading to skin inflammation and potentially systemic disease flares.

SUMMARY

The pathogenesis of skin injury in CLE is complex but recent studies highlight the importance of mechanisms driving dysregulated epidermal cell death likely influenced by genetic risk factors, environmental triggers (UV light), and cytotoxic cells and cellular signaling.

Bioinformatic analysis of key biomarkers and immune filtration of skin biopsy in discoid lupus erythematosus

OBJECTIVE

Discoid lupus erythematosus (DLE) is the most common category of chronic cutaneous lupus erythematosus, where the pathological process is proved to be closely associated with immunity. This bioinformatic analysis sought to identify key biomarkers and to perform immune infiltration analysis in the skin biopsy samples of DLE.

METHODS

GSE120809, GSE100093, GSE72535, GSE81071 were used as the data source of gene expression profiles, altogether containing 79 DLE samples and 47 normal controls (NC). Limma package was applied to identify differentially expressed genes (DEGs) and additional Gene Ontology (GO) together with The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were done. Protein-protein interaction network (PPI) was constructed using STRING and Cytoscape. Hub genes were selected by CytoHubba. Finally, immune filtration analysis was finished by the CIBERSORT algorithm, and comparisons between the two groups were accomplished.

RESULTS

A total of 391 DEGs were identified, which were composed of 57 up-regulated genes and 334 down-regulated genes. GO and KEGG enrichment analyses revealed that DEGs were closely related with different steps in the immune response. Top 10 hub genes included GBP2, HLA-F, IFIT2, RSAD2, ISG15, IFIT1, IFIT3, MX1, XAF1 and IFI6. Immune filtration analysis from CIBERSORT had found that compared with NC, DLE samples had higher percentages of CD8+ T cells, T cells CD4 memory activated, T cells gamma delta, macrophages M1 and lower percentages of T cells regulatory, macrophages M2, dendritic cells resting, mast cells resting, mast cells activated.

CONCLUSION

This bioinformatic study selected key biomarkers from the contrast between DLE and NC skin samples and is the first research to analyze immune cell filtration in DLE.

Shared inflammatory and skin-specific gene signatures reveal common drivers of discoid lupus erythematosus in canines, humans and mice

Autoimmune skin diseases are complex and are thought to arise from a combination of genetics and environmental exposures, which trigger an ongoing immune response against self-antigens. Companion animals including cats and dogs are known to develop inflammatory skin conditions similar to humans and share the same environment, providing opportunities to study spontaneous disease that encompasses genetic and environmental factors with a One Health approach. A strength of comparative immunology approaches is that immune profiles may be assessed across different species to better identify shared or conserved pathways that might drive inflammation. Here, we performed a comparative study of skin from canine discoid lupus erythematosus (DLE) using NanoString nCounter technology. We compared these gene expression patterns to those of human DLE and a mouse model of cutaneous lupus. We found strong interferon signatures, with CXCL10, ISG15, and an S100 gene family member among the highest, most significant DEGs upregulated across species. Cell type analysis revealed marked T-cell and B-cell infiltration. Interestingly, canine DLE samples also recapitulated downregulated skin homeostatic genes observed in human DLE. We conclude that spontaneous DLE in dogs captures many features that are present in human disease and may serve as a more complete model for conducting further genomic and/or transcriptomic studies.

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Canine DLE lesions express known drivers of pathogenesis including CXCL10, IFNG, FAS.

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Enrichment of key cell types, including T, B, NK cells, is observed in canine DLE.

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Canine, mouse and human DLE share similar proinflammatory profiles.

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Canine DLE exhibits downregulated skin homeostatic and immune regulatory genes.

Study on the correlation between anti-ribosomal P protein antibody and systemic lupus erythematosus

The aims of this study were to compare diagnostic value of anti-ribosomal P protein antibody (anti-P), anti-Smith antibody (anti-Sm), anti-double-stranded DNA antibody (anti-dsDNA), anti-nucleosome antibody (ANuA), and anti-histone antibody (AHA) for systemic lupus erythematosus (SLE) as well as explore the correlation between anti-P and SLE.A retrospective study was performed with 487 SLE patients, 235 non-SLE rheumatic diseases, and 124 healthy subjects from January 2015 to December 2018. Clinical manifestations, laboratory results and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)-2000 scores were analyzed between anti-P/+/ and anti-P/-/ patients. SPSS19.0 statistical software was used for data analysis.The sensitivities of anti-P, anti-Sm, anti-dsDNA, ANuA, and AHA in SLE were 31.6%, 20.7%, 45.0%, 27.9%, and 14.6%, and the specificities were 99.2%, 99.4%, 98.9%, 98.3%, and 96.7%, respectively. Only 27.9% of SLE had a single positive anti-P while the other 4 antibodies were all negative. There were significant differences in the age of onset, skin erythema, urinary protein, creatinine and serum IgG, IgM, C3, C4 between anti-P/+/ and anti-P/-/ patients (P < .05). When anti-Sjogren syndrome A antibody, anti-P were positive and anti-dsDNA was negative, the incidence of skin erythema was the highest (35.1%). Compared with anti-P/-/ patients, anti-P/+/ patients had higher SLEDAI scores (P < .001).Anti-P, anti-Sm, anti-dsDNA, ANuA, and AHA have high specificity but poor sensitivity in the diagnosis of SLE; combined detection can greatly improve the detection rate. Anti-P is more valuable in the diagnosis of SLE when other specific autoantibodies are negative. SLE patients with positive anti-P have an earlier onset age and are more prone to skin erythema, lupus nephritis as well as higher disease activity.

