Relevant new insights into the effects of photoprotection in cutaneous lupus erythematosus

Cutaneous lupus erythematosus (CLE) denotes a heterogeneous spectrum of autoimmune diseases that primarily affect the skin. Ultraviolet irradiation (UV) is one of the most important environmental factors that can trigger skin lesions in CLE or even induce systemic organ manifestation. It has been shown that broad‐spectrum sunscreen with high sun protection factors can effectively prevent UV‐induced skin lesions in patients with different subtypes of CLE. In a recent issue of Experimental Dermatology, Zahn and colleagues demonstrate that potent photoprotection blocks disease‐specific skin lesions in CLE patients by reducing lesional tissue damage and interferon‐driven inflammation.     

Tissue microarray analysis of RANKL in cutaneous lupus erythematosus and psoriasis

Recently, it was discovered that the receptor activator of nuclear factor κB (RANK)/RANK ligand (RANKL) is part of an important signal transduction pathway for tissue homoeostasis. Therefore, we were interested in investigating RANKL expression in the epidermis of skin lesions from patients with different subtypes of cutaneous lupus erythematosus (CLE) and psoriasis as well as normal healthy donors. Using the tissue microarray technique, skin biopsy specimens were evaluated by immunohistochemistry. RANKL showed a significantly increased expression in the epidermis of skin biopsy specimens from patients with psoriasis (median: 4, range: 0-5) compared to patients with CLE (median: 0, range: 0-4) (P<0.001). No significant differences in epidermal RANKL expression between the CLE subtypes were detected. These data show a different expression of RANKL in the epidermis of skin lesions from patients with CLE compared to those with psoriasis suggesting that RANKL might play an important role in the pathogenesis of the disease.     

Varied responses to and efficacies of hydroxychloroquine treatment according to cutaneous lupus erythematosus subtypes in Japanese patients

Hydroxychloroquine is recommended as the first‐line systemic treatment for cutaneous lupus erythematosus (CLE) in Western countries, and it was approved in Japan in 2016. However, the efficacy of hydroxychloroquine in various cutaneous lupus erythematosus subtypes in Japanese patients has not been elucidated to date. Therefore, we investigated the efficacy of hydroxychloroquine for the treatment of cutaneous manifestations according to CLE subtypes in Japanese patients. We enrolled 35 patients (29 diagnosed with systemic lupus erythematosus and six with CLE) in this retrospective study. We analyzed the efficacy of hydroxychloroquine for the treatment of cutaneous manifestations according to cutaneous lupus erythematosus subtypes, time to the first skin improvement, as well as effects on laboratory data and reduction of concomitant immunosuppressive drug administration at 16 and 32 weeks of therapy. Complete improvement was observed at high rates for acute CLE (ACLE); however, partial or non‐improvement rates were higher for chronic CLE (CCLE) at 16 weeks. Several patients with alopecia without scarring achieved complete improvement at 32 weeks. CCLE tended to take more time to improve than ACLE. Overall, hydroxychloroquine was highly effective for skin: 87% of patients had at least some beneficial response at 16 weeks. Nevertheless, there were wide variations in complete improvement rates and duration for improvement among CLE subtypes. Our findings suggest that a therapeutic approach considering the subtypes of CLE will improve its management.     

Photoprovocation in cutaneous lupus erythematosus: a multicenter study evaluating a standardized protocol

Photosensitivity is an important and distinguishing sign in various subtypes of cutaneous lupus erythematosus (CLE); however, it remains poorly defined. The purpose of this study was to evaluate whether standardized photoprovocation is a reproducible method to assess photosensitivity in subjects with CLE. A total of 47 subjects with CLE (subacute cutaneous lupus erythematosus (SCLE), n=14; discoid lupus erythematosus (DLE), n=20; lupus erythematosus tumidus (LET), n=13) and 13 healthy volunteers underwent photoprovocation at seven European sites. Of these, 22 (47%) subjects (57% SCLE, 35% DLE, and 54% LET) and none of the healthy volunteers developed photoprovoked lesions according to clinical analysis. Of these 22 subjects, 19 (86%) developed lesions that were histopathologically confirmed as specific for lupus erythematosus (LE). In CLE subjects who developed UV-induced lesions, 86% had Fitzpatrick's phototypes I or II, and the mean minimal erythema dose (MED) was significantly lower compared with subjects without UV-induced lesions (P=0.004). No significant differences in photoprovocation results were observed between study sites. Safety parameters showed no clinically meaningful differences between CLE subjects and healthy volunteers after photoprovocation. In conclusion, a standardized, safe, and reproducible protocol for photoprovocation using UVA and UVB radiation induced skin lesions in approximately half of all CLE subjects and showed comparable results across multiple sites. This method may therefore be used for future diagnostic testing and clinical trials.     

