Balance between inflammatory and regulatory cytokines in systemic lupus erythematosus

Is Th17-Targeted Therapy Effective in Systemic Lupus Erythematosus?

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a broad spectrum of clinical manifestations. The proposed pathophysiological hypotheses of SLE are numerous, involving both innate and adaptive abnormal immune responses. SLE is characterized by the overproduction of different autoantibodies that form immune complexes, which cause damage in different organs. Current therapeutic modalities are anti-inflammatory and immunosuppressive. In the last decade, we have witnessed the development of many biologicals targeting different cytokines and other molecules. One of them is interleukin-17 (IL-17), a central cytokine of a proinflammatory process that is mediated by a group of helper T cells called Th17. Direct inhibitors of IL-17 are used in psoriatic arthritis, spondyloarthritis, and other diseases. Evidence about the therapeutic potential of Th17-targeted therapies in SLE is scarce, and probably the most promising is related to lupus nephritis. As SLE is a complex heterogeneous disease with different cytokines involved in its pathogenesis, it is highly unlikely that inhibition of only one molecule, such as IL-17, will be effective in the treatment of all clinical manifestations. Future studies should identify SLE patients that are eligible for Th17-targeted therapy.

The conundrum of neuropsychiatric systemic lupus erythematosus: Current and novel approaches to diagnosis

Recognising neuropsychiatric involvement by systemic lupus erythematosus (SLE) is of growing importance, however many barriers to this exist at multiple levels of our currently available diagnostic algorithms that may ultimately delay its diagnosis and subsequent treatment. The heterogeneous and non-specific clinical syndromes, serological and cerebrospinal fluid (CSF) markers and neuroimaging findings that often do not mirror disease activity, highlight important research gaps in the diagnosis of neuropsychiatric SLE (NPSLE). Formal neuropsychological assessments or the more accessible screening metrics may also help improve objective recognition of cognitive or mood disorders. Novel serum and CSF markers, including autoantibodies, cytokines and chemokines have also shown increasing utility as part of diagnosis and monitoring, as well as in distinguishing NPSLE from SLE patients without SLE-related neuropsychiatric manifestations. Novel neuroimaging studies also expand upon our existing strategy by quantifying parameters that indicate microarchitectural integrity or provide an assessment of neuronal function. Some of these novel markers have shown associations with specific neuropsychiatric syndromes, suggesting that future research move away from considering NPSLE as a single entity but rather into its individually recognized neuropsychiatric manifestations. Nevertheless, it is likely that a composite panel of these investigations will be needed to better address the gaps impeding recognition of neuropsychiatric involvement by SLE.

Longitudinal comparison of IL-6, IL-10, and IL-12 cytokine profiles in adult and childhood-onset systemic lupus erythematosus

Objective

To compare the levels of Th1 (IL-12) and Th2 (IL-6 and IL10) cytokines over a two-year period among systemic lupus erythematosus patients with childhood-onset (cSLE), adult-onset (sSLE), and healthy controls, and correlate with their clinical, laboratory, and treatment manifestations.

Methods

The study included 63 patients with cSLE [57 (90%) women; mean age 19.7 ± 4.3 years (range = 10-29); mean disease duration 7.3 ± 4.2 years (range 2-15)], 67 patients with aSLE [65 (97%) women; mean age of 39.9 ± 11.8 years (range 21-68); disease duration 7.7 ± 3.1 years (range 4-16)], and 40 healthy controls [36 (90%) women; mean age of 29.6 ± 10 years (range 12-49)]. cSLE and aSLE patients were paired by disease duration. Clinical and laboratory manifestations, disease activity (SLEDAI), cumulative damage (SDI), and current drug exposures were evaluated. Symptoms of anxiety and depression were evaluated by the Beck inventory (BAI and BDI, respectively). Th1 (IL-12) and Th2 (IL-6 and IL-10) cytokines were measured by the ELISA test. Data were collected at four different time points (TI, TII, TIII, and TIV) and compared by non-parametric tests.