Association of interleukin-6 and tumor necrosis factor-α with mortality in hospitalized patients with cancer

BACKGROUND

Severe cutaneous adverse reactions (SCARs) are associated with high morbidity and mortality in patients with cancer. Early identification and treatment of SCARs may improve outcomes.

OBJECTIVE

To identify biomarkers to predict outcomes in hospitalized patients with cancer who developed SCARs.

METHODS

Retrospective review of 144 hospitalized patients with cancer with a morbilliform rash, recorded testing for serum cytokines (interleukin [IL]-6, IL-10, and tumor necrosis factor [TNF]-α) or elafin, and a dermatology consultation. Rashes were categorized as simple morbilliform rash without systemic involvement or complex morbilliform rash with systemic involvement.

RESULTS

Fifty-four of 144 (37.5%) patients died during follow-up. Elevated levels of IL-6, IL-10, and TNF-α were associated with decreased survival. Overall survivals in patients with elevated levels of IL-6, IL-10, and TNF-α were 53.7%, 56.6%, 53.6%, respectively, compared with 85.7%, 82.5% and 83.6%, respectively, in those with lower levels. Patients with increased levels of both IL-6 and TNF-α had a nearly 6-fold increase in mortality (hazard ratio, 5.82) compared with patients with lower levels.

LIMITATIONS

Retrospective design, limited sample size, and high-risk population.

CONCLUSIONS

Hospitalized patients with cancer with rash and elevated IL-6 and TNF-α were nearly 6 times more likely to die over the course of follow-up. These biomarkers may serve as prognostic biomarkers and therapeutic targets for this high-risk population.

Assessment of Response to B-Cell Depletion Using Rituximab in Cutaneous Lupus Erythematosus

Importance

Cutaneous lupus erythematosus (CLE) can be severe and treatment resistant. B-cell depletion therapy (BCDT) with rituximab is well recognized in organ involvement in systemic lupus erythematosus (SLE), but its efficacy in cutaneous manifestations is less well established.

Objective

To evaluate the outcomes of BCDT in CLE and its clinical subtypes in the setting of associated SLE.

Design, Setting, and Participants

This single-center, retrospective, cohort study was performed at the adult tertiary referral Rheumatology Department of University College London Hospital, London, United Kingdom, from January 1, 2000, through March 31, 2016, with 12-month follow-up completed on March 31, 2017. Adult patients with carefully classified CLE and mucocutaneous British Isles Lupus Assessment Group (BILAG) grade A or B who were treated with rituximab BCDT were selected from a prospective database of 709 patients with SLE. Data were analyzed from April through December 2017.

Main Outcomes and Measures

Clinical response was examined at 6 and 12 months after treatment for CLE and its subtypes acute CLE (ACLE), subacute CLE (SCLE), chronic CLE (CCLE), and nonspecific LE (NSLE). A complete response was defined as achieving BILAG grade D; partial response, BILAG grade C; stable disease, no change; and disease flare, change from BILAG grade C or D to grade A or B.

Results

A total of 50 patients with SLE were eligible for inclusion; mean (SD) age at diagnosis was 26.9 (12.1) years, and 49 (98%) were women. Twenty-one patients had ACLE; 6, SCLE; 10, CCLE; and 11, NSLE (including 2 with concurrent ACLE and CCLE). Overall, at 6 months, 38 patients (76%) improved their mucocutaneous BILAG grade A or B status, including 20 (40%) with a complete response. At 12 months, 28 of 46 patients (61%) maintained this response, including 24 (52%) with a complete response. Two of 6 patients (33%) with SCLE showed a complete response at 6 and 12 months. Five of 12 patients (42%) with CCLE showed a complete response at 6 months, and 5 of 11 (45%), at 12 months. Fifteen patients (30%) required further rituximab therapy within 12 months for cutaneous involvement.

Conclusions and Relevance

B-cell depletion therapy using rituximab appears effective in patients with SLE and severe active CLE; however, outcomes are variable in those with SCLE and CCLE subtypes.

