Cutaneous lupus erythematosus: first multicenter database analysis of 1002 patients from the European Society of Cutaneous Lupus Erythematosus (EUSCLE)

Systemic correlates of cutaneous manifestations of lupus erythematosus

BACKGROUND

We aimed to investigate the prevalence of skin disease among patients with systemic lupus erythematosus (SLE) and determine whether LE skin disease had clinical or serologic correlates with SLE.

METHODS

We reviewed records of 335 patients with SLE (seen at Mayo Clinic, Rochester, Minnesota, USA) and abstracted skin manifestations, fulfilled mucocutaneous SLE criteria, and clinical and serologic parameters.

RESULTS

Of the 231 patients with skin manifestations, 57 (24.7%) had LE-specific conditions, 102 (44.2%) had LE-nonspecific conditions, and 72 (31.2%) had both. LE skin disease was associated with photosensitivity, anti-Smith antibodies, and anti-U1RNP antibodies (all P < 0.001). Patients without LE skin disease more commonly had elevated C-reactive protein levels (P = 0.01). Patients meeting 2-4 mucocutaneous American College of Rheumatology criteria less commonly had cytopenia (P = 0.004) or anti-double-stranded DNA antibodies (P = 0.004). No significant associations were observed for systemic involvement (renal, hematologic, neurologic, and arthritis) when comparing patients with or without LE skin involvement. LE skin involvement was not significantly associated with internal SLE disease flare, number of medications, or overall survival.

CONCLUSIONS

LE skin disease commonly occurs in patients with SLE. The presence of LE skin disease had no mitigating impact on the severity of SLE sequelae, disease flares, number of medications, or overall survival.

[Ultraviolet radiation in the pathogenesis of lupus erythematosus]

Photosensitivity represents an increased inflammatory reaction to sunlight, which can be observed particularly in the autoimmune disease lupus erythematosus. Cutaneous lupus erythematosus (CLE) can be provoked by ultraviolet (UV) radiation and can cause both acute, nonscarring and chronic, scarring skin changes. In systemic lupus erythematosus, on the other hand, provocation by UV radiation can lead to flare or progression of systemic involvement. The etiology of lupus erythematosus is multifactorial and includes genetic, epigenetic and immunologic mechanisms. In this review, we address the effect of UV radiation on healthy skin and photosensitive skin using the example of lupus erythematosus. We describe possible mechanisms of UV-triggered immune responses that could offer therapeutic approaches. Currently, photosensitivity can only be prevented by avoiding UV exposure itself. Therefore, it is important to better understand the underlying mechanisms in order to develop strategies to counteract the deleterious effects of photosensitivity.

Plasmacytoid Dendritic Cells Are Not Major Producers of Type 1 IFN in Cutaneous Lupus: An In-Depth Immunoprofile of Subacute and Discoid Lupus

The immunologic drivers of cutaneous lupus erythematosus (CLE) and its clinical subtypes remain poorly understood. We sought to characterize the immune landscape of discoid lupus erythematosus and subacute CLE using multiplexed immunophenotyping. We found no significant differences in immune cell percentages between discoid lupus erythematosus and subacute CLE (P > .05) with the exception of an increase in TBK1 in discoid lupus erythematosus (P < .05). Unbiased clustering grouped subjects into 2 major clusters without respect to clinical subtype. Subjects with a history of smoking had increased percentages of neutrophils, disease activity, and endothelial granzyme B compared with nonsmokers. Despite previous assumptions, plasmacytoid dendritic cells (pDCs) did not stain for IFN-1. Skin-eluted and circulating pDCs from subjects with CLE expressed significantly less IFNα than healthy control pDCs upon toll-like receptor 7 stimulation ex vivo (P < .0001). These data suggest that discoid lupus erythematosus and subacute CLE have similar immune microenvironments in a multiplexed investigation. Our aggregated analysis of CLE revealed that smoking may modulate disease activity in CLE through neutrophils and endothelial granzyme B. Notably, our data suggest that pDCs are not the major producers of IFN-1 in CLE. Future in vitro studies to investigate the role of pDCs in CLE are needed.

Systemic Lupus Erythematosus: A Review

Importance

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by inflammation and immune-mediated injury to multiple organ systems, including the mucocutaneous, musculoskeletal, hematologic, and kidney systems. Approximately 3.4 million people worldwide have received a diagnosis of SLE.

Observations

Approximately 90% of people with SLE are female. Although there are no uniformly accepted diagnostic criteria for SLE, the 2019 European Alliance of Associations for Rheumatology (formerly the European League Against Rheumatism)/American College of Rheumatology classification criteria developed for scientific study are an estimated 96.1% sensitive and 93.4% specific for SLE. These classification criteria include both clinical factors, such as fever, cytopenia, rash, arthritis, and proteinuria, which may be indicative of lupus nephritis; and immunologic measures, such as SLE-specific autoantibodies and low complement levels. Approximately 40% of people with SLE develop lupus nephritis, and an estimated 10% of people with lupus nephritis develop end-stage kidney disease after 10 years. The primary goal of treatment is to achieve disease remission or quiescence, defined by minimal symptoms, low levels of autoimmune inflammatory markers, and minimal systemic glucocorticoid requirement while the patient is treated with maintenance doses of immunomodulatory or immunosuppressive medications. Treatment goals include reducing disease exacerbations, hospitalizations, and organ damage due to the disease or treatment toxicity. Hydroxychloroquine is standard of care for SLE and has been associated with a significant reduction in mortality. Treatments in addition to hydroxychloroquine are individualized, with immunosuppressive agents, such as azathioprine, mycophenolate mofetil, and cyclophosphamide, typically used for treating moderate to severe disease. Three SLE medications were recently approved by the Food and Drug Administration: belimumab (for active SLE in 2011 and for lupus nephritis in 2020), voclosporin (for lupus nephritis), and anifrolumab (for active SLE).

Conclusions and Relevance

Systemic lupus erythematosus is associated with immune-mediated damage to multiple organs and increased mortality. Hydroxychloroquine is first-line therapy and reduces disease activity, morbidity, and mortality. When needed, additional immunosuppressive and biologic therapies include azathioprine, mycophenolate mofetil, cyclophosphamide, belimumab, voclosporin, and anifrolumab.

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.