Clinical Manifestations of Cutaneous Lupus Erythematosus

Cutaneous lupus erythematosus (CLE) is a chronic inflammatory autoimmune disease with a broad spectrum of clinical manifestations and a variable course. In numerous investigations, it has been shown that exogenous factors, such as UV‐light and drugs, can induce this disease. However, not all clinical aspects can be explained and therefore, the pathogenesis of CLE is currently under extensive research. The various cutaneous manifestations of LE are divided into LE‐nonspecific and LE‐specific skin disease based on histologic criteria. LE‐nonspecific manifestations are mostly associated with systemic LE but can also occur in other diseases and include particularly vascular skin lesions such as pe‐riungual telangiectases. LE‐specific skin disease includes the subtypes of CLE such as acute cutaneous LE (ACLE), subacute cutaneous LE (SCLE), chronic cutaneous LE (CCLE), and intermittent CLE (ICLE). The subdivision of these subtypes with different prognosis and course is supported by genetic, clinical, histologic, and immunoserologic findings. The subtypes of CLE require a specific morphological and clinical analysis, which is described in the first part of this review. In the second part of this review, further diagnostic procedures and therapeutic strategies in patients with CLE are discussed.     

Spleen tyrosine kinase (SYK) is a potential target for the treatment of cutaneous lupus erythematosus patients

Spleen tyrosine kinase (SYK) is a protein kinase involved in cell proliferation and the regulation of inflammatory pathways. Due to the increasing evidence that kinase inhibitors have potential as specific anti‐inflammatory drugs, we have investigated the potential for SYK inhibition as a therapeutic target in autoimmune diseases, particularly cutaneous lupus erythematosus (CLE). Skin samples of patients with different CLE subtypes and appropriate controls were analysed for the expression of SYK and SYK‐associated pro‐inflammatory mediators via gene expression analysis and immunohistochemistry. The functional role of SYK in keratinocytes was investigated in vitro, using LE‐typical pro‐inflammatory stimuli and a selective inhibitor of SYK. SYK‐associated genes are strongly upregulated in CLE skin lesions. Importantly, phosphorylated SYK (pSYK) is strongly expressed by several immune cell types and also keratinocytes in CLE skin. In vitro, immunostimulatory nucleic acids are capable of inducing SYK phosphorylation in keratinocytes leading to the induction of pro‐inflammatory cytokines, while small‐molecule SYK inhibition decreases the expression of these proteins. The results demonstrate that pSYK is expressed by immune cells and keratinocytes in skin lesions of CLE patients. LE‐typical stimuli induce the expression of pSYK in vitro. Small‐molecule SYK inhibition leads to a reduction of pSYK expression and downregulation of pro‐inflammatory cytokines in keratinocytes. We therefore believe that pSYK provides a potential future drug target for the treatment of patients who suffer from CLE and related skin disorders. Specifically, our study reveals evidence supporting the use of topical SYK inhibitors in treating lupus.     

Upregulation of epidermal surface molecule expression in primary and ultraviolet-induced lesions of lupus erythematosus tumidus

BACKGROUND: Lupus erythematosus tumidus (LET), a photosensitive skin disorder with characteristic clinical and histological features, has not been generally accepted as a subset of cutaneous lupus erythematosus (CLE). OBJECTIVES: To analyse the expression of epidermal surface molecules in skin biopsy specimens from patients with LET and to relate the results to other variants of CLE, such as discoid lupus erythematosus (DLE) and subacute CLE (SCLE). METHODS: In total, 45 patients with different subtypes of CLE were included in the study, and cryostat sections from primary and ultraviolet (UV) A- and UVB-induced skin lesions were investigated using immunohistochemical methods. RESULTS: In contrast to healthy controls, skin lesions of LET showed upregulation of intercellular adhesion molecule-1 (ICAM-1) and histocompatibility class II molecules (HLA-DR), with an expression pattern resembling that seen in DLE and SCLE. Furthermore, staining with a monoclonal antibody against 27E10, a distinct marker for cell activation and differentiation, revealed intense focal or band-like labelling of all epidermal layers independent of the type of lesion. CONCLUSIONS: Expression of epidermal surface molecules such as ICAM-1, HLA-DR and 27E10 is equally upregulated in primary and UV-induced lesions of patients with LET, DLE and SCLE. These results support our recent clinical findings that LET represents a distinct subset of CLE with a similar immunopathomechanism rather than a different disease.     

Ten‐year retrospective clinicohistological study of cutaneous lupus erythematosus in Korea

An understanding of the differences in clinical manifestations and laboratory abnormalities between subtypes of cutaneous lupus erythematosus (CLE) is still lacking. The purpose of this study was to analyze demographic, clinical and histological features of CLE according to three main presentation subsets: acute (ACLE), subacute (SCLE) and chronic (CCLE). A 10‐year retrospective analysis was performed on data from patients who were diagnosed with CLE between March 2005 and September 2015 in a Korean tertiary referral dermatology clinic. We compared demographic data and clinical and histological findings between three different CLE groups. An overall sample of 220 patients with CLE consisted of 67 patients with ACLE, 25 patients with SCLE and 135 patients with CCLE. Patients with CCLE regardless of systemic lupus erythematosus (SLE) presence had lower prevalence of anemia, urinary abnormalities and elevated erythrocyte sedimentation rate. Furthermore, CCLE patients who only had skin lesions showed lower female predominance, lower extracutaneous manifestation, fewer laboratory and immunological abnormalities including low antinuclear antibody titers and the lowest positivity for C3, C4 and anti‐dsDNA, anti‐Ro, anti‐Sm and anti‐RNP antibodies, and more prominent perieccrine inflammation and dermal fibrosis in histological findings. Considering distinct cutaneous manifestations of LE, a comprehensive awareness of each CLE subtype is important for achieving a favorable prognosis through appropriate diagnosis and management. This study provides comparative clinical and histological profiles of patients with different CLE subtypes in Korea.     

Cutaneous lupus erythematosus: The impact of self-amplifying innate and adaptive immune responses and future prospects of targeted therapies

Cutaneous lupus erythematosus (CLE) is a heterogeneous autoimmune disease encompassing a broad spectrum of skin conditions including localized plaques or widespread lesions, which may be accompanied by systemic involvement (systemic lupus erythematosus (SLE)). The disease is characterized by necroptotic keratinocytes and a cytotoxic immune cell infiltrate at the dermo-epidermal junction (DEJ), orchestrated by interferon (IFN)-regulated proinflammatory cytokines. Molecular analyses revealed a strong upregulation of innate and adaptive immune pathways in lesional skin including DNA-recognition pathways, chemokine signalling, antigen presentation and B- and T-cell activation, which are believed to interact in a complex self-amplifying network. Concerning adaptive immune signalling, particularly B cells are currently being studied as there is growing evidence for additional abilities besides autoantibody expression in skin autoimmunity. These detailed insights have paved the way for the development of drugs targeting crucial molecules of pathogenic immune cells and pathways. Moreover, they forwarded the understanding of distinct molecular mechanisms within CLE subtypes, which might enable a more mechanism-directed, stratified pharmacotherapy of LE skin lesions in the future.     

