Systemic lupus erythematosus

Emerging concepts and treatments in autoinflammatory interferonopathies and monogenic systemic lupus erythematosus

Over the past two decades, the number of genetically defined autoinflammatory interferonopathies has steadily increased. Aicardi-Goutières syndrome and proteasome-associated autoinflammatory syndromes (PRAAS, also known as CANDLE) are caused by genetic defects that impair homeostatic intracellular nucleic acid and protein processing respectively. Research into these genetic defects revealed intracellular sensors that activate type I interferon production. In SAVI and COPA syndrome, genetic defects that cause chronic activation of the dinucleotide sensor stimulator of interferon genes (STING) share features of lung inflammation and fibrosis; and selected mutations that amplify interferon-α/β receptor signalling cause central nervous system manifestations resembling Aicardi-Goutières syndrome. Research into the monogenic causes of childhood-onset systemic lupus erythematosus (SLE) demonstrates the pathogenic role of autoantibodies to particle-bound extracellular nucleic acids that distinguishes monogenic SLE from the autoinflammatory interferonopathies. This Review introduces a classification for autoinflammatory interferonopathies and discusses the divergent and shared pathomechanisms of interferon production and signalling in these diseases. Early success with drugs that block type I interferon signalling, new insights into the roles of cytoplasmic DNA or RNA sensors, pathways in type I interferon production and organ-specific pathology of the autoinflammatory interferonopathies and monogenic SLE, reveal novel drug targets that could personalize treatment approaches.

Downregulated YTHDF2 expression in systemic lupus erythematosus is associated with inflammatory and neutrophil cytokine production

OBJECTIVES

An increasing body of evidence suggests that N6-methyladenosine (m6A) plays a crucial role in the etiology of SLE. We focused on YTHDF2 expression in neutrophils and the relationship between YTHDF2 and the pathogenesis of SLE.

METHODS

Sixty-one patients with SLE and 48 healthy controls (HC) were recruited, and their clinical characteristics were recorded. The mRNA levels of m6A "writers" (METTL3, METTL14, WTAP), "erasers" (FTO and ALKBH5), "readers" (YTHDF2), and inflammatory factors (interleukin-1β, interleukin-6, interleukin-8, and TNF-α) in neutrophils were determined by reverse transcription-quantitative PCR. The protein of YTHDF2 was determined by Western blotting. The correlations between the YTHDF2 in neutrophils of SLE patients and clinical features were examined by Spearman's method. YTHDF2 and TNF-α expression in neutrophils were examined after stimulation by SLE serums.

RESULTS

The mRNA expression of YTHDF2 in neutrophils was significantly decreased, and the protein level of YTHDF2 in neutrophils was decreased. The mRNA expression of YTHDF2 in neutrophils correlated with L% (rs = 0.5796, P < 0.0001), LMR (rs = 0.3524, P = 0.0062), WBC (rs =  - 0.3186, P = 0.0123), N (rs =  - 0.4141, P = 0.0010), N% (rs =  - 0.4813, P < 0.0001), NLR (rs =  - 0.5301, P < 0.0001), dNLR (rs =  - 0.4945, P < 0.0001), and SII (rs =  - 0.3930, P = 0.0019), which were suggested as the inflammatory conditions of SLE. In addition, the mRNA expression of TNF-α in neutrophils was significantly increased in SLE patients. Further analysis revealed that the mRNA expression of YTHDF2 in neutrophils was inversely correlated with TNF-α in SLE. Neutrophils from health control were significantly downregulated in their YTHDF2 expression and upregulated in their TNF-α expression following stimulation by serum from SLE patients.

CONCLUSION

This study indicates that the levels of YTHDF2 in peripheral blood neutrophils may be involved in the pathogenesis of SLE and could be a novel target for diagnosis and therapy. Key points • The mRNA expression of YTHDF2 in neutrophils of SLE and described that decreased mRNA of YTHDF2 in neutrophils correlated with L%, LMR, WBC, N, N%, NLR, dNLR, and SII. • The mRNA expression of TNF-α in neutrophils was significantly increased and correlated with YTHDF2 in SLE patients. • Neutrophils from health control were significantly downregulated in their YTHDF2 expression and upregulated in their TNF-α expression following stimulation by serum from SLE patients.

The 100 top-cited studies in systemic lupus erythematosus: A bibliometric analysis

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory tissue disease. In view of the explosive growth in research on SLE, bibliometrics was performed to evaluate the 100 top-cited papers in this realm. We performed the search with terms "systemic lupus erythematosus" the Web of Science Core Collection database on May 3, 2023. Relevant literatures were screened. Data were extracted and analyzed by SPSS. The citations of 100 top-cited SLE studies spanned from 472 to 13,557. Most studies (60 out of 100) were conducted in the United States. Total citation times were positively associated with ACY, which was negatively correlated with the length of time since publication. Approximately half of the studies focused on the underlying mechanisms of SLE. New biologic therapies garnered attention and development. Our findings provide valuable insights into the developments in crucial areas of SLE and shed contributions to future studies.

KLF2 controls the apoptosis of neutrophils and is associated with disease activity of systemic lupus erythematosus

BACKGROUND

Neutropenia is more common in patients with systemic lupus erythematosus (SLE) and is a major cause of life-threatening infections. The increased apoptosis of neutrophils is likely to be an essential cause of neutropenia in SLE. However, the detailed mechanisms of increased neutrophil apoptosis in SLE remain unknown. This study focused on the role of Krüppel-like factor 2 (KLF2) in the regulation of neutrophil apoptosis and its association with SLE disease activity.

METHODS

The levels of KLF2 in neutrophils from SLE patients and healthy controls (HCs) were detected by RT-PCR and western blot. The relationship between the levels of KLF2 and the apoptosis levels of neutrophils in SLE patients was analyzed. The KLF2 inhibitor Geranylgeranyl pyrophosphate (GGPP) and the KLF2 inducer geranylgeranyl transferase inhibitor (GGTI-298) were used to incubate with neutrophils to investigate the role of KLF2 in the regulation of neutrophil apoptosis. To clarify whether serum from SLE patients affects neutrophil KLF2 expression and apoptosis, sera from SLE patients were collected and used to incubate with neutrophils from HCs, followed by the detection of KLF2 levels and apoptosis levels of neutrophils. Additionally, the correlation between KLF2 levels and SLE disease activity index (SLEDAI) was analyzed.

RESULTS

The expression of KLF2 in neutrophils of SLE patients was significantly suppressed, and the decreased KLF2 was associated with the upregulation of neutrophil apoptosis. Moreover, newly diagnosed SLE patients, SLE patients with higher serum IgG and positive anti-Smith antibodies had lower KLF2 expression. Furthermore, we demonstrated that modulating the expression of KLF2 can regulate the apoptosis of neutrophils. The levels of KLF2 in neutrophils were associated with the SLEDAI. In addition, we found that serum from SLE patients could induce apoptosis in neutrophils by down-regulating the expression of KLF2.

CONCLUSIONS

KLF2 controls the apoptosis of neutrophils and is associated with SLEDAI, which suggests that KLF2 in neutrophils may be involved in the occurrence and development of SLE.

Circulating prolactin levels and the effect of dopaminergic agonists in systemic lupus erythematosus: a systematic review and meta-analysis

This systematic review of clinical studies investigated whether circulating PRL levels differed between subjects with systemic lupus erythematosus (SLE) and healthy controls, the correlation between circulating PRL and SLE activity, and the effect of dopaminergic agonists as adjuvant therapy for SLE. We searched PubMed, Scopus, Web of Science, Cochrane, Embase, and Google Scholar for case-control and cross-sectional studies investigating circulating PRL levels in subjects with SLE and/or its correlation with disease activity, and clinical trials examining the effect of dopaminergic agonists on SLE activity assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score. Forty-five studies addressing circulating PRL levels in SLE met our inclusion criteria. SLE was associated with an increased odds of hyperprolactinemia (OR 11.69, 95%CI 5.64-24.22) and circulating PRL levels were significantly higher in subjects with SLE than in controls (standardized mean difference of 1.62, 95%CI 1.14-2.09). Circulating PRL was positively correlated with SLE activity assessed by the SLEDAI (correlation coefficient 0.38, 95% CI 0.26-0.48). Two randomized clinical trials with bromocriptine and three prospective open-label trials with quinagolide reported that treatment with dopaminergic agonists was associated with reduced frequency of disease flares and decreased SLEDAI score. Circulating PRL levels were higher in subjects with SLE than in healthy controls and were significantly associated with disease activity. In addition, treatment with the dopaminergic agonists bromocriptine and quinagolide reduced SLE disease activity in small studies and may be a beneficial adjuvant therapy for the disease if larger trials confirm these findings. This review was registered in PROSPERO (CRD42021237156).

Risk factors of disease activity and renal damage in patients with systemic lupus erythematosus

PURPOSE

To evaluate the clinical features of patients with Systemic Lupus Erythematosus (SLE) and explore the risk factors of disease activity and renal damage.

METHODS

A retrospective study involving 194 patients were performed. Patients were divided into lupus nephritis (LN) group (63.40%) and non-LN group (36.60%), different disease activity group, and different renal function group according to the clinical data. Multivariate logistic regression analysis showed that albumin (ALB), uric acid (UC), total cholesterol (TC), and anti-dsDNA antibodies were the influencing factors of LN in patients with SLE (P < 0.05); ALB, UC, and complement 3(C3) were the influencing factors of lupus disease activity (P < 0.05); UC, C3, and hemoglobin (HB) were the influencing factors of abnormal renal function in SLE patients.