Immune checkpoint inhibitor-induced subacute cutaneous lupus erythematosus: a case report and review of the literature

Immune checkpoint inhibitor (ICI) use has been associated with numerous autoimmune side effects, known as immune related adverse events (irAEs). Cutaneous irAEs are common and affect up to 50% of patients treated with ICIs. There have been an increasing number of cases reported in the literature regarding ICI-induced subacute cutaneous lupus erythematosus (SCLE). ICI-induced SCLE is important to recognize as it can result in a delayed and/or prolonged skin reaction despite treatment discontinuation. We describe a patient with gastro-esophageal adenocarcinoma who developed SCLE following one cycle of nivolumab treatment. A 75-year-old man presented to our clinic with a new photo-distributed rash composed of oval scaly pink papules and plaques involving his chest and arms. Despite treatment with topical corticosteroids, he presented to the emergency department 1 week later with worsening rash. Skin biopsy showed vacuolar interface pattern, along with superficial perivascular lymphocytic infiltrate, consistent with a drug eruption. The clinicopathological presentation was consistent with ICI-induced SCLE. Nivolumab treatment was discontinued due to the severity of the rash. The rash remitted with systemic corticosteroids, high potency topical steroids, and hydroxychloroquine. Unfortunately, the patient developed intraperitoneal metastatic disease, and was enrolled in hospice care. In this paper, we highlight the importance of early identification and treatment of this irAE. A review of the literature, including a discussion on the management of ICI-induced SCLE is also provided.

Increased cardiovascular risk in Korean patients with systemic lupus erythematosus: a population-based cohort study

To determine the increased risk of major adverse cardiovascular events (MACE) in patients with systemic lupus erythematosus (SLE) compared to the general population in Korea. Using data from the National Health Insurance Service database spanning 2008 to 2018, incident SLE patients aged 18 years and above were selected along with a 1:4 age- and sex-matched control group. The crude incidence rate (IR) of MACE was calculated as the number of events per 1000 person-years and the IR ratio (IRR) for MACE was adjusted using generalized estimating equations. Subgroup analysis was conducted to evaluate the risk differences of overall MACE and its composites based on age and sex stratification. The study included 8568 SLE patients and 34,272 controls. The cumulative IR of MACE per 1000 person-years in SLE patients and controls were 4.08 and 1.30, respectively. After adjusting for confounders, SLE patients had a higher risk of MACE compared to the general population (adjusted IRR of 2.40 [95% confidence interval [CI] 1.88-3.05]), with no gender differences observed. The increased risk of MACE in SLE patients was highest in the 18-39 age group (IRR 11.70, 95% CI 5.95-23.01) and gradually decreased with age. The increased risk of ischemic stroke (IRR 2.41, 95% CI 1.84-3.15) and myocardial infarction (IRR 2.19, 95% CI 1.30-3.68) in SLE patients was comparable. The risk of MACE in SLE patients is 2.40 times higher than that of the general population, with a higher relative risk observed in younger individuals.

Epidemiology of systemic lupus erythematosus in Korea

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by diverse organ system disabilities, predominantly affecting young females. The clinical manifestations of SLE encompass various organs, including the kidney, cardiovascular system, and central nervous system. Young females with SLE experience higher mortality rates than the general population, making it imperative to gain insights into the disease patterns and associated factors. The current review examines the epidemiological studies to analyze the prevalence, incidence, and mortality trends of SLE in Korea and compares them with the findings from other countries. We aim to identify potential similarities, differences, and factors contributing to the burden of SLE in different populations by exploring the comparative epidemiological aspects. The knowledge derived from this comparison would aid in advancing the overall management of SLE in Korea.

The differential panorama of clinical features of lupus erythematosus patients with different onset ages: a cross-sectional multicenter study from China

OBJECTIVES

This study aims to compare the differences among patients of different onset ages in various subtypes of lupus erythematosus (LE) and to draw a panorama of the clinical characteristics of patients with different onset ages.

METHOD

Subjects were recruited from the Lupus Erythematosus Multicenter Case-control Study in Chinese populations (LEMCSC), grouped by the age of onset (childhood-onset: onset < 18 years, adult-onset: onset 18-50 years, late-onset: onset > 50 years). The data collected included demographic characteristics, LE-related systemic involvement, LE-related mucocutaneous manifestations, and laboratory results. All included patients were assigned into three groups: systemic LE (SLE) group (with systemic involvement, with or without mucocutaneous lesions), cutaneous LE (CLE) group (patients who were accompanied by any type of LE-specific cutaneous manifestations), and isolated cutaneous LE (iCLE) group (patients who were in CLE group without systemic involvements). Data were analyzed using R version 4.0.3.

RESULTS

A total of 2097 patients were involved, including 1865 with SLE and 232 with iCLE. We also identified 1648 patients with CLE among them, as there was some overlap between the SLE population and CLE population (patients with SLE and LE-specific cutaneous manifestations). Later-onset lupus patients seemed to be less female predominance (p < 0.001) and have less systemic involvement (except arthritis), lower positive rates of autoimmune antibodies, less ACLE, and more DLE. Moreover, childhood-onset SLE patients presented a higher risk of LE family history (p = 0.002, vs adult-onset SLE). In contrast to other LE-nonspecific manifestations, the self-reported photosensitivity history decreased with the age of onset in SLE patients (51.8%, 43.4%, and 39.1%, respectively) but increased in iCLE patients (42.4%, 64.9%, and 89.2%, respectively). There was also a gradual increase in self-reported photosensitivity from SLE, CLE, to iCLE in both adult-onset and late-onset lupus patients.

CONCLUSIONS

A negative correlation was suggested between the age of onset and the likelihood of systemic involvement, except for arthritis. As the age of onset increases, patients have a greater propensity to exhibit DLE compared to ACLE. Moreover, the presence of rapid response photodermatitis (i.e., self-reported photosensitivity) was associated with a lower rate of systemic involvement.

TRIAL REGISTRATION

This study was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR2100048939) on July 19, 2021, retrospectively registered. Key Points • We confirmed some phenomena that have been found in patients with SLE, such as the highest proportion of females of reproductive age, the higher risk of LE family history in childhood-onset SLE patients, and the less self-reported photosensitivity in the late-onset SLE group. We also compared the similarities and differences of these phenomena in patients with CLE or iCLE for the first time. • In patients with SLE, the proportion of females peaked in adult-onset patients, but this phenomenon disappeared in iCLE patients: the female-male ratio tends to decrease from childhood-onset iCLE, adult-onset iCLE, to late-onset iCLE. • Patients with early-onset lupus are more likely to have acute cutaneous lupus erythematosus (ACLE), and patients with late-onset lupus are more likely to have discoid lupus erythematosus (DLE). • In contrast to other LE-nonspecific manifestations, the incidence of rapid response photodermatitis (i.e., self-reported photosensitivity) decreased with the age of onset in SLE patients but increased with the age of onset in iCLE patients.