Lupus erythematosus tumidus is a separate subtype of cutaneous lupus erythematosus

Background  Lupus erythematosus tumidus (LET) is a rare disease which was first described in 1909 but has not always been considered as a separate entity of cutaneous lupus erythematosus (CLE) in the international literature.
Objectives  To compare characteristic features of different subtypes of CLE and to analyse whether LET can be distinguished as a separate entity in the classification system of the disease.
Methods  The study involved 44 patients with CLE, including 24 patients with LET, 12 with discoid lupus erythematosus (DLE) and eight with subacute CLE (SCLE), from two centres in Germany. A core set questionnaire and an SPSS database were designed to enable a consistent statistical analysis.
Results  Location of skin lesions did not differ significantly between the CLE subtypes; however, the activity score was significantly lower in LET than in DLE ( P  <   0·01), and the damage score was significantly lower in LET than in SCLE ( P  <   0·01) and DLE ( P  <   0·01). Photosensitivity and antinuclear antibodies were confirmed to be different in LET compared with SCLE and DLE but without statistical significance. Moreover, histological analysis of skin biopsy specimens showed that abundant mucin deposition is significantly more present in LET compared with SCLE ( P  <   0·01) and DLE ( P  <   0·01) while prominent interface dermatitis and alteration of hair follicles were absent in LET.
Conclusions  Several significant differences were found between LET and other subtypes of CLE with regard to clinical, histological and laboratory parameters. These data strongly indicate that LET should be defined as a separate entity in the classification of CLE.     

Increased expression of guanylate binding protein-1 in lesional skin of patients with cutaneous lupus erythematosus

The large GTPase human guanylate binding protein-1 (GBP-1) is a key mediator of angiostatic effects of inflammation and is induced by interferon (IFN)-α and IFN-γ in endothelial cells (ECs). The aim of this study was to investigate whether GBP-1 is a marker of skin lesions in patients with cutaneous lupus erythematosus (CLE). Western blotting revealed that GBP-1 was in vitro induced by IFN-α and -γ in primary keratinocytes obtained from healthy controls. Moreover, we found that this protein was expressed by keratinocytes and ECs in primary and ultraviolet (UV)-induced skin lesions from patients with various subtypes of CLE, when compared to non-lesional skin. No GBP-1 expression was noted in skin biopsy specimens 24 or 72 h after UV irradiation prior to lesion formation in patients with CLE or in healthy control specimens with or without UV irradiation. Initial findings suggest that GBP-1 is not expressed in other skin diseases with different inflammatory aetiology, such as atopic dermatitis. We conclude that GBP-1 expression is closely associated with skin lesions in patients with CLE, suggesting a contribution of GBP-1 in the pathogenesis of this disease.     

Scarring skin lesions of discoid lupus erythematosus are characterized by high numbers of skin-homing cytotoxic lymphocytes associated with strong expression of the type I interferon-induced protein MxA

BACKGROUND: Infiltrating T lymphocytes are considered to play a major pathological role in skin lesions of cutaneous lupus erythematosus (CLE), a cutaneous autoimmune disease of unknown aetiology. Earlier histological studies revealed that the inflammatory infiltrate in CLE skin lesions is predominantly composed of T lymphocytes, with a slight predominance of CD4+ over CD8+ T cells, but failed to explain the development of scarring skin lesions, characteristic for chronic discoid lupus erythematosus (CDLE). Because recent investigations have highlighted the relevance of cytotoxic lymphocytes in autoimmune tissue destruction, we hypothesized that the scarring CDLE lesions might be caused by cytotoxic T lymphocytes. OBJECTIVES: To analyse skin biopsies of 15 patients with CLE [10 female, five male; localized CDLE (lCDLE), n = 5; disseminated CDLE (dCDLE), n = 5, subacute CLE (SCLE), n = 5] and five control biopsies taken from healthy controls and to characterize the inflammatory infiltrate. Methods We used immunohistochemistry, including staining for the cytotoxic molecule granzyme B, the skin-homing molecule cutaneous lymphocyte antigen (CLA) and the protein MxA, which is specifically induced by type I interferons (IFNs). RESULTS: We found a strong coexpression of granzyme B and CLA on lesional lymphocytes of patients with scarring lCDLE and dCDLE, which was significantly enhanced when compared with nonscarring SCLE and healthy controls. The increased expression of granzyme B was closely associated with the lesional expression of the type I IFN-induced protein MxA. CONCLUSIONS: Our results provide evidence that type I IFNs and potentially autoreactive cytotoxic lymphocytes targeting adnexal structures are highly associated with scarring lupus erythematosus lesions and might be responsible for their scarring character.     

Identification of type I interferon-associated inflammation in the pathogenesis of cutaneous lupus erythematosus opens up options for novel therapeutic approaches

Cutaneous lupus erythematosus (CLE) is one of the most common dermatological autoimmune disorders worldwide. Recently, several studies provided evidence for a pathogenic role of type I interferons (IFNs) in this disease. Plasmacytoid dendritic cells are major type I IFN producers in CLE skin lesions. Type I IFNs are able to induce the expression of several proinflammatory chemokines, including CXCL9 and 10, and enhance the cytotoxic capacity of infiltrating cells. Additionally, adhesion molecules and chemokine receptors, such as intercellular adhesion molecule-1, cutaneous lymphocyte antigen, E-selectin, CCR4 and CXCR3, are involved in the recruitment of potentially autoreactive lymphocytes into the skin. Here, we review the role of type I IFNs, adhesion molecules and chemokine receptors in CLE and discuss options for novel therapeutic approaches.     

Characterization of the inflammatory infiltrate and expression of endothelial cell adhesion molecules in lupus erythematosus tumidus

Lupus erythematosus tumidus (LET) is a disease with characteristic clinical and histopathologic features that has not always been considered a subset of cutaneous lupus erythematosus (CLE). Although LET was first mentioned in the literature in 1930, it has rarely been documented, and immunohistochemical studies have never been performed. The aim of the present study was to characterize the inflammatory infiltrate and to analyze the expression of endothelial cell adhesion molecules in skin specimens from patients with LET and to compare the results with those from patients with other variants of CLE, such as discoid lupus erythematosus (DLE) and subacute cutaneous lupus erythematosus (SCLE). Cryostat sections of lesional skin specimens from ten patients with LET demonstrated an infiltrate composed of more than 75% CD4+, CD8+, and HLA-DR+ cells. Interestingly, CD45RO+ cells, in contrast to CD45RA+ cells, were the prevailing inflammatory cell population. Compared with skin specimens from patients with DLE and SCLE, the mean expression of CD4+ and CD8+ cells was higher (but not significantly so) in LET, and no differences were observed with the other three antibodies. Furthermore, in contrast to controls, intercellular adhesion molecule-1, vascular adhesion molecule-1, E-selectin, and P-selectin showed the same expression pattern in skin specimens from patients with DLE, SCLE, and LET. In conclusion, the inflammatory infiltrate of LET primarily consists of CD4+/CD8+ lymphocytes. Furthermore, expression of endothelial cell adhesion molecules was equally upregulated in LET compared with the expression in DLE and SCLE, suggesting a similar immunopathomechanism of these subtypes of CLE.     

Apoptotic signal molecules in skin biopsies of cutaneous lupus erythematosus: analysis using tissue microarray

Cutaneous lupus erythematosus (CLE) is a heterogeneous autoimmune disease. Different pathogenetic mechanisms, including the accumulation of apoptotic keratinocytes in CLE, have been reported. Therefore, we investigated whether CLE and other inflammatory skin diseases differ with regard to the epidermal expression of molecules that are crucial for the initiation and regulation of apoptosis. In this study, 241 skin biopsies from patients with CLE, psoriasis (PSO), lichen planus (LP) and healthy controls (HCs) were analysed immunohistochemically using the tissue microarray (TMA) technique. The TUNEL assay and anti‐activated caspase‐3 antibodies revealed a significant increase of apoptotic keratinocytes in CLE lesions compared with HCs. Furthermore, we detected a significant increase in the epidermal expression of CD95 in CLE specimens compared with PSO, LP and HCs. These data suggest that the accumulation of apoptotic keratinocytes in CLE might be due to the increased epidermal expression of CD95, resulting in increased activity of the extrinsic apoptotic pathway in the disease.     

Hydroxychloroquine administration for Japanese lupus erythematosus in Wakayama: a pilot study

Hydroxychloroquine (HCQ) is used as the first-line systemic treatment for severe, widespread or refractory cutaneous lupus erythematosus (CLE) in many countries. However HCQ is not an approved drug in Japan. For the establishment of HCQ therapy as the alternative treatment for CLE in Japan, we conducted a pilot study in Japanese patients with refractory CLE by administrating HCQ, and evaluated the improvements in the skin lesions using the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI). We administrated HCQ to seven CLE cases, including four systemic lupus erythematosus (SLE) cases. The skin lesions of the four cases improved dramatically, and their mean CLASI activity index decreased significantly following HCQ treatment. Arthralgia improved in all three cases with arthralgia and general malaise also improved in two of the three cases who had complained. In three cases who discontinued HCQ therapy after 16 weeks of treatment, their skin lesions and general malaise worsened soon, and after the resumption of HCQ therapy these symptoms improved again. The mean serum triglyceride and total cholesterol levels also decreased significantly at the end of this study. Our results suggest that HCQ might be effective for Japanese SLE skin lesions and CLE, and support the studies which reported that HCQ prevented clinical flare ups of SLE. An additional effect to improve lipid profiles was also observed in our Japanese cases. It is necessary to confirm that these effects are reproducible when Japanese lupus erythematosus cases are given HCQ.     

皮肤型红斑狼疮皮损中SASPase的表达和意义

目的 探讨SASPase在皮肤型红斑狼疮皮损中的表达水平及其在发病机制中的意义.方法 无血清培养原代角质形成细胞,将提取的蛋白样品采用固相pH梯度双向凝胶电泳进行分离,应用ImageMaster 2D Platinum 5.0软件对图像进行匹配分析,选取差异表达蛋白质点,经基质辅助激光解吸附飞行时间质谱进行质谱鉴定.并通过免疫印迹验证表达水平.结果 成功培养角质形成细胞,获得重复性较好的双向电泳图谱,匹配点数在1200个左右,匹配率＞80％.鉴定SASPase在CLE皮损角质形成细胞表达升高,免疫印迹验证与双向电泳结果一致.结论 皮肤型红斑狼疮皮损的发生发展可能与SASPase的异常激活和过度表达有关.     

Diagnostic approach and treatment of cutaneous lupus erythematosus

Cutaneous lupus erythematosus (CLE) is a heterogeneous disorder with a wide range of skin manifestations. In the second part of this review, diagnostic procedures and treatment options in CLE are summarized.The diagnosis of the various subtypes of CLE is based on patients's history,clinical findings,laboratory features, and histological and immunofluorescent examinations of skin biopsies. In case of systemic organ involvement, further adequate technical investigations are necessary. The therapy has to be adjusted to the subtype of CLE and its inflammatory activity as well as the extent of skin involvement. The skin manifestations of CLE are primarily treated by topical therapy, such as glucocorticosteroids, in combination with antimalarials. The response of CLE to immunosuppressive drugs that control organ involvement in systemic lupus erythematosus is often disappointing. Recent advances in biotechnology resulted in the development of several novel systemic agents for the treatment of autoimmune diseases; however, controlled clinical trials are still necessary for the approval of new therapies in CLE.     

Evaluation of the reliability and validity of the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) in paediatric cutaneous lupus among paediatric dermatologists and rheumatologists

The term ‘lupus erythematosus’ refers to a range of related disorders. As many as 70–80% of lupus patients will develop skin lesions (abnormal patches) at some point during the course of their disease. Types of lupus affecting the skin are collectively known as cutaneous lupus erythematosus (CLE). The Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) is a tool for classifying how severe the skin symptoms are in people with CLE. Being able to accurately and reliably measure skin lesions is an important way to monitor any improvement or worsening of the disease, which is useful in clinical trials to see if a treatment is working. It is already known that the CLASI is a reliable (accurate) measure in adults, but researchers based in the USA conducted this study to validate the reliability of the CLASI in the pediatric (child) population, where CLE can appear differently than in adults. This validation will allow clinical trials to reliably assess treatment efficacy in CLE. The researchers recruited 11 pediatric patients with active CLE, 6 dermatologists, and 6 rheumatologists to attend a one-day event at the University of Pennsylvania. Physicians were trained to use the CLASI as well as another scoring system called the Physician Global Assessment (PGA) to allow for comparison. Physicians (doctors) individually rated all patients using both tools. Each physician reassessed two randomly selected patients. CLASI proved to be a reliable and valid measurement tool and superior to the PGA for pediatric CLE, and the researchers conclude that it can be used in future clinical trials.