Cluster Analysis of Autoantibodies in 852 Patients with Systemic Lupus Erythematosus from a Single Center

Association of autoantibodies with the IFN signature and NETosis in patients with systemic lupus erythematosus

Objective

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by a variety of disease symptoms and an unpredictable clinical course. To improve treatment outcome, stratification based on immunological manifestations commonly seen in patients with SLE such as autoantibodies, type I interferon (IFN) signature and neutrophil extracellular trap (NET) release may help. It is assumed that there is an association between these immunological phenomena, since NET release induces IFN production and IFN induces autoantibody formation via B-cell activation. Here we studied the association between autoantibodies, the IFN signature, NET release, and clinical manifestations in patients with SLE.

Methods

We performed principal component analysis (PCA) and hierarchical clustering of 57 SLE-related autoantibodies in 25 patients with SLE. We correlated each autoantibody to the IFN signature and NET inducing capacity.

Results

We observed two distinct clusters: one cluster contained mostly patients with a high IFN signature. Patients in this cluster often present with cutaneous lupus, and have higher anti-dsDNA concentrations. Another cluster contained a mix of patients with a high and low IFN signature. Patients with high and low NET inducing capacity were equally distributed between the clusters. Variance between the clusters is mainly driven by antibodies against histones, RibP2, RibP0, EphB2, RibP1, PCNA, dsDNA, and nucleosome. In addition, we found a trend towards increased concentrations of autoantibodies against EphB2, RibP1, and RNP70 in patients with an IFN signature. We found a negative correlation of NET inducing capacity with anti-FcER (r = -0.530; p = 0.007) and anti-PmScl100 (r = -0.445; p = 0.03).

Conclusion

We identified a subgroup of patients with an IFN signature that express increased concentrations of antibodies against DNA and RNA-binding proteins, which can be useful for further patient stratification and a more targeted therapy. We did not find positive associations between autoantibodies and NET inducing capacity. Our study further strengthens the evidence of a correlation between RNA-binding autoantibodies and the IFN signature.

Cluster analysis of clinical manifestations assigns systemic lupus erythematosus-phenotype subgroups: A multicentre study on 440 patients

OBJECTIVE

Systemic lupus erythematous (SLE) is a heterogenous disease characterised by a large panel of autoantibodies and a wide spectrum of clinical signs and symptoms that engender different outcomes. We aimed to identify distinct, homogeneous SLE patients' phenotypes.

METHODS

This retrospective study enrolled SLE patients meeting the Systemic Lupus International Collaborating Clinics (SLICC) classification criteria, enrolled in the French multicentre "APS (antiphospholipid syndrome) and SLE" Registry. Based on 29 variables selected to cover a broad range of clinical and laboratory (excluding autoantibodies) SLE manifestations, unsupervised multiple correspondence analysis followed by hierarchical ascendent-clustering analysis assigned different phenotypes.

RESULTS

We included 440 patients, mostly women (94.3%). Median age at SLE diagnosis was 24 (IQR 19-32) years. Cluster analysis yielded three distinct subgroups based on cumulative clinical manifestations, not autoantibody pattern. Cluster 1 (n=91) comprised mostly Caucasian patients, with APS-associated clinical and biological manifestations, e.g., livedo, seizure, thrombocytopaenia and haemolytic anaemia. Cluster 2 (n=221), the largest, included patients with mild clinical manifestations, mainly articular, more frequently associated with Sjögren's syndrome and with less frequent autoantibody-positivity. Cluster 3 (n=128) consisted of patients with the largest panel of SLE-specific clinical manifestations (cutaneous, articular, proliferative nephritis, pleural, cardiac and haematological), the most frequent autoantibody-positivity, low complement levels, and more often of Asian and sub-Saharan African origin.

CONCLUSION

This unsupervised clustering method distinguished three distinct SLE patient subgroups, highlighting SLE heterogeneity.

Evaluation of a novel particle-based assay for detecting SLE-related autoantibodies

Anti-dsDNA, anti-Sm, and anti-ribosomal-P autoantibodies are hallmarks of systemic lupus erythematosus (SLE), being anti-dsDNA and anti-Sm included in 2019-ACR/EULAR SLE-Classification Criteria. Enzyme-linked (ELISA) and chemiluminescence assays (CIA) are widely established in immunology laboratories, but new technologies, such as particle-based multi-analyte technology (PMAT), are nowadays available. The present study aimed to compare the presence of anti-dsDNA and anti-Sm autoantibodies measured by CIA and PMAT and analyze diagnostic and clinical SLE activity performance. Anti-ribosomal-P autoantibodies by PMAT were also included. Consequently, anti-dsDNA and anti-Sm detected by CIA showed substantial agreement with PMAT (Cohen's kappa = 0.662 and 0.671, respectively). Anti-dsDNA autoantibodies measured by PMAT showed a positive correlation with clinical SLEDAI-2K (p < 0.001) and a negative correlation with complement consumption (p < 0.001). Anti-Sm and anti-ribosomal-P autoantibodies showed a positive correlation with SLEDAI-2K (p < 0.001 and p = 0.001, respectively) and a negative correlation with complement consumption (p < 0.001 and p = 0.001, respectively). Finally, anti-Sm autoantibodies were associated with renal involvement (p < 0.05).

