Pyroptosis and its role in autoimmune skin disease.

Autoimmune skin disease is a kind of heterogeneous disease with complicated pathogenesis. Many factors such as genetic, infectious, environmental and even psychological factors may interact together to trigger a synergistic effect for the development of abnormal innate and adaptive immune responses. Although the exact mechanisms remain unclear, recent evidence suggests that pyroptosis plays a pivotal role in the development of autoimmune skin disease. The feature of pyroptosis is the first formation of pores in cellular membranes, then cell rupture and the release of intracellular substances and pro-inflammatory cytokines, such as interleukin-1 beta (IL-1ß) and IL-18. This hyperactive inflammatory programmed cell death damages the homeostasis of the immune system and advances autoimmunity. This review briefly summarises the molecular regulatory mechanisms of pyrin domain-containing protein 3 (NLRP3) inflammasome and gasdermin family, as well as the molecular mechanisms of pyroptosis, highlights the latest progress of pyroptosis in autoimmune skin disease, including systemic lupus erythematosus, psoriasis, atopic dermatitis and systemic scleroderma and attempts to identify its potential advantages as a therapeutic target or prognostic biomarker for these diseases.

The dualistic role of Lyn tyrosine kinase in immune cell signaling: implications for systemic lupus erythematosus.

Systemic lupus erythematosus (SLE, lupus) is a debilitating, multisystem autoimmune disease that can affect any organ in the body. The disease is characterized by circulating autoantibodies that accumulate in organs and tissues, which triggers an inflammatory response that can cause permanent damage leading to significant morbidity and mortality. Lyn, a member of the Src family of non-receptor protein tyrosine kinases, is highly implicated in SLE as remarkably both mice lacking Lyn or expressing a gain-of-function mutation in Lyn develop spontaneous lupus-like disease due to altered signaling in B lymphocytes and myeloid cells, suggesting its expression or activation state plays a critical role in maintaining tolerance. The past 30 years of research has begun to elucidate the role of Lyn in a duplicitous signaling network of activating and inhibitory immunoreceptors and related targets, including interactions with the interferon regulatory factor family in the toll-like receptor pathway. Gain-of-function mutations in Lyn have now been identified in human cases and like mouse models, cause severe systemic autoinflammation. Studies of Lyn in SLE patients have presented mixed findings, which may reflect the heterogeneity of disease processes in SLE, with impairment or enhancement in Lyn function affecting subsets of SLE patients that may be a means of stratification. In this review, we present an overview of the phosphorylation and protein-binding targets of Lyn in B lymphocytes and myeloid cells, highlighting the structural domains of the protein that are involved in its function, and provide an update on studies of Lyn in SLE patients.

Association of education attainment and risk of connective tissue diseases.

OBJECTIVE: We employed two-sample Mendelian randomization (MR) to assess the genetic causal relationship between educational attainment (EA) and risk of five common connective tissue diseases (CTDs). METHODS: Educational attainment (self-reported at age ≥30 years) was obtained from a meta-analysis of years of schooling in 766 345 participants of European ancestry from genome-wide association studies (GWAS). A total of 1265 signals associated with EA were identified. Genetic data for five CTDs [rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), polymyositis (PM), and dermatomyositis (DM)] were obtained from the FinnGen consortium. Two-sample MR analyses were performed separately for EA and the five CTDs. RESULTS: We found a negative causal relationship between EA and RA (ORIVW = 0.627, 95% CI = 0.537-0.732, p < .001), and SLE (ORIVW = 0.341, 95% CI = 0.123-0.944, p = .038). There were no genetic causal association between EA and SSc (ORIVW = 0.647, 95% CI = 0.351-1.195, p = .164), PM (ORIVW = 0.938, 95% CI = 0.320-2.746, p = .907), or DM (ORIVW = 0.754, 95% CI = 0.351-1.619, p = .468). None of the analyses revealed any horizontal pleiotropy or heterogeneity. CONCLUSION: Our findings indicated a potential causal association between EA and RA, SLE, emphasizing the need for further investigation and potential integration of EA into clinical practice to enhance treatment strategies.

Challenges and opportunities in access to care for systemic lupus erythematosus patients across Europe and worldwide.