RESULTS

The results of the ROC curve showed that ALB, UA, and TC had certain predictive value for combined LN in patients with SLE, and the predictive value of ALB was greater than that of TC (P < 0.05); ALB, UA, and C3 being predictors of the activity of patients with SLE; BUN, UA, and HB all had certain predictive value for the abnormal renal function in patients with LN. SLE patients have the high incidence of renal impairment.

CONCLUSION

The results of this study suggest that patients with SLE should regularly monitor the levels of ALB, UA, TC, C3, and HB, as well as pay attention to the intervention of hyperlipidemia and hyperuricemia in patients with SLE to better control disease progression.

Harnessing the potential of CAR-T cell in lupus treatment: From theory to practice

Systemic Lupus Erythematosus (SLE) is a rare, heterogeneous, potentially life-threatening autoimmune disease. Presence of kidney or other major organ (brain, heart or lung) involvement are predictors of poor outcome and in a subset of patients resistant to 1st or 2nd line conventional treatment. The 10-year mortality remains around 10-15 %. Chimeric Antigen Receptors (CAR) are molecules that allow to redirect the engineered immune cells towards specific target antigens and to simultaneously boost their activation. Following breakthrough results observed in the treatment of hematological malignancies, conventional CAR T-cell therapy has recently been applied to refractory SLE patients. Compared to the use of monoclonal antibodies, anti-CD19 CAR T-cells allow to achieve deeper depletion of autoreactive B cells, notably at site of inflamed tissues and lymphoid organs (i.e. lymph node), to suppress interferon signature and to restore the immune tolerance with the reemergence of naïve B-cells with a new repertoire. All clinical data reported in SLE patients so far showed that autologous anti-CD19 CAR T-cell treatment allowed impressive short- and longer-term resolution of lupus nephritis and other severe disease-related manifestations, without major toxicities and only mild cytokine-release syndrome. These clinical effects persisted after B-cell reconstitution and were associated with normalization of double-stranded DNA antibodies and complement levels in drug-free patients until three years after the procedure. Overall, these pioneering experiences show unique clinical and immunological response to CAR T-cell therapy in SLE, and the need for extended follow-up to determine its long-term efficacy.

Prodrug Nanomedicine for Synovium Targeted Therapy of Inflammatory Arthritis: Insights from Animal Model and Human Synovial Joint Fluid

Many patients cannot tolerate low-dose weekly methotrexate (MTX) therapy for inflammatory arthritis treatment due to life-threatening toxicity. Although biologics offer a target-specific therapy, it raises the risk of serious infections and even cancer due to immune system suppression. We introduce an anti-inflammatory arthritis MTX ester prodrug using a long-circulating biocompatible polymeric macromolecule: folic acid (FA) functionalized hyperbranched polyglycerol (HPG). In vitro the drug MTX is incrementally released through pH and enzymatic degradation over 2 weeks. The role of matrix metalloproteinases (MMPs) in site-specific prodrug activation was verified using synovial fluid (SF) of 26 rheumatology patients and 4 healthy controls. Elevated levels of specific MMPs-markers of joint inflammation-positively correlated with enhanced prodrug release explained by acid-catalyzed hydrolysis of esters by proteases. Intravenously administered 111In-radiolabeled prodrug confirmed by SPECT/CT imaging that it accumulated preferentially in inflamed joints while reducing off-target side-effects in a mouse model of rheumatoid arthritis (RA). Added FA as a targeting vector prolonged prodrug action; prodrug with 4x less MTX applied every 2 weeks was as effective as weekly MTX therapy. The preclinical results suggest a prodrug-based strategy for the treatment of inflammatory joint diseases, with potential for other chronic inflammatory diseases and cancer.

Belimumab 10 years later: how drug positioning has changed

We analysed the change in the positioning of belimumab (BLM) in systemic lupus erythematosus (SLE) treatment in the first decade of real-life use, by providing data about patients treated by this biological drug in the Sapienza Lupus Cohort. We evaluated SLE patients treated by BLM according to the current clinical practice. Data of each patient were collected, focusing on previous and concomitant treatments. Finally, the drug retention rate was assessed. Since August 2013, 138 SLE patients started BLM (M/F 7/131; median age 49 years, IQR 13.25; median disease duration 214 months, IQR 180). To evaluate the change in BLM positioning, we divided patients according to the date of starting treatment as below: patients treated from 2013 to 2018 (period 1) and those treated since 2019 to date (period 2). Indeed, the median number of previous immunosuppressant drugs was significantly higher in patients treated in period 1 [3 (IQR 1.25) versus 1 (IQR 1.75), p = 0.0002]. Furthermore, 15.9% of patients treated in period 2 were not previously treated by immunosuppressant drugs, compared with 5.2% in period 1 (p = 0.01). Finally, the 24-month drug survival was significantly higher in patients previously treated with ≤ 1 immunosuppressant drug in comparison with those treated with ≥ 2 drugs (69.1% versus 43.4%, p = 0.0097, HR 0.49; 95% CI 0.27-0.88). Our data clearly described the progressive anticipation of BLM prescription in the first 10 years of clinical practice, underlining as choosing earlier biological agents could positively influence the drug retention rate.

Animal models of neuropsychiatric systemic lupus erythematosus: deciphering the complexity and guiding therapeutic development

Systemic lupus erythematosus (SLE) poses formidable challenges due to its multifaceted etiology while impacting multiple tissues and organs and displaying diverse clinical manifestations. Genetic and environmental factors contribute to SLE complexity, with relatively limited approved therapeutic options. Murine models offer insights into SLE pathogenesis but do not always replicate the nuances of human disease. This review critically evaluates spontaneous and induced animal models, emphasizing their validity and relevance to neuropsychiatric SLE (NPSLE). While these models undoubtedly contribute to understanding disease pathophysiology, discrepancies persist in mimicking some NPSLE intricacies. The lack of literature addressing this issue impedes therapeutic progress. We underscore the urgent need for refining models that truly reflect NPSLE complexities to enhance translational fidelity. We encourage a comprehensive, creative translational approach for targeted SLE interventions, balancing scientific progress with ethical considerations to eventually improve the management of NPSLE patients. A thorough grasp of these issues informs researchers in designing experiments, interpreting results, and exploring alternatives to advance NPSLE research.

The association between systemic lupus erythematosus (SLE) and early psychiatric background

BACKGROUND

The etiology of Systemic Lupus Erythematosus (SLE) remains elusive. Research has established links between SLE and various mental health issues, including associations with psychiatric illness, unique symptomatology in SLE, a relationship between stress and disease exacerbation, and improvement in SLE patients after psychiatric and psychological treatment. However, the hypothesis that psychiatric conditions might precede SLE onset by long periods has not been empirically established. This study aims to address this gap.

METHODS

This matched cohort study conducted a retrospective analysis using the electronic database of Clalit Health Services (CHS), Israel's largest HMO, comparing 2786 individuals diagnosed with SLE with 8358 non-SLE matched controls.

RESULTS

Two logistic regression analysis tests revealed significant associations between SLE diagnosis and prior psychiatric conditions. the first (p < 0.001) showed a 120% higher likelihood of psychiatric history among those diagnosed at least 10 years later with SLE compared to controls, and the second (p = 0.008) showed a 61% greater likelihood of a psychiatric history among those diagnosed at least 15 years with SLE. Investigation into the association between specific psychiatric indices and the later development of SLE found significant correlations between an SLE diagnosis and four psychiatric indices 10 years prior: dispensing of antipsychotics, anxiolytics, hypnotics, and sedatives; dispensing of antidepressants, psychostimulants, ADHD agents, and nootropics; diagnosis of mood disorders; and phobic and anxiety disorders.

CONCLUSIONS

The increased probability of pre-existing mental health issues preceding SLE onset by extended durations suggests a potential etiological role in SLE development.

In vitro silencing of RIP2 in naive CD4+ T cells from lupus-prone mice promotes pathogenic Th17 cell differentiation

OBJECTIVE

This work aims to investigate whether RIP2 silencing in naive CD4+ T cells from lupus-prone mice impacts Th17 cell activity or differentiation in vitro.

METHODS

Naive CD4+ T cells isolation from MRL/lpr mice's spleens. Three RNA interference target sequences of RIP2 were packaged with lentivirus and transfected into naive CD4+ T cells. The shRIP2 with the highest interference efficiency was selected and transfected into naive CD4+ T cells. Naive CD4+ T cells were cultured under conventional (TGF-β1 and IL-6) and pathogenic (IL-6, IL-23, IL-1β) differentiation environments, respectively. Then, RT-qPCR, Western blot or Flow Cytometry were used for measuring the amounts of RIP2 and IL-17 and the differentiation of Th17 cells in two settings.

RESULTS

Under the conventional Th17 (cTh17) cell differentiation environment (TGF-β1 and IL-6), RIP2 deficiency is linked to decreased IL-17A levels (1.00 ± 0.03 vs 0.80 ± 0.03) and attenuated cTh17 cell (2.46 ± 0.08 vs 0.78 ± 0.03) differentiation (all, P < 0.05). Under the pathogenic Th17 (pTh17) cell environment (IL-1β, IL-23, IL-6), RIP2 deficiency is linked to elevated IL-17A levels (1.03 ± 0.05 vs 1.63 ± 0.07) and enhanced pTh17 cell (3.69 ± 0.19 vs 5.49 ± 0.10) differentiation (all, P < 0.05).

CONCLUSION

Our data suggest that RIP2 inhibition induces preferential differentiation of naive CD4+ T cells to pathogenic Th17 cells, while being able to upregulate IL-17A levels in the context of pTh17 cell differentiation. Our study opens up new research areas to reveal the underlying mechanisms and potential therapeutic targets for the prevention and treatment of SLE patients. Key Points • Silencing of RIP2 in naive CD4+ T cells from lupus-prone mice promotes pathogenic Th17 (pTh17) cell differentiation and IL-17A production under pTh17 cell (IL-1β, IL-23, and IL-6) conditions. • RIP2 deficiency in naive CD4+ T cells reduces conventional Th17 (cTh17) cell differentiation and IL-17A production under cTh17 cell (TGF-β1 and IL-6) conditions. • RIP2-deficient naive CD4+ T cells preferentially differentiate towards pTh17 cells rather than cTh17 cells in vitro. • Inhibition of RIP2 may be involved in the development of SLE via effects on Th17/IL-17.