Results

IL-6 levels were significantly higher in aSLE patients compared to healthy controls at times I, II, and III (TI p = 0.013, TII p = 0.015, TIII p = 0.004, and TIV p = 0.634). However, no difference was observed between cSLE patients and healthy controls (TI p = 0.223, TII p = 0.613, TIII p = 0.341, and TIV p = 0.977). In addition, no difference was observed between aSLE and cSLE patients (TI p = 0.377, TII p = 0.123, TIII p = 0.105, and TIV p = 0.591). The levels of IL-12 were significantly higher in cSLE patients compared to healthy controls at all time points (TI p = 0.04, TII p < 0.001, TIII p = 0.015, and TIV p = 0.021). aSLE patients showed significantly elevated levels when compared to healthy controls at time III and IV (TI p = 0.752, TII p = 0.827, TIII p = 0.011*, and TIV p < 0.001*). cSLE patients showed significantly higher levels than aSLE patients at times I and II (TI p = 0.07*, TII p < 0.001*, TIII p = 0.998, and TIV p = 0.140). In aSLE patients, IL-6 was associated with headache (p = 0.006), arthritis (p = 0.044), and nephritis (p = 0.012); IL-10 was associated with nephritis (p = 0.043), hypocomplementemia (p = 0.001), and disease activity (p = 0.001); in these patients, IL-12 was associated with alopecia (p = 0.025) and leukopenia (p = 0.044). In cSLE patients, IL-6 was associated with arthritis (p = 0.022) and malar rash (p = 0.012).

Conclusion

aSLE and cSLE patients with long disease duration present similar levels of cytokines, despite differences in clinical activity patterns over time.

Circulating IL-17 Level Is Positively Associated with Disease Activity in Patients with Systemic Lupus Erythematosus: A Systematic Review and Meta-Analysis

Previous studies on the relationship between the circulating level of interleukin-17 (IL-17) and disease activity in systemic lupus erythematosus (SLE) were contradictory. This study is aimed at quantitatively assessing the correlation between the circulating IL-17 level and disease activity in SLE patients. A systematic search for related literature was conducted via PubMed, Web of Science, EMBASE, and Cochrane Library (up to January 26, 2021). The relationship between circulating IL-17 levels and SLE activity was evaluated using Fisher's z value, which was then converted to r. The standardized mean difference (SMD) and its 95% confidence interval (CI) were used to describe the difference between the circulating IL-17 level in patients with active and inactive SLE. STATA 16.0 was used to perform statistical analysis. Random-effects model was performed to synthesize data. Twenty-six studies involving 1,560 SLE patients were included in this review. The pooled r value was 0.38 (95% CI: 0.25-0.50; I² = 83.8%, P < 0.001) between the SLE activity and circulating level of IL-17. Patients with active SLE had higher level of circulating IL-17 than that of inactive (pooled SMD = 0.95, 95% CI: 0.38-1.53; I² = 90.5%, P < 0.001). The subgroup analysis suggested that the region and detection method of circulating IL-17 might not be a source of heterogeneity. No significant publication bias was found. In summary, circulating IL-17 level has a low positive relationship with SLE activity. It is necessary to carefully consider the use of circulating IL-17 as a biomarker of the disease activity in SLE patients. The relationship between the circulating level of IL-17 and SLE activity should be further confirmed in randomized controlled studies.

Aspergillus fumigatus Induces the Release of IL-8 and MCP-1 by Activating Nuclear Transcription Through Dectin-1 and CR3 Receptors in Alveolar Epithelial Cells

Invasive pulmonary aspergillosis induced by the pathogenic fungus Aspergillus fumigatus is one of the common fatal complications in immunocompromised patients. Lung epithelial cells play an important role in host immune defense against A. fumigatus. However, the interaction between lung epithelial cells and A. fumigatus conidia is not fully understood. In this study, we used the swollen conidia of A. fumigatus to stimulate the type II lung epithelial A549 cells. Results showed that swollen conidia could significantly increase RNA transcription and protein expression of interleukin 8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1), but not TNF-α in A549 cells in a time-dependent manner. Moreover, serum opsonization was able to improve the release of inflammatory factors induced by swollen conidia. Blocking of the dectin-1 or CR3 receptors, or both simultaneously, in the A549 cells could decrease the release of IL-8 and MCP-1. Additionally, blocking dectin-1 or CR3 could inhibit the transcription of nuclear factor NF-κB that was activated by swollen conidia. Here we reported for the first time that dectin-1 and CR3 receptors in A549 cells mediate the release of pro-inflammatory factors IL-8 and MCP-1 induced by A. fumigatus.

Cytokine clusters as potential diagnostic markers of disease activity and renal involvement in systemic lupus erythematosus

OBJECTIVE

To describe interactions among cytokines and to identify subgroups of systemic lupus erythematosus (SLE) patients based on cytokine levels using principal component analysis and cluster analysis.

METHODS

Levels of 12 cytokines were measured using sensitive multiplex bead assays and associations with SLE features including disease activity and renal involvement were assessed.

RESULTS

In a group of 203 SLE patients, strong correlations were observed between interleukin (IL)6 and interferon (IFN)γ levels (r = 0.624), IL17 and IFNγ levels (r = 0.768), and macrophage inflammatory protein (MIP)1α and MIP1β levels (r = 0.675). Cluster analysis revealed two distinct patient groups characterized by high levels of IL8, MIP1α, and MIP1β (group 1) or of IL2, IL6, IL10, IL12, IFNγ, and tumor necrosis factor α (group 2). Active disease was more common in group 1 (49/88, 55.7%) than in group 2 (40/115, 34.8%). More patients in group 2 had renal involvement (42/115, 36.5%) than in group 1 (22/88, 25%).

CONCLUSIONS

Assessment of cytokine profiles can identify distinct SLE patient subgroups and aid in understanding clinical heterogeneity and immunological phenotypes.

Seizures in systemic lupus erythematosus: A scoping review

Systemic lupus erythematosus is a systemic autoimmune disease that affects the central nervous system, either by direct neuronal damage, injury to brain vessels, or by pathogenic mechanisms indirectly induced by immune mechanisms related to the production and deposition of immune complexes. The prevalence of explicit episodes of seizures among SLE patients, varies from 2 to 8%. In some cases, patients with positivity for antiphospholipid or anti-β2 glycoprotein antibodies are found to be more prone to exhibit seizures compared to seronegative patients, other subjects at risk are carries of gene abnormalities codifying for ion channels. The exclusion of vasculitis or thrombosis is required for accurate treatment, imaging studies and alternative sequences are mandatory in patients with known SLE who present with a seizure. Several statements regarding SLE-related seizure remain to be decoded. In this scoping review we analyzed published information about prevalence, pathogenesis, clinical characteristics, diagnostic and therapeutic SLE patients that manifest a seizure, our objective is to provide with useful information for prompt diagnosis and individualized treatment.

Clinical disease activity and flare in SLE: Current concepts and novel biomarkers

Systemic lupus erythematosus (SLE) is a complex and heterogeneous systemic autoimmune disease associated with innate and adaptive immune dysregulation. SLE occurs primarily in females of childbearing age, with increased prevalence and severity in minority populations. Despite improvements in treatment modalities, SLE patients frequently experience periods of heightened disease activity and flare that can lead to permanent organ damage, increased morbidity, and early mortality. Such outcomes impair quality of life and inflict a significant socioeconomic burden. Predicting changes in SLE disease activity could allow for closer monitoring and preemptive treatment, but existing clinical, demographic and serologic markers have been only modestly predictive. Novel, proactive approaches to clinical disease management are thus critically needed. Panels of blood biomarkers can detect a breadth of immune pathway dysregulation that captures SLE heterogeneity and disease activity. Alterations in the balance of pro-inflammatory and regulatory soluble mediators have been associated with changes in clinical disease activity and are detectable several weeks prior to clinical flare occurrence. A soluble mediator score has been highly predictive of impending flare in both European American and African American SLE patients, and this score does not require a priori knowledge of specific pathway activation in the patient. We review current concepts of disease activity and flare in SLE, focusing on the potential of novel blood biomarkers to characterize and predict changes in disease activity. Measuring the disordered immune response in SLE in this way promises to improve disease management and prevent organ damage in SLE.