SLE presents significant challenges for patients and health-care professionals (HCPs), both across Europe and worldwide. Improving health-care outcomes for patients with SLE requires a comprehensive understanding of patient disease pathways. In particular, the geographical distance between SLE patients and specialized care centres, combined with the scarcity of rheumatologists, exacerbates delays in diagnosis and management. Also, the initial SLE symptoms can often be non-specific, and providing guidelines for primary HCPs and other non-specialists is extremely important. Improvement in access to treatment is also important, with several recently approved therapies for SLE not being available in several European countries and many low- and middle-income countries (LMICs). Furthermore, in the LMICs in which these treatments are available, they are not always covered by the health-care system, making their access almost impossible for those of lower socio-economic status. A number of provisions are already in place within the European Union, to improve access to care for patients with rare and complex diseases, including those with SLE. In particular, European Reference Networks (ERNs), such the ERN for Autoimmune Diseases ReCONNET, are virtual networks involving HCPs across Europe with the aim of improving the care of patients with rare and complex diseases that require highly specialized treatment and a concentration of knowledge and resources. In addition, lupus patient organizations such as Lupus Europe play a crucial role in raising awareness of SLE and advocating for improved access to care. Together, we can work towards a future where all people living with lupus receive the comprehensive and timely care they deserve.

Frequency and predictors for early-achieved lupus low disease activity state in systemic lupus erythematosus patients treated with telitacicept or belimumab: A real-life, single-center observational study.

Objective: To collect real-world data regarding the attainment of the early-achieved lupus low disease activity state (LLDAS) in systemic lupus erythematosus (SLE) patients receiving telitacicept or belimumab treatment, and identify factors predictive of target achievement. Methods: Eighty-seven SLE patients who received telitacicept (N=42) or belimumab (N=45) were retrospectively reviewed in this observational study. Clinical and laboratory data, disease activity assessment, and glucocorticoid dosage were collected for analysis. Achieving LLDAS at least once within 24 weeks post-treatment was considered as early-achieved LLDAS. Multivariate regression was used to assess baseline predictive variables for early-achieved LLDAS. Subgroup analysis and interaction tests were also performed to examine the robustness of the results across different sets of baseline characteristics. Prognostic stratification for early-achieved LLDAS was established based on the identified risk factors. Results: During the 24-week follow-up period, LLDAS was achieved by at least one time in 49.43% (43/87) of the patients, with sustained achievement through week 24 observed in 36 out of these 43 patients (83.27%). Multivariate analysis revealed that early achievement of LLDAS was particularly observed in patients with higher baseline lymphocyte counts [HR=1.79, 95% CI (1.19-2.67), P=0.005]and serum albumin levels [HR=1.06, 95% CI (1.003-1.12), P=0.039]. Conversely, hematological involvement [HR=0.48, 95% CI (0.24-0.93), P=0.031] predicted lower attainment of early-achieved LLDAS. The use of telitacicept was associated with a reduced risk of failing to attain early achievement of LLDAS [HR=2.55, 95% CI (1.36-4.79), P=0.004]. Subgroup analyses and interaction tests showed a stable relationship between the telitacicept use and LLDAS achievement. The results remained consistent across all subgroup analyses. Significant differences (P<0.001) were observed in the Kaplan-Meier estimates for LLDAS among risk groups based on the number of identified risk factors. Conclusion: The achievement of LLDAS is attainable in the management of SLE patients undergoing treatment with telitacicept or belimumab in real-life clinical practice. Baseline lymphocyte counts, serum albumin levels, hematological involvement and the use of telitacicept serve as robust predictors for early-achieved LLDAS, helping to identify patients who are likely to benefit on the treatment.

[Humoral Immunity Abnormalities in Advanced Maternal-Age Women With Recurrent Spontaneous Abortion: A Single Center Study]. / é«˜é¾„å¤å‘æ€§æµäº§æ‚£è€ ä½“æ¶²å ç–«å¼‚å¸¸çš„å•ä¸­å¿ƒç ”ç©¶.

Objective: To determine the humoral immunity in advanced maternal-age women with recurrent spontaneous abortion (RSA). Methods: A retrospective study was performed between January 2022 and October 2023 in the Department of Reproductive Immunity of Shanghai First Maternity and Infant Hospital. Women with RSA were recruited and multiple autoantibodies were tested. Multivariate logistic regression was performed to compare the associations between different age groups (20 to 34 years old in the low maternal-age group and 35 to 45 years in the advanced maternal-age group) and multiple autoantibodies, while controlling for three confounding factors, including body mass index (BMI), previous history of live birth, and the number of spontaneous abortions. Then, we investigated the differences in the humoral immunity of advanced maternal-age RSA women and low maternal-age RSA women. Result: A total of 4009 women with RSA were covered in the study. Among them, 1158 women were in the advanced maternal-age group and 2851 women were in the low maternal-age group. The prevalence of antiphospholipid syndrome, systemic lupus erythematosus, Sjogren's syndrome, rheumatoid arthritis, and undifferentiated connective tissue disease was 15.6% and 14.1%, 0.0% and 0.1%, 0.9% and 0.9%, 0.3% and 0.0%, and 23.7% and 22.6% in the advanced maternal-age group and low maternal-age group, respectively, showing no statistical difference between the two groups. The positive rates of antiphospholipid antibodies (aPLs), antinuclear antibody (ANA), extractable nuclear antigen (ENA) antibody, anti-double stranded DNA (dsDNA) antibody, anti single-stranded DNA (ssDAN) antibody, antibodies against alpha-fodrin (AAA), and thyroid autoimmunity (TAI) were 19.1% and 19.5%, 6.6% and 6.6%, 9.2% and 10.5%, 2.0% and 2.0%, 2.2% and 1.2%, 5.1% and 4.9%, and 17.8% and 16.8%, respectively. No differences were observed between the two groups. 1.6% of the women in the advanced maternal-age group tested positive for lupus anticoagulant (LA), while 2.7% of the women in the low maternal-age group were LA positive, with the differences being statistically significant (odds ratio=0.36, 95% confidence interval: 0.17-0.78). In the 4008 RSA patients, the cumulative cases tested positive for the three antibodies of the aPLs spectrum were 778, of which 520 cases were positive for anti-ß2 glycoprotein Ⅰ antibodies (ß2GPⅠ Ab)-IgG/IgM, 58 were positive for aCL-IgG/IgM, 73 were positive for LA, 105 were positive for both ß2GPⅠ Ab-IgG/IgM and aCL-IgG/IgM, 17 were positive for both ß2GPⅠ Ab-IgG/IgM and LA, 2 were positive for both aCL-IgG/IgM and LA, and 3 were positive for all three antibodies. Conclusion: Our study did not find a difference in humoral immunity between RSA women of advanced maternal age and those of low maternal age.

Referrals for rheumatologic evaluation following a positive antinuclear antibody test result. A cross-sectional single center Brazilian study.

BACKGROUND: In general, patients are referred for rheumatological evaluation due to isolated laboratory abnormalities, especially antinuclear antibody (ANA) positivity, with the risk of more severe patients remaining on the waiting list for longer than desired. The aim of this study was to analyze the demographic, clinical, and laboratory information of patients referred to a specialized rheumatological care unit because of positive antinuclear antibody. METHODS: This is a retrospective study of 99 out of 1670 patients seen by the same rheumatologist between 01/01/2011 and 01/01/2019. Patients whose referrals were exclusively due to the ANA test result and the specialist's final diagnosis being "abnormal finding of serum immunological test" (ICD-10 R769) were included. Sociodemographic, clinical, and laboratory information were extracted from the consulting rheumatologist's chart. Descriptive statistics were used for data analysis. RESULTS: A total of 99 patients were included, most of whom were female (84.8%) with a median age of 49 years. At the moment of specialist's appointment, 97 patients (97.9%) repeated the ANA test, and 77 patients remained positive. Of these, only 35 (35.35%) were in a high titer range (greater than or equal to 1:320). Complete blood count for cytopenia's investigation was not performed in a high percentage of patients (22.2%), as well as urinalysis (31.3%). In addition, more than 70% of patients score 0 to 1 classification criteria for Systemic Lupus Erythematosus, according to SLE - ACR 1987 (American College of Rheumatology) and SLICC 2012 (Systemic Lupus International Collaborating Clinics). CONCLUSIONS: Most patients are still referred for specialized evaluation due to the misinterpretation of laboratory tests that were inappropriately requested in patients without clinical evidence of autoimmune rheumatic disease.

Harnessing cGAS-STING axis for therapeutic benefits in systemic lupus erythematosus.

The cyclic GMP-AMP synthase (cGAS), a prominent intracellular DNA sensor in mammalian cells, controls the innate immune response and the stimulator of interferon genes (STING)-mediated synthesis of pro-inflammatory cytokines, such as type-I interferon (IFN-I). For decades, IFN-I has been hypothesized to be essential in the development of systemic lupus erythematosus (SLE), a chronic multisystem autoimmunity characterized by immune complex (IC) deposition in small vessels. Recent findings revealed that the activation of the cGAS-STING pathway by self-DNA would propagate the autoimmune responses via upregulating IFN-I production in SLE. In this review, we aimed to provide a comprehensive outlook of the role of the cGAS-STING pathway in SLE pathobiology, as well as, a better understanding of current therapeutic opportunities targeting this axis.

Outcome clusters and their stability over 1 year in patients with SLE: self-reported and performance-based cognitive function, disease activity, mood and health-related quality of life.

OBJECTIVE: To determine if self-reported fatigue, anxiety, depression, cognitive difficulties, health-related quality of life, disease activity scores and neuropsychological battery (NB) cluster into distinct groups in patients with SLE based on symptom intensity and if they change at 1-year follow-up. METHODS: This is a retrospective analysis of consecutive consenting patients, followed at a single centre. Patients completed a comprehensive NB, the Beck Anxiety Inventory, Beck Depression Inventory, Fatigue Severity Scale, Short-Form Health Survey Physical Component Summary and Mental Component Summary scores and the Perceived Deficits Questionnaire. Disease activity was assessed by Systemic Lupus Erythematosus Disease Activity Index 2000. Ward's method was used for clustering and principal component analysis was used to visualise the number of clusters. Stability at 1 year was assessed with kappa statistic. RESULTS: Among 142 patients, three clusters were found: cluster 1 had mild symptom intensity, cluster 2 had moderate symptom intensity and cluster 3 had severe symptom intensity. At 1-year follow-up, 49% of patients remained in their baseline cluster. The mild cluster had the highest stability (77% of patients stayed in the same cluster), followed by the severe cluster (51%), and moderate cluster had the lowest stability (3%). A minority of patients from mild cluster moved to severe cluster (19%). In severe cluster, a larger number moved to moderate cluster (40%) and fewer to mild cluster (9%). CONCLUSION: Three distinct clusters of symptom intensity were documented in patients with SLE in association with cognitive function. There was a lower tendency for patients in the mild and severe clusters to move but not moderate cluster over the course of a year. This may demonstrate an opportunity for intervention to have moderate cluster patients move to mild cluster instead of moving to severe cluster. Further studies are necessary to assess factors that affect movement into moderate cluster.

Real-world effectiveness of belimumab in patients with lupus in China: RELIABLE observational cohort study protocol.

INTRODUCTION: The efficacy of belimumab in SLE has been demonstrated in randomised clinical trials, and its real-world effectiveness has been shown in studies in several countries. While belimumab was approved for treating SLE in China in 2019, data on its benefit in clinical practice are limited. This study will evaluate belimumab's effectiveness in China, using practical clinical measures, such as Lupus Low Disease Activity State (LLDAS), to add to the body of real-world evidence. METHODS AND ANALYSIS: The Real-world Effectiveness of beLImumAB in patients with systemic Lupus Erythematosus in China (RELIABLE) is an ambidirectional, observational descriptive cohort study across approximately 15 centres in China. Adults with SLE newly initiating belimumab with ≥1 measure of all five LLDAS components (SLE Disease Activity Index-2000; no new lupus disease activity; Physician Global Assessment; prednisolone-equivalent dose; immunosuppressants/biologics use) in the 3 months preceding belimumab initiation (index date) will be eligible and retrospectively and/or prospectively enrolled, depending on data availability. The retrospective follow-up will be ≤6 months, and retrospective and prospective patients will have a maximum 24-month follow-up. The primary objectives will be to describe the proportion of patients achieving LLDAS at 12 and 24 months post-index. The key secondary objective will be to describe the proportion of patients achieving LLDAS and each component at 3, 6, 9 and 18 months post-index. All data will be analysed descriptively; a statistical estimand will be applied to account for intercurrent events expected in a real-world setting. ETHICS AND DISSEMINATION: This study will comply with all applicable laws regarding patient privacy; institutional review board approval will be obtained before the study commencement. CONCLUSIONS: This study will evaluate belimumab's effectiveness in patients with SLE initiating belimumab in clinical practice in China. Using LLDAS will provide clinicians with valuable insights into the impact of belimumab on the treat-to-target strategy with a relevant measure that can be repeated across the clinical practice.

Impact of the COVID-19 pandemic on psychosocial health in rheumatic patients: A longitudinal study.