The Possible Clinical Significance of a Decreased Serum Level of Soluble PD-L1 in Discoid Lupus Erythematosus, but Not in Subacute Cutaneous Lupus Erythematosus-A Pilot Study

Cutaneous lupus erythematosus (CLE) is an autoimmune skin disease with various clinical forms, including the subtypes of discoid lupus erythematosus (DLE) and subacute cutaneous lupus erythematosus (SCLE). The altered function of the programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) axis in CLE pathogenesis has been suggested. Here, the soluble forms of PD-1 (sPD-1) and PD-L1 (sPD-L1) were explored in untreated DLE and SCLE. Levels of sPD-1 and sPD-L1 were determined by enzyme-linked immunosorbent assay in serums of 21 DLE, 18 SCLE, 13 systemic lupus erythematosus (SLE) patients and 20 healthy controls (HCs). Differences between patient groups and HCs, and the association between clinical activity of skin symptoms and sPD-1/sPD-L1 levels were analyzed with Mann-Whitney U-test and Spearmann's correlation. Regarding sPD-1 levels, no statistically significant differences were found between DLE and SCLE groups, nor compared to HCs. As for sPD-L1, a significantly lower level was found in the DLE group compared to the SCLE and HC groups (p = 0.027 and p = 0.009, respectively). In SLE, significantly higher sPD-1 was found compared to HCs (p = 0.002). No association between skin symptom activity and sPD-1/sPD-L1 levels was found in CLE. Alterations of the inhibitory effect of sPD-L1 on T-cell activity might elucidate the differences between DLE and SCLE.

Panoramic view of clinical features of lupus erythematosus: a cross-sectional multicentre study from China

OBJECTIVE

Lupus erythematosus (LE) is a complicated disease with highly heterogeneous clinical manifestations. Previous studies have rarely included all subgroups of patients with lupus and have overlooked the importance of the cutaneous manifestations thereof. We aimed to compare the demographic and clinical differences among patients with different subtypes of lupus.

METHODS

This is the first real-world study with a relatively large sample size that simultaneously includes patients with isolated cutaneous lupus erythematosus (iCLE) and SLE. All samples were obtained from the Lupus Erythematosus Multicenter Case-control Study in Chinese populations (LEMCSC) (registration number: ChiCTR2100048939). Comparative analyses between different LE subgroups were performed.

RESULTS

A total of 2097 patients with lupus were included, with 1865 patients with SLE, 1648 with cutaneous lupus erythematosus (CLE), and 232 with iCLE. Among the patients with CLE, 1330 had acute cutaneous lupus erythematosus (ACLE); 160 had subacute cutaneous lupus erythematosus (SCLE); and 546 had chronic cutaneous lupus erythematosus (CCLE). The study included a relatively large number of patients with CCLE subtypes, including 311 with discoid lupus erythematosus (DLE), 262 with chilblain lupus erythematosus (CHLE) and 45 with lupus erythematosus profundus (LEP). Demographic characteristics, systemic involvement, mucocutaneous manifestations and autoantibodies were significantly different among the groups.

CONCLUSIONS

CLE and iCLE are two distinct disease states, and the selection of broad or narrow CLE definitions should be emphasised in scientific reports. LE-non-specific cutaneous lesions imply more severity, while self-reported photosensitivity and LE-specific cutaneous manifestations imply milder severity. Generalised ACLE appears to be a more severe state than localised ACLE, and CHLE appears to be more severe than DLE. Anti-Sjögren's syndrome-related antigen B (SSB) antibodies have higher specific directivity than anti-Sjögren's syndrome-related antigen A (SSA) antibodies for SCLE lesions. Anti-double-stranded DNA antibodies have a higher co-occurrence with ACLE and a lower co-occurrence with SCLE and CCLE. Compared with DLE, CHLE has significantly higher positive rates of anti-SSA/Ro60 (71%) and anti-SSA/Ro52 (42.4%) antibodies, whereas LEP is associated with a higher positive rate of antinucleosome antibodies (31.1%).

Circulating and skin biopsy-present cytokines related to the pathogenesis of cutaneous lupus erythematosus

Cutaneous lupus erythematosus (CLE) is a common disease that may appear as a separate entity from systemic lupus erythematosus (SLE), precede SLE development, or occur as a manifestation of this systemic disease. It has a complex pathophysiology that involves genetic, environmental, and immune-mediated factors creating a self-amplification pro-inflammatory cycle. CLE is characterized by prominent type I interferons (IFNs) inflammation which are considered as the first precursors of the inflammatory cascade generated within the pathophysiology of CLE. TNF-α enhances the production of antibodies through the activation of B cells, and favors the expression of surface nuclear antigens on keratinocytes. UV light exposure favors keratinocyte apoptosis or necroptosis, which results in the release of multiple proinflammatory cytokines, including IL-6, IL-1α, IL-1β, TNF-α, IFNs, and CXCL10. Serum levels of IL-17 are elevated in patients with ACLE, SCLE, and DLE. Evidence suggests IL-22 plays a role primarily in tissue repair rather than in inflammation. High expression of BAFF and its receptors have been found in lesioned keratinocytes of patients with CLE, and patients with CLE have lower serum levels of the regulatory cytokines TGF-β and IL-10. The chemokines CXCL9 and CXCL10 (CXCR3 ligands) have an increased expression among these patients, and their expression is correlated with IFNs levels. CXCR3 ligands recruit cytotoxic type I cells through this receptor, further supporting the death of keratinocytes via necroptosis with the subsequent release of eNAs perpetuating the inflammatory cycle. Interface dermatitis is characterized by the presence of CXCR3-positive lymphocytes. This review describes the leading cytokines and chemokines present in the circulation and skin that play a fundamental role in the pathogenesis of CLE.

Current Knowledge of the Molecular Pathogenesis of Cutaneous Lupus Erythematosus

Cutaneous lupus erythematosus (CLE) is an autoimmune disease, which can be limited to the skin or associated with systemic lupus erythematosus (SLE). Gene expression analysis has revealed that both the innate and adaptive immune pathways are activated in CLE. Ultraviolet (UV) light, the predominant environmental factor associated with CLE, induces apoptosis in keratinocytes, and the endogenous nucleic acids released from the apoptotic cells are recognized via pattern recognition receptors, including Toll-like receptors. This leads to the production of type I interferon, a major contributor to the pathogenesis of CLE, by plasmacytoid dendritic cells. UV irradiation can also induce the externalization of autoantigens, such as SS-A/Ro, exposing them to circulating autoantibodies. T-helper 1 cells have been reported to play important roles in the adaptive immune response to CLE. Other environmental factors associated with CLE include drugs and cigarette smoke. Genetic factors also confer a predisposition to the development of CLE, and many susceptibility genes have been identified. Monogenetic forms of CLE also exist. This article aims to review current knowledge about the pathogenesis of CLE. A better understanding of the environmental, genetic, and immunoregulatory factors that drive CLE may provide important insights for the treatment of CLE.

Cutaneous Involvement in Systemic Lupus Erythematosus: A Review for the Rheumatologist

The majority of patients with systemic lupus erythematosus (SLE) have cutaneous manifestations at some point in their disease course. The skin findings in SLE are classified as SLE-specific or SLE-nonspecific based on histopathologic findings. SLE-specific skin diseases include chronic cutaneous lupus erythematosus (CLE), subacute CLE, and acute CLE. There are subsets of skin lesions within each group and the likelihood of associated SLE varies among them. SLE-nonspecific lesions are more common in patients with SLE and tend to coincide with active systemic disease. SLE-nonspecific lesions may be seen as a feature of another disease process, including other connective tissue diseases. It is important for the rheumatologist to be familiar with the spectrum of cutaneous diseases in SLE to help prognosticate the likelihood of systemic disease and to ensure patients receive timely dermatologic care with the goal of controlling disease activity to prevent damage.

Review of an Anti-CD20 Monoclonal Antibody for the Treatment of Autoimmune Diseases of the Skin

Biologic therapies targeting B-cells are emerging as an effective strategy to treat a variety of immune-mediated diseases. One of the most studied B-cell-targeted therapies is rituximab, an anti-CD20 monoclonal antibody that exemplifies B-cell depletion therapy and has served as the prototype for other anti-CD20 monoclonal antibodies and the development of biosimilars. While there are multiple studies on the use of rituximab in dermatology, a comprehensive review of rituximab therapy in autoimmune skin conditions is lacking. In this literature review, we summarize indications, treatment efficacy, and safety of rituximab among common autoimmune diseases of the skin: pemphigus vulgaris, cutaneous lupus erythematous, dermatomyositis, systemic sclerosis, thyroid dermopathy, autoimmune pemphigoid diseases, and cutaneous vasculitis diseases. Existing data on rituximab support the approach of rituximab, biosimilars, and newer B-cell-targeting therapies in immune-mediated cutaneous diseases. Overall, rituximab, which targets CD20, provides an effective alternative or concomitant option to traditional immunosuppressants in the management of various autoimmune diseases of the skin. Further studies are necessary to expand the understanding and possible utility of B-cell-targeted therapies among autoimmune skin diseases.

Modulation of Immune Cells as a Therapy for Cutaneous Lupus Erythematosus

Cutaneous lupus erythematosus (CLE) is an autoimmune disorder like systemic lupus erythematosus (SLE). Both SLE and CLE characterize autoantibody secretion and immune cell recruitment. In particular, CLE can be divided into three more frequent types, varying in the severity of the skin lesions they present. The role of type I IFN was shown to be one of the leading causes of the development of this pathology in the skin. Different treatments have been developed and tested against these different variants of CLE to decrease the increasing levels of CLE in humans. In this article, a literature revision discussing the similarities between SLE and CLE is carried out. In addition, new advances in understanding the development of CLE and the leading treatments being evaluated in animal models and clinical trials are reviewed.

Immunohistochemical Study of the PD-1/PD-L1 Pathway in Cutaneous Lupus Erythematosus

The pathomechanism of various autoimmune diseases is known to be associated with the altered function of programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) axis. We aimed to investigate the role of this pathway and inflammatory cell markers in subtypes of cutaneous lupus erythematosus (CLE): discoid lupus erythematosus (DLE), subacute CLE (SCLE) and toxic epidermal necrolysis (TEN)-like lupus, a hyperacute form of acute CLE (ACLE). Ten skin biopsy samples from 9 patients were analyzed with immunohistochemistry regarding the following markers: CD3, CD4, CD8, Granzyme B, CD123, CD163, PD-1, PD-L1. Our group consisted of 4 SCLE (2 idiopathic (I-SCLE) and 2 PD-1 inhibitor-induced (DI-SCLE)), 4 DLE and 1 TEN-like lupus cases. From the latter patient two consecutive biopsies were obtained 1 week apart. Marker expression patterns were compared through descriptive analysis. Higher median keratinocyte (KC) PD-L1 expression was observed in the SCLE group compared to the DLE group (65% and 5%, respectively). Medians of dermal CD4, Granzyme B (GB), PD-1 positive cell numbers and GB+/CD8⁺ ratio were higher in the DLE group than in the SCLE group. The I-SCLE and DI-SCLE cases showed many similarities, however KC PD-L1 expression and dermal GB positive cell number was higher in the former. The consecutive samples of the TEN-like lupus patient showed an increase by time within the number of infiltrating GB+ cytotoxic T-cells and KC PD-L1 expression (from 22 to 43 and 30%–70%, respectively). Alterations of the PD-1/PD-L1 axis seems to play a role in the pathogenesis of CLE.

Trial of Anti-BDCA2 Antibody Litifilimab for Cutaneous Lupus Erythematosus

BACKGROUND

Blood dendritic cell antigen 2 (BDCA2) is a receptor that is exclusively expressed on plasmacytoid dendritic cells, which are implicated in the pathogenesis of lupus erythematosus. Whether treatment with litifilimab, a humanized monoclonal antibody against BDCA2, would be efficacious in reducing disease activity in patients with cutaneous lupus erythematosus has not been extensively studied.

METHODS

In this phase 2 trial, we randomly assigned adults with histologically confirmed cutaneous lupus erythematosus with or without systemic manifestations in a 1:1:1:1 ratio to receive subcutaneous litifilimab (at a dose of 50, 150, or 450 mg) or placebo at weeks 0, 2, 4, 8, and 12. We used a dose-response model to assess whether there was a response across the four groups on the basis of the primary end point, which was the percent change from baseline to 16 weeks in the Cutaneous Lupus Erythematosus Disease Area and Severity Index-Activity score (CLASI-A; scores range from 0 to 70, with higher scores indicating more widespread or severe skin involvement). Safety was also assessed.

RESULTS

A total of 132 participants were enrolled; 26 were assigned to the 50-mg litifilimab group, 25 to the 150-mg litifilimab group, 48 to the 450-mg litifilimab group, and 33 to the placebo group. Mean CLASI-A scores for the groups at baseline were 15.2, 18.4, 16.5, and 16.5, respectively. The difference from placebo in the change from baseline in CLASI-A score at week 16 was -24.3 percentage points (95% confidence interval [CI] -43.7 to -4.9) in the 50-mg litifilimab group, -33.4 percentage points (95% CI, -52.7 to -14.1) in the 150-mg group, and -28.0 percentage points (95% CI, -44.6 to -11.4) in the 450-mg group. The least squares mean changes were used in the primary analysis of a best-fitting dose-response model across the three drug-dose levels and placebo, which showed a significant effect. Most of the secondary end points did not support the results of the primary analysis. Litifilimab was associated with three cases each of hypersensitivity and oral herpes infection and one case of herpes zoster infection. One case of herpes zoster meningitis occurred 4 months after the participant received the last dose of litifilimab.

CONCLUSIONS

In a phase 2 trial involving participants with cutaneous lupus erythematosus, treatment with litifilimab was superior to placebo with regard to a measure of skin disease activity over a period of 16 weeks. Larger and longer trials are needed to determine the effect and safety of litifilimab for the treatment of cutaneous lupus erythematosus. (Funded by Biogen; LILAC ClinicalTrials.gov number, NCT02847598.).

Sjögren's syndrome

Sjögren’s syndrome (SjS) is an autoimmune disease characterized by the triad of sicca symptoms, fatigue and pain. This diagnosis is usually made in women at the average age of 60 years. Diagnosis is made when sicca symptoms persist for more than three months, after the exclusion of possible differential diagnoses, and using the ACR/EULAR 2016 classification criteria for SjS. Many organs can be affected in the course of this disease. Xerosis cutis and pruritus are the most common skin manifestations, followed by leukocytoclastic vasculitis and subacute cutaneous lupus erythematosus. In addition, SjS patients often have myoarthralgia and neuropsychiatric symptoms. In the long term, attention must be paid to the increased risk of cardiovascular disease and lymphoma. Due to the multiorgan involvement in SjS patients, interdisciplinary care is required.

Current Concepts on Pathogenic Mechanisms and Histopathology in Cutaneous Lupus Erythematosus

Cutaneous lupus erythematosus (CLE) is an interferon (IFN)-driven autoimmune disease that may be limited to the skin or can be associated with systemic lupus erythematosus (SLE). CLE occurs in several morphologic subtypes ranging from isolated, disc-shaped plaques to disseminated skin lesions. The typical histopathologic pattern of skin lesions is named interface dermatitis and characterized by a lymphocytic infiltrate and necroptotic keratinocytes at the dermo-epidermal junction. Other histopathologic patterns primarily involve the dermis or subcutis, depending on the subtype. One critical mechanism in CLE is the chronic reactivation of innate and adaptive immune pathways. An important step in this process is the recognition of endogenous nucleic acids released from dying cells by various pattern recognition receptors (PRRs), including Toll-like receptors (TLRs) and other cytosolic receptors. Crucial cells in CLE pathogenesis comprise plasmacytoid dendritic cells (pDCs) as major producers of type I IFN, T cells exerting cytotoxic effects, and B cells, previously believed to contribute via secretion of autoantibodies. However, B cells are increasingly considered to have additional functions, supported by studies finding them to occur in highest numbers in chronic discoid lupus erythematosus (CDLE), a subtype in which autoantibodies are often absent. More precise knowledge of how CLE subtypes differ pathophysiologically may allow a tailored pharmacotherapy in the future, taking into account the specific molecular signature in relation to the morphologic subtype.

Acitretin treatment in antimalarial-refractory/intolerant discoid lupus erythematosus: A prospective, open-label, uncontrolled study

Background

The treatment of discoid lupus erythematosus (DLE) is often challenging, especially in patients who are refractory or intolerant to topical treatments and first-line systemic drugs, specifically antimalarial drugs. Although acitretin has been shown to be effective in patients with DLE in a few studies, there is no published study describing the long-term efficacy of acitretin with a validated score.

Objectives

To evaluate the efficacy and safety of acitretin in patients with antimalarial-refractory/intolerant DLE.

Methods

A prospective, open-label, uncontrolled study was conducted in patients with antimalarial-refractory/intolerant DLE. All patients were treated with an initial dosage of 10 mg acitretin daily. Clinical response was assessed using the Revised Cutaneous Lupus Erythematosus Disease Area and Severity Index (RCLASI) at weeks 4, 8, 12, and 24. Acitretin was increased to 25 mg daily unless an adequate response was achieved at week 8.

Results

Fourteen patients were recruited. Of these, 10 were antimalarial-refractory and four were antimalarial-intolerant. The acitretin therapy was discontinued in one patient after 20 weeks of treatment because of active systemic disease. Of the 13 remaining patients, the mean RCLASI activity scores declined from 21 ± 9 at baseline to 9 ± 4 at week 24. A significant reduction in RCLASI was initially observed at week four and consistently noted at each follow-up visit ( p ≤ 0.01). At the end of the study, a marked response was achieved in approximately 80% of patients. There were no statistically significant differences in the clinical response or in the requirement of the up-dosing of acitretin between the refractory and intolerance groups ( p = 0.88 and p = 0.326, respectively). Age ≥50 years old, female sex, and generalized DLE were the favorable prognostic factors. No serious adverse events were noted.

Conclusions

Acitretin appears to be an effective treatment with acceptable safety profiles for antimalarial-refractory/intolerant DLE.

Case Report: Rowell Syndrome-Like Flare of Cutaneous Lupus Erythematosus Following COVID-19 Infection

The current COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had an important impact on dermatology practice, posing diagnostic and therapeutic challenges especially in patients with inflammatory and autoimmune skin disorders. Disease-specific and nonspecific cutaneous manifestations have been increasingly reported in the spectrum of COVID-19 but the influence of the infection on pre-existing dermatologic diseases has not been clearly defined. There has been a debate in the literature as to whether patients suffering from autoimmune dermatoses, including cutaneous lupus erythematosus (CLE), are at increased risk of SARS-CoV-2 infection, as well as if they experience worsening of their lupus erythematosus (LE)-related clinical symptoms. This article reports on a case of Rowell syndrome occurring after COVID-19 in a 67-year old woman with pre-existing chronic CLE manifesting with few discoid lesions on the face, scalp, and upper chest, successfully controlled with topical corticosteroids and photoprotection. Erythema multiforme (EM)-like eruption developed approximately two weeks after the SARS-CoV-2 infection, the latter being confirmed by positive nasopharyngeal swab and successfully treated with systemic antibiotics and antiaggregants. Diffuse hair loss and patches of cicatricial alopecia were also present upon scalp examination. Laboratory workup, including routine tests, histologic, immunofluorescent, and serologic investigations, was supportive to the diagnosis. Administration of topical and systemic corticosteroids along with peroral hydroxychloroquine resulted in the progressive improvement of the cutaneous lesions. Rowell syndrome is a rare entity in the spectrum of LE, characterized by EM-like lesions, photosensitivity, and positive antinuclear and anti-Ro antibodies, that is currently considered to be a variant of subacute CLE (SCLE). Several cases of SCLE have been described in association with medications, including anti-SARS-CoV-2 vaccines but only a few reports incriminate the infection itself as a potential exacerbating factor. Based on the clinical course of the disease, we suggest that the observed Rowell syndrome-like flare of CLE was related to the COVID-19 infection in this patient.

Lupus erythematosus: correlation of clinical and histological findings and proposal for a modified disease classification

BACKGROUND

Classification of lupus erythematosus (LE) is conflicting as it is carried out from different starting points. Whereas dermatological classifications categorize LE morphologically based on specific cutaneous lesions, rheumatologic classifications are based on symptomatic aspects. Indeed, LE is a systemic autoimmune disease with variable acuity and organ involvement. All cutaneous disease patterns may occur in both limited-cutaneous and systemic LE.

PATIENTS AND METHODS

76 LE-patients with complete clinical data, clinical photographs and biopsy of cutaneous manifestations as well as paraclinical findings were retrospectively analyzed. Based on a published two-dimensional classification system that considers disease-specific skin manifestations and final disease diagnosis separately, patients' diagnoses were revised and compared with those in medical records. In addition, the extent to which patients could be clustered by diagnosis based on their LE-specific skin manifestations, corresponding histopathological changes, and paraclinical data was investigated.

RESULTS

After re-evaluation, the proportion of patients with limited-cutaneous LE decreased from 82% previously to 24%. More than two-thirds of patients indeed showed intermediate or systemic LE. Disease-specific skin manifestations, histologic characteristics and paraclinical data did not cluster with final diagnoses.

CONCLUSIONS

First, the work underlines the systemic character of the disease. Second, a two-dimensional approach can help overcome classification difficulties in LE, as skin-morphologic and symptomatic aspects can be considered separately.

Cutaneous drug-induced lupus erythematosus: Clinical and immunological characteristics and update on new associated drugs

Cutaneous drug-induced lupus erythematosus (CDILE) is a lupus-like syndrome related to drug exposure which typically resolves after drug discontinuation. It can present as a systemic or a sole cutaneous form and different drugs may be associated with each form. CDILE pharmacoepidemiology is constantly changing. Indeed, older drugs primarily associated with systemic CDILE are no longer prescribed and new drugs associated with either cutaneous or systemic CDILE have emerged. The present study discusses the clinical and laboratory aspects of CDILE and the postulated pathogenesis, and it provides an update on implicated drugs. We performed a literature review to single out the new drugs associated with CDILE in the past decade (January 2010-June 2020). Among 109 drugs reported to induce CDILE in 472 patients, we identified anti-TNFα, proton-pump inhibitors, antineoplastic drugs, and, in particular, checkpoint inhibitors, as emerging drugs in CDILE. Most of the published studies are cases reports or small case series, and further larger studies as well as the development of validated classification criteria are needed to better understand and characterize their implication in CDILE.

Long-Term Risk of Autoimmune Diseases other than Systemic Lupus Erythematosus in Cutaneous Lupus Erythematosus-Alone Patients: A 10-Year Nationwide Cohort Study

BACKGROUND

Up to 25% of patients with cutaneous lupus erythematosus (CLE) can develop systemic lupus erythematosus (SLE). However, the risk of autoimmune diseases other than SLE in CLE patients who have only skin manifestations (CLE-alone) has rarely been explored.

OBJECTIVE

To investigate the long-term risk and independent factors of non-SLE autoimmune diseases among CLE-alone patients.

METHOD

A nationwide cohort study using the Taiwanese National Health Insurance Research Database 1997-2013. CLE patients and matched subjects were included. Cumulative incidences of autoimmune diseases after 1 year of CLE-alone diagnosis were compared. Cox proportional hazard model was also performed.

RESULTS

A total of 971 CLE-alone patients and 5,175 reference subjects were identified. The 10-year cumulative incidence of autoimmune diseases other than SLE was significantly elevated in the CLE-alone cohort (9.00%, 95% confidence interval [CI] 6.72-11.29) than in the reference cohort (4.20%, 95% CI 3.53-4.87%) (p < 0.001). CLE-alone was independently associated with non-SLE autoimmune diseases (adjusted hazard ratio 1.55, 95% CI 1.10-2.18). Among CLE-alone patients, females and those taking long-term systemic corticosteroids (a proxy for extensive disease) were associated with non-SLE autoimmune diseases after adjusting for the number of repeated autoimmune laboratory tests.

CONCLUSION

CLE-alone is independently associated with future non-SLE autoimmune diseases.

Differences in quality of life in patients with cutaneous lupus erythematosus with varying income levels

BACKGROUND

Cutaneous lupus erythematosus (CLE) is an autoimmune photosensitive skin condition. The impact of income on quality of life has been incompletely characterized in CLE.

OBJECTIVES

We aimed to assess how annual income affects quality of life among CLE patients.

METHODS

In this cross-sectional study of 238 patients with CLE, relationships between predictor variables including annual income and each SKINDEX-29 + 3 subdomain were identified using univariate and multivariable analyses. In addition, answers to individual SKINDEX-29 + 3 questions were compared across income groups. Clinical factors in patients making less than <10,000 USD (N = 85) with worse SKINDEX-29 + 3 scores were also identified by univariate and multivariable analyses.

RESULTS

Patients making <10,000 USD annually experienced worse quality of life across multiple SKINDEX-29 + 3 subdomains (p < 0.05). These patients specifically experienced poorer quality of life relating to social isolation and self-consciousness. (p < 0.001). Among those making <10,000 USD, predictors for worse quality of life included females, smokers, and those with higher skin disease activity were identified (p < 0.05).Limitations: This is a single center study. Income was also self-reported and could not be verified.

CONCLUSIONS

Lower income is related to poorer quality of life in patients with CLE. Specifically, patients experience limitations regarding social isolation and self-consciousness.

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.

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.

Modular gene analysis reveals distinct molecular signatures for subsets of patients with cutaneous lupus erythematosus

BACKGROUND

Cutaneous lupus erythematosus (CLE) is a heterogeneous autoimmune disease with clinical sequelae such as itching, dyspigmentation and scarring.

OBJECTIVES

We applied a previously described modular analysis approach to assess the molecular heterogeneity of patients with CLE.

METHODS

Whole-blood transcriptomes of RNA sequencing data from a racially and ethnically diverse group of patients with CLE (n = 62) were used to calculate gene co-expression module scores. An unsupervised cluster analysis and k-means clustering based on these module scores were then performed. We used Fisher's exact tests and Kruskal-Wallis tests to compare characteristics between patient clusters.

RESULTS

Six unique clusters of patients with CLE were identified from the cluster analysis. We observed that seven inflammation modules were elevated in two clusters of patients with CLE. Additionally, these clusters were characterized by interferon, neutrophil and cell-death signatures, suggesting that interferon-related proteins, neutrophils and cell-death processes could be driving the inflammatory response in these subgroups. Three different clusters had a predominant T-cell signature, which were supported by lymphocyte counts.

CONCLUSIONS

Our data support a diverse molecular profile in CLE that further adds to the clinical variations of this skin disease, and may affect disease course and treatment selection. Future studies with a larger and diverse cohort of patients with CLE are warranted to confirm these findings.

Dermatologic Manifestations, Histologic Features and Disease Progression among Cutaneous Lupus Erythematosus Subtypes: A Prospective Observational Study in Asians

Introduction

Cutaneous manifestations are central to the primary diagnosis of systemic lupus erythematosus (SLE). However, information on the clinical, histopathologic, and direct immunofluorescence (DIF) features among subtypes of cutaneous lupus erythematosus (CLE), as well as longitudinal prospective observational study to evaluate the natural history and the progression to SLE, is lacking among Asians. Our objectives are to summarize the differences in the clinical, histopathologic, and DIF characteristics and serological profiles between various subtypes of CLE, and to provide its natural history and the association with disease activity in our Asian population.

Methods

A prospective observational study on CLE patients was performed between May 2016 and May 2020. Patients underwent full physical/dermatologic examination, skin biopsy for histology, and DIF. Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) scores and laboratory data were evaluated. Time schedule and characteristics for resolution and/or the disease progression to SLE were recorded in subsequent follow-ups.

Results

Of 101 biopsy-proven CLE patients, 25 had acute CLE (ACLE), 8 had subacute CLE (SCLE), 39 had chronic CLE (CCLE) only, 22 had CCLE with SLE, and 7 had LE-nonspecific cutaneous lesions only. Patients with exclusive CLE showed lower female preponderance, serological abnormalities, and correlation to systemic disease. However, when CLE was accompanied with any LE-nonspecific cutaneous manifestations, they were associated with high antinuclear antibody (ANA) titer, renal, hematologic, joint involvement, and greater SLEDAI score. Of 207 biopsy sections, SCLE/CCLE regardless of systemic involvement showed significantly higher percentage of superficial/deep perivascular and perieccrine infiltration than ACLE. On DIF, deposition of multiple immunoreactants was associated with higher systemic disease. Approximately 10% of CLE-only patients later developed SLE but had mild systemic involvement.

Conclusion

Our findings support that each CLE subtype has a diverse and unique character. Comprehensive understanding of the differences among CLE subtypes is important for achieving the correct diagnosis and providing appropriate disease monitoring and management.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-020-00471-y.

Discoid Lupus Erythematosus: A Cross-Sectional Study From the Sindh Institute of Skin Diseases, Karachi, Pakistan

Introduction

Discoid lupus erythematosus (DLE) is the most common form of cutaneous lupus erythematosus. It is a chronic, scar-forming, photosensitive autoimmune dermatosis presenting with erythematous and scaly lesions. Predisposed areas include sun-exposed areas like the nose, forehead, and cheeks, as well as the upper body and extremities. The histological findings are typical, with interface dermatitis. Immunoglobulin M (IgM) and immunoglobulin G (IgG) are the most common deposits in the dermoepidermal junction of the involved skin. The most common treatments used are sunscreens, topical corticosteroids, and antimalarials. Immunosuppressive agents, thalidomide, dapsone, and retinoids can be used in refractory cases. The aim of this study was to study the clinicopathologic patterns of DLE in patients presenting to the Institute of Skin Diseases in Sindh, Karachi.

Methods

A total of 53 consecutive patients with DLE meeting the inclusion criteria were evaluated between February 18, 2018 to March 2, 2019 at the Institute of Skin Diseases. Patients with clinical suspicion of DLE were evaluated and studied prospectively after written informed consent was obtained. Information was then collected from their medical histories, physical examination records, and laboratory investigation reports.

Results

A total of 53 consecutive patients with clinical and/or histological diagnosis of DLE was included in this study, out of which 75.5% (40) were females with a male to female ratio of 1:3.1. The mean age of the patients at the time of presentation was 36.02 ± 10.04 years, ranging from 14 to 65 years. More than half of the patients (35, 66.0%) were under 40 years of age and 20.8% (11) had a positive family history of DLE. DLE was localized in 36 patients (67.9%) and exposure to the ultraviolet radiation (UVR) was found to be the most frequent induced factor in 46 patients (86.8%), followed by stress which was observed in 14 patients (26.4%). The distribution of commonly affected sites were the face (81.1%), the limbs (71.7%), and the scalp (48.4%) of the patients. Serology antinuclear antibody (ANA) was positive in 56.6% and serology anti-double-stranded deoxyribonucleic acid antibodies (anti-dsDNA) were positive in 45.3% of patients. Smoking, as an induced factor, was more commonly observed among male patients as compared to the female patients with a proportion of 53.8% vs. 2.5%, p < 0.001, while stress was more common among female patients with a proportion of 35% vs. 0%, p = 0.013, respectively. Histopathology with direct immunofluorescence was done in 33 cases which included cases with negative serology or where the diagnosis was in doubt clinically. The main histopathological features observed were periadnexal and perivascular dermal infiltrates, basal cells vacuolization, epidermal atrophy, hyperkeratosis, and follicular plugging. The commonest morphological form observed was the classic discoid plaque form.

Conclusion

Clinical patterns of DLE in our population comprises of female dominance. Exposure to UVR was the leading inducing factor. The face and limbs were the most commonly involved sites, and the majority of the patients had localized DLE with positive ANA in more than half of those patients. The importance of limiting ultraviolet radiation exposure and toxins (drugs and smoking) should be emphasized in our population.

Leveraging Heterogeneity in Systemic Lupus Erythematosus for New Therapies

Systemic lupus erythematosus (SLE) is a multisystem, chronic autoimmune disease where treatment varies by patient and disease activity. Strong preclinical results and clinical correlates have motivated development of many drugs, but many of these have failed to achieve efficacy in clinical trials. FDA approval of belimumab in 2011 was the first successful SLE drug in nearly six decades. In this article, we review insights into the molecular and clinical heterogeneity of SLE from transcriptomics studies and detail their potential impact on drug development and clinical practices. We critically examine the pipeline of SLE drugs, including past failures and their associated lessons and current promising approaches. Finally, we identify opportunities for integrating these findings and drug development with new multidisciplinary advances to enhance future SLE treatment.

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.

New insights into the progression from cutaneous lupus to systemic lupus erythematosus

INTRODUCTION

Between 5 and 25% of patients with cutaneous lupus erythematosus (CLE) can progress to systemic lupus erythematosus (SLE) during the course of the disease. There is no clear predictive guideline for the progression of CLE to SLE.

AREAS COVERED

Lupus erythematosus (LE), a chronic autoimmune disease, has a wide spectrum of manifestations. On one side of the spectrum is CLE, in which patients only display skin lesions. On the other side of the spectrum is SLE, which develops severe systemic involvement. CLE has even been considered as a separate entity from LE, while CLE is also proposed to be associated with SLE. In this review, the authors will describe the relationship between CLE and SLE; summarize the incidence, risk factors, systemic involvement, and management of patients who transition to SLE. The literature search was conducted mainly through PubMed from March to July 2020.

EXPERT OPINION

The identification of clinical characteristics and biomarkers in patients facing risk of developing SLE and monitoring the disease on a regular basis are essential to promptly manage and hopefully prevent transition to the systemic form.

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.

Treatment of cutaneous lupus erythematosus: current approaches and future strategies

PURPOSE OF REVIEW

Cutaneous lupus erythematosus (CLE) is a highly heterogeneous autoimmune disease. No specific Federal Drug Administration-approved therapies for CLE-alone are available, and resistance to conventional treatments is common. This review will summarize current treatment approaches and pending treatment strategies.

RECENT FINDINGS

Research into the pathogenesis of CLE is accelerating. A skewed type I interferon production and response contribute to CLE lesions. The pathophysiology of lesions may be similar among the lesional subtypes, and patients with a more TLR9-driven disease mechanism may have more benefit from hydroxychloroquine. Case reports continue to support the use of dapsone for CLE, especially bullous lupus erythematosus. Rituximab and Belimumab have efficacy in patients with systemic lupus erythematosus and severe active CLE. The significant role for type I interferons in CLE and encouraging clinical data suggest anifrolumab as a very promising agent for CLE. Dapirolizumab, BIIB059, Ustekinumab and Janus kinase inhibitors also have supportive early data as promising new strategies for CLE treatment.

SUMMARY

Continued research to understand the mechanisms driving CLE will facilitate the development and approval of new targets. The pipeline for new treatments is rich.

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.

A Missense Variant Affecting the C-Terminal Tail of UNC93B1 in Dogs with Exfoliative Cutaneous Lupus Erythematosus (ECLE)

Cutaneous lupus erythematosus (CLE) in humans encompasses multiple subtypes that exhibit a wide array of skin lesions and, in some cases, are associated with the development of systemic lupus erythematosus (SLE). We investigated dogs with exfoliative cutaneous lupus erythematosus (ECLE), a dog-specific form of chronic CLE that is inherited as a monogenic autosomal recessive trait. A genome-wide association study (GWAS) with 14 cases and 29 controls confirmed a previously published result that the causative variant maps to chromosome 18. Autozygosity mapping refined the ECLE locus to a 493 kb critical interval. Filtering of whole genome sequence data from two cases against 654 controls revealed a single private protein-changing variant in this critical interval, UNC93B1:c.1438C>A or p.Pro480Thr. The homozygous mutant genotype was exclusively observed in 23 ECLE affected German Shorthaired Pointers and an ECLE affected Vizsla, but absent from 845 controls. UNC93B1 is a transmembrane protein located in the endoplasmic reticulum and endolysosomes, which is required for correct trafficking of several Toll-like receptors (TLRs). The p.Pro480Thr variant is predicted to affect the C-terminal tail of the UNC93B1 that has recently been shown to restrict TLR7 mediated autoimmunity via an interaction with syndecan binding protein (SDCBP). The functional knowledge on UNC93B1 strongly suggests that p.Pro480Thr is causing ECLE in dogs. These dogs therefore represent an interesting spontaneous model for human lupus erythematosus. Our results warrant further investigations of whether genetic variants affecting the C-terminus of UNC93B1 might be involved in specific subsets of CLE or SLE cases in humans and other species.

Lupus erythematosus tumidus: clinical perspectives

Lupus erythematosus tumidus (LET) is an uncommon and photosensitive inflammatory skin disorder which is characterised by erythematous urticarial plaques. In the last 20 years, extensive research on clinical and histological aspects of the disease have led to a better characterization of this nosological entity and to differentiate it from other similar or related diseases. Today, LET is considered as a separate subtype of cutaneous lupus erythematosus (CLE) with a benign, intermittent clinical course (intermittent CLE, ICLE) and only rarely associated with systemic lupus erythematosus (SLE).

Suspected inflammatory rheumatic diseases in patients presenting with skin rashes

Skin lesions occur, often at very early stages, in many of the most frequent inflammatory rheumatic diseases such as in systemic lupus erythematosus (SLE), dermatomyositis (DM), systemic sclerosis (SSc), Sjögren's syndrome, rheumatoid arthritis (RA), and psoriatic arthritis. It is important to recognize the different specific cutaneous lesions in SLE (e.g., "butterfly" rash in acute, annular or psoriasiform photosensitive lesions in the subacute form, and discoid lesions in the chronic form) for an early diagnosis and to estimate the associated risks of internal disease, whereas nonspecific lesions (exanthema, vasculitis, and alopecia) can be part of SLE flares. Cutaneous lesions in DM (Gottron's papules and sign, heliotrope rash, dystrophic cuticles, and nailfold capillary abnormalities) may occur before any clinically evident muscular or systemic organ involvement and are of utmost importance for early diagnosis. The pattern of cutaneous lesions and associated autoantibodies also allow the distinction of different phenotypes, either more prone to life-threatening interstitial lung disease (MDA-5) or with higher risk for neoplasia (TIF1-γ). Many other skin lesions, although not specific, require further investigation to look for a possible underlying inflammatory rheumatic disease: non-pruritic urticarial lesions in anti-C1q-associated urticarial vasculitis, Still's disease or hereditary auto-inflammatory syndromes, transient macular purpura of vasculitis in Sjögren's syndrome, Behçet's disease, or RA, Raynaud's phenomenon in SSc and mixed connective tissue disease, erythema nodosum or other panniculitis in RA, Behçet's disease and SLE, pustular eruptions in Behçet's disease, psoriasis, and hereditary auto-inflammatory syndromes. After reviewing in detail the cutaneous manifestations of the most frequent inflammatory rheumatic diseases, we describe a topographic and morphological approach to skin rashes, calling attention to facial rashes, hand involvement, scalp, nail, or leg lesions or to some morphological aspects of skin lesions (annular, pustular, urticarial, or exanthematous) that may be the initial manifestations of inflammatory rheumatic diseases. The importance of skin lesions is confirmed by their presence as part of the classification criteria of many inflammatory rheumatic diseases. They also contribute to early diagnosis, to characterize disease phenotypes, to aid in effective patient management, and, ultimately, to impact on disease prognosis.

Autoimmune Diseases in Patients With Cutaneous Lupus Erythematosus

Importance

Increased rates of autoimmune conditions have been reported in association with systemic lupus erythematosus (SLE). Little is known about coexisting autoimmune conditions in patients with cutaneous lupus erythematosus (CLE) without SLE.

Objective

To determine the prevalence and risk factors of having coexisting autoimmune conditions in patients with CLE.

Design, Setting, and Participants

This cross-sectional study was performed from November 2008 to February 2017 at the University of Texas Southwestern Medical Center (UTSW) and Parkland Health and Hospital System, Dallas, Texas. Participants were identified through the UTSW Cutaneous Lupus Registry. All participants had a dermatologist-confirmed diagnosis of CLE using clinicopathological correlation. Exclusion criteria included age younger than 18 years, and meeting at least 4 American College of Rheumatology diagnostic criteria for SLE. Participants with CLE and without concomitant autoimmune diseases were compared by demographic and disease characteristics.

Main Outcomes and Measures

The primary and secondary outcomes were presence of coexisting autoimmune condition(s) and individual autoimmune diseases, respectively. Predictor variables significantly associated with coexisting autoimmune diseases were identified by univariate and multivariable logistic regression analyses.

Results

Among the 285 participants initially screened, 129 participants with CLE were included (102 [79.1%] female; median age, 49 years [interquartile range, 38.3-57.1 years]). Coexisting autoimmune conditions were found in 23 (17.8%). Autoimmune thyroid disease had the highest frequency at 4.7% (n = 6). Multivariable logistic regression analyses showed that patients with CLE who were white (odds ratio [OR], 2.88; 95% CI, 1.00-8.29; P = .0498), never smokers (OR, 3.28; 95% CI, 1.14-9.39; P = .03), had family history of autoimmune disease (OR, 3.54; 95% CI, 1.21-10.39; P = .02), and history of positive antinuclear antibody test result (OR, 4.87; 95% CI, 1.69-14.03; P = .003) had a significant association with having coexisting autoimmune conditions.

Conclusions and Relevance

This study suggests that patients with CLE without concurrent SLE can have increased rates of coexisting autoimmune conditions. Collecting a thorough review of systems can prompt clinicians to pursue further testing and evaluation by other specialists. Future studies investigating development of coexisting autoimmune conditions over time in the CLE population are necessary to confirm these findings.