Increased CD69+CCR7+ circulating activated T cells and STAT3 expression in cutaneous lupus erythematosus patients recalcitrant to antimalarials.

BACKGROUND: Antimalarials are first-line systemic therapy for cutaneous lupus erythematosus (CLE). While some patients unresponsive to hydroxychloroquine (HCQ) alone benefit from the addition of quinacrine (QC), a subset of patients is refractory to both antimalarials. METHODS: We classified CLE patients as HCQ-responders, HCQ+QC-responders, or HCQ+QC-nonresponders to compare immune profiles. Immunohistochemistry, immunofluorescence, and qRT-PCR were used to characterize inflammatory cells and cytokines in lesional skin. RESULTS: Immunohistochemistry showed that CD69+ T cells were higher in HCQ+QC-nonresponders compared to HCQ- and HCQ+QC-responders (p < 0.05). Immunofluorescence further identified these cells as CD69+CCR7+ circulating activated T cells. Myeloid dendritic cells were significantly higher in HCQ+QC-responders compared to both HCQ-responders and HCQ+QC-nonresponders. Plasmacytoid dendritic cells were significantly increased in HCQ-responders compared to HCQ- and HCQ+QC-nonresponders. No differences were found in the number of autoreactive T cells, MAC387+ cells, and neutrophils among the groups. CLASI scores of the HCQ+QC-nonresponder group positively correlated with CD69+CCR7+ circulating activated T cells (r = 0.6335, p < 0.05) and MAC387+ cells (r = 0.5726, p < 0.05). IL-17 protein expression was higher in HCQ+QC-responders compared to HCQ-responders or HCQ+QC-nonresponders, while IL-22 protein expression did not differ. mRNA expression demonstrated increased STAT3 expression in a subset of HCQ+QC-nonresponders. CONCLUSION: An increased number of CD69+CCR7+ circulating activated T cells and a strong correlation with CLASI scores in the HCQ+QC-nonresponders suggest these cells are involved in antimalarial-refractory skin disease. STAT3 is also increased in HCQ+QC-nonresponders and may also be a potential target for antimalarial-refractory skin disease.

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.

Lupus band test can be used in combination with anti-chromatin antibodies and complement analysis to predict transition from cutaneous to systemic lupus.

The lupus band test (LBT) is frequently performed for patients with lupus erythematosus (LE) but its capacity to discriminate cutaneous (C)LE from systemic (S)LE is debated, as well as its association with serum antinuclear antibodies (ANA) and complement reduction. Among 158 patients, 56 received retrospectively a diagnosis of CLE, 37 have SLE and 65 other skin disorders. Considering 29 clinical, histopathologic, LBT, and serological parameters: 5 parameters were effective in distinguishing LE from other skin disorders (e.g. skin photosensitivity, LBT positivity, basal vacuolar changes, thickening of the basement membrane, and anti-SSA-60 kDa); and 8 parameters were able to separate SLE from CLE (e.g. arthritis, lupus nephritis, hematological manifestations, Raynaud/sicca manifestations, anti-chromatin, anti-dsDNA, and low levels of C3/4). A positive LBT was further determined to be associated with systemic manifestations when associated with anti-chromatin response and complement reduction in the profile of patients evolving to a systemic form of lupus.

A novel humanized cutaneous lupus erythematosus mouse model mediated by IL-21-induced age-associated B cells.

Cutaneous lupus erythematosus (CLE) is a relapsing autoimmune disease, but key elements that drive disease initiation and progression remain elusive. To date, the lack of ideal murine model which resemble human cutaneous lupus makes it extremely challenging for moving mechanistic discoveries and novel therapeutics. Here, we prompt a humanized murine model to develop an inducible rapid-onset murine that performs cutaneous rather than systemic lupus, depending on the successful human immune system reconstruction from active lupus patients and UVB irradiation as for essentially pathogenic triggers. In addition, we demonstrate a newly discovered population of B cell with a unique phenotype, that of the age-associated B cell (ABC, T-bet+ CD11b+), exhibits B cell clusters in humanized cutaneous lupus. In the response of IL-21 and TLR7/9 signals, recruitment of autoreactive B cells to the position of inflammation with subsequent localized antibody production of IgG2a, IgG2b, IgG3, has the potential to exacerbate ongoing inflammation and thus driving lupus-like autoimmunity in a B-cell-dominant fashion. Overall, our model provides a relevant system for exploring the pathophysiology of cutaneous lupus, a suitable model for drug development, as well as updating a potential role of IL-21 and TLR7/9 to be targeted by biologics.

B cell subset composition segments clinically and serologically distinct groups in chronic cutaneous lupus erythematosus.

OBJECTIVE: While the contribution of B-cells to SLE is well established, its role in chronic cutaneous lupus erythematosus (CCLE) remains unclear. Here, we compare B-cell and serum auto-antibody profiles between patients with systemic lupus erythematosus (SLE), CCLE, and overlap conditions. METHODS: B-cells were compared by flow cytometry amongst healthy controls, CCLE without systemic lupus (CCLE+/SLE-) and SLE patients with (SLE+/CCLE+) or without CCLE (SLE+/CCLE-). Serum was analyed for autoreactive 9G4+, anti-double-stranded DNA, anti-chromatin and anti-RNA antibodies by ELISA and for anti-RNA binding proteins (RBP) by luciferase immunoprecipitation. RESULTS: Patients with CCLE+/SLE- share B-cell abnormalities with SLE including decreased unswitched memory and increased effector B-cells albeit at a lower level than SLE patients. Similarly, both SLE and CCLE+/SLE- patients have elevated 9G4+ IgG autoantibodies despite lower levels of anti-nucleic acid and anti-RBP antibodies in CCLE+/SLE-. CCLE+/SLE- patients could be stratified into those with SLE-like B-cell profiles and a separate group with normal B-cell profiles. The former group was more serologically active and more likely to have disseminated skin lesions. CONCLUSION: CCLE displays perturbations in B-cell homeostasis and partial B-cell tolerance breakdown. Our study demonstrates that this entity is immunologically heterogeneous and includes a disease segment whose B-cell compartment resembles SLE and is clinically associated with enhanced serological activity and more extensive skin disease. This picture suggests that SLE-like B-cell changes in primary CCLE may help identify patients at risk for subsequent development of SLE. B-cell profiling in CCLE might also indentify candidates who would benefit from B-cell targeted therapies.

Expression pattern of tissue-resident memory T cells in cutaneous lupus erythematosus.

BACKGROUND: Tissue resident memory T cells (TRMs) persist long-term in peripheral tissues without recirculation, triggering an immediate protective inflammatory state upon the re-recognition of the antigen. Despite evidence incriminating the dysregulation of TRMs in autoimmune diseases, few studies have examined their expression in cutaneous lupus erythematosus (CLE). OBJECTIVES: We aimed to examine whether there are differences among TRM populations in CLE depending on different clinical conditions, such as the CLE subtype or association with systemic lupus erythematosus, and to determine the effect of type I interferon (IFN) on the development of TRMs in CLE. METHODS: CLE disease activity was evaluated using the Cutaneous Lupus Erythematosus Disease Area and Severity Index. The expression of the TRM markers CD69 and CD103 in CLE lesions was evaluated by immunofluorescence. Flow cytometry was performed on peripheral blood mononuclear cells after IFNα treatment. RESULTS: The number of TRMs expressing either CD69 or CD103 was significantly higher in CLE lesions than in control skin; however, it was not significantly different between discoid lupus erythematosus and subacute CLE, or dependent on the presence of concomitant systemic lupus. Lesional severity was not correlated with an increase in TRMs in CLE. IFNα treatment induced a conspicuous increase in CD69 expression in skin-homing T cells, more profoundly in CD4+ T cells than in CD8+ T cells. CONCLUSIONS: Skin TRMs, either CD69 or CD103-positive cells, showed increased levels in the lesional skin of CLE, and IFNα increased the expression of CD69 in T cells.

Cutaneous, systemic features and laboratory characteristics of late- versus adult-onset systemic lupus erythematosus in 1006 Thai patients.