Plasma exosomes may mediate the development of lupus nephritis in patients with systemic lupus erythematosus

BACKGROUND

Lupus nephritis (LN) is the most serious complication of systemic lupus erythematosus (SLE), and plasma exosomes may serve as a bridge. MicroRNAs (miRNAs) are abundant in exosomes, so this study aimed to explore the role of exosome-derived miRNA in the development of LN.

METHODS

The publicly available data containing plasma exosomal miRNAs in SLE patients and healthy controls were researched, and differential expression and functional enrichment analysis of exosomal miRNA was conducted. Then, plasma exosomes from SLE patients were extracted, and the accuracy of differential expression and functional enrichment analysis was preliminarily verified. PKH26 dye was used to label exosomes to detect whether exosomes can enter HK2 cells. Evaluation of plasma exosomes impact on cell viability was done by utilizing CCK-8 assay. Flow cytometry was used to measure cell apoptosis.

RESULTS

Plasma exosomes were successfully extracted and identified. Through differential expression analysis of the pulbilic data and subsequent qPCR validation, we observed that miR-20b-5p is overexpressed in plasma exosomes of SLE patients, whereas miR-181a-2-3p is downregulated. Then functional enrichment analysis revealed that these differential miRNAs primarily regulate processes such as apoptosis, autophagy, and inflammation. Then, flow cytometry analysis conducted after co-incubation of plasma exosomes and peripheral blood mononuclear cells confirmed that exosomes can indeed regulate apoptosis. And plasma exosomes can successfully enter HK2 cells without affecting cell activity. In addition, plasma exosomes promote HK2 cell apoptosis and autophagy. Overexpression of miR-181a-2-3p could inhibit HK2 cells apoptosis and upregulate the expression of bcl2, and beclin1. At the same time, a trend towards increased apoptosis rates was observed in HK2 overexpressed miR-20b-5p, although the difference did not reach statistical significance. And miR-20b-5p can enhance the expression of caspase3 and becin1 while suppressing the expression of bcl2 and LC3β.

CONCLUSION

Our research indicates that the abundant presence of miR-20b-5p and the depletion of miR-181a-2-3p in plasma exosomes of SLE patients may mediate the promotion of apoptosis and autophagy in HK2 cells, thereby causing kidney damage and the development of LN.

Therapeutically targeting proinflammatory type I interferons in systemic lupus erythematosus: efficacy and insufficiency with a specific focus on lupus nephritis

Type I interferons (IFN-Is) are important players in the immunopathogenesis of systemic lupus erythematosus (SLE). Pathogenic events in patients with SLE are potent triggers of IFN-I induction, yet IFN-I may induce or initiate the immunopathogenesis leading to these events. Because blocking IFN-I is effective in some clinical manifestations of SLE patients, concerns about the efficacy of anti-IFN-I therapy in patients with lupus nephritis remain. Tissues from kidney biopsies of patients with lupus nephritis revealed infiltration of various immune cells and activation of inflammatory signals; however, their correlation with renal damage is not clear, which raises serious concerns about how critical the role of IFN-I is among the potential contributors to the pathogenesis of lupus nephritis. This review addresses several issues related to the roles of IFN-I in SLE, especially in lupus nephritis, including (1) the contribution of IFN-I to the development and immunopathogenesis of SLE; (2) evidence supporting the association of IFN-I with lupus nephritis; (3) therapies targeting IFN-I and IFN-I downstream signaling molecules in SLE and lupus nephritis; (4) findings challenging the therapeutic benefits of anti-IFN-I in lupus nephritis; and (5) a perspective associated with anti-IFN-I biologics for lupus nephritis treatment. In addition to providing clear pictures of the roles of IFN-I in SLE, especially in lupus nephritis, this review addresses the lately published observations and clinical trials on this topic.

Systemic lupus erythematosus in Aboriginal and Torres Strait Islander peoples in Australia: addressing disparities and barriers to optimising patient care

The first inhabitants of Australia and the traditional owners of Australian lands are the Aboriginal and Torres Strait Islander peoples. Aboriginal and Torres Strait Islander peoples are two to four times more likely to have systemic lupus erythematosus (SLE) than the general Australian population. Phenotypically, SLE appears distinctive in Aboriginal and Torres Strait Islander peoples and its severity is substantially increased, with mortality rates up to six times higher than in the general Australian population with SLE. In particular, Aboriginal and Torres Strait Islander peoples with SLE have increased prevalence of lupus nephritis and increased rates of progression to end-stage kidney disease. The reasons for the increased prevalence and severity of SLE in this population are unclear, but socioeconomic, environmental, and biological factors are all likely to be implicated, although there are no published studies investigating these factors in Aboriginal and Torres Strait Islander peoples with SLE specifically, indicating an important knowledge gap. In this Review, we summarise the data on the incidence, prevalence, and clinical and biological findings relating to SLE in Aboriginal and Torres Strait Islander peoples and explore potential factors contributing to its increased prevalence and severity in this population. Importantly, we identify health disparities and deficiencies in health-care provision that limit optimal care and outcomes for many Aboriginal and Torres Strait Islander peoples with SLE and highlight potentially addressable goals to improve outcomes.

Active implementation of low disease activity state as a treatment endpoint in childhood-onset systemic lupus erythematosus in routine practice is both feasible and associated with better outcomes

INTRODUCTION

Treat-to-target (T2T) strategies aim to facilitate tight disease control to improve outcomes. No previous studies evaluated prospectively the feasibility and impact of the T2T strategy in routine practice in childhood-onset SLE (cSLE).

METHODS

Adolescents and young adults (AYA) with cSLE were recruited for T2T implementation from a large tertiary centre over a period of 6 months and followed up at least twice over a prospective period of 12 months.

RESULTS

During Oct 2022-April 2023, 135/162 (83.3%) AYA with cSLE had disease scores evaluated at their routine appointment to enable inclusion in the study, and 122/135 (91.2%) had their disease assessed, and a suitable treatment target agreed and documented at each routine clinical appointment over the 12 months prospective follow-up. T2T strategy led to improved disease control at 12 months: more AYA with cSLE achieved clinical remission off steroids (4.1% vs. 10.7%, P = 0.048), or minimum childhood-lupus low disease activity (cLLDAS) (81.9% vs. 91.8%, P = 0.022). Achieving minimum cLLDAS for longer than 3 months was associated with reduced damage accrual (HR = 1.7; 95%CI = 1.1-2.5; P < 0.0001) at 12 months.

CONCLUSION

T2T strategy implementation was achievable and associated with improved cSLE control. Spending at least 3/12 months in cLLDAS led to less damage accumulation. Key Points • This is the first large prospective study in AYA with cSLE to evaluate the impact of active T2T implementation in routine practice. • T2T strategies were feasible to implement in 122/135 (91.2%) AYA with cSLE in routine practice. • The T2T approach was associated with improved disease control and decreased damage accrual at 12 months.

Development and Validation of Nosocomial Bacterial Infection Prediction Models for Patients With Systemic Lupus Erythematosus

BACKGROUND

Hospital-acquired bacterial infections are associated with high morbidity and mortality rates in patients with systemic lupus erythematosus (SLE). This study aimed to develop and validate predictive models for the risk of hospital-acquired bacterial infections in patients with SLE.

METHODS

A historical cohort study was designed for development, and another bidirectional cohort study was used for external validation. The risk of bacterial infection was assessed upon admission and after 5 days of hospitalization. Predictor selection employed the least absolute shrinkage and selection operator (LASSO) techniques. Multiple imputations were used to handle missing data. Logistic regression models were applied, and the properties of discrimination, calibration, and decision curve analysis were evaluated.

RESULTS

The development cohort comprised 1686 patients and 237 events (14.1%) from 3 tertiary hospitals. The external validation cohort included 531 patients and 84 infection outcomes (15.8%) from 10 hospital centers in Colombia (secondary and tertiary level). The models applied at admission and after 120 hours of stay exhibited good discrimination (AUC > 0.74). External validation demonstrated good performance among patients from the same tertiary institutions where the models were developed. However, geographic validation at other institutions has been suboptimal.

CONCLUSIONS

Two predictive models for nosocomial bacterial infections in patients with SLE are presented. All infection prevention recommendations should be maximized in patients at moderate/high risk. Further validation studies in diverse contexts, as well as clinical impact trials, are necessary before potential applications in research and clinical care.

Diagnosis of pulmonary lophomoniasis infection in patient with systemic lupus erythematosus; A case report and literature review

Over the past 30 years, there has been an increasing number of documented human infections associated with the protozoan Lophomonas, specifically Lophomonas blattarum, which is considered a relatively rare infection. These infections are primarily associated with states of immune suppression, including those resulting from corticosteroid therapy. We report a 61-year-old female patient with a 20-year medical history of Systemic lupus erythematosus (SLE) who was admitted due to persistent respiratory symptoms that were unresponsive to treatment. The patient was receiving immunosuppressive therapy for SLE. Upon hospitalization, computed tomography of the lungs revealed the presence of centrilobular nodules exhibiting tree-in-bud patterns, as well as bronchiectasis, predominantly in the middle and lower lobes. Subsequently, the patient underwent bronchoscopy, during which a BAL sample was obtained. Microscopic analysis of the sample indicated the presence of L. blattarum. Clinicians often focus on the primary symptoms of SLE, but they must also consider the risk of severe respiratory complications like lophomoniasis. This condition is critical to address in the management of SLE patients, who are immunosuppressed due to the disease's nature and its treatment.

Intra-bone marrow mesenchymal stem cell transplantation modulates myeloid bias tendency of hematopoietic stem and progenitor cells in severe MRL/lpr lupus mice

The hematopoietic homeostasis in the bone marrow is inextricably intertwined with the immune milieu in peripheral circulation. Researches investigating the pathogenesis of systemic lupus erythematosus (SLE) have defined considerable secretion of inflammatory mediators and activation of pro-inflammatory cells. However, the impacts of "extrinsic" factors on hematopoietic stem and progenitor cells (HSPCs) remain unclear, and it is uncertain whether treatments can help coordinate the biased differentiation. In this study, we showed differences in the proportions of common myeloid progenitors (CMP) and myeloid output in the bone marrow of premorbid and morbid MRL/lpr mice using flow cytometry. RNA-seq analysis of lineage-affiliated transcriptional factors and dysregulated genes within lin- HSPCs revealed inflammation potentiation during disease progression. Further, intra-bone marrow mesenchymal stem cells transplantation (IBM-MSCT) partially coordinated myeloid generation and counteracted lupus-associated inflammation gene alterations, compared to intravenous injection. Additionally, co-culturing with umbilical cord mesenchymal stem cells (UC-MSCs) intervened in myeloid lineage tendency, as detected by RT-qPCR of myeloid-related genes. Our research demonstrated enhanced tendency toward myeloid differentiation and highlighted the feasibility of IBM-MSCT for lineage-biased HSPCs in MRL/lpr lupus model, providing novel insight into hematopoiesis and MSC-related treatments for SLE.

Molecular and therapeutic landscape of ferroptosis in skin diseases

ABSTRACT

Regulated cell death (RCD) is a critical physiological process essential in maintaining skin homeostasis. Among the various forms of RCD, ferroptosis stands out due to its distinct features of iron accumulation, lipid peroxidation, and involvement of various inhibitory antioxidant systems. In recent years, an expanding body of research has solidly linked ferroptosis to the emergence of skin disorders. Therefore, understanding the mechanisms underlying ferroptosis in skin diseases is crucial for advancing therapy and prevention strategies. This review commences with a succinct elucidation of the mechanisms that underpin ferroptosis, embarks on a thorough exploration of ferroptosis's role across a spectrum of skin conditions, encompassing melanoma, psoriasis, systemic lupus erythematosus (SLE), vitiligo, and dermatological ailments precipitated by ultraviolet (UV) exposure, and scrutinizes the potential therapeutic benefits of pharmacological interventions aimed at modulating ferroptosis for the amelioration of skin diseases.

Chronic interstitial lung disease associated with systemic lupus erythematosus: A multicentric study of 89 cases

BACKGROUND AND OBJECTIVE

Chronic interstitial lung disease (ILD) occurs rarely with systemic lupus erythematosus (SLE) as compared with other connective tissue diseases. This multicentric retrospective study of patients with SLE-ILD from the OrphaLung and French SLE networks during 2005-2020 aimed to describe the characteristics of patients with SLE-ILD and analyse factors associated with prognosis.

METHODS

We analysed data for 89 patients with SLE-ILD (82 women, 92.1%) (median age at SLE diagnosis: 35 years [interquartile range 27-47]). All patients met the 2019 EULAR/ACR criteria for the diagnosis of SLE.

RESULTS

Forty two (47.2%) patients were positive for anti-ribonuclear protein antibodies and 45 (50.6%) for anti SSA/Ro antibodies. A total of 58 (65.2%) patients had another connective tissue disease: Sjögren's syndrome (n = 33, 37.1%), systemic sclerosis (n = 14, 15.7%), inflammatory myopathy (n = 6, 6.7%), or rheumatoid arthritis (n = 6, 6.7%). ILD was diagnosed along with SLE in 25 (28.1%) patients and at a median of 6 (0-14) years after the SLE diagnosis. The most frequent CT pattern was suggestive of non-specific interstitial pneumonia (n = 41, 46.0%) with or without superimposed organizing pneumonia. After a median follow-up of 86.5 [39.5-161.2] months, 18 (20.2%) patients had died and 6 (6.7%) underwent lung transplantation. The median 5-year and 10-year transplantation-free survival were 96% (92-100) and 87% (78-97). In total, 44 (49.4%) patients showed ILD progression. Cutaneous manifestations and Raynaud's phenomenon were associated with better survival. Only forced vital capacity was significantly associated with survival and ILD progression.

CONCLUSION

ILD is a rare manifestation of SLE with good overall prognosis but with possible risk of ILD progression. Patients with SLE-ILD frequently have another connective tissue disease.

Single-cell RNA sequencing of peripheral blood mononuclear cells from pregnant women with Systemic lupus erythematosus

Systemic lupus erythematosus (SLE), an autoimmune condition, presents pregnancy-related risks, impacting maternal and fetal health. The immune cell composition and gene expression profiles in pregnant SLE patients, as well as the molecular mechanisms of active SLE patients during pregnancy, remain unclear. In our study, we enrolled 12 patients: three active SLE individuals (SLE-AT group, SLEDAI > 12, non-pregnant women), three inactive SLE individuals (SLE-NP group, SLEDAI ranging 0 to 6, non-pregnant women), three pregnant women with active SLE (SLE-C group, SLEDAI > 12), and three pregnant women with inactive SLE (SLE-NC group, SLEDAI range 0 to 6 score). Transcriptome analysis of peripheral blood mononuclear cells (PBMCs) was conducted using the 10x Genomics technique. We observed upregulation of genes like CCDC15 and TRBV4-2 in T cells and CMPK2, IFIT1, and OAS2 in monocytes in the SLE-C group. Notably, gene sets related to Cell Cycle and IFN Response showed significant differences between the SLE-C and SLE-NC groups in naïve CD8 T cells. Our comparison of immune cell type ratios and transcriptional patterns between active and inactive SLE during pregnancy sheds light on the single-cell level changes in SLE status during pregnancy, offering insights for future SLE prediction and treatment strategies.

Single-cell mass cytometry in immunological skin diseases

Immune-related skin diseases represent a collective of dermatological disorders intricately linked to dysfunctional immune system processes. These conditions are primarily characterized by an immoderate activation of the immune system or deviant immune responses, involving diverse immune components including immune cells, antibodies, and inflammatory mediators. However, the precise molecular dysregulation underlying numerous individual cases of these diseases and unique subsets respond under disease conditions remains elusive. Comprehending the mechanisms and determinants governing the homeostasis and functionality of diseases could offer potential therapeutic opportunities for intervention. Mass cytometry enables precise and high-throughput quantitative measurement of proteins within individual cells by utilizing antibodies labeled with rare heavy metal isotopes. Imaging mass cytometry employs mass spectrometry to obtain spatial information on cell-to-cell interactions within tissue sections, simultaneously utilizing more than 40 markers. The application of single-cell mass cytometry presents a unique opportunity to conduct highly multiplexed analysis at the single-cell level, thereby revolutionizing our understanding of cell population heterogeneity and hierarchy, cellular states, multiplexed signaling pathways, proteolysis products, and mRNA transcripts specifically in the context of many autoimmune diseases. This information holds the potential to offer novel approaches for the diagnosis, prognostic assessment, and monitoring responses to treatment, thereby enriching our strategies in managing the respective conditions. This review summarizes the present-day utilization of single-cell mass cytometry in studying immune-related skin diseases, highlighting its advantages and limitations. This technique will become increasingly prevalent in conducting extensive investigations into these disorders, ultimately yielding significant contributions to their accurate diagnosis and efficacious therapeutic interventions.

Targeted metabolomics combined with machine learning to identify and validate new biomarkers for early SLE diagnosis and disease activity

BACKGROUND

The early diagnosis of systemic lupus erythematosus (SLE) and the assessment of disease activity progression remain a great challenge. Targeted metabolomics has great potential to identify new biomarkers of SLE.

METHODS

Serum from 44 healthy participants and 89 SLE patients were analyzed using HM400 high-throughput targeted metabolomics. Machine learning (ML) with seven learning models and trained the model several times iteratively selected the two best prediction model in a competitive way, which were independent validated by enzyme-linked immunosorbent (ELISA) with 90 SLE patients.

RESULTS

In this study, 146 differential metabolites, most of them organic acids, amino acids, and bile acids, were detected between patients with initial SLE and healthy participants, and 8 potential biomarkers were found by intersection of ML and statistics (area under the curve [AUC] > 0.95) showing a significant positive correlation with clinical indicators. In addition, we identified and validated 2 potential biomarkers for SLE classification (P < 0.05, AUC > 0.775; N-Methyl-L-glutamic acid, L-2-aminobutyric acid) showing a significant correlation with the SLE Disease Activity Index. These differential metabolites were mainly involved in metabolic pathways, amino acid biosynthesis, 2-oxocarboxylic acid metabolism and other pathways.

CONCLUSION

This study indicated that the tricarboxylic acid cycle might be associated with SLE drug therapy. We identified 8 diagnostic models biomarkers and 2 biomarkers that could be used to identify initial SLE and distinguish different activity degree, which will promote the development of new tools for the diagnosis and evaluation of SLE.

Clinical and laboratory characteristics of early-onset and delayed-onset lupus nephritis patients: A single-center retrospective study

BACKGROUND

Lupus nephritis (LN) manifests systemic lupus erythematosus (SLE) and is characterized by various clinical and laboratory features. This study aimed to comprehensively evaluate the characteristics of LN patients according to the time of LN diagnosis: early-onset (LN diagnosed within one year from SLE diagnosis) vs. delayed-onset (LN diagnosed more than one year after SLE diagnosis).

METHODS

We conducted a retrospective analysis of medical records from all SLE patients treated at the University Hospital in Kraków, Poland, from 2012 to 2022. We collected data on demographic, clinical, and laboratory characteristics, including histological findings, treatment modalities, and disease outcomes. Statistical analyses were performed to identify factors impacting LN development and prognosis.

RESULTS

Among 331 LN patients, early-onset was diagnosed in 207 (62.54%) and delayed-onset was documented in 122 cases (36.86%). In 2 (0.6%) LN cases, the time of first kidney manifestation in the SLE course was unknown. Delayed-onset LN had a higher female-to-male ratio and younger age at SLE diagnosis. This group was associated with more severe clinical manifestations. In turn, studied subgroups did not differ in internist comorbidities, kidney histopathology, and family history regarding autoimmune diseases. Delayed-onset LN exhibited a higher frequency of anti-dsDNA, anti-Smith, anti-Ro, anti-RNP, and anti-cardiolipin IgG autoantibodies. During a 14-year follow-up period, 16 patients died. Mortality rate and causes of death were comparable in both analyzed subgroups.

CONCLUSIONS

More severe clinical manifestations in delayed-onset LN prompt strict monitoring of non-LN SLE patients to diagnose and treat kidney involvement early. Also, recognizing the higher frequency of autoantibodies such as anti-dsDNA or anti-Smith in delayed-onset LN underscores the potential value of autoantibody profiling as a diagnostic and prognostic tool.

Prolactin: A Mammalian Stress Hormone and Its Role in Cutaneous Pathophysiology

The hormone prolactin (PRL) is best recognised for its indispensable role in mammalian biology, specifically the regulation of lactation. Bearing in mind that the mammary gland is a modified sweat gland, it is perhaps unsurprising to discover that PRL also plays a significant role in cutaneous biology and is implicated in the pathogenesis of a range of skin diseases, often those reportedly triggered and/or exacerbated by psychological stress. Given that PRL has been implicated in over 300 biological processes, spanning reproduction and hair growth and thermo- to immunoregulation, a comprehensive understanding of the relationship between PRL and the skin remains frustratingly elusive. In an historical curiosity, the first hint that PRL could affect skin biology came from the observation of seborrhoea in patients with post-encephalitic Parkinsonism as a result of another global pandemic, encephalitis lethargica, at the beginning of the last century. As PRL is now being postulated as a potential immunomodulator for COVID-19 infection, it is perhaps timeous to re-examine this pluripotent hormone with cytokine-like properties in the cutaneous context, drawing together our understanding of the role of PRL in skin disease to illustrate how targeting PRL-mediated signalling may represent a novel strategy to treat a range of skin diseases and hair disorders.

Longitudinal assessment of urinary ALCAM, HPX, and PRDX6 in Korean patients with systemic lupus erythematosus: implications for disease activity monitoring and treatment response

Introduction

This study aimed to demonstrate the potential of activated leukocyte cell adhesion molecule (ALCAM), hemopexin (HPX), and peroxiredoxin 6 (PRDX6) as urine biomarkers for systemic lupus erythematosus (SLE).

Methods

Urine samples were collected from 138 Korean patients with SLE from the Ajou Lupus Cohort and 39 healthy controls (HC). The concentrations of urine biomarkers were analyzed using enzyme-linked immunosorbent assay kits specific for ALCAM, HPX, and PRDX6, respectively. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic utility, and Pearson's correlation analysis was conducted to assess the relationships between the disease activity and urine biomarkers.

Results

Patients with SLE and patients with lupus nephritis (LN) showed significantly elevated ALCAM, HPX, and PRDX6 levels compared with HCs. ALCAM, HPX, and PRDX6 showed significant diagnostic values, especially for lupus nephritis (LN), with areas under the receiver operating characteristic curve for LN was 0.850 for ALCAM (95% CI, 0.778-0.921), 0.781 for HPX (95% CI, 0.695-0.867), and 0.714 for PRDX6 (95% CI, 0.617-0.812). Correlation analysis revealed that all proteins were significantly associated with anti-double stranded DNA antibody (ALCAM, r = 0.350, p < 0.001; HPX, r = 0.346, p < 0.001; PRDX6, r = 0.191, p = 0.026) and SLEDAI (ALCAM, r = 0.526, p < 0.001; HPX, r = 0.479, p < 0.001; PRDX6, r = 0.262, p = 0.002). Results from the follow-up of the three biomarker levels in these patients revealed a significant decrease, showing a positive correlation with changes in SLEDAI-2k scores (ALCAM, r = 0.502, p < 0.001; HPX, r = 0.475, p < 0.001; PRDX6, r = 0.245, p = 0.026), indicating their potential as indicators for tracking disease activity.

Discussions

Urinary ALCAM, HPX, and PRDX6 levels have diagnostic value and reflect disease activity in Korean patients with SLE, emphasizing their potential for non-invasive monitoring and treatment response evaluation.

Investigating the causal association between systemic lupus erythematosus and migraine using Mendelian randomization analysis

OBJECTIVE

To assess whether systemic lupus erythematosus (SLE) may be genetically causally associated with migraine, including the two primary subtypes: migraine with aura (MWA) and migraine without aura (MWoA).

BACKGROUND

The association between SLE and migraine has been investigated extensively. Previous studies have shown a higher prevalence of migraine in patients with SLE, although the exact relationship remains unclear. This study investigated the potential causal association between SLE and migraine using the powerful analytical tool of Mendelian randomization (MR).

METHODS

We performed two-sample MR analysis of publicly available summary statistic datasets using inverse variance-weighted (IVW), weighted median, and MR-Egger methods based on an SLE genome-wide association study (GWAS; 5201 cases; 9066 controls; the exposure frequency is 36.5%) as an exposure and migraine GWAS (15,905 cases; 264,662 controls) in individuals with European ancestry as outcomes, focusing on the two migraine subtypes MWA (6780 cases; 264,662 controls) and MWoA (5787 cases; 264,662 controls). Thepleiotropy and heterogeneity were performed.

RESULTS

We selected 42 single-nucleotide polymorphisms from SLE GWAS as instrumental variables (IVs) for SLE on migraine, and 41 SNP IVs for SLE on MWA or MWoA. The IVW (odds ratio [OR] = 1.01, 95% confidence interval [CI] = [0.99, 1.03], p = 0.271), weighted median (OR = 1.00, 95% CI = [0.97, 1.03], p = 0.914), and MR-Egger (OR = 1.04, 95% CI = [0.99, 1.09], p = 0.153) methods showed no causal effect of SLE on migraine. A causal effect of SLE was observed on MWA (IVW: OR = 1.05, 95% CI = [1.02, 1.08], p = 0.001; weighted median: OR = 1.05, 95% CI = [1.01, 1.10], p = 0.018; MR-Egger: OR = 1.07, 95% CI = [1.01, 1.14], p = 0.035 and pIVW < 0.017 [Bonferroni correction]) but not MWoA (IVW: OR = 0.99, 95% CI = [0.96, 1.02], p = 0.331; weighted median: OR = 0.98, 95% CI = [0.94, 1.03], p = 0.496; MR-Egger: OR = 1.02, 95% CI = [0.95, 1.09], p = 0.652). The results showed no significant pleiotropy or heterogeneity.

CONCLUSION

Our MR analysis demonstrated the complex relationship between SLE and migraine, suggesting a potential effect of SLE on the risk of MWA but not MWoA. These findings can aid in the development of improved subtype-specific management of migraine in patients with SLE.

Relevance of acquired T cell molecular defects in the immunopathogenesis of SLE

Systemic lupus erythematosus (SLE) and other autoimmune diseases are thought to develop in genetically predisposed individuals when triggered by environmental factors. This paradigm does not fully explain disease development, as it fails to consider the delay between birth and disease expression. In this review, we discuss observations described in T cells from patients with SLE that are not related to hereditary factors and have therefore been considered secondary to the disease process itself. Here, we contextualize some of those observations and argue that they may represent a pathogenic layer between genetic factors and disease development. Acquired changes in T cell phenotype and function in the setting of SLE may affect the immune system, creating a predisposition towards a more inflammatory and pathogenic system that amplifies autoimmunity and facilitates disease development.

Immune cells in skin inflammation, wound healing, and skin cancer

Given the self-evident importance of cutaneous immunity in the maintenance of body-surface homeostasis, disturbance of the steady-state skin is inextricably intertwined with dysfunction in cutaneous immunity. It is often overlooked by people that skin, well-known as a solid physical barrier, is also a strong immunological barrier, considering the abundant presence of immune cells including lymphocytes, granulocytes, dendritic cells, and macrophages. What's more, humoral immune components including cytokines, immunoglobulins, and antimicrobial peptides are also rich in the skin. This review centers on skin inflammation (acute and chronic, infection and aseptic inflammation), wound healing, and skin cancer to elucidate the elaborate network of immune cells in skin diseases.

Mapping theme evolution and identifying hotspots in biomarkers of systemic lupus erythematosus based on global research

Objective: To perform a bibliometric analysis in the field of biomarkers for systemic lupus erythematosus. Methods: Publications were from Web of Science. Microsoft Excel, VOSviewer, Science Mapping Analysis software Tool, CiteSpace and Tableau were used for analysis. Results: A total of 1112 publications were identified; 1503 institutions from 69 countries contributed, with the highest outputs from China and Karolinska University Hospital. Petri had a tremendous impact. Academic collaborations were localized. Lupus and Arthritis & Rheumatology were the top two journals in terms of publications and citations. Lymphocyte, autoantibody, type I interferon, genetic polymorphisms and urinary biomarkers have been high-frequency themes. Conclusion: Global collaboration needs to be further strengthened. Immune cell, cytokine and gene-level research as a whole and noninvasive tests are the future trends.