Tyrosine Kinases in Autoimmune and Inflammatory Skin Diseases

Tyrosine kinases relay signals from diverse leukocyte antigen receptors, innate immune receptors, and cytokine receptors, and therefore mediate the recruitment and activation of various leukocyte populations. Non-receptor tyrosine kinases of the Jak, Src, Syk, and Btk families play major roles in various immune-mediated disorders, and small-molecule tyrosine kinase inhibitors are emerging novel therapeutics in a number of those diseases. Autoimmune and inflammatory skin diseases represent a broad spectrum of immune-mediated diseases. Genetic and pharmacological studies in humans and mice support the role of tyrosine kinases in several inflammatory skin diseases. Atopic dermatitis and psoriasis are characterized by an inflammatory microenvironment which activates cytokine receptors coupled to the Jak-Stat signaling pathway. Jak kinases are also implicated in alopecia areata and vitiligo, skin disorders mediated by cytotoxic T lymphocytes. Genetic studies indicate a critical role for Src-family kinases and Syk in animal models of autoantibody-mediated blistering skin diseases. Here, we review the various tyrosine kinase signaling pathways and their role in various autoimmune and inflammatory skin diseases. Special emphasis will be placed on identification of potential therapeutic targets, as well as on ongoing preclinical and clinical studies for the treatment of inflammatory skin diseases by small-molecule tyrosine kinase inhibitors.

In silico Analyses of Skin and Peripheral Blood Transcriptional Data in Cutaneous Lupus Reveals CCR2-A Novel Potential Therapeutic Target

Cutaneous lesions feature prominently in lupus erythematosus (LE). Yet lupus and its cutaneous manifestations exhibit extraordinary clinical heterogeneity, making it imperative to stratify patients with varying organ involvement based on molecular criteria that may be of clinical value. We conducted several in silico bioinformatics-based analyses integrating chronic cutaneous lupus erythematosus (CCLE)-skin and blood expression profiles to provide novel insights into disease mechanisms and potential future therapy. In addition to substantiating well-known prominent apoptosis and interferon related response in both tissue environments, the overrepresentation of GO categories in the datasets, in the context of existing literature, led us to model a “disease road-map” demonstrating a coordinated orchestration of the autoimmune response in CCLE reflected in three phases: (1) initiation, (2) amplification, and (3) target damage in skin. Within this framework, we undertook in silico interactome analyses to identify significantly “over-connected” genes that are potential key functional players in the metabolic reprogramming associated with skin pathology in CCLE. Furthermore, overlapping and distinct transcriptional “hot spots” within CCLE skin and blood expression profiles mapping to specified chromosomal locations offer selected targets for identifying disease-risk genes. Lastly, we used a novel in silico approach to prioritize the receptor protein CCR2, whose expression level in CCLE tissues was validated by qPCR analysis, and suggest it as a drug target for use in future potential CCLE therapy.

Fn14 deficiency protects lupus-prone mice from histological lupus erythematosus-like skin inflammation induced by ultraviolet light

The cytokine TNF-like weak inducer of apoptosis (TWEAK) and its receptor Fn14 are involved in cell survival and cytokine production. The TWEAK/Fn14 pathway plays a role in the pathogenesis of spontaneous cutaneous lesions in the MRL/lpr lupus strain; however, the role of TWEAK/Fn14 in disease induced by ultraviolet B (UVB) irradiation has not been explored. MRL/lpr Fn14 knockout (KO) was compared to MRL/lpr Fn14 wild-type (WT) mice following exposure to UVB. We found that irradiated MRL/lpr KO mice had significantly attenuated cutaneous disease when compared to their WT counterparts. There were also fewer infiltrating immune cells (CD3⁺ , IBA-1⁺ and NGAL⁺ ) in the UVB-exposed skin of MRL/lpr Fn14KO mice, as compared to Fn14WT. Furthermore, we identified several macrophage-derived proinflammatory chemokines with elevated expression in MRL/lpr mice after UV exposure. Depletion of macrophages, using a CSF-1R inhibitor, was found to be protective against the development of skin lesions after UVB exposure. In combination with the phenotype of the MRL/lpr Fn14KO mice, these findings indicate a critical role for Fn14 and recruited macrophages in UVB-triggered cutaneous lupus. Our data strongly suggest that TWEAK/Fn14 signalling is important in the pathogenesis of UVB-induced cutaneous disease manifestations in the MRL/lpr model of lupus and further support this pathway as a possible target for therapeutic intervention.