BACKGROUND: Age at disease onset may modulate systemic lupus erythematosus (SLE), but its relation to cutaneous/extracutaneous manifestation remains understudied. OBJECTIVE: To compare the cutaneous, systemic features, laboratory characteristics, and disease severity between late- and adult-onset SLE patients. METHODS: Analyses of the cutaneous, systemic involvement, laboratory investigations, SLE disease activity index 2000 (SLEDAI-2K), and disease damage were performed to compare between groups. RESULTS: Of 1006 SLE patients, 740 and 226 had adult- (15-50 years) and late-onset (>50 years), respectively. Among 782 with cutaneous lupus erythematosus (CLE), acute CLE (ACLE) and chronic CLE (CCLE) were more common in the adult- and late-onset SLE, respectively (p = 0.001). Multivariable logistic regression analysis demonstrated that male patients and skin signs, including papulosquamous subacute CLE, discoid lupus erythematosus, and lupus profundus, were associated with late-onset SLE (all p < 0.05). Late-onset SLE had lower lupus-associated autoantibodies, and systemic involvement (all p < 0.05). ACLE, CCLE, mucosal lupus, alopecia, and non-specific lupus were related to higher disease activity in adult-onset SLE (all p < 0.001). There was no difference in the damage index between the two groups. CONCLUSIONS: Late-onset SLE had a distinct disease expression with male predominance, milder disease activity, and lower systemic involvement. Cutaneous manifestations may hold prognostic values for SLE.

Subacute cutaneous lupus erythematosus triggered after measles vaccination.

Subacute cutaneous lupus erythematosus (SCLE) is a subtype of cutaneous lupus erythematosus that can be triggered by endogenous or exogenous factors. Among the exogenous factors are some medications, drugs, tobacco, infections, and vaccines. In this context, the benefits of vaccination are questioned because although it is important to prevent infections in immunosuppressed patients a theoretical risk of developing systemic lupus erythematosus (SLE) remains in these patients. This report presents a case of a previously healthy female patient who developed SCLE after measles vaccination and progressed to SLE and thereby suggests a possible trigger of the disease.

Characterization of autoantibodies and cytokines related to cutaneous lupus erythematosus.

OBJECTIVE: To investigate the profiles of anti-RPLP0, anti-galectin3 antibodies, interferon-α (IFN-α), interferon-λ1(IFN-λ1) and interleukin-17A/F(IL-17A/F) in the subtypes of cutaneous lupus erythematosus (CLE) including acute CLE (ACLE), subacute CLE (SCLE) and discoid lupus erythematosus (DLE). METHODS: Serum levels of autoantibodies and cytokines were determined by enzyme-linked immunoabsorbent assay (ELISA). Lupus lesions were evaluated by cutaneous lupus erythematosus disease area and severity index (CLASI). RESULTS: Serum anti-RPLP0, anti-galectin3 antibodies and IFN-λ1 were higher in systemic lupus erythematosus (SLE) patients with skin lesions than those without skin lesions, compared to healthy controls. IFN-α, IL-17A and IL-17F was elevated in all patients regardless of skin lesions. The two antibodies, IFN-α and IL-17A were positively correlated with the CLASI score in all patients with CLE. In addition, serum IL-17A was positively correlated to the CLASI score of ACLE, SCLE and DLE, while anti-RPLP0 and anti-galectin3 antibodies were only correlated to the score of SCLE and IL-17F to DLE. CONCLUSION: Serum anti-RPLP0, anti-galectin3 antibodies, IFN-α, IFN-λ1 and IL-17A/F are associated with the occurrence of lupus skin lesions regardless of the systemic complications, whereas the profiles of these inflammatory mediators vary with the subtypes of lupus skin lesions.

Oxidative DNA Damage Accelerates Skin Inflammation in Pristane-Induced Lupus Model.

Systemic Lupus Erythematosus (SLE) is a chronic inflammatory autoimmune disease in which type I interferons (IFN) play a key role. The IFN response can be triggered when oxidized DNA engages the cytosolic DNA sensing platform cGAS-STING, but the repair mechanisms that modulate this process and govern disease progression are unclear. To gain insight into this biology, we interrogated the role of oxyguanine glycosylase 1 (OGG1), which repairs oxidized guanine 8-Oxo-2'-deoxyguanosine (8-OH-dG), in the pristane-induced mouse model of SLE. Ogg1-/- mice showed increased influx of Ly6Chi monocytes into the peritoneal cavity and enhanced IFN-driven gene expression in response to short-term exposure to pristane. Loss of Ogg1 was associated with increased auto-antibodies (anti-dsDNA and anti-RNP), higher total IgG, and expression of interferon stimulated genes (ISG) to longer exposure to pristane, accompanied by aggravated skin pathology such as hair loss, thicker epidermis, and increased deposition of IgG in skin lesions. Supporting a role for type I IFNs in this model, skin lesions of Ogg1-/- mice had significantly higher expression of type I IFN genes (Isg15, Irf9, and Ifnb). In keeping with loss of Ogg1 resulting in dysregulated IFN responses, enhanced basal and cGAMP-dependent Ifnb expression was observed in BMDMs from Ogg1-/- mice. Use of the STING inhibitor, H151, reduced both basal and cGAMP-driven increases, indicating that OGG1 regulates Ifnb expression through the cGAS-STING pathway. Finally, in support for a role for OGG1 in the pathology of cutaneous disease, reduced OGG1 expression in monocytes associated with skin involvement in SLE patients and the expression of OGG1 was significantly lower in lesional skin compared with non-lesional skin in patients with Discoid Lupus. Taken together, these data support an important role for OGG1 in protecting against IFN production and SLE skin disease.

Cutaneous and systemic connections in lupus.

PURPOSE OF REVIEW: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with multiple manifestations, with a majority of SLE patients having cutaneous involvement. Despite ongoing research, the relationship between SLE and cutaneous lupus erythematosus (CLE) pathogeneses remains unknown. This review will compare advances in understanding the cause and pathogenesis of SLE and CLE. RECENT FINDINGS: Recently, mechanisms by which immune cell populations contribute to the pathogenesis of SLE and CLE have been queried. Studies have pointed to transitional B cells and B-cell activating factor (BAFF) signaling as potential drivers of SLE and CLE, with belimumab clinical data supporting these hypotheses. Ustekinumab trials and an exciting regulatory T cell (Treg) adoptive transfer in an SLE patient with cutaneous disease have suggested a role for T-cell-targeted therapies. The theory that neutrophil extracellular traps may be a source of autoantigens in SLE remains controversial, while neutrophils have been suggested as early drivers of cutaneous disease. Finally, plasmacytoid dendritic cells (pDCs) have been studied as a potential therapeutic target in SLE, and anti-blood DC antigen (anti-BDCA) antibody clinical trials have shown promise in treating cutaneous disease. SUMMARY: Although recent findings have contributed to understanding SLE and CLE pathogenesis, the mechanistic link between these diseases remains an area requiring further research.

Current Insights in Cutaneous Lupus Erythematosus Immunopathogenesis.

Cutaneous Lupus Erythematosus (CLE) is a clinically diverse group of autoimmune skin diseases with shared histological features of interface dermatitis and autoantibodies deposited at the dermal-epidermal junction. Various genetic and environmental triggers of CLE promote infiltration of T cells, B cells, neutrophils, antigen presenting cells, and NK cells into lesional skin. In this mini-review, we will discuss the clinical features of CLE, insights into CLE immunopathogenesis, and novel treatment approaches.

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.

Revisiting hydroxychloroquine and chloroquine for patients with chronic immunity-mediated inflammatory rheumatic diseases.

Hydroxychloroquine and chloroquine, also known as antimalarial drugs, are widely used in the treatment of rheumatic diseases and have recently become the focus of attention because of the ongoing COVID-19 pandemic. Rheumatologists have been using antimalarials to manage patients with chronic immune-mediated inflammatory rheumatic diseases for decades. It is an appropriate time to review their immunomodulatory and anti-inflammatory mechanisms impact on disease activity and survival of systemic lupus erythematosus patient, including antiplatelet effect, metabolic and lipid benefits. We also discuss possible adverse effects, adding a practical and comprehensive approach to monitoring rheumatic patients during treatment with these drugs.