Polygenic Risk Score Predicts Earlier-Onset Adult Systemic Lupus Erythematosus and First-Year Renal Diseases in a Taiwanese Cohort

OBJECTIVES

This study aimed to develop a predictive model using polygenic risk score (PRS) to forecast renal outcomes for adult systemic lupus erythematosus (SLE) in a Taiwanese population.

METHODS

Patients with SLE (n=2782) and matched non-SLE controls (n=11 128) were genotyped using Genome-Wide TWB 2.0 single-nucleotide polymorphism (SNP) array. PRS models (C+T, LDpred2, Lassosum, PRSice-2, PRS-continuous shrinkage (CS)) were constructed for predicting SLE susceptibility. Logistic regression was assessed for C+T-based PRS association with renal involvement in patients with SLE.

RESULTS

In the training set, C+T-based SLE-PRS, only incorporating 27 SNPs, outperformed other models with area under the curve (AUC) values of 0.629, surpassing Lassosum (AUC=0.621), PRSice-2 (AUC=0.615), LDpred2 (AUC=0.609) and PRS-CS (AUC=0.602). Additionally, C+T-based SLE-PRS demonstrated consistent predictive capacity in the testing set (AUC=0.620). Individuals in the highest quartile exhibited earlier SLE onset (39.06 vs 44.22 years, p<0.01), higher Systemic Lupus Erythematosus Disease Activity Index scores (3.00 vs 2.37, p=0.04), elevated risks of renal involvement within the first year of SLE diagnosis, including WHO class III-IV lupus nephritis (OR 2.36, 95% CI 1.47 to 3.80, p<0.01), estimated glomerular filtration rate <60 mL/min/1.73m2 (OR 1.49, 95% CI 1.18 to 1.89, p<0.01) and urine protein-to-creatinine ratio >150 mg/day (OR 2.07, 95% CI 1.49 to 2.89, p<0.01), along with increased seropositivity risks, compared with those in the lowest quartile. Furthermore, among patients with SLE with onset before 50 years, the highest PRS quartile was significantly associated with more serious renal diseases within the first year of SLE diagnosis.

CONCLUSIONS

PRS of SLE is associated with earlier onset, renal involvement within the first year of SLE diagnosis and seropositivity in Taiwanese patients. Integrating PRS with clinical decision-making may enhance lupus nephritis screening and early treatment to improve renal outcomes in patients with SLE.

Higher mortality risk from gynaecological neoplasms and non-Hodgkin's lymphoma in patients with systemic lupus erythematosus: an observational study from the Spanish National Registry

OBJECTIVE

To evaluate the impact of the different types of neoplasms and lineages on mortality of patients with SLE.

METHODS

Retrospective and observational comparison of the neoplasm-related deaths in patients with SLE and the general Spanish population reported in the Spanish Hospital Discharge Database. To determine the impact of SLE on the risk of dying from each neoplasm lineage, a binary logistic regression considering age, female sex, tobacco and alcohol consumption, was performed.

RESULTS

During 2016-2019, 139 531 in-hospital deaths from neoplasms were certified in Spain (91 in patients with SLE). Patients with SLE presented a lower mortality rate from solid organ neoplasms, (80.2% vs 91.1%, OR 0.393), linked to their lower risk of colorectal carcinoma (1.1% vs 10.8%, OR 0.110). By contrast, gynaecological neoplasms presented a higher risk (8.8% vs 3%, OR 3.039) in the deceased patients with SLE, associated with the higher frequency of vulvar neoplasms (2% vs 0.2%, OR 14.767) and cervical carcinomas (3.3% vs 0.5%, OR 3.809). Haematological neoplasm-related deaths were also more prevalent in patients with SLE (19.8% vs 8.9%, OR 2.546), mostly attributable to the higher proportion of deaths due to non-Hodgkin's lymphoma (11% vs 2.9%, OR 4.060) of B cell lineage (9.9% vs 2.5%, OR 4.133).

CONCLUSIONS

Patients with SLE present a higher risk of death from vulvar neoplasms, cervical carcinomas and B-cell non-Hodgkin's lymphoma in comparison with the general Spanish population. In addition to developing strategies that might help to attenuate their occurrence and impact, such as decreasing the immunosuppressive burden, specific early detection programmes for these conditions should be investigated and considered carefully.

The multifaceted role of autophagy in skin autoimmune disorders: a guardian or culprit?

Autophagy is a cellular process that functions to maintain intracellular homeostasis via the degradation and recycling of defective organelles or damaged proteins. This dynamic mechanism participates in various biological processes, such as the regulation of cellular differentiation, proliferation, survival, and the modulation of inflammation and immune responses. Recent evidence has demonstrated the involvement of polymorphisms in autophagy-related genes in various skin autoimmune diseases. In addition, autophagy, along with autophagy-related proteins, also contributes to homeostasis maintenance and immune regulation in the skin, which is associated with skin autoimmune disorders. This review aims to provide an overview of the multifaceted role of autophagy in skin autoimmune diseases and shed light on the potential of autophagy-targeting therapeutic strategies in dermatology.

Hormones and B-cell development in health and autoimmunity

The development of B cells into antibody-secreting plasma cells is central to the adaptive immune system as they induce protective and specific antibody responses against invading pathogens. Various studies have shown that, during this process, hormones can play important roles in the lymphopoiesis, activation, proliferation, and differentiation of B cells, and depending on the signal given by the receptor of each hormone, they can have a positive or negative effect. In autoimmune diseases, hormonal deregulation has been reported to be related to the survival, activation and/or differentiation of autoreactive clones of B cells, thus promoting the development of autoimmunity. Clinical manifestations of autoimmune diseases have been associated with estrogens, prolactin (PRL), and growth hormone (GH) levels. However, androgens, such as testosterone and progesterone (P4), could have a protective effect. The objective of this review is to highlight the links between different hormones and the immune response mediated by B cells in the etiopathogenesis of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS). The data collected provide insights into the role of hormones in the cellular, molecular and/or epigenetic mechanisms that modulate the B-cell response in health and disease.

Rapid diagnosis of systemic lupus erythematosus by Raman spectroscopy combined with spiking neural network

Multiple organs are affected by the autoimmune inflammatory connective tissue disease known as systemic lupus erythematosus (SLE). If not diagnosed and treated in a timely manner, it can lead to nephritis and damage to the blood system in severe cases, resulting in the patient's death. Therefore, correct and timely diagnosis and treatment are essential for patients. In this study, a framework based on neural network algorithm and Raman spectroscopy technique was established to diagnose SLE patients. Firstly, we pre-processed the obtained Raman data by three methods: baseline correction, smoothing processing and normalization methods, before using it as input for the model, and then ANN, ResNet and SNN classification models were established. The respective classification accuracies for SLE patients were 89.61%, 85.71%, and 95.65% for the three models, with corresponding AUC values of 0.8772, 0.8100, and 0.9555. The results of the experimental indicate that SNN possesses a good classification effect, and the number of model parameters is only 525,826, which is 414,221 less than that of ResNet model. Since the network only uses 0 and 1 to transmit information, and only has basic operations such as summation, compared with the second-generation artificial neural network, which simplifies the product operation of floating point numbers into multiple addition operations, the network has low energy consumption and is suitable for embedding portable Raman spectrometer for clinical diagnosis. This research highlights the significant potential for quick and precise SLE patient discrimination offered by Raman spectroscopy in conjunction with spiking neural networks.

Under the dual effect of inflammation and pulmonary fibrosis, CTD-ILD patients possess a greater susceptibility to VTE

As an autoimmune disease, the persistent systemic inflammatory response associated with connective tissue disease (CTD) is involved in the development of venous thromboembolism (VTE). However, clinical data showed that the risk of VTE in patients differed between subtypes of CTD, suggesting that different subtypes may have independent mechanisms to promote the development of VTE, but the specific mechanism lacks sufficient research at present. The development of pulmonary fibrosis also contributes to the development of VTE, and therefore, patients with CTD-associated interstitial lung disease (CTD-ILD) may be at higher risk of VTE than patients with CTD alone or patients with ILD alone. In addition, the activation of the coagulation cascade response will drive further progression of the patient's pre-existing pulmonary fibrosis, which will continue to increase the patient's risk of VTE and adversely affect prognosis. Currently, the treatment for CTD-ILD is mainly immunosuppressive and antirheumatic therapy, such as the use of glucocorticoids and janus kinase-inhibitors (JAKis), but, paradoxically, these drugs are also involved in the formation of patients' coagulation tendency, making the clinical treatment of CTD-ILD patients with a higher risk of developing VTE challenging. In this article, we review the potential risk factors and related mechanisms for the development of VTE in CTD-ILD patients to provide a reference for clinical treatment and prevention.

Recent advances of aggregation‐induced emission in body surface organs

The surface organs mainly comprise the superficial layers of various parts of the mammalian body, including the skin, eyes, and ears, which provide solid protection against various threats to the entire body. Damage to surface organs could lead to many serious diseases or even death. Currently, despite significant advancements in this field, there remain numerous enigmas that necessitate expeditious resolution, particularly pertaining to diagnostic and therapeutic objectives. The advancements in nanomedicine have provided a significant impetus for the development of novel approaches in the diagnosis, bioimaging, and therapy of superficial organs. The aggregation‐induced emission (AIE) phenomenon, initially observed by Prof. Ben Zhong Tang, stands out due to its contrasting behavior to the aggregation‐caused quenching effect. This discovery has significantly revolutionized the field of nanomedicine for surface organs owing to its remarkable advantages. In this review of literature, we aim to provide a comprehensive summary of recent advances of AIE lumenogen (AIEgen)‐based nanoplatforms in the fields of detection, diagnosis, imaging, and therapeutics of surface organ‐related diseases and discuss their prospects in the domain. It is hoped that this review will help attract researchers’ attention toward the utilization of this field for the exploration of a wider range of biomedical and clinical applications.

The role of online hemodiafiltration with endogenous reinfusion in the treatment of systemic lupus erythematosus activity resistant to conventional therapy

Introduction

Lupus is a diverse autoimmune disease with autoantibody formation. Lupus nephritis carries a grave prognosis. Complement involvement, namely, C1q deficiency, is linked to activity and renal involvement and could help in their assessment. LN therapies include plasma exchange, immune adsorption, and probably hemodiafiltration with online endogenous reinfusion (HFR), together with traditional immunosuppressive therapies.

Aim

The aim of this study was to evaluate the role of HFR in improving signs and symptoms of systemic lupus erythematosus (SLE) activity and laboratory parameters in cases not responding to traditional immunosuppressive therapy.

Settings and design

A controlled clinical study was conducted on 60 patients with lupus from Group A that was subdivided into two groups: cases 1 (47 patients), those who received traditional medical treatment, and cases 2 (13 patients), those who underwent HFR in addition to medical treatment. Group B consisted of two subgroups: control 1, composed of 20 healthy age- and sex-matched volunteers, and control 2, consisting of 10 cases with different glomerular diseases other than lupus.

Methods and materials

Serum C1q was determined before and after the HFR as well as induction by medical treatment. Disease activity was assessed using SLEDAI-2K with a responder index of 50; quality of life was assessed using SLEQOL v2, and HFR was performed for the non-responder group.

Results

C1q was lower in cases. It can efficiently differentiate between SLE patients and healthy controls with a sensitivity of 81.67% and a specificity of 90%. It can also efficiently differentiate between SLE patients and the control 2 group (non-lupus patients with renal glomerular disease) with a sensitivity of 83.33% and a specificity of 100%. C1q was more consumed in proliferative lupus, and correlated with anti-ds DNA, C3, and C4.

Conclusions

C1q efficiently discriminates lupus patients and correlates with proliferative forms. HFR might ameliorate lupus activity and restore C1q.

Mathematical modeling in autoimmune diseases: from theory to clinical application

The research & development (R&D) of novel therapeutic agents for the treatment of autoimmune diseases is challenged by highly complex pathogenesis and multiple etiologies of these conditions. The number of targeted therapies available on the market is limited, whereas the prevalence of autoimmune conditions in the global population continues to rise. Mathematical modeling of biological systems is an essential tool which may be applied in support of decision-making across R&D drug programs to improve the probability of success in the development of novel medicines. Over the past decades, multiple models of autoimmune diseases have been developed. Models differ in the spectra of quantitative data used in their development and mathematical methods, as well as in the level of "mechanistic granularity" chosen to describe the underlying biology. Yet, all models strive towards the same goal: to quantitatively describe various aspects of the immune response. The aim of this review was to conduct a systematic review and analysis of mathematical models of autoimmune diseases focused on the mechanistic description of the immune system, to consolidate existing quantitative knowledge on autoimmune processes, and to outline potential directions of interest for future model-based analyses. Following a systematic literature review, 38 models describing the onset, progression, and/or the effect of treatment in 13 systemic and organ-specific autoimmune conditions were identified, most models developed for inflammatory bowel disease, multiple sclerosis, and lupus (5 models each). ≥70% of the models were developed as nonlinear systems of ordinary differential equations, others - as partial differential equations, integro-differential equations, Boolean networks, or probabilistic models. Despite covering a relatively wide range of diseases, most models described the same components of the immune system, such as T-cell response, cytokine influence, or the involvement of macrophages in autoimmune processes. All models were thoroughly analyzed with an emphasis on assumptions, limitations, and their potential applications in the development of novel medicines.

Celastrol ameliorates lupus by promoting apoptosis of autoimmune T cells and preventing autoimmune response in MRL/lpr mice

OBJECTIVE

Celastrol is a bioactive constituent extracted from Tripterygium wilfordii (thunder god vine). It has been demonstrated to have a therapeutic effect on experimental disease models for chronic inflammatory and immune disorders. In the present study, we investigated whether and how celastrol exerts a regulatory effect on the autoimmune response in MRL/lpr mice.

METHODS

We performed an in vivo study to determine the therapeutic effects of celastrol in MRL/lpr mice and then further investigated the underlying mechanism of celastrol in the regulation of the autoimmune response in MRL/lpr mice.

RESULTS

Celastrol showed a therapeutic effect in MRL/lpr mice by preventing the enlargement of the spleen and lymph nodes, alleviating renal injury, and reducing the levels of ANA and anti-double-stranded DNA antibodies. Furthermore, celastrol suppressed the in vivo inflammatory response in MRL/lpr mice by reducing the serum levels of multiple cytokines, including interleukin (IL)-6, tumour necrosis factor (TNF) and interferon (IFN)-γ, and the production of multiple antibody subsets, including total IgG, IgG1 and IgG2b. In vitro, celastrol reduced anti-CD3 antibody stimulation-induced T helper 1 and TNF-producing cells in CD4+ T cells of MRL/lpr mice. In addition, celastrol significantly affected B cell differentiation and prevented the generation of plasma cells from B cells in MRL/lpr mice by reducing the frequency of activated and germinal centre B cells. Celastrol treatment also affected T cell differentiation and significantly reduced central memory T cell frequencies in MRL/lpr mice. Importantly, celastrol treatment specifically promoted apoptosis of CD138+ but not CD138- T cells to suppress autoimmune T cell accumulation in MRL/lpr mice.

CONCLUSIONS

Celastrol exerted therapeutic effects on lupus by specifically promoting apoptosis of autoimmune T cells and preventing the progression of autoimmune response.

Autophagy: a necessary evil in cancer and inflammation

Autophagy, a highly regulated cellular process, assumes a dual role in the context of cancer. On the one hand, it functions as a crucial homeostatic pathway, responsible for degrading malfunctioning molecules and organelles, thereby maintaining cellular health. On the other hand, its involvement in cancer development and regression is multifaceted, contingent upon a myriad of factors. This review meticulously examines the intricacies of autophagy, from its molecular machinery orchestrated by Autophagy-Related Genes (ATG) initially discovered in yeast to the various modes of autophagy operative within cells. Beyond its foundational role in cellular maintenance, autophagy reveals context-specific functions in processes like angiogenesis and inflammation. Our analysis delves into how autophagy-related factors directly impact inflammation, underscoring their profound implications for cancer dynamics. Additionally, we extend our inquiry to explore autophagy's associations with cardiovascular conditions, neurodegenerative disorders, and autoimmune diseases, illuminating the broader medical relevance of this process. Furthermore, this review elucidates how autophagy contributes to sustaining hallmark cancer features, including stem cell maintenance, proliferation, angiogenesis, metastasis, and metabolic reprogramming. Autophagy emerges as a pivotal process that necessitates careful consideration in cancer treatment strategies. To this end, we investigate innovative approaches, ranging from enzyme-based therapies to MTOR inhibitors, lysosomal blockers, and nanoparticle-enabled interventions, all aimed at optimizing cancer treatment outcomes by targeting autophagy pathways. In summary, this comprehensive review provides a nuanced perspective on the intricate and context-dependent role of autophagy in cancer biology. Our exploration not only deepens our understanding of this fundamental process but also highlights its potential as a therapeutic target. By unraveling the complex interplay between autophagy and cancer, we pave the way for more precise and effective cancer treatments, promising better outcomes for patients.

Mendelian randomization reveals systemic lupus erythematosus and rheumatoid arthritis and risk of adverse pregnancy outcomes

BACKGROUND

The effect of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) on adverse pregnancy outcomes is a controversial topic. This study aimed to use Mendelian randomization (MR) analysis to assess the causal relationship between SLE, RA and adverse pregnancy outcomes.

METHODS

Genetic variants for SLE and RA, as well as adverse pregnancy outcomes, were derived from pooled statistics from large public genome-wide association studies. Several methods, such as inverse variance weighting (IVW), MR-Egger, weighted median and MR-Pleiotropic Residuals Sum and Outliers, were employed to estimate two-sample causality.

RESULTS

Genetic prediction of SLE was associated with higher odds of preterm labour [odds ratio (OR) 1.03, 95 % confidence interval (CI) 1.01-1.05; p = 0.008]. RA was associated with higher odds of preterm labour (OR 1.03, 95 % CI 1.01-1.06; p = 0.009), pre-eclampsia or eclampsia (OR 1.04, 95 % CI 1.01-1.07; p = 0.005), and poor fetal growth (OR 1.08, 95 % CI 1.04-1.12; p = 2.91 × 10-5). The results of bidirectional MR analysis did not indicate that SLE was associated with spontaneous abortion, pre-eclampsia or eclampsia, preterm rupture of membranes, or poor fetal growth (p-value for IVW 0.13-0.97).

CONCLUSIONS

This study found a genetic association between SLE and the risk of preterm labour, and highlights the importance of perinatal care and monitoring for patients with SLE. Furthermore, RA was found to be associated with a wide range of adverse outcomes, including preterm labour, pre-eclampsia or eclampsia, and poor fetal growth; as such, there is a need for more intensive therapeutic interventions and prenatal monitoring.

Novel multiclass classification machine learning approach for the early-stage classification of systemic autoimmune rheumatic diseases

OBJECTIVE

Systemic autoimmune rheumatic diseases (SARDs) encompass a diverse group of complex conditions with overlapping clinical features, making accurate diagnosis challenging. This study aims to develop a multiclass machine learning (ML) model for early-stage SARDs classification using accessible laboratory indicators.

METHODS

A total of 925 SARDs patients were included, categorised into SLE, Sjögren's syndrome (SS) and inflammatory myositis (IM). Clinical characteristics and laboratory markers were collected and nine key indicators, including anti-dsDNA, anti-SS-A60, anti-Sm/nRNP, antichromatin, anti-dsDNA (indirect immunofluorescence assay), haemoglobin (Hb), platelet, neutrophil percentage and cytoplasmic patterns (AC-19, AC-20), were selected for model building. Various ML algorithms were used to construct a tripartite classification ML model.

RESULTS

Patients were divided into two cohorts, cohort 1 was used to construct a tripartite classification model. Among models assessed, the random forest (RF) model demonstrated superior performance in distinguishing SLE, IM and SS (with area under curve=0.953, 0.903 and 0.836; accuracy= 0.892, 0.869 and 0.857; sensitivity= 0.890, 0.868 and 0.795; specificity= 0.910, 0.836 and 0.748; positive predictive value=0.922, 0.727 and 0.663; and negative predictive value= 0.854, 0.915 and 0.879). The RF model excelled in classifying SLE (precision=0.930, recall=0.985, F1 score=0.957). For IM and SS, RF model outcomes were (precision=0.793, 0.950; recall=0.920, 0.679; F1 score=0.852, 0.792). Cohort 2 served as an external validation set, achieving an overall accuracy of 87.3%. Individual classification performances for SLE, SS and IM were excellent, with precision, recall and F1 scores specified. SHAP analysis highlighted significant contributions from antibody profiles.

CONCLUSION

This pioneering multiclass ML model, using basic laboratory indicators, enhances clinical feasibility and demonstrates promising potential for SARDs classification. The collaboration of clinical expertise and ML offers a nuanced approach to SARDs classification, with potential for enhanced patient care.

Janus-kinase inhibitors in dermatology: A review of their use in psoriasis, vitiligo, systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease

Recent studies on molecular pathways have elucidated novel therapeutic approaches in inflammatory and autoimmune skin disorders. Specifically, the dysregulation of the Janus kinase signal transducer and activator of transcription (JAK-STAT) cascade plays a central role in the pathogenesis of many skin conditions. JAK inhibitors, with their ability to selectively target immune responses, are potential treatment options. Using the National Library of Medicine, we provide a comprehensive review of the use of United States Food and Drug Administration (FDA)-approved and emerging JAK or tyrosine kinase 2 (TYK2) inhibitors in a wide range of dermatologic conditions, including psoriasis, vitiligo, systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease. In patients with psoriasis, oral deucravacitinib (TYK2 inhibitor) has been approved as a once-daily therapy with demonstrated superiority and efficacy over apremilast and placebo and tolerable safety profiles. In patients with vitiligo, topical ruxolitinib (JAK1 inhibitor) is approved as a twice-daily treatment for repigmentation. The efficacy of several other JAK inhibitors has also been demonstrated in several clinical trials and case studies for systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease. Further investigations with long-term clinical trials are necessary to confirm their utility in treatment and safety for these diseases.

Response to belimumab among patients with refractory lupus nephritis: a real-world observational retrospective multicenter study

OBJECTIVES

Belimumab is a biological agent approved for the treatment of active lupus nephritis (LN), but its efficacy on refractory lupus nephritis (LN) is unknown. This study aims to evaluate the efficacy and safety of belimumab in Chinese patients with refractory LN.

METHODS

This multicenter, observational, and retrospective study enrolled patients with refractory LN who failed induction therapy with steroids, cyclophosphamide, mycophenolate, and calcineurin inhibitors and received 24-week belimumab treatment before data analysis. Treatment outcomes include the overall clinical response (physician judgment, disease activity, organ damage) and renal response (complete renal response, partial renal response, no renal response). Laboratory indices and adverse events were recorded as well.

RESULTS

Of the 45 patients enrolled in the study, 6 (13.3%) achieved complete renal response, 19 (42.2%) achieved partial renal response, and the overall renal response rate was 55.6%. Median rSLEDAI decreased from 12 (IQR 8-12) at baseline to 8 (IQR 4-8) (p < 0.0001), 4 (IQR 4-8) (p < 0.0001) at 12 and 24 weeks. Mean urinary protein decreased more than 50% from 3.2 g/24 h at baseline to 1.0 g/24 h at 24 weeks (p < 0.0001). The conditions of hypoalbuminemia and hypocomplementemia had also gradually improved. The levels of autoantibodies showed a significant downward trend. Additionally, 9 (20.0%) patients successfully reduced the dosage of prednisone to a safe range, and 3 of them achieved their treatment goal of prednisone cessation. The mean prednisone dosage decreased from 32.7 mg/day at baseline to 18.6 mg/day (p < 0.0001), 13.3 mg/day (p < 0.0001) at 12 and 24 weeks. There were 3 adverse events reported, including 2 cases of infection, and 1 case of allergy. No serious events occurred during the follow-up.

CONCLUSIONS

Belimumab is effective and safe when used in clinical practice, which can be considered as an add-on therapy for refractory LN. Key Points • A multicenter observational study in the real clinical settings of China. • First revealed the efficacy and safety of belimumab in Chinese patients with refractory LN.

Increased formation of neutrophil extracellular traps induced by autophagy and identification of autophagy-related biomarkers in systemic lupus erythematosus

Abnormal death of neutrophils and the subsequent ineffective clearance of cell fragments result in production of autoantigens that can lead to systemic lupus erythematosus (SLE). Excessive formation of neutrophil extracellular traps (NETs) can trigger the synthesis of pro-inflammatory cytokines such as type I interferons, leading to tissue damage and immune dysfunction in SLE patients. In this study, we found that a decrease in neutrophil counts in the peripheral blood was correlated with clinical parameters in SLE patients. Patients with low neutrophil counts had high renal activity index and chronicity index scores. NET formation and neutrophil autophagy in SLE patients were increased. The autophagy inhibitor hydroxychloroquine was shown to restrict NET formation. Using comprehensive bioinformatics analysis, we found that the expression of the autophagy-related gene, hypoxia-inducible factor 1A (HIF1A), was enhanced in peripheral neutrophils and in the renal glomeruli in SLE patients. Targeting HIF1A could be a potential therapeutic approach for SLE.

Systemic Lupus Erythematosus and Cytokine Storm

Systemic lupus erythematosus (SLE) is the prototype of autoimmune diseases and can manifest with a plethora of clinical signs and symptoms associated with a myriad of laboratory abnormalities. An infrequent but potentially lethal complication of SLE is macrophage activation syndrome (MAS). The diagnosis of MAS in SLE can be very challenging due to similarities in presentation of both flares and infections, such as fever, lymphadenopathy, splenomegaly, and cytopenias. These aggravating factors contribute to the increased risk of poor outcomes in SLE-associated MAS. Indeed, at the moment MAS remains invariably lethal if untreated and still has a high mortality rate with treatment. In this chapter, we discuss several aspects of MAS in the context of SLE and in particular, the pathogenesis of MAS in SLE, how MAS presents in pediatric versus adult SLE, and, finally, MAS treatment in SLE and future directions.

CD138 promotes the accumulation and activation of autoreactive T cells in autoimmune MRL/lpr mice

Autoreactive T cells, specifically CD138+ (syndecan-1) T cells produced in Fas-deficient systemic lupus erythematosus (SLE) mouse models, were shown to significantly promote the generation of autoantibodies. In the present study, Murphy Roths Large lymphoproliferative (MRL/lpr) lupus mice were used to investigate the role of CD138 protein expression in T cells in the progression of SLE. Measurement of flow cytometry, immunofluorescence and Luminex were performed to determine the effect of CD138 on T cells in MRL/lpr mice. The results demonstrate that CD138+ T cells induce apoptosis via a Fas-dependent pathway. CD138 protein expression in T cells of MRL/lpr mice significantly reduced T cell apoptosis and contributed to the accumulation of T cells and double negative (DN) T cells, whilst simultaneously promoting T cell activation in Fas-deficient lupus mice. CD138 protein expression in DN T cells also significantly increased the protein expression of Fas ligand to enhance the cytotoxicity of DN T cells. Furthermore, phorbol 12-myristate 13-acetate and ionomycin (PI) stimulation reduced CD138 protein expression in CD3+ T cells and prevented CD138+ T cell accumulation by inducing specific apoptosis. PI stimulation also activated T cells in MRL/lpr mice to increase CD69 protein expression. CD69 protein expression in CD138+ T cells significantly increased the frequency of apoptotic CD138+ T cells. In addition, results from the present study demonstrated that CD138- T cells of MRL/lpr lupus mice had an activation defect. CD138 protein expression in T cells significantly reversed the defective activation and activating T cells could significantly reduce CD138 protein expression in CD3+ T cells of MRL/lpr mice. This suggests that CD138 protein expression in CD3+CD138- T cells of MRL/lpr mice may be a consequence of the impaired activation in autoreactive T cells prior to exposure to self-antigens by the immune system. CD138 expression in autoreactive T cells has a central role in promoting the progression and development of autoimmune response in MRL/lpr mice.

Sphingosine 1-phosphate signaling during infection and immunity

Sphingolipids are essential components of all eukaryotic membranes. The bioactive sphingolipid molecule, Sphingosine 1-Phosphate (S1P), regulates various important biological functions. This review aims to provide a comprehensive overview of the role of S1P signaling pathway in various immune cell functions under different pathophysiological conditions including bacterial and viral infections, autoimmune disorders, inflammation, and cancer. We covered the aspects of S1P pathways in NOD/TLR pathways, bacterial and viral infections, autoimmune disorders, and tumor immunology. This implies that targeting S1P signaling can be used as a strategy to block these pathologies. Our current understanding of targeting various components of S1P signaling for therapeutic purposes and the present status of S1P pathway inhibitors or modulators in disease conditions where the host immune system plays a pivotal role is the primary focus of this review.