Low CD4 + T cell count is related to specific anti-nuclear antibodies, IFNα protein positivity and disease activity in systemic lupus erythematosus pregnancy

BACKGROUND

Lymphopenia, autoantibodies and activation of the type I interferon (IFN) system are common features in systemic lupus erythematosus (SLE). We speculate whether lymphocyte subset counts are affected by pregnancy and if they relate to autoantibody profiles and/or IFNα protein in SLE pregnancy.

METHODS

Repeated blood samples were collected during pregnancy from 80 women with SLE and 51 healthy controls (HC). Late postpartum samples were obtained from 19 of the women with SLE. Counts of CD4 + and CD8 + T cells, B cells and NK cells were measured by flow cytometry. Positivity for anti-nuclear antibodies (ANA) fine specificities (double-stranded DNA [dsDNA], Smith [Sm], ribonucleoprotein [RNP], chromatin, Sjögren's syndrome antigen A [SSA] and B [SSB]) and anti-phospholipid antibodies (cardiolipin [CL] and β2 glycoprotein I [β2GPI]) was assessed with multiplexed bead assay. IFNα protein concentration was quantified with Single molecule array (Simoa) immune assay. Clinical data were retrieved from medical records.

RESULTS

Women with SLE had lower counts of all lymphocyte subsets compared to HC throughout pregnancy, but counts did not differ during pregnancy compared to postpartum. Principal component analysis revealed that low lymphocyte subset counts differentially related to autoantibody profiles, cluster one (anti-dsDNA/anti-Sm/anti-RNP/anti-Sm/RNP/anti-chromatin), cluster two (anti-SSA/anti-SSB) and cluster three (anti-CL/anti-β2GPI), IFNα protein levels and disease activity. CD4 + T cell counts were lower in women positive to all ANA fine specificities in cluster one compared to those who were negative, and B cell numbers were lower in women positive for anti-dsDNA and anti-Sm compared to negative women. Moreover, CD4 + T cell and B cell counts were lower in women with moderate/high compared to no/low disease activity, and CD4 + T cell count was lower in IFNα protein positive relative to negative women. Finally, CD4 + T cell count was unrelated to treatment.

CONCLUSION

Lymphocyte subset counts are lower in SLE compared to healthy pregnancies, which seems to be a feature of the disease per se and not affected by pregnancy. Our results also indicate that low lymphocyte subset counts relate differentially to autoantibody profiles, IFNα protein levels and disease activity, which could be due to divergent disease pathways.

Risk factors of pulmonary arterial hypertension in patients with systemic lupus erythematosus: A meta-analysis

OBJECTIVE

To determine the risk factors of pulmonary arterial hypertension (PAH) related to systemic lupus erythematosus (SLE) through systematic reviews and meta-analyses.

METHODS

We undertook electronic search strategies using Medline via PubMed, Embase, Web of Science, and Cochrane Library up to April 11, 2023. Study selection and data extraction were performed by 2 authors independently. We made risk of bias judgments based on the Newcastle-Ottawa Scale (NOS). Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated to estimate the overall effect sizes of potential risk factors for PAH in SLE patients. Univariate and multivariate meta-regression models were used to assess the independent effects of each risk factor on PAH. Sensitivity analyses were also conducted to explore potential sources of heterogeneity.

RESULTS

A total of 19 articles were included in this meta-analysis, and the results showed that gender (female) [RR = 1.04, 95% CI (1.02, 1.06), p = .0001], interstitial lung disease [RR = 4.36, 95% CI (2.42, 7.85), p = .0001], alopecia [RR = 1.39, 95% CI (1.06, 1.83), p = .017], Raynaud's phenomenon [RR = 1.83, 95% CI (1.41, 2.37), p = .0001], systemic hypertension [RR = 1.30, 95% CI (1.07, 1.58), p = .007], serositis [RR = 2.29, 95% CI (1.89, 2.77), p = .0001], pericardial effusion [RR = 3.33, 95% CI (2.20, 5.05), p = .0001], anti-RNP [RR = 1.86, 95% CI (1.19, 2.91), p = .006], anti-SSA [RR = 1.28, 95% CI (1.01, 1.62), p = .041], anti-SSB [RR = 1.38, 95% CI (1.19, 1.60), p = .0001], anti-U1RNP [RR = 1.58, 95% CI (1.07, 2.34), p = .023], thrombocytopenia [RR = 1.38, 95% CI (1.14, 1.68), p = .001], and current smokers [RR = 2.20, 95% CI (1.19, 4.06), p = .012] were all risk factors for PAH related to SLE.