Tissue-resident macrophages actively suppress IL-1beta release via a reactive prostanoid/IL-10 pathway

The alarm cytokine interleukin‐1β (IL‐1β) is a potent activator of the inflammatory cascade following pathogen recognition. IL‐1β production typically requires two signals: first, priming by recognition of pathogen‐associated molecular patterns leads to the production of immature pro‐IL‐1β; subsequently, inflammasome activation by a secondary signal allows cleavage and maturation of IL‐1β from its pro‐form. However, despite the important role of IL‐1β in controlling local and systemic inflammation, its overall regulation is still not fully understood. Here we demonstrate that peritoneal tissue‐resident macrophages use an active inhibitory pathway, to suppress IL‐1β processing, which can otherwise occur in the absence of a second signal. Programming by the transcription factor Gata6 controls the expression of prostacyclin synthase, which is required for prostacyclin production after lipopolysaccharide stimulation and optimal induction of IL‐10. In the absence of secondary signal, IL‐10 potently inhibits IL‐1β processing, providing a previously unrecognized control of IL‐1β in tissue‐resident macrophages.

Relationship between Neutrophil-to-Lymphocyte Ratio and Systemic Lupus Erythematosus: A Meta-analysis

Systemic lupus erythematosus (SLE) is a chronic systematic autoimmune disease. Current methods of diagnosing SLE or evaluating its activity are complex and expensive. Numerous studies have suggested that neutrophil-to-lymphocyte ratio (NLR) is closely correlated with the presence of SLE and its activity, suggesting that it may serve as a diagnostic and monitoring indicator for SLE. Therefore, we performed a meta-analysis to systematically assess the association between NLR and SLE. We performed a literature search until 12 April 2019 in the PubMed, Web of Science, and China National Knowledge Infrastructure databases. Cross-sectional studies comparing the NLR of SLE patients versus those of healthy controls, of active versus inactive SLE patients, and of SLE patients with versus without lupus nephritis were considered for inclusion. Mean intergroup NLR differences were estimated using standardized mean differences and their 95% confidence intervals. Study quality was assessed using the Agency for Healthcare Research and Quality instrument for cross-sectional studies. Fourteen studies with 1,781 SLE patients and 1,330 healthy controls were included in this meta-analysis. The pooled results showed that the NLR was significantly higher in SLE patients than in healthy controls, in active SLE patients than in inactive SLE patients, and in SLE patients with lupus nephritis than in those without lupus nephritis. NLR may be an indicator for monitoring disease activity and reflecting renal involvement in SLE patients. Nevertheless, more high-quality studies are warranted to further validate our findings.

Elevated Circulating Interleukin-17 Levels in Patients with Systemic Lupus Erythematosus: A Meta-analysis

BACKGROUND

Previous studies concerning the circulating interleukin-17 (IL-17) in systemic lupus erythematosus (SLE) were contradictory.

AIMS

To further precisely investigate circulating IL-17 in SLE and evaluate its influential factors by meta-analysis.

METHODS

EMBASE, PubMed and Cochrane Library were comprehensively searched to obtain studies on circulating IL-17 in SLE patients by November 22, 2018. The results were illustrated by pooled standard mean difference (SMD) with corresponding 95% confidence interval (CI) using random-effects model as there was significant heterogeneity, which was estimated using Cochran Q and I² statistics. Subgroup analyses and sensitivity analyses were also conducted.

RESULTS

Overall, 1872 articles were reviewed and 20 studies involving 1067 subjects with SLE and 721 healthy controls (HCs) were enrolled in the final analysis according to inclusion criteria. Compared with HCs, circulating IL-17 levels in SLE patients were elevated (SMD: 1.183, 95% CI: 0.763-1.603; P < .001). Moreover, in comparison to HCs, European and Asian SLE patients, age <30 years, disease duration ≥5 years, NOS scores <7 and using ELISA showed increased circulating IL-17 status, whereas no significant change was observed in other subgroups. There was no significant publication bias. Sensitivity analyses demonstrated that the results of our meta-analysis were robust.

CONCLUSIONS

SLE patients have higher circulating IL-17 levels, which is influenced by ethnic, age and disease duration, literature quality and measurements.

Increased interferon-1α, interleukin-10 and BLyS concentrations as clinical activity biomarkers in systemic lupus erythematosus

BACKGROUND AND OBJECTIVE

to analyse the association between interferon-1α (INF1α), interleukin-10 (IL-10) and BLyS concentrations and clinical activity in systemic lupus erythematosus (SLE).

PATIENTS AND METHODS

A cross-sectional, observational study of 142 SLE patients and 34 healthy controls was performed, through a complete blood and urine test and review of their medical history. Serum concentration of INF1α, IL-10 and BLyS was determined by colorimetric methods. A biostatistical analysis was performed with R (3.3.2.).

RESULTS

69% of our SLE patients showed at least one cytokine increased. INF1α, IL-10 and BLyS are higher in SLE patients than in healthy controls (P<.001, P=.005 and P=.043, respectively), being INF1α the most frequent. Patients were categorised according to low or high concentrations of the three cytokines. We found a significant association between increased IL-10/INF1α concentrations and a higher clinical activity measured by SELENA-SLEDAI (P<.0001) and, to a lesser extent, an association with increased INF1α/IL-10/BLyS concentrations. Elevated levels of IL-10/INF1α and INF1α/IL-10/BLyS related to increased C3-C4 consumption (P<.001 and P=.001 respectively) and anti-dsDNA titres (P=.001 and P=.002 respectively). Elevated INF1α/BLyS related to higher anti-dsDNA titres (P=.004) and ENA positivity (P<.001). Increased levels of INF1α/IL-10/BLyS related to positivity of ANAs (P<.001) and APL (P=.004).

CONCLUSIONS

INF1α, IL-10 and BLyS are higher in SLE patients than in healthy controls. Increased IL-10 levels, regardless of whether or not there were also increased levels of BLyS and/or INF1α, was the cytokine that best fit with clinical activity in SLE measured with classic methods.

Stability and inhibitory function of Treg cells under inflammatory conditions in vitro

Immunotherapy with transplanted T-regulatory (Treg) cells is currently in use. However, patients have complex internal environments with confounding factors, including the presence of inflammatory cytokines. The present study aimed to detect Treg cell function under simulated inflammatory conditions to provide a foundation for Treg cell-based immunotherapy. CD4⁺CD25^high Treg cells were sorted from peripheral blood mononuclear cells and cultured for 14 days in the presence of recombinant human interleukin-2 (rhIL-2) and anti-CD3/CD28 beads, with or without 25 ng/ml rhIL-6. Next, the absolute count of Treg cells was determined, the stability and activity were detected by measuring the expression levels of forkhead box (Fox)P3 and CD39, and the suppressive function of Treg cells was investigated by assessing the suppression of T-effector cell proliferation by Treg cells after co-culture for 5 days. The number of Treg cells cultured in the presence of 25 ng/ml rhIL-6 for 14 days was reduced by 49.7% when compared with that of cells cultured without rhIL-6. Of the Treg cells continually cultured for 14 days without or with 25 ng/ml rhIL-6, 56.15 and 24.7% expressed FoxP3, respectively. There was no difference in the activity of the FoxP3⁺ Treg cells after culture for 14 days without or with 25 ng/ml rhIL-6. The suppressive function of Treg cells tended to deteriorate in the presence of rhIL-6. In conclusion, IL-6 inhibited the proliferation and stability of Treg cells, suggesting that administration of increased numbers of Treg cells may be required during Treg cell-based immunotherapy.

MicroRNA Post-transcriptional Regulation of the NLRP3 Inflammasome in Immunopathologies

Inflammation has a crucial role in protection against various pathogens. The inflammasome is an intracellular multiprotein signaling complex that is linked to pathogen sensing and initiation of the inflammatory response in physiological and pathological conditions. The most characterized inflammasome is the NLRP3 inflammasome, which is a known sensor of cell stress and is tightly regulated in resting cells. However, altered regulation of the NLRP3 inflammasome is found in several pathological conditions, including autoimmune disease and cancer. NLRP3 expression was shown to be post-transcriptionally regulated and multiple miRNA have been implicated in post-transcriptional regulation of the inflammasome. Therefore, in recent years, miRNA based post-transcriptional control of NLRP3 has become a focus of much research, especially as a potential therapeutic approach. In this review, we provide a summary of the recent investigations on the role of miRNA in the post-transcriptional control of the NLRP3 inflammasome, a key regulator of pro-inflammatory IL-1β and IL-18 cytokine production. Current approaches to targeting the inflammasome product were shown to be an effective treatment for diseases linked to NLRP3 overexpression. Although utilizing NLRP3 targeting miRNAs was shown to be a successful therapeutic approach in several animal models, their therapeutic application in patients remains to be determined.

Anti-IL-10 antibody in systemic lupus erythematosus

Purpose

IL-10 is a cytokine known to inhibit inflammatory cytokines. To determine its role in the pathogenesis of systemic lupus erythematosus (SLE), the presence of anti-IL-10 antibody is required to be examined. Although antibodies against cytokines are known to be present in SLE, no studies have determined the role of IL-10, particularly in Japanese patients. We assayed anti-IL-10 antibody in SLE and examined the clinical significance.

Patients and methods

We performed a retrospective study of 80 Japanese patients with SLE. Sixteen scleroderma patients, 19 rheumatoid arthritis (RA) patients, 23 Behcet’s disease patients, and 23 healthy subjects were selected as control groups. Clinical information was abstracted from medical records. Anti-IL-10 antibody level was determined with an ELISA.

Results

With the cutoff established as serum absorbance +2 SDs (OD 0.729) in healthy subjects, we defined any sample above this cutoff as anti-IL-10 antibody-positive. Fourteen patients with SLE (17.5%) were found to be anti-IL-10 antibody positive. Absorbance was significantly higher in serum from patients with SLE and RA than in healthy individuals. In SLE, patients with low complement values were significantly more common in the antibody-positive group. Serum IgG levels were significantly higher in the antibody-positive group. In multivariable analysis, high level of serum IgG is associated with anti-IL-10 antibody positive.

Conclusion

The present study found that anti-IL-10 antibody is present in SLE and related to clinical parameters. These results suggest that the presence of anti-IL-10 antibody was associated with high level of serum IgG, but is not associated with disease activity in patients with SLE.

Mycophenolate mofetil reduces STAT3 phosphorylation in systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) is a highly variable autoimmune disease that can involve severe organ-threatening symptoms, such as lupus nephritis. Certain drugs, such as mycophenolate mofetil (MMF), are effective at reducing morbidity associated with nephritis; however, the immune pathways associated with disease suppression are poorly defined. Here, we provide evidence that MMF inhibits phosphorylation of STAT3 and other associated immune pathways. Using mass cytometry and bead-based or ELISA assays, the systemic phenotype of SLE patients not taking (MMF-) or taking (MMF+) MMF were studied. MMF+ SLE patients had significant reductions in total numbers of transitional B cells, plasmablasts, and T cells, specifically CD4+ Th17-type and CD4+ Treg-type cells, compared with MMF- patients. Plasma soluble mediators were decreased in MMF+ patients including chemokines (MIG/CXCL9 and SDF-1α/CXCL12) and growth factors (VEGF-A and PDGF-BB). Soluble mediators and cell subsets grouped by functional properties revealed significant modifications associated with STAT3 and B cell pathways. Further, healthy PBMCs treated with IL-6 revealed a reduction in p-STAT3 following the addition of mycophenolic acid (the active metabolite of MMF). In conclusion, the inhibition of STAT3 phosphorylation by MMF may explain the effectiveness of this treatment in SLE patients, since increased levels of p-STAT3 are associated with disease pathology.

Analysis of Serum Interleukin (IL)-1β and IL-18 in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disease characterized by biological and clinical heterogeneity. The interleukin (IL)-1 superfamily is a group of innate cytokines that contribute to pathogenesis in many autoimmune diseases. IL-1β and IL-18 are two members that have been shown to play a role in murine lupus-like models, but their role in human SLE remains poorly understood. Here, IL-1β and IL-18 were quantified by enzyme-linked immunosorbent assay in the serum of healthy controls (HCs) and SLE patients from a prospectively followed cohort. Disease activity and organ damage were assessed using SLE disease activity index 2000 (SLEDAI-2K) and SLE damage index scores (SDI), respectively. 184 SLE patients (mean age 44.9 years, 91% female, 56% double-stranded deoxyribonucleic acid positive) were compared to 52 HC. SLE patients had median [IQR] SLEDAI-2K of 4 [2,6], and SDI of 1 [0–2]. Serum IL-18 levels were statistically significantly higher in SLE patients compared to HCs. Univariable linear regression analyses showed that patients with active renal disease or irreversible organ damage had statistically significantly elevated serum IL-18 levels. The association between serum IL-18 and active renal disease was confirmed in multivariable analysis after adjusting for ethnicity and organ damage. High baseline serum IL-18 levels were associated with organ damage at the subsequent visit. Serum IL-1β levels were not significantly elevated in SLE patients when compared to HCs and had no association with overall or organ-specific disease activity or organ damage in cross-sectional and longitudinal analyses. Our data suggest that serum IL-18 and IL-1β have different clinical implications in SLE, with IL-18 being potentially associated with active renal disease.

Pathways of impending disease flare in African-American systemic lupus erythematosus patients

Immune dysregulation in systemic lupus erythematosus (SLE) contributes to increased disease activity. African-American (AA) SLE patients have an increased prevalence of complications from disease flares and end-organ damage that leads to increased morbidity and early mortality. We previously reported alterations in inflammatory and regulatory immune mediator levels prior to disease flare in European American (EA) SLE patients. In the current study, we assessed baseline and follow-up plasma levels of 52 soluble mediators, including innate, adaptive, chemokine, and TNF superfamily members, in AA SLE patients who developed SELENA-SLEDAI defined flare 6 or 12 weeks after baseline assessment. These patients were compared to themselves during a comparable, clinically stable period (SNF, n = 18), or to demographically matched SLE patients without impending disease flare (NF, n = 13 per group). We observed significant (q < 0.05) alterations in 34 soluble mediators at baseline, with increased levels of both innate (IL-1α and type I interferons [IFN]) and adaptive cytokines (Th1-, Th2-, and Th17-type), as well as IFN-associated chemokines and soluble TNF superfamily members weeks before clinical disease flare. In contrast, stable SLE patients exhibited increased levels of the regulatory mediators IL-10 (q ≤ 0.0045) and TGF-β (q ≤ 0.0004). Because heterogeneous immune pathways were altered prior to clinical disease flare, we developed a soluble mediator score that encapsulates all mediators tested. This score is the sum of all log transformed, standardized soluble mediator levels assessed at baseline (pre-flare), weighted by their Spearman correlation coefficients for association with the SELENA-SLEDAI score at time of concurrent flare. While baseline SELENA-SLEDAI scores were similar between flare vs. NF (p = 0.7214) and SNF (p = 0.5387), the SMS was significantly higher in pre-flare SLE patients (Flare vs NF or SNF, p < 0.0001). By capturing alterations in the balance between inflammatory and regulatory mediators associated with SLE pathogenesis, the soluble mediator score approximates the immune status of SLE patients and provides a robust, predictive gauge of impending disease flare.