AIM: To describe the impact of the COVID-19 on the psychosocial health of patients with rheumatoid arthritis (RA), spondyloarthritis (SpA), and systemic lupus erythematosus (SLE). DESIGN: Longitudinal observational study of a series of patients with rheumatic disease. METHODS: The main outcome measure was impairment of the ability to participate in social activities, as measured using the PROMIS-APS instrument Short Form-8a. We evaluated social activities in various settings and performed a multivariate analysis to study the association between worsening of social participation during the COVID-19 pandemic and implicated factors. RESULTS: One hundred and twenty-five patients had completed the prospective follow-up: 40 with AR (32%), 42 with SpA (33.6%), and 43 with SLE (34.4%). Overall, poorer mean PROMIS scores were recorded after the COVID-19 pandemic for: satisfaction with social roles (p=0.029), depression (p=0.039), and ability to participate in social activities (p=0.024). The factors associated with ability to participate in social activities after the COVID-19 pandemic were older age (ß=-0.215; p=0.012), diagnosis of SLE (ß=-0.203; p=0.015), depression (ß=-0.295; p=0.003) and satisfaction with social roles (ß=0.211; p=0.037). CONCLUSION: The ability to participate in social activities after the COVID-19 pandemic is affected in patients with rheumatic disease, especially in SLE.

Deletion of the Mitochondrial Membrane Protein Fam210b Is Associated with the Development of Systemic Lupus Erythematosus.

Mitochondrial dysfunction has been increasingly recognized as a trigger for systemic lupus erythematosus (SLE). Recent bioinformatics studies have suggested Fam210b as a significant candidate for the classification and therapeutic targeting of SLE. To experimentally prove the role of Fam210b in SLE, we constructed Fam210b knockout (Fam210b-/-) mice using the CRISPR-Cas9 method. We found that approximately 15.68% of Fam210b-/- mice spontaneously developed lupus-like autoimmunity, which was characterized by skin ulcerations, splenomegaly, and an increase in anti-double-stranded DNA (anti-dsDNA) IgG antibodies and anti-nuclear antibodies(ANA). Single-cell sequencing showed that Fam210b was mainly expressed in erythroid cells. Critically, the knockout of Fam210b resulted in abnormal erythrocyte differentiation and development in the spleens of mice. Concurrently, the spleens exhibited an increased number of CD71+ erythroid cells, along with elevated levels of reactive oxygen species (ROS) in the erythrocytes. The co-culture of CD71+ erythroid cells and lymphocytes resulted in lymphocyte activation and promoted dsDNA and IgG production. In summary, Fam210b knockout leads to a low probability of lupus-like symptoms in mice through the overproduction of ROS in CD71+ erythroid cells. Thus, Fam210b reduction may serve as a novel key marker that triggers the development of SLE.

Food consumption, physical activity and aerobic capacity in systemic lupus erythematosus patients with high cardiovascular risk.

Systemic Lupus Erythematosus (SLE) is a chronic, autoimmune and multisystemic rheumatic disease. Patients with SLE have decreased functional and aerobic capacity, as well as increased prevalence of Cardiovascular Diseases (CVD), which are the primary causes of morbimortality in this condition. Dietary intake and physical activity are well-known modifiable cardiovascular risk factors. The aim of this study is to describe food consumption, sedentary behavior, physical activity level, and functional and aerobic capacity in a sample of SLE patients with high cardiovascular risk. This was a cross-sectional study in which patients were assessed for (i) Demographic, anthropometric, and disease-related parameters; (ii) Food consumption; (iii) Physical activity level and sedentary behavior; (iv) Functional and aerobic capacity. Patients averaged 41.7 ± 9 years, and most were classified as overweight/obese (87%). Average macronutrient intake was within recommendations; however, fiber (16 ± 9g) and calcium (391 ± 217 mg) intakes were below, and sodium intake (2.9 ± 1.3 mg) was above recommendations. Besides, food consumption assessed by the Nova system showed a predominance of unprocessed foods (43.8 ± 14.0%TEI), although ultraprocessed food intake (20.0 ± 13.9%TEI) was slightly higher than that seen in the Brazilian population. Patients also exhibited high sedentary behavior (8.2 ± 2.2h) and only eighteen participants reached the minimum recommended amount of moderate-to-vigorous physical activity. Overall, patients had a low functional and aerobic capacity compared to the general population. Data from this study may help design dedicated clinical trials aiming to investigate the effects of lifestyle intervention to mitigate CVD in SLE.

Sex-specific differences in SLE - Significance in the experimental setting of inflammation and kidney damage in MRL-Faslpr mice.

Animal models are an important tool in the research of chronic autoimmune diseases, like systemic lupus erythematosus (SLE). MRL-Faslpr mice are one of different lupus models that develop spontaneously an SLE-like disease with autoantibodies and immune complex deposition that leads into damage of different organs. In contrast to human SLE, both sexes of MRL-Faslpr mice develop a similar autoimmune disease. Due to the sex bias in human and the delayed disease progression in male MRL-Faslpr mice, the majority of studies have been performed in female mice. To determine the suitability of male MRL-Faslpr mice for SLE research, especially with regard to the 3 R-principle and animal welfare, analyses of phenotype, inflammation and damage with focus on kidney and spleen were performed in mice of both sexes. Female mice developed lymphadenopathy and skin lesions earlier as males. At an age of 3.5 month, more immune cells infiltrated kidney and spleen in females compared to males. At the age of 5 months, however, substantially less sex-specific differences were detected. Since other studies have shown differences between both sexes on other manifestations like autoimmune pancreatitis and Sjögren syndrome in MRL-Faslpr mice, the use of male mice as part of 3 R-principle and animal welfare must be carefully considered.

[Rare Autoimmune Diseases Role of Genetics - Example of Systemic Lupus Erythematosus]. / Maladies auto-immunes rares : place de la génétique, exemple du lupus systémique.

Systemic lupus erythematosus (SLE) presents a complex clinical landscape with diverse manifestations, suggesting a multifactorial etiology. However, the identification of rare monogenic forms of the disease has shed light on specific genetic defects underlying SLE pathogenesis, offering valuable insights into its underlying mechanisms and clinical heterogeneity. By categorizing these monogenic forms based on the implicated signaling pathways, such as apoptotic body clearance, type I interferon signaling, JAK-STAT pathway dysregulation, innate immune receptor dysfunction and lymphocytic abnormalities, a more nuanced understanding of SLE's molecular basis emerges. Particularly in pediatric populations, where monogenic forms are more prevalent, routine genetic testing becomes increasingly important, with a diagnostic yield of approximately 10% depending on the demographic and methodological factors involved. This approach not only enhances diagnostic accuracy but also informs personalized treatment strategies tailored to the specific molecular defects driving the disease phenotype.

Title: Maladies auto-immunes rares : place de la génétique, exemple du lupus systémique. Abstract: Le lupus érythémateux systémique (LES) est une maladie auto-immune chronique caractérisée par une grande hétérogénéité clinique. Certaines formes rares de LES sont causées par des mutations génétiques spécifiques, contrairement à la nature multifactorielle généralement associée à la maladie. Ces formes monogéniques ont été décrites particulièrement dans les cas de LES à début pédiatrique. Leur découverte a permis une meilleure compréhension de la physiopathologie du LES, mettant en lumière la grande complexité des présentations cliniques. Nous proposons ici une classification basée sur les voies de signalisation sous-jacentes, impliquant la clairance des corps apoptotiques et des complexes immuns, les interférons de type I, les voies JAK-STAT, les récepteurs de l'immunité innée et les fonctions lymphocytaires. Dans les formes pédiatriques, un test génétique devrait être proposé systématiquement avec un rendement diagnostique autour de 10 % selon la population et les approches utilisées.

Lupus IgA1 autoantibodies synergize with IgG to enhance plasmacytoid dendritic cell responses to RNA-containing immune complexes.

Autoantibodies to nuclear antigens are hallmarks of systemic lupus erythematosus (SLE) where they contribute to pathogenesis. However, there remains a gap in our knowledge regarding how different isotypes of autoantibodies contribute to this autoimmune disease, including the production of the critical type I interferon (IFN) cytokines by plasmacytoid dendritic cells (pDCs) in response to immune complexes (ICs). We focused on IgA, which is the second-most prevalent isotype in serum and, along with IgG, is deposited in glomeruli in individuals with lupus nephritis. We show that individuals with SLE have serum IgA autoantibodies against most nuclear antigens, correlating with IgG against the same antigen. We investigated whether IgA autoantibodies against a major SLE autoantigen, Smith ribonucleoprotein (Sm/RNP), played a role in IC activation of pDCs. We found that pDCs expressed the IgA-specific Fc receptor, FcαR, and IgA1 autoantibodies synergized with IgG in RNA-containing ICs to generate robust primary blood pDC IFN-α responses in vitro. pDC responses to these ICs required both FcαR and FcγRIIa, showing synergy between these Fc receptors. Sm/RNP IC binding to and internalization by pDCs were greater when ICs contained both IgA1 and IgG. Circulating pDCs from individuals with SLE had higher binding of IgA1-containing ICs and higher expression of FcαR than pDCs from healthy control individuals. Although pDC FcαR expression correlated with the blood IFN-stimulated gene signature in SLE, Toll-like receptor 7 agonists, but not IFN-α, up-regulated pDC FcαR expression in vitro. Together, we show a mechanism by which IgA1 autoantibodies contribute to SLE pathogenesis.

tRF-His-GTG-1 enhances NETs formation and interferon-α production in lupus by extracellular vesicle.

BACKGROUND: Hyperactive neutrophil extracellular traps (NETs) formation plays a crucial role in active severe systemic lupus erythematosus (SLE). However, what triggers the imbalance in dysregulated NETs formation in SLE is elusive. Transfer RNA-derived small RNAs (tsRNAs) are novel non-coding RNAs, which participate in various cellular processes. We explore the role of tsRNAs on NETs formation in SLE. METHODS: We analyzed the levels of NETs DNA and platelet-derived extracellular vesicles (pEVs) from 50 SLE patients and 20 healthy control subjects. The effects of pEVs on NETs formation were evaluated by using immunofluorescence assay and myeloperoxidase-DNA PicoGreen assay. The regulatory mechanism of pEVs on NETs formation and inflammatory cytokines production were investigated using an in vitro cell-based assay. RESULTS: Increased circulating NETs DNA and pEVs were shown in SLE patients and were associated with disease activity (P < 0.005). We demonstrated that SLE patient-derived immune complexes (ICs) induced platelet activation, followed by pEVs release. ICs-triggered NETs formation was significantly enhanced in the presence of pEVs through Toll-like receptor (TLR) 8 activation. Increased levels of tRF-His-GTG-1 in pEVs and neutrophils of SLE patients were associated with disease activity. tRF-His-GTG-1 interacted with TLR8 to prime p47phox phosphorylation in neutrophils, resulting in reactive oxygen species production and NETs formation. Additionally, tRF-His-GTG-1 modulated NF-κB and IRF7 activation in neutrophils upon TLR8 engagement, resulting IL-1ß, IL-8, and interferon-α upregulation, respectively. CONCLUSIONS: The level of tRF-His-GTG-1 was positively correlated with NETs formation in SLE patients; tRF-His-GTG-1 inhibitor could efficiently suppress ICs-triggered NETs formation/hyperactivation, which may become a potential therapeutic target.

Neutrophils and platelets are key members in the immunopathogenesis of SLE. EVs play a key role in intercellular communication. Abnormal NETs formation promotes vascular complications and organ damage in SLE patients. tsRNA is a novel regulatory small non-coding RNA and participates in diverse pathological processes. Herein, we showed that SLE patient-derived ICs activates platelets directly, followed by intracellular tRF-His-GTG-1 upregulation, which is loaded into pEVs. The pEV-carried tRF-His-GTG-1 could interact with TLR8 in neutrophils, followed by activation of the downstream signaling pathway, including p47phox-NOX2-ROS, which causes NETs enhancement, while IRF7 promotes the expression of IFN-α. The tRF-His-GTG-1 inhibitor could suppress efficiently SLE ICs-induced NETs formation and pEVs primed NETs enhancement. This study offers new molecular machinery to explain the association between the platelets-derived tsRNAs, pEVs, and hyperactive NETs formation in lupus. tRF-His-GTG-1 may serve as a potential therapeutic target and help to advance our understanding of tsRNAs in SLE pathogenesis.

Multidisciplinary consensus on the use of hydroxychloroquine in patients with systemic lupus erythematosus.

BACKGROUND: Hydroxychloroquine (HCQ) is the first-line treatment for systemic lupus erythematosus (SLE); however, there is heterogeneity in its clinical use. This consensus aims to bridge the gap in SLE treatment by providing practical and valuable recommendations for health professionals. METHODS: The methodology used is based on a systematic literature review and a nominal group technique (NGT). A ten-member scientific committee formulated eight clinically relevant questions. First, a systematic review was conducted to identify the available evidence, which the scientific committee evaluated to developed recommendations based on their expertise, achieving consensus through NGT. RESULTS: 1673 titles and abstracts were screened, and 43 studies were included for meeting the inclusion criteria. The scientific committee established 11 recommendations for HCQ use in initiation, maintenance, and monitoring, considering benefits and potential adverse effects of HCQ. Unanimous agreement was achieved on all recommendations. CONCLUSIONS: The available evidence supports HCQ's effectiveness and safety for SLE. Individualized assessment of the initial HCQ dose is important, especially in situations requiring dose reduction or discontinuation. This risk-benefit assessment, specifically focusing on the balance between retinal toxicity and the risk of SLE relapse, should guide decisions regarding medication withdrawal, considering disease activity, risk factors, and HCQ potential benefits. Close monitoring is essential for optimal disease management and minimize potential risks, such as QT prolongation or retinal toxicity.

Correction of omega-3 fatty acid deficiency and improvement in disease activity in patients with systemic lupus erythematosus treated with krill oil concentrate: a multicentre, randomised, double-blind, placebo-controlled trial.

OBJECTIVE: Omega-3 polyunsaturated fatty acids (PUFAs) play a critical role in regulating inflammation and lipid metabolism. This study sought to ascertain the frequency of omega-3 deficiency in patients with SLE and investigate whether supplementation with krill oil concentrate (KOC) could replenish omega-3 levels and decrease SLE disease activity. METHODS: A multicentre, randomised, double-blind, placebo-controlled trial was conducted in adult patients with active SLE. Eligible patients were randomised to receive 4 g/day KOC or placebo (vegetable oil mixture) for the first 24 weeks, and thereafter patients could opt to enter an open-label extension. The primary end point was improvement of the red blood cell Omega-3 Index from baseline to week 24. Changes in clinical features, including SLE Disease Activity Index 2000 (SLEDAI-2K) disease activity scores, were also monitored. RESULTS: Seventy-eight patients met eligibility criteria and were randomised to a treatment group (n=39 per group). The baseline Omega-3 Index in the total SLE cohort was a mean 4.43% (±SD 1.04%). After 4 weeks of KOC treatment, the Omega-3 Index rapidly increased to 7.17%±1.48% (n=38) and after 24 weeks to 8.05%±1.79% (n=25) (each p<0.001 vs baseline), whereas no significant change from baseline was noted in patients receiving placebo. Increases in the Omega-3 Index in KOC-treated patients persisted through week 48. After patients switched from placebo to KOC at 24 weeks, the mean Omega-3 Index showed a rapid and significant increase (from 4.63%±1.39% at week 24 (n=26) to 7.50%±1.75% at week 48 (n=12); p<0.001). Although there were no changes in disease activity in the study population overall, SLEDAI-2K scores decreased significantly in the KOC group during the 24-week randomised period among those who had high disease activity at baseline (SLEDAI-2K ≥9) (p=0.04, p=0.02 and p=0.01 vs placebo at 4, 8 and 16 weeks, respectively; n=9 per group). KOC was well-tolerated, with no significant safety concerns. CONCLUSION: KOC corrected omega-3 deficiency in patients with SLE. Supplementation with KOC was safe and decreased disease activity in those with more active disease. These findings warrant further evaluation of omega-3 fatty acid supplementation with KOC in the management of SLE. TRIAL REGISTRATION NUMBER: NCT03626311.

[Clinical characteristics and labial gland pathological features in children with systemic lupus erythematosus complicated by Sjögren's syndrome]. / å„¿ç«¥ç³»ç»Ÿæ€§çº¢æ–‘ç‹¼ç–®åˆå¹¶å¹²ç‡¥ç»¼åˆå¾çš„ä¸´åºŠç‰¹ç‚¹åŠå”‡è ºç— ç†ç‰¹å¾åˆ†æž.

OBJECTIVES: To study the clinical manifestations, laboratory features, and labial gland pathological features in children with systemic lupus erythematosus (SLE) complicated by Sjögren's syndrome (SS). METHODS: A retrospective analysis was conducted on 102 children with SLE who underwent labial gland biopsies at Renji Hospital, Shanghai Jiao Tong University School of Medicine from January 2013 to December 2022. The children were divided into two groups based on the presence of SS: the SLE with SS group (SLE-SS; 60 children) and the SLE-only group (42 children). According to the focus score (FS) of the labial glands, children in the SLE-SS group were further subdivided into FS≥4 subgroup (26 children) and FS<4 subgroup (34 children). The clinical data of the groups were compared. RESULTS: Compared to the SLE-only group, children in the SLE-SS group had less skin and mucosal involvement, were more likely to have positive anti-SSA and anti-SSB antibodies, and had higher levels of rheumatoid factor (P<0.05). There was no significant difference in treatment protocols between the two groups (P>0.05). Compared to the FS<4 subgroup, the FS≥4 subgroup had more frequent musculoskeletal involvement (P<0.05), but there was no significant difference in SLE disease activity or other major organ involvement between the subgroups (P>0.05). CONCLUSIONS: Children with SLE complicated by SS are less likely to have skin and mucous membrane involvement and exhibit specific serological characteristics. The SLE-SS children with an FS≥4 are more likely to experience musculoskeletal involvement. However, FS is not associated with disease activity or other significant organ damage.