CONCLUSION

PAH is a serious complication of SLE. Since prognosis of SLE patients after the occurrence of PAH is poor, routine examination should be conducted for SLE patients with PAH risk factors.

Machine learning identifies clusters of longitudinal autoantibody profiles predictive of systemic lupus erythematosus disease outcomes

OBJECTIVES

A novel longitudinal clustering technique was applied to comprehensive autoantibody data from a large, well-characterised, multinational inception systemic lupus erythematosus (SLE) cohort to determine profiles predictive of clinical outcomes.

METHODS

Demographic, clinical and serological data from 805 patients with SLE obtained within 15 months of diagnosis and at 3-year and 5-year follow-up were included. For each visit, sera were assessed for 29 antinuclear antibodies (ANA) immunofluorescence patterns and 20 autoantibodies. K-means clustering on principal component analysis-transformed longitudinal autoantibody profiles identified discrete phenotypic clusters. One-way analysis of variance compared cluster enrolment demographics and clinical outcomes at 10-year follow-up. Cox proportional hazards model estimated the HR for survival adjusting for age of disease onset.

RESULTS

Cluster 1 (n=137, high frequency of anti-Smith, anti-U1RNP, AC-5 (large nuclear speckled pattern) and high ANA titres) had the highest cumulative disease activity and immunosuppressants/biologics use at year 10. Cluster 2 (n=376, low anti-double stranded DNA (dsDNA) and ANA titres) had the lowest disease activity, frequency of lupus nephritis and immunosuppressants/biologics use. Cluster 3 (n=80, highest frequency of all five antiphospholipid antibodies) had the highest frequency of seizures and hypocomplementaemia. Cluster 4 (n=212) also had high disease activity and was characterised by multiple autoantibody reactivity including to antihistone, anti-dsDNA, antiribosomal P, anti-Sjögren syndrome antigen A or Ro60, anti-Sjögren syndrome antigen B or La, anti-Ro52/Tripartite Motif Protein 21, antiproliferating cell nuclear antigen and anticentromere B). Clusters 1 (adjusted HR 2.60 (95% CI 1.12 to 6.05), p=0.03) and 3 (adjusted HR 2.87 (95% CI 1.22 to 6.74), p=0.02) had lower survival compared with cluster 2.

CONCLUSION

Four discrete SLE patient longitudinal autoantibody clusters were predictive of long-term disease activity, organ involvement, treatment requirements and mortality risk.

Using two-step cluster analysis to classify inpatients with primary biliary cholangitis based on autoantibodies: A real-world retrospective study of 537 patients in China

Background

A variety of autoantibodies have been detected in primary biliary cholangitis (PBC), while the presence of autoantibody clusters and their clinical significance have not been fully understood. We aimed at defining autoantibody clusters and to better understand the clinical features and prognosis of PBC patients based on autoantibody clusters under real-world conditions.

Methods

We retrospectively analyzed 788 inpatients with PBC evaluated between October 2008 and July 2019, and included 537 patients. Nineteen autoantibodies which were measured routinely were investigated for cluster analysis. Two-step clustering, Kaplan-Meier survival, and Cox regression analyses were used.

Results

Five clusters were defined. A cluster of antinuclear antibodies (ANA) and anti-gp210 positive patients were identified with a high rate of cirrhosis at baseline and low survival rate; a cluster of ANA, anti-centromere antibodies (ACA) and/or anti-CENP-B female dominant patients with older disease onset, low level of platelet count at baseline, high rate of hepatic decompensation, and low survival rate was also characterized; and another cluster of anti-mitochondrial antibodies (AMA) and/or AMA-M2, anti-Ro52 and a high rate of anti-gp210 positive patients were identified with a high proportion of male patients and low survival rate. A subgroup of patients with anti-SSA and/or anti-SSB coexists with SjS was also identified; patients with only AMA and/or AMA-M2-positive with a benign clinical outcome and relatively high complication of non-alcoholic fatty liver disease (NAFLD) were also identified. Only anti-gp210 was considered as a significant predictor for poor outcomes especially in patients with cirrhosis.

Conclusion

Clustering methods allow the identification of distinct autoantibody profiles of PBC that form clinical subsets and can be useful for personalized approaches to diagnosis, clinical management, and the prediction of clinical outcomes. Anti-gp210 was the strongest predictive factor for poor outcomes especially in PBC patients with cirrhosis under real-world conditions.

Thrombocytopenia in primary antiphospholipid syndrome: association with prognosis and clinical implications

OBJECTIVES

Thrombocytopenia, a frequent clinical manifestation in patients with APS, could be an independent predictor of recurrent thrombotic, obstetric and severe extracriteria events.

METHODS

This single-centre prospective study enrolled 218 consecutive patients diagnosed with primary APS between 2010 and 2021. Thrombocytopenia was defined as a platelet count less than 100 × 109/L.

RESULTS

Our cohort included 74 (33.94%) patients with thrombocytopenia and 144 patients with a continuous normal platelet count. Comparison of baseline characteristics indicated that patients with thrombocytopenia had more visceral venous thromboses [10 (13.51%) vs 5(3.47%); P = 0.009] and extracriteria manifestations [mainly haemolytic anaemia; 20 (27.03%) vs 17 (11.81%); P = 0.007]. Hypocomplementemia was more likely among patients with thrombocytopenia [19 (25.68%) vs 16 (11.11%); P = 0.01]. The presence of aCL-IgG/IgM, anti-β2-glycoprotein I and lupus anticoagulant were more frequently detected in patients with thrombocytopenia. In survival analysis, thrombotic, obstetric and severe extracriteria survival rates were significantly worse in patients with thrombocytopenia. In multivariate Cox regression, thrombocytopenia was an independent risk factor for all endpoint events, including thrombotic events [hazard ratio (HR) 2.93 (95% CI 1.31, 6.56), P = 0.009], pregnancy morbidity [HR 8.00 (95% CI 2.43, 26.37), P = 0.0006] and severe extracriteria events [HR 15.27 (95% CI 1.85, 125.98), P = 0.01].

CONCLUSION

Thrombocytopenia could identify primary APS patients at high risk of developing thrombotic events, pregnancy morbidity and severe extracriteria events.

Clinical and immunological phenotypes of systemic lupus erythematosus, identified based on cluster analysis of data from 400 patients from V.A. Nasonova Research Institute of Rheumatology

Objective: to identify clinical and immunological variants (phenotypes) of systemic lupus erythematosus (SLE) using cluster analysis.

Patients and methods. The study included 400 patients with diagnosis of SLE according to the 2012 SLICC classification criteria. Patients underwent laboratory and immunological workup according to accepted standards of medical care for patients with SLE, and therapy was prescribed in accordance with disease activity.

Results and discussion. Among patients, most were females (ratio of men and women – 1:10), and people of young age (34.2±11.5 years), with an average duration of illness of 6 [3; 12] years. In 98 (25%) patients with SLE, the disease debuted before the age of 18 years. Lupus nephritis (LN) was detected in 192 (48%) patients, SLE with antiphospholipid syndrome (APS) – in 48 (12%), SLE with Sjцgren's syndrome – in 44 (11%). For cluster analysis 30 clinical, 4 laboratory, 12 immunological and 10 therapeutic parameters were selected and a dendrogram was constructed with the calculation of the Euclidean distance using the Ward method. As a result, five clusters of SLE were identified: with the development of LN; with predominantly extrarenal manifestations; SLE combined with APS; SLE combined with Sjцgren's syndrome; SLE with a debut in childhood (up to 18 years of age). Clusters differed in clinical, laboratory and immunological parameters, as well as in therapy.

Conclusion. Cluster analysis data made it possible to group the selected signs into five clinical and immunological variants (phenotypes) of SLE. Identification of SLE phenotypes as a set of characteristics that, individually or in combination, make it possible to determine differences between patients based on clinical, laboratory and immunological parameters, variants of the onset and course of the disease, response to therapy and prognosis, will contribute to a personalized approach in choosing the therapy, improving its long-term results, as well as quality of life and prognosis in patients with SLE.

The promise of precision medicine in rheumatology

Systemic autoimmune rheumatic diseases (SARDs) exhibit extensive heterogeneity in clinical presentation, disease course, and treatment response. Therefore, precision medicine - whereby treatment is tailored according to the underlying pathogenic mechanisms of an individual patient at a specific time - represents the 'holy grail' in SARD clinical care. Current strategies include treat-to-target therapies and autoantibody testing for patient stratification; however, these are far from optimal. Recent innovations in high-throughput 'omic' technologies are now enabling comprehensive profiling at multiple levels, helping to identify subgroups of patients who may taper off potentially toxic medications or better respond to current molecular targeted therapies. Such advances may help to optimize outcomes and identify new pathways for treatment, but there are many challenges along the path towards clinical translation. In this Review, we discuss recent efforts to dissect cellular and molecular heterogