Author Correction: STEEP mediates STING ER exit and activation of signaling.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

STEEP mediates STING ER exit and activation of signaling.

STING is essential for control of infections and for tumor immunosurveillance, but it can also drive pathological inflammation. STING resides on the endoplasmic reticulum (ER) and traffics following stimulation to the ERGIC/Golgi, where signaling occurs. Although STING ER exit is the rate-limiting step in STING signaling, the mechanism that drives this process is not understood. Here we identify STEEP as a positive regulator of STING signaling. STEEP was associated with STING and promoted trafficking from the ER. This was mediated through stimulation of phosphatidylinositol-3-phosphate (PtdIns(3)P) production and ER membrane curvature formation, thus inducing COPII-mediated ER-to-Golgi trafficking of STING. Depletion of STEEP impaired STING-driven gene expression in response to virus infection in brain tissue and in cells from patients with STING-associated diseases. Interestingly, STING gain-of-function mutants from patients interacted strongly with STEEP, leading to increased ER PtdIns(3)P levels and membrane curvature. Thus, STEEP enables STING signaling by promoting ER exit.

Inter-α-trypsin inhibitor heavy chain 4 (ITIH4) as a compensatory protease inhibitor in hereditary angioedema.

BACKGROUND: Hereditary angioedema (HAE) is a genetic disorder that manifests as recurrent angioedema attacks, most frequently due to absent or reduced C1 inhibitor (C1INH) activity. C1INH is a crucial regulator of enzymatic cascades in the complement, fibrinolytic, and contact systems. Inter-α-trypsin inhibitor heavy chain 4 (ITIH4) is an abundant plasma protease inhibitor that can inhibit enzymes in the proteolytic pathways associated with HAE. Nothing is known about its role in HAE. OBJECTIVE: We investigated ITIH4 activation in HAE, establishing it as a potential biomarker, and explored its involvement in HAE-associated proteolytic pathways. METHODS: Specific immunoassays for noncleaved ITIH4 (intact ITIH4) and an assay detecting both intact and cleaved ITIH4 (total ITIH4) were developed. We initially tested serum samples from HAE patients (n = 20), angiotensin-converting enzyme inhibitor-induced edema patients (ACEI) (n = 20), and patients with HAE of unknown cause (HAE-UNK) (n = 20). Validation involved an extended cohort of 80 HAE patients (60 with HAE-C1INH type 1, 20 with HAE-C1INH type 2), including samples taken during attack and quiescent disease periods, as well as samples from 100 healthy controls. RESULTS: In 63% of HAE patients, intact ITIH4 assay showed lower signals than total ITIH4 assay. This difference was not observed in ACEI and HAE-UNK patients. Western blot analysis confirmed cleaved ITIH4 with low intact ITIH4 samples. In serum samples lacking intact endogenous ITIH4, we observed immediate cleavage of added recombinant ITIH4, suggesting continuous enzymatic activity in the serum. Confirmatory HAE cohort analysis revealed significantly lower intact ITIH4 levels in both type 1 and type 2 HAE patients compared to controls, with consistently low intact/total ITIH4 ratios during clinical HAE attacks. CONCLUSION: The disease-specific low intact ITIH4 levels highlight its unique nature in HAE. ITIH4 may exhibit compensatory mechanisms in HAE, suggesting its utility as a diagnostic and prognostic biomarker. The variations during quiescent and active disease periods raise intriguing questions about the dynamics of proteolytic pathways in HAE.

Anifrolumab treatment improves patient-reported quality of life and decreases disease activity and corticosteroid use in patients with systemic lupus erythematosus: A qualitative study in Denmark.

Anifrolumab is a new therapeutic approach for individuals with systemic lupus erythematosus (SLE) directed at blocking the type 1 interferon pathway. Despite the expanding body of literature on Anifrolumab, an essential aspect remains absent: the subjective patient experience of treatment effects and implications on patients' health-related quality of life (HRQoL). The present study aimed to fill this void by elucidating the nuanced perspectives of SLE patients receiving Anifrolumab treatment by conducting qualitative in-depth interviews (IDIs). SLE patients at Aarhus University Hospital who had received at least three infusions of Anifrolumab were approached for inclusion in the study, which comprised two main elements: (1) qualitative IDIs and (2) collection of patient data from electronic medical records (EMRs). The IDIs were semi-structured and based on a discussion guide that included open-ended and close-ended questions. Verbatim transcripts were coded and analysed using qualitative software to understand concepts important to patients and to understand patients' own experiences before and after Anifrolumab therapy. A clinical chart review was conducted using EMR data at baseline, 3 months, and 6 months after Anifrolumab initiation. IDIs were completed with 14 patients, and EMR data was collected from 16 patients (treatment days range: 62-474). Of the 23 symptoms spontaneously reported by patients prior to Anifrolumab treatment, fatigue, joint pain, sun sensitivity, joint stiffness, skin rashes, and hair loss were the most common. Most symptoms improved, and none worsened during treatment. Patients reported significant impacts of disease on daily life before treatment: day-to-day activities, social life, emotional aspects, physical activity, concentration/memory, work/employment, and family/romantic relationships. Patients reported improvements in all aspects after treatment but were still impacted. From the EMR data, we observed a fall in disease activity after treatment initiation with a concomitant reduction in the use of corticosteroids. This study provides valuable insights into the subjective experiences of SLE patients treated with Anifrolumab, and the findings collectively contribute to a comprehensive understanding of the treatment's efficacy from the patients' perspective and its tangible effects on both subjective and objective parameters in SLE patients.

Revaccination of patients with systemic lupus erythematosus or rheumatoid arthritis without an initial COVID-19 vaccine response elicits seroconversion in half of the patients.

OBJECTIVES: To investigate the effect of COVID-19 mRNA revaccination (two doses) on the antibody response in patients with rheumatic diseases (RD) who were initial vaccine non-responders. Further, to examine if B-cell levels or T-cell responses before revaccination predicted seroconversion. METHODS: From a RD cohort vaccinated with the standard two-dose COVID-19 vaccinations, we enrolled cases without detectable antibody responses (n=17) and controls with detectable antibody response (n=29). Blood donors (n=32) were included as additional controls. Samples were collected before and six weeks after completed revaccination. Total antibodies and specific IgG, IgA, and IgM against SARS-CoV-2 spike protein, SARS-CoV-2 neutralising antibodies, and SARS-CoV-2 reacting CD4+ and CD8+ T-cells were measured before and after revaccination. B-cells (CD19+CD45+) were quantified before revaccination. RESULTS: Forty-seven percent of cases had detectable neutralising antibodies after revaccination. However, antibody levels were significantly lower than in controls and blood donors. Revaccination induced an antibody class switch in cases with a decrease in IgM and increase in IgG. No significant difference was observed in T-cell responses before and after revaccination between the three groups. Only 29% of cases had measurable B-cells compared to 100% of controls and blood donors. Fifty percent of revaccinated cases who seroconverted had measurable B-cells before revaccination. CONCLUSIONS: Forty-seven percent of initial non-responders seroconverted after two-dose revaccination but still had lower levels of SARS-CoV-2 antibodies compared with controls and blood donors. RD patients without a detectable serological response after the initial COVID-19 mRNA vaccine had a T-cell response similar to immunocompetent controls and blood donors.

Systemic Lupus Erythematosus-related Lung Disease.

Systemic Lupus Erythematosus (SLE) is a multifaceted, multisystem autoimmune disorder with diverse clinical expressions. While prevalence reports vary widely, pulmonary involvement accounts for significant morbidity and mortality in SLE. This comprehensive review explores the spectrum of pulmonary disease in SLE, including upper airway manifestations (e.g., laryngeal affection), lower airway conditions (e.g., bronchitis, bronchiolitis, bronchiectasis), parenchymal diseases (e.g., interstitial lung disease, acute lupus pneumonitis, diffuse alveolar hemorrhage), pleural diseases (e.g., serositis, shrinking lung syndrome), and vascular diseases (e.g., pulmonary arterial hypertension, pulmonary embolism, acute reversible hypoxemia syndrome). We discuss diagnostic modalities, treatment strategies, and prognosis for each pulmonary manifestation. With diagnostics remaining a challenge and with the absence of standardized treatment guidelines, we emphasize the need for evidence-based guidelines to optimize patient care and improve outcomes in this complex disease.

Characterization of DNA-protein complexes by nanoparticle tracking analysis and their association with systemic lupus erythematosus.

Nanotechnology enables investigations of single biomacromolecules, but technical challenges have limited the application in liquid biopsies, for example, blood plasma. Nonetheless, tools to characterize single molecular species in such samples represent a significant unmet need with the increasing appreciation of the physiological importance of protein structural changes at nanometer scale. Mannose-binding lectin (MBL) is an oligomeric plasma protein and part of the innate immune system through its ability to activate complement. MBL also serves a role as a scavenger for cellular debris, especially DNA. This may link functions of MBL with several inflammatory diseases in which cell-free DNA now appears to play a role, but mechanistic insight has been lacking. By making nanoparticle tracking analysis possible in human plasma, we now show that superoligomeric structures of MBL form nanoparticles with DNA. These oligomers correlate with disease activity in systemic lupus erythematosus patients. With the direct quantification of the hydrodynamic radius, calculations following the principles of Taylor dispersion in the blood stream connect the size of these complexes to endothelial inflammation, which is among the most important morbidities in lupus. Mechanistic insight from an animal model of lupus supported that DNA-stabilized superoligomers stimulate the formation of germinal center B cells and drive loss of immunological tolerance. The formation involves an inverse relationship between the concentration of MBL superoligomers and antibodies to double-stranded DNA. Our approach implicates the structure of DNA-protein nanoparticulates in the pathobiology of autoimmune diseases.

Differentiating between activation via the lectin or the classical complement pathway in patients with systemic lupus erythematosus.

Complement activation is a hallmark of systemic lupus erythematosus (SLE) and can proceed through the classical (CP), lectin (LP), or alternative pathway (AP). When managing SLE patients, pathway-specific complement activation is rarely monitored as clinical assays are unavailable. In this study, we aim to differentiate between CP- or LP-mediated complement activation in SLE patients by quantifying pathway-specific protein complexes, namely C1s/C1-inhibitor (C1-INH) (CP-specific activation) and MASP-1/C1-INH (LP-specific activation). Levels for both complexes were assessed in 156 SLE patients and 50 controls using two newly developed ELISAs. We investigated whether pathway-specific complement activation was associated with disease activity and lupus nephritis (LN). Disease activity stratification was performed using SLEDAI scores assessed at inclusion. C1s/C1-INH concentrations were significantly increased in active SLE patients (SLEDAI ≥6) when compared with SLE patients with low disease activity (SLEDAI <6, P < 0.01) and correlated with SLEDAI score (r = .29, P < 0.01). In active LN, MASP-1/C1-INH plasma concentrations were significantly increased compared with nonactive LN (P = 0.02). No differences in MASP-1/C1-INH plasma concentrations were observed between active SLE patients and patients with low disease activity (P = 0.11) nor did we observe a significant correlation with disease activity (r = 0.12, P = 0.15). Our data suggest that the CP and the LP are activated in SLE. The CP is activated in active SLE disease, whereas activation of the LP might be more specific to disease manifestations like LN. Our results warrant further research into specific complement pathway activation in SLE patients to potentially improve specific-targeted and tailored-treatment approaches.

Rituximab-treated rheumatic patients: B cells predict seroconversion after COVID-19 boost or revaccination in initial vaccine non-responders.

OBJECTIVES: To investigate the effect of either a booster vaccine (one dose) or revaccination (two doses 3 weeks apart) on the antibody response to the COVID-19 mRNA vaccines in patients with rheumatic disease (RD) treated with rituximab (RTX) who had not produced vaccine-reactive antibodies after the initial two vaccine doses. Further, to examine if B cell levels in peripheral blood predicted seroconversion. METHODS: We included 91 RTX-treated RD patients previously vaccinated against COVID-19. Patients were offered revaccination or a single booster vaccination with an mRNA vaccine. Serum total antibodies against SARS-CoV-2 spike protein were measured before and 6 weeks after the last vaccine dose. B cells (CD19+CD45+) were measured by flow cytometry at inclusion. RESULTS: Of RD patients with undetectable SARS-CoV-2 antibody levels before inclusion, seroconversion was seen in 38% 6 weeks after the booster dose and 32% after revaccination. Patients receiving revaccination had significantly higher antibody levels than patients receiving a booster dose (P < 0.001). In both univariate and multivariate logistic regression analysis, only B cells higher than 10/µl before boost or revaccination were associated with seroconversion (P = 0.009 and P = 0.01, respectively). Seroconversion was independent of age, gender, diagnosis, cumulative RTX dose, RTX treatment time and time since last RTX treatment. CONCLUSION: Continuously impaired humoral response to mRNA vaccines was found in most RTX-treated patients after a booster dose or revaccination. Seroconversion was observed in approximately one-third of the patients. Measurable B cells before boosting or revaccination was the strongest predictor of antibody response after boost or revaccination.

Absolute risk estimation of new-onset proteinuria in patients with systemic lupus erythematosus: a Danish nationwide cohort study.

OBJECTIVES: Kidney involvement and medical compliance are frequent challenges in systemic lupus erythematosus (SLE). Additional data reporting such as absolute risk estimates may strengthen risk stratification and compliance. This study provides absolute risk estimations of risk of new-onset proteinuria among SLE patients. METHODS: Danish SLE centres provided clinical data on first time observations of proteinuria and other clinical parameters listed in the 1997 American College of Rheumatology Classification Criteria for SLE. Time from first occurring non-renal manifestation to new-onset proteinuria or censoring defined time at risk. Multivariate Cox-regression models were used to identify risk factors for new-onset proteinuria and to calculate risk of proteinuria stratified by risk factor debut age, duration, and sex. RESULTS: The patient population consisted of 586 patients with SLE, mainly Caucasian (94%) women (88%), mean age at inclusion of 34.6 years (standard deviation, SD=14.4 years), observed for a mean of 14.9 years (SD=11.2 years). The cumulative prevalence of proteinuria was 40%. Discoid rash, HR =0.42 (p=0.01) and lymphopenia HR=1.77 (p=0.005) were associated with new-onset proteinuria. Male patients with lymphopenia had the highest predictive risks of proteinuria with a 1-, 5- and 10-year risk of proteinuria ranging from 9-27%, 34-75% and 51-89%, depending on the age at presentation (debut at 20, 30, 40 or 50 years). The corresponding risk profiles for women with lymphopenia were 3-9%, 8-34% and 12-58%, respectively. CONCLUSIONS: Large differences in absolute risk estimates for new-onset proteinuria were identified. The differences may aid risk stratification and patient compliance among high-risk individuals.

COVID-19 vaccination in patients with rheumatic diseases leads to a high seroconversion rate and reduced self-imposed isolation and shielding behaviour.

OBJECTIVES: We investigated the effect of a two-dose messenger ribonucleic acid (mRNA) vaccine on antibody levels against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and patient behaviour and shielding concerning fear of coronavirus disease 2019 (COVID-19) in patients with systemic lupus erythematosus or rheumatoid arthritis. METHODS: Three hundred and three patients and 44 blood donors were included. All patients received two doses of an mRNA vaccine and had total antibodies against SARS-CoV-2 measured before vaccination and 2 and 9 weeks after the second vaccination. Further, patients answered an electronic questionnaire before and after vaccination concerning behaviour, anxiety, and symptoms of depression (Patient Health Questionnaire-9). RESULTS: Significantly fewer patients (90%) had measurable antibodies against SARS-CoV-2 compared to blood donors (100%) after the second vaccination (P < .001). Treatment with rituximab was the strongest predictor of an unfavourable vaccine response, as only 27% had measurable antibodies. Nearly all patients (97%) not treated with rituximab experienced seroconversion. Prednisone and methotrexate had a negative effect on seroconversion, but no effect of age or comorbidity was observed. Patients experienced significant improvement after vaccination in 10 out of 12 questions regarding behaviour and fear of COVID-19, while no change in Patient Health Questionnaire-9 or anxiety was observed. CONCLUSION: We find a very high seroconversion rate among rheumatic patients and reduced self-imposed isolation and shielding after COVID-19 vaccination.

Improved pregnancy outcomes in systemic lupus erythematosus: A retrospective study of pregnancies from a single centre in Denmark from 2010-2020 compared with the period 1990-2010.

OBJECTIVES: Over the past decades new international guidelines recommend that pregnant Systemic lupus erythematosus (SLE) patients are monitored closely in a multi-professional team throughout pregnancy. The importance of low disease activity before pregnancy and continued treatment during pregnancy has been established. However, there is still a high risk of adverse pregnancy outcome (APO).The APO in a Danish SLE cohort was evaluated and compared with the results in a previous study cohort from the same centre and referral area. METHODS: This retrospective cohort study used the local patient registry to identify pregnancies in SLE patients followed at the Department of Rheumatology, Aarhus University Hospital, Denmark, from January 2010 to October 2020. In total, 66 pregnancies were registered in 41 women. Data were compared with a previous retrospective study (1990-2010) from the same hospital. RESULTS: Adverse pregnancy outcome occurred in 65% of pregnancies. Forty-seven pregnancies resulted in a live birth, while 15 ended in miscarriages. Compared to the 1990-2010 cohort, a numerical reduction in preterm deliveries (7.58% vs. 17.9%) and emergent caesarean (6.1% vs. 15.5%) was observed, although not reaching statistical significance (p = .07 in both cases). Further, a higher average birth weight (3045 g vs. 2870 g) as well as a higher number of pregnancies and live births per year were observed. Gestational hypertension was significantly reduced from 23.8% to 13.6% (p = .05). Significantly more patients were treated with prednisolone (66.7% vs 35.7%, p = .0002), hydroxychloroquine (6% vs. 73.4%, p < .0001) and acetylsalicylic acid (39.3% vs. 73.1%, p = .0001) in 2010-2020 compared to the 1990-2010. CONCLUSION: We observed significant improvements in the frequency of some APOs in the recent 2010-2020 cohort compared with the previous cohort followed from 1990 to 2010. However, even though a specialized multi-professional team closely follows SLE patients through their pregnancies, pregnancy in SLE still carries a high risk of APO.

Rare clinical manifestations in systemic lupus erythematosus: a review on frequency and clinical presentation.

OBJECTIVES: The purpose of this study was to review the frequency and clinical presentation of the rarest clinical manifestations of systemic lupus erythematosus (SLE). METHODS: A list of 6 rare SLE manifestations were defined: gastrointestinal, liver, pulmonary, cardiac, ocular and neurological manifestations. Each topic was assigned to a pair of authors to perform a literature search and article review. RESULTS: In total, 149 articles were included in the literature review: 37 for gastrointestinal manifestations, 6 for liver manifestations, 27 for pulmonary manifestations, 50 for cardiac manifestations, 16 for ocular manifestations, 13 for neurological manifestations. Gastrointestinal disorders included several clinical presentations with variable frequency (from 0.5% to 10.7% of the cases); liver involvement included lupus-related hepatitis (9.3%) and autoimmune hepatitis (2.3%). The rarest pulmonary manifestations identified were shrinking lung syndrome, described in 1.5% of patients, while interstitial lung disease and lupus pneumonia were reported in 4% and 3% of patients respectively. Myocarditis and pulmonary hypertension were also rarely described in SLE patients although ranging from 0.4-16% and 1-14% respectively, depending on the methodology used for its identification. Ocular manifestations in SLE included some rare manifestations (reported in less than 5% of patients) and lupus retinopathy that is described in 1.2-28.8% of patients depending on methods of ascertainment. Aseptic meningitis and chorea were also confirmed as very rare manifestations being reported in less than 1% and in 0.3-2.4% of cases respectively. CONCLUSIONS: The results of this literature review provide the basis for a better understanding of some less-known manifestations of SLE and for stressing the need for a higher awareness in diagnostic and therapeutic protocols regarding these rare disease aspects.

Variants in BANK1 are associated with lupus nephritis of European ancestry.

The genetic background of lupus nephritis (LN) has not been completely elucidated. We performed a case-only study of 2886 SLE patients, including 947 (33%) with LN. Renal biopsies were available from 396 patients. The discovery cohort (Sweden, n = 1091) and replication cohort 1 (US, n = 962) were genotyped on the Immunochip and replication cohort 2 (Denmark/Norway, n = 833) on a custom array. Patients with LN, proliferative nephritis, or LN with end-stage renal disease were compared with SLE without nephritis. Six loci were associated with LN (p < 1 × 10-4, NFKBIA, CACNA1S, ITGA1, BANK1, OR2Y, and ACER3) in the discovery cohort. Variants in BANK1 showed the strongest association with LN in replication cohort 1 (p = 9.5 × 10-4) and proliferative nephritis in a meta-analysis of discovery and replication cohort 1. There was a weak association between BANK1 and LN in replication cohort 2 (p = 0.052), and in the meta-analysis of all three cohorts the association was strengthened (p = 2.2 × 10-7). DNA methylation data in 180 LN patients demonstrated methylation quantitative trait loci (meQTL) effects between a CpG site and BANK1 variants. To conclude, we describe genetic variations in BANK1 associated with LN and evidence for genetic regulation of DNA methylation within the BANK1 locus. This indicates a role for BANK1 in LN pathogenesis.

Interaction between the STAT4 rs11889341(T) risk allele and smoking confers increased risk of myocardial infarction and nephritis in patients with systemic lupus erythematosus.

OBJECTIVE: To investigate how genetics influence the risk of smoking-related systemic lupus erythematosus (SLE) manifestations. METHODS: Patients with SLE (ndiscovery cohort=776, nreplication cohort=836) were genotyped using the 200K Immunochip single nucleotide polymorphisms (SNP) Array (Illumina) and a custom array. Sixty SNPs with SLE association (p<5.0×10-8) were analysed. Signal transducer and activator of transcription 4 (STAT4) activation was assessed in in vitro stimulated peripheral blood mononuclear cells from healthy controls (n=45). RESULTS: In the discovery cohort, smoking was associated with myocardial infarction (MI) (OR 1.96 (95% CI 1.09 to 3.55)), with a greater effect in patients carrying any rs11889341 STAT4 risk allele (OR 2.72 (95% CI 1.24 to 6.00)) or two risk alleles (OR 8.27 (95% CI 1.48 to 46.27)).Smokers carrying the risk allele also displayed an increased risk of nephritis (OR 1.47 (95% CI 1.06 to 2.03)). In the replication cohort, the high risk of MI in smokers carrying the risk allele and the association between the STAT4 risk allele and nephritis in smokers were confirmed (OR 6.19 (95% CI 1.29 to 29.79) and 1.84 (95% CI 1.05 to 3.29), respectively).The interaction between smoking and the STAT4 risk allele resulted in further increase in the risk of MI (OR 2.14 (95% CI 1.01 to 4.62)) and nephritis (OR 1.53 (95% CI 1.08 to 2.17)), with 54% (MI) and 34% (nephritis) of the risk attributable to the interaction. Levels of interleukin-12-induced phosphorylation of STAT4 in CD8+ T cells were higher in smokers than in non-smokers (mean geometric fluorescence intensity 1063 vs 565, p=0.0063).Lastly, the IL12A rs564799 risk allele displayed association with MI in both cohorts (OR 1.53 (95% CI 1.01 to 2.31) and 2.15 (95% CI 1.08 to 4.26), respectively). CONCLUSIONS: Smoking in the presence of the STAT4 risk gene variant appears to increase the risk of MI and nephritis in SLE. Our results also highlight the role of the IL12-STAT4 pathway in SLE-cardiovascular morbidity.

Molecular pathways in patients with systemic lupus erythematosus revealed by gene-centred DNA sequencing.

OBJECTIVES: Systemic lupus erythematosus (SLE) is an autoimmune disease with extensive heterogeneity in disease presentation between patients, which is likely due to an underlying molecular diversity. Here, we aimed at elucidating the genetic aetiology of SLE from the immunity pathway level to the single variant level, and stratify patients with SLE into distinguishable molecular subgroups, which could inform treatment choices in SLE. METHODS: We undertook a pathway-centred approach, using sequencing of immunological pathway genes. Altogether 1832 candidate genes were analysed in 958 Swedish patients with SLE and 1026 healthy individuals. Aggregate and single variant association testing was performed, and we generated pathway polygenic risk scores (PRS). RESULTS: We identified two main independent pathways involved in SLE susceptibility: T lymphocyte differentiation and innate immunity, characterised by HLA and interferon, respectively. Pathway PRS defined pathways in individual patients, who on average were positive for seven pathways. We found that SLE organ damage was more pronounced in patients positive for the T or B cell receptor signalling pathways. Further, pathway PRS-based clustering allowed stratification of patients into four groups with different risk score profiles. Studying sets of genes with priors for involvement in SLE, we observed an aggregate common variant contribution to SLE at genes previously reported for monogenic SLE as well as at interferonopathy genes. CONCLUSIONS: Our results show that pathway risk scores have the potential to stratify patients with SLE beyond clinical manifestations into molecular subsets, which may have implications for clinical follow-up and therapy selection.

Proteolysis and inflammation of the kidney glomerulus.

Proteases play a central role in regulating renal pathophysiology and are increasingly evaluated as actionable drug targets. Here, we review the role of proteolytic systems in inflammatory kidney disease. Inflammatory kidney diseases are associated with broad dysregulations of extracellular and intracellular proteolysis. As an example of a proteolytic system, the complement system plays a significant role in glomerular inflammatory kidney disease and is currently under clinical investigation. Based on two glomerular kidney diseases, lupus nephritis, and membranous nephropathy, we portrait two proteolytic pathomechanisms and the role of the complement system. We discuss how profiling proteolytic activity in patient samples could be used to stratify patients for more targeted interventions in inflammatory kidney diseases. We also describe novel comprehensive, quantitative tools to investigate the entirety of proteolytic processes in a tissue sample. Emphasis is placed on mass spectrometric approaches that enable the comprehensive analysis of the complement system, as well as protease activities and regulation in general.

Local and systemic reactogenicity of COVID-19 vaccine BNT162b2 in patients with systemic lupus erythematosus and rheumatoid arthritis.

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were launched in December 2020. Vaccination of patients with rheumatic diseases is recommended, as they are considered at higher risk of severe COVID-19 than the general population. Patients with rheumatic disease have largely been excluded from vaccine phase 3 trials. This study explores the safety and reactogenicity of BNT162b2 among patients with rheumatic diseases. Patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), median age 58.8 years, 285 subjects in total, were vaccinated twice with the BNT162b2 (Pfizer/BioNTech). Questionnaires on reactogenicity matching the original phase 3 study were answered seven days after completed vaccination. The majority of SLE and RA patients experienced either local (78.0%) or systemic reactions (80.1%). Only 1.8% experienced a grade-4 reaction. Compared to the original study, we found more frequent fatigue [Odds ratio (OR) 2.2 (1.7-2.8)], headache [OR 1.7 (1.3-2.2)], muscle pain [OR 1.8 (1.4-2.3)], and joint pain [OR 2.3 (1.7-3.0)] in patients. In contrast, the use of antipyretics was less frequent [OR 0.5 (0.3-0.6)]. Patients with SLE and RA experience reactogenicity to the Pfizer-BioNTech BNT162b2 COVID-19 vaccine. Reactogenicity was more frequent in patients, however, not more severe compared with healthy controls.

Ficolin-3 Deficiency Is Associated with Disease and an Increased Risk of Systemic Lupus Erythematosus.

PURPOSE: Ficolin-3 deficiency is caused by a mutation (+1637delC) in the FCN3 gene. It is a rare condition and has been associated with both infection and autoimmune disease including systemic lupus erythematosus (SLE). Here we investigated if ficolin-3 deficiency is more frequent in patients than in controls and tried to identify a common phenotype among ficolin-3 deficient individuals. Since a significant part of patients identified with ficolin-3 deficiency was diagnosed with SLE, we explored whether the heterozygous state of the FCN3+1637delC variant represents a risk factor in the development of SLE. Further, we examined other possible causes of ficolin-3 deficiency when the FCN3+1637delC is not present. METHODS: A systematic literature search for studies measuring ficolin-3 was carried out. We examined 362 SLE patients and 596 controls for the presence of the variant FCN3+1637delC. We established assays for measurements of ficolin-3 and of auto-antibodies against ficolin-3. We sequenced the coding and non-coding regions of the FCN3 gene in an SLE patient with ficolin-3 deficiency not carrying the +1637delC. RESULTS: Ficolin-3 deficiency leads to an 8-time increased odds of having a disease (p < 0.05). Three out of nine patients with deficiency had SLE. The heterozygous state of the deficiency variant is not associated with increased risk of developing SLE (p = 0.18). CONCLUSION: By systematically reviewing the literature for the described cases of ficolin-3 deficiency, an autoimmune phenotype is emerging. Thirty-three percent of the ficolin-3 deficient patients had SLE. Heterozygosity for the FCN3 gene deletion causing the deficiency does not seem to be associated with the development of SLE.

2019 update of the EULAR recommendations for the management of systemic lupus erythematosus.

Our objective was to update the EULAR recommendations for the management of systemic lupus erythematosus (SLE), based on emerging new evidence. We performed a systematic literature review (01/2007-12/2017), followed by modified Delphi method, to form questions, elicit expert opinions and reach consensus. Treatment in SLE aims at remission or low disease activity and prevention of flares. Hydroxychloroquine is recommended in all patients with lupus, at a dose not exceeding 5 mg/kg real body weight. During chronic maintenance treatment, glucocorticoids (GC) should be minimised to less than 7.5 mg/day (prednisone equivalent) and, when possible, withdrawn. Appropriate initiation of immunomodulatory agents (methotrexate, azathioprine, mycophenolate) can expedite the tapering/discontinuation of GC. In persistently active or flaring extrarenal disease, add-on belimumab should be considered; rituximab (RTX) may be considered in organ-threatening, refractory disease. Updated specific recommendations are also provided for cutaneous, neuropsychiatric, haematological and renal disease. Patients with SLE should be assessed for their antiphospholipid antibody status, infectious and cardiovascular diseases risk profile and preventative strategies be tailored accordingly. The updated recommendations provide physicians and patients with updated consensus guidance on the management of SLE, combining evidence-base and expert-opinion.