Pathogenesis of cutaneous lupus erythema associated with and without systemic lupus erythema

Cutaneous lupus erythematosus (CLE) can be an individual disease only involving skin, or presents as part of the manifestations of SLE. A small proportion of CLE may progress into SLE, however, the underlying pathogenic mediators remain elusive. By only including researches that clearly described if the subtypes of CLE presented by enrolled subjects was associated with or without SLE, we provided an overview of antibodies, inflammatory cells and inflammatory molecular mediators identified in blood and skin that were possibly involved in lupus skin damages. IgG autoantibodies are crucial for the development of CLE associated with SLE, but the circulating inflammatory cells and molecular mediators require further studies to provide definitive proof for their association with skin damages. Discoid lupus erythematosus (DLE) is the most common subtype of CLE. For DLE without associated with SLE (CDLE), it is lack of evidences if autoantibodies and circulating inflammatory cells are involved in the pathogenesis or not, but is clear that the cutaneous inflammatory infiltrates are dominated by Th1, but not Th17 cells in contrast to the various complex profile in SLE. As the major target cells in skin, keratinocytes may participate the pathophysiological process by increase cell apoptosis and the production of proinflammatory cytokines in SLE and CDLE. Insights into the similarities and differences of the pathogenesis of CLE and CLE associated with SLE will also improve our therapeutic strategies for CLE that is currently adopted from SLE, and prevent the progression of CLE to SLE by providing interventions within an appropriate window of disease development.

Lupus profundus limited to a site of trauma: Case report and review of the literature

Lupus erythematosus profundus (LEP) is a rare form of chronic cutaneous lupus erythematosus. We report on a case of a 56-year-old Caucasian woman who presented with a single, persistent, painful rash on the left hip and lateral aspect of the left upper thigh, which had been present for 2.5 years. The patient had a history of previous injury to this area before the rash started. Clinical findings showed an inflamed, hyperpigmented, and indurated plaque with a linear skin invagination and no associated systemic symptoms. A skin biopsy test result confirmed the diagnosis of LEP and the clinical and laboratory examinations ruled out systemic lupus erythematosus. After 2 months of treatment with methotrexate 20 mg weekly and 1 month of prednisolone 7.5 mg daily, the skin rash improved considerably. We also present a brief review of the epidemiology, etiology, clinical features, histopathology, laboratory findings, differential diagnosis, and treatment of LEP.

Crosstalk Between Apoptosis and Autophagy: Environmental Genotoxins, Infection, and Innate Immunity

Autoimmune disorders constitute a major and growing health concern. However, the genetic and environmental factors that contribute to or exacerbate disease symptoms remain unclear. Type I interferons (IFNs) are known to break immune tolerance and be elevated in the serum of patients with autoimmune diseases such as lupus. Extensive work over the past decade has characterized the role of a protein termed stimulator of interferon genes, or STING, in mediating IFN expression and activation in response to cytosolic DNA and cyclic dinucleotides. Interestingly, this STING-dependent innate immune pathway both utilizes and is targeted by the cell's autophagic machinery. Given that aberrant interplay between the apoptotic and autophagic machineries contributes to deregulation of the STING-dependent pathway, IFN-regulated autoimmune phenotypes may be influenced by the combined exposure to environmental carcinogens and pathogenic microorganisms and viruses. This review therefore summarizes recent data regarding these important issues in the field of autoimmunity.

Panniculitis: A summary

The diagnosis of panniculitis is felt to be a confusing topic by some pathologists. This summarical article presents inflammatory diseases of the subcutis in a systematic fashion, based on whether they are centered on fibrovascular septa or the adipose lobules, and whether morphologic vasculitis is present or not. Septocentric, non-vasculitis disorders include erythema nodosum, panniculitis that follows the use of "biological" therapeutic agents, lipodermatosclerosis, post-irradiation panniculitis, morphea profunda, and necrobiosis lipodica profunda. Polyarteritis nodosa and Behçet's disease are the conditions that are based in the subcutaneous septa with vasculitis. Predominantly-lobular panniculitides with no vasculitis include pancreatogenic panniculitis, the panniculitis of alpha-1-antitrypsin deficiency, panniculitis associated with lupus erythematosus and dermatomyositis, subcutaneous Sweet syndrome, eosinophilic panniculitis, factitial panniculitis, cold panniculitis, panniculitis following injections of corticosteroids, lipomembranous (ischemic) panniculitis; sclerema neonatorum and subcutaneous fat necrosis of the newborn, and Rosai-Dorfman disease of the subcutis. Erythema induratum and infectious panniculitis are vasculitic and lobulocentric conditions. This article reviews the histological features of these diseases.

S2k guideline for treatment of cutaneous lupus erythematosus - guided by the European Dermatology Forum (EDF) in cooperation with the European Academy of Dermatology and Venereology (EADV)

Cutaneous lupus erythematosus (CLE) is a rare inflammatory autoimmune disease with heterogeneous clinical manifestations. To date, no therapeutic agents have been licensed specifically for patients with this disease entity, and topical and systemic drugs are mostly used 'off-label'. The aim of the present guideline was to achieve a broad consensus on treatment strategies for patients with CLE by a European subcommittee, guided by the European Dermatology Forum (EDF) and supported by the European Academy of Dermatology and Venereology (EADV). In total, 16 European participants were included in this project and agreed on all recommendations. Topical corticosteroids remain the mainstay of treatment for localized CLE, and further topical agents, such as calcineurin inhibitors, are listed as alternative first-line or second-line topical therapeutic option. Antimalarials are recommended as first-line and long-term systemic treatment in all CLE patients with severe and/or widespread skin lesions, particularly in patients with a high risk of scarring and/or the development of systemic disease. In addition to antimalarials, systemic corticosteroids are recommended as first-line treatment in highly active and/or severe CLE. Second- and third-line systemic treatments include methotrexate, retinoids, dapsone and mycophenolate mofetil or mycophenolate acid, respectively. Thalidomide should only be used in selected therapy-refractory CLE patients, preferably in addition to antimalarials. Several new therapeutic options, such as B-cell- or interferon α-targeted agents, need to be further evaluated in clinical trials to assess their efficacy and safety in the treatment of patients with CLE.

Cutaneous characteristics and association with antinuclear antibodies in 402 patients with different subtypes of lupus erythematosus

BACKGROUND

Lupus erythematosus (LE) is an autoimmune disease characterized by a heterogeneous spectrum of skin manifestations and organ affection, and is frequently associated with serum autoantibodies, which mostly remain positive through the course of the disease. The classification of LE is still a controversial topic.

OBJECTIVES

To examine the prevalence and long-term course of autoantibodies in patients with cutaneous LE (CLE) and/or systemic LE (SLE) treated in the outpatient clinic for connective tissue diseases of the department of Dermatology in Bochum, Germany.

METHODS

Four hundred and two patients with LE were evaluated for antinuclear antibodies at a whole of 1572 time points. The prevalence as well as the long-term positivity of antinuclear antibodies and their correlation with the various subtypes of disease was examined.

RESULTS

Antinuclear antibody (ANA) testing and anti-ds-DNA antibodies were not only more prevalent in SLE patients (as expected from the ACR criteria for diagnosis of SLE, P < 0.0001), but also have had a more consistent course in the long-term evaluation (P = 0.0001 and P = 0.0111 respectively). Subacute cutaneous LE (SCLE) was associated with ANA (P = 0.0075), anti-Ro (P < 0.0001) and anti-La (P < 0.0001) antibodies, showing also higher consistency rates for these antibodies than discoid LE (DLE, P = 0.049, P = 0.004, P = 0.0004). Our data from 100 patients with LE tumidus (LET) support its perception as a distinct subtype of LE, not correlating with systemic disease or antinuclear antibodies (P < 0.0001). Anti-U1-ribonucleoprotein antibodies correlated with CLE in SLE patients (P = 0.0237), whereas non-LE-specific antinuclear antibodies were a rare, inconsistent autoimmune epiphenomenon in patients with SLE.

CONCLUSION

Long-term analysis of antinuclear antibodies has shown significant differences in various clinical subtypes of LE, confirming the actual classification of the disease. A serial evaluation of antinuclear antibodies may support the classification of disease in LE patients with overlapping clinical features.

Cutaneous lupus erythematosus and systemic lupus erythematosus are associated with clinically significant cardiovascular risk: a Danish nationwide cohort study

Systemic lupus erythematosus (SLE) is a well-known cardiovascular risk factor. Less is known about cutaneous lupus erythematosus (CLE) and the risk of developing cardiovascular disease (CVD). Therefore, we investigated the risk of mortality and adverse cardiovascular events in patients diagnosed with SLE and CLE. We conducted a cohort study of the entire Danish population aged ≥ 18 and ≤ 100 years, followed from 1997 to 2011 by individual-level linkage of nationwide registries. Multivariable adjusted Cox regression models were used to estimate the hazard ratios (HRs) for a composite cardiovascular endpoint and all-cause mortality, for patients with SLE and CLE. A total of 3282 patients with CLE and 3747 patients with SLE were identified and compared with 5,513,739 controls. The overall HR for the composite CVD endpoint was 1.31 (95% CI 1.16–1.49) for CLE and 2.05 (95% CI 1.15–3.44) for SLE. The corresponding HRs for all-cause mortality were 1.32 (95% CI 1.20–1.45) for CLE and 2.21 (95% CI 2.03–2.41) for SLE. CLE and SLE were associated with a significantly increased risk of CVD and all-cause mortality. Local and chronic inflammation may be the driver of low-grade systemic inflammation.

Microarray study reveals a transforming growth factor-β-dependent mechanism of fibrosis in discoid lupus erythematosus

BACKGROUND

Discoid lupus erythematosus (DLE) is characterized by scarring lesions that develop and perpetuate fibrotic lesions. These are not observed in subacute cutaneous lupus erythematosus (SCLE). The pathophysiological basis of this is currently unknown.

OBJECTIVES

To identify contradistinctive signalling pathways and cellular signatures between the two type of lupus, with a focus on the molecular mechanisms leading to fibrosis.

METHODS

We conducted a gene expression microarray analysis in lesional and nonlesional skin biopsy specimens of patients with DLE (n = 10) and SCLE (n = 10). Confirmatory reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry were performed on selected transcripts in a new cohort of paraffin-embedded skin biopsies (n = 20). Changes over time of a group of selected inflammatory and fibrotic genes were also evaluated in a second biopsy taken 12 weeks later. In vitro functional studies were performed in primary isolated fibroblasts.

RESULTS

Compared with nonlesional skin, DLE samples expressed a distinctive T-cell gene signature. DLE samples displayed a significant CD4 T-cell enrichment with an imbalance towards T helper 1 cytokine predominance and a relative increased forkhead box (FOX)P3 response. RT-qPCR and immunochemical analysis over time showed a progressive increment of fibrotic markers and persistent FOXP3 recruitment. Ex vivo upregulation of SERPINE1, MMP9, TGFBR1, phosphorylated SMAD3 and TGFB1 suggested a transforming growth factor (TGF)-β-dependent mechanism of fibrosis in DLE, also confirmed by the results observed following in vitro stimulation with TGF-β.

CONCLUSIONS

These results highlight major pathogenic pathways in DLE and provide novel molecular targets for the development of new therapies. The data suggest the existence of a TGF-β-dependent pathway inducing fibrosis in DLE.

Cutaneous Lupus Erythematosus: An Update on Pathogenesis, Diagnosis and Treatment

Cutaneous lupus erythematosus (CLE) includes a broad range of dermatologic manifestations, which may or may not be associated with systemic disease. Recent studies in this area continue to shape our understanding of this disease and treatment options. Epidemiologic studies have found an incidence of CLE of 4.30 per 100,000, which approaches similar analysis for systemic lupus erythematosus (SLE). Although there have been extensive efforts to define SLE, the classification of CLE and its subgroups remains a challenge. Currently, diagnosis relies on clinical and laboratory findings as well as skin histology. The Cutaneous Lupus Area and Severity Index™ (CLASI™) is a validated measure of disease activity and damage. CLE pathogenesis is multifactorial and includes genetic contributions as well as effects of ultraviolet (UV) light. Immune dysregulation and aberrant cell signaling pathways through cytokine cascades are also implicated. Patient education and avoidance of triggers are key to disease prevention. Antimalarials and topical steroids continue to be the standard of care; however, immunosuppressants, thalidomide analogs and monoclonal antibodies are possible systemic therapies for the treatment of recalcitrant disease.

Association Between Discoid Lupus Erythematosus and Chronic Granulomatous Disease--Report of Two Cases and Review of the Literature

Discoid lupus erythematosus (DLE) is known to be associated with chronic granulomatous disease (CGD), but most DLE occurs in female carriers of X-linked CGD, with few reports of these lesions in CGD-affected individuals--this observation is unexplained. We describe two cases of DLE-like lesions in boys with CGD: one boy with partial neutrophil function and another whose lesions were related to voriconazole use. Reviewing other previously reported cases, we conclude that the risk of developing DLE-like lesions appears to be greater primarily in two subsets of the population with CGD: those with partial neutrophil function and those with near-absent neutrophil function in whom there is a second trigger. In light of recent literature on the role of neutrophils in lupus pathogenesis, we propose that pathogenesis of DLE in CGD may be related to NETosis, neutrophil dysfunction and a deficiency of reactive oxygen species, which medications such as voriconazole also influence.

Lupus erythematosus revisited

Lupus erythematosus (LE) is a multifactorial autoimmune disease with clinical manifestations of differing severity. The exact pathomechanisms and interactions resulting in the inflammatory and immunological processes of this heterogeneous disease remain elusive. Approaches in the understanding of the pathomechanisms revealed that the clinical expression of LE is predisposed by susceptibility genes and that various environmental factors are responsible for an abnormal immune response. Several studies demonstrated that ultraviolet (UV) light is one of the major factors in the pathogenesis of the disease. Standardized photoprovocation in patients with LE has been shown to be a safe and efficient model for evaluating the underlying pathomechanisms which lead to the production of autoantibodies and immune complexes. In particular, interferons were defined as important players in the early activation of the immune system and were observed to play a specific role in the immunological interface between the innate and the adaptive immune system. Abnormalities or disturbances in the different processes of cell death, such as apoptosis or necrosis, have also been recognized as crucial in the pathogenesis of LE. Although each process is different and characterized by unique features, the processes are interrelated and result in a complex disease.

Cutaneous lupus erythematosus: pathogenesis, clinical pattern, diagnostics, therapy

This article contains the latest information about the mechanisms of development of lupus erythematosus based on the literature review. The modern classification of specific and non-specific skin lesions in lupus erythematosus is shown.The authors described the clinical pattern of cutaneous forms of lupus erythematosus very detailed. the data about pathological and immunological criteria for the disease diagnostics, modern methods of pharmacotherapy lupus erythematosus was classified.

Silicone implants and lymphoma: The role of inflammation

The risk of hematological malignancies is mainly determined by genetic background, age, sex, race and ethnicity, geographic location, exposure to certain chemicals and radiation; along with the more recently proposed immune factors such as chronic inflammation, immunodeficiencies, autoimmunity, and infections. Paradigmatic examples include the development of lymphoma in Sjögren's syndrome and Hashimoto thyroiditis, gastric MALT lymphoma in Helicobacter pylori infection, or lymphomas associated with infections by Epstein-Barr virus, human herpes virus 8 (HHV 8) and leukemia/lymphoma virus 1 (HTLV-1). A growing number of reports indicates an increased risk of lymphoma, particularly of the anaplastic large cell (ALCL) type. The implants, specifically those used in the past, elicit chronic stimulation of the immune system against the prosthetic material. This is particularly the case in genetically susceptible hosts. We suggest that polyclonal activation may result in monoclonality in those at risk hosts, ultimately leading to lymphoma. We suggest that patients with an inflammatory response against silicone implants be monitored carefully.

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.

Mucocutaneous lupus erythematosus in dogs (21 cases)

BACKGROUND

The diagnosis of dogs with chronic juxtamucosal erosive lesions and histopathology typical of cutaneous lupus erythematosus (CLE) is unclear.

HYPOTHESIS/OBJECTIVES

We report herein 21 dogs with mucocutaneous erosive lesions and lupus-specific histopathology that we propose to be affected with mucocutaneous lupus erythematosus (MCLE), another variant of chronic CLE.

METHODS

Inclusion criteria were the presence of the following: (i) a >2 month history of chronic or recurrent skin lesions; (ii) erosions or ulcers predominating at mucosae or mucocutaneous junctions; (iii) microscopic lesions of CLE (i.e. a lymphocyte-rich interface dermatitis with basal keratinocyte damage); and (iv) a lack of complete remission following antimicrobials. Clinical questionnaires and skin biopsies were reviewed. Direct immunofluorescence and antinuclear antibody serology were performed whenever possible.

RESULTS

More than half of the 21 dogs were German shepherds or their crosses. The disease affected mostly dogs in their mid-adulthood and there was an over-representation of females. Erosions and ulcers predominated at genital/perigenital and anal/perianal areas, with a lower frequency of involvement of periocular, perioral and perinasal regions. In these dogs, there were no clinical signs suggestive of an associated systemic lupus erythematosus. Microscopic lesions were specific for CLE, but they were patchy and often infected with bacteria. The most common immunological finding was focal IgG deposition at the basement membrane zone. Lesions responded to varying interventions, but oral glucocorticoids led to a shorter time to complete remission. Relapses were common upon treatment tapering.

CONCLUSIONS AND CLINICAL IMPORTANCE

These observations support MCLE being another variant of canine CLE.

UV Light Potentiates STING (Stimulator of Interferon Genes)-dependent Innate Immune Signaling through Deregulation of ULK1 (Unc51-like Kinase 1)

The mechanism by which ultraviolet (UV) wavelengths of sunlight trigger or exacerbate the symptoms of the autoimmune disorder lupus erythematosus is not known but may involve a role for the innate immune system. Here we show that UV radiation potentiates STING (stimulator of interferon genes)-dependent activation of the immune signaling transcription factor interferon regulatory factor 3 (IRF3) in response to cytosolic DNA and cyclic dinucleotides in keratinocytes and other human cells. Furthermore, we find that modulation of this innate immune response also occurs with UV-mimetic chemical carcinogens and in a manner that is independent of DNA repair and several DNA damage and cell stress response signaling pathways. Rather, we find that the stimulation of STING-dependent IRF3 activation by UV is due to apoptotic signaling-dependent disruption of ULK1 (Unc51-like kinase 1), a pro-autophagic protein that negatively regulates STING. Thus, deregulation of ULK1 signaling by UV-induced DNA damage may contribute to the negative effects of sunlight UV exposure in patients with autoimmune disorders.

Genome-wide transcriptional profiling data from skin of chronic cutaneous lupus erythematosus (CCLE) patients

Cutaneous features manifest as a wide range of clinically significant, and in many cases disfiguring and debilitating components of lupus erythematosus (LE). While the definitive etiology is in question, multifactorial and polygenic causes are likely to be involved in the production of the characteristic anti-nuclear autoantibody titers and immune cell infiltrates observed in chronic cutaneous LE (CCLE) [1-3]. There is significant overlap of patients with systemic and cutaneous manifestations of LE, which suggests shared pathways and genetic background between the two. We have employed genome-wide microarray technology along with pathway-based analyses to investigate transcriptional differences between lesional and non-lesional skin from CCLE patients to address existing gaps in knowledge regarding disease mechanisms in lupus [4].

Efficacy of Intravenous Immunoglobulin Monotherapy in Patients with Cutaneous Lupus Erythematosus: Results of Proof-of-Concept Study

Cutaneous lupus erythematosus (CLE) is a chronic inflammatory autoimmune skin disease. Evidence-based therapy for CLE is lacking in the most part. Intravenous immunoglobulin (IVIg) is being increasingly utilized as off-label therapy for a variety of autoimmune and inflammatory conditions, especially in dermatology. The usefulness of IVIg in CLE is not well established. The goal of the present study was to obtain the proof-of-concept evidence that IVIg can control acute CLE and thus replace current systemic immunosuppressive therapy that causes severe side effects and adverse reactions. Sixteen patients who tried and failed various systemic treatments for CLE were screened and consented to use IVIg as a monotherapy. The IVIg was administered at 500 mg/kg/day on 4 consecutive days up to a total of 2 g/kg/month for 3 months, and the subjects were monitored for additional 6 months off any drug for a possible relapse. The cumulative results revealed an overall improvement, as evinced by a decrease of both objective and subjective measures of disease activity. The most sensitive and specific objective and subjective instruments for assessment of the therapeutic effect of IVIg were CLASI-A (Cutaneous Lupus Erythematosus Disease Area and Severity Index) measuring disease activity and Skindex-29 scores, respectively. The CLASI-A score dropped down from the initial value taken as 100%, and remained in the range of approximately 70% until the last visit. Three patients (18.8%) had a temporary flare of CLE symptoms but recovered within a month from the relapse. No serious side effects and adverse reactions occurred. Thus, IVIg monotherapy in CLE allowed to achieve: i) rapid and persistent decreased in disease activity; ii) steady improvement of patients’ quality of life assessed by Skindex-29; iii) low relapse rate; and iv) mild nature and short duration of relapses. Since healing was maintained for months after IVIg treatment, it is possible that the IVIgtriggered molecular events mediating the therapeutic action of IVIg that continued to unfold after the end of therapy.

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.

Genome-wide transcriptional profiling of chronic cutaneous lupus erythematosus (CCLE) peripheral blood identifies systemic alterations relevant to the skin manifestation

Major gaps remain regarding pathogenetic mechanisms underlying clinical heterogeneity in lupus erythematosus (LE). As systemic changes are likely to underlie skin specific manifestation, we analyzed global gene expression in peripheral blood of a small cohort of chronic cutaneous LE (CCLE) patients and healthy individuals. Unbiased hierarchical clustering distinguished patients from controls revealing a "disease" based signature. Functional annotation of the differentially expressed genes (DEGs) highlight enrichment of interferon related immune response and apoptosis signatures, along with other key pathways. There is a 26% overlap of the blood and lesional skin transcriptional profile from a previous analysis by our group. We identified four transcriptional "hot spots" at chromosomal regions harboring statistically increased numbers of DEGs which offer prioritized potential loci for downstream fine mapping studies in the search for CCLE specific susceptibility loci. Additionally, we uncover evidence to support both shared and distinct mechanisms for cutaneous and systemic manifestations of lupus.

Erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis: a comparative review

BACKGROUND

Human erythema multiforme (EM) and Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) are separate conditions. There is no consensus on classification criteria for the eponymous diseases in animals.

RESULTS

Animal EM is very different from 90% of human EM, which is herpes virus associated (HAEM). Animals lack acrally distributed, typical raised targets. Unlike canine parvovirus 'EM', HAEM is not an active infection. Animal EM is often attributed to drugs, but this is rarely proved. Conversely, human and animal SJS/TEN are almost identical, life-threatening disorders of epidermal necrosis and detachment, typically triggered by drugs (occasionally by infectious agents). Both EM and SJS/TEN are mediated by cytotoxic lymphocyte responses against altered keratinocytes (infectious agents or drugs). Apoptosis results from direct cytotoxicity or through soluble mediators, namely Fas ligand, granzymes, perforin and granulysin. Diagnosis in humans is clinicopathological, with emphasis on clinical lesions; histopathology confirms the pathological process as interface (cytotoxic) dermatitis. Human EM is self-limiting; only recurrent and rare persistent cases require antiviral/immunosuppressive therapies. Drug-induced EM responds to drug withdrawal. Idiopathic canine EM (>40%) is usually chronic, refractory to treatment and may represent heterogeneous conditions. Early identification and removal of the causative drug and high-quality supportive care are critical in SJS/TEN. Mortality rate is nevertheless high.

CONCLUSIONS AND CLINICAL IMPORTANCE

(1) Histopathological lesions do not reliably differentiate EM, SJS and TEN. (2) A multicentre study to develop a consensus set of clinical criteria for EM and SJS/TEN in animals is overdue. (3) No adjunctive therapies, including intravenous immunoglobulin and ciclosporin, have met evidence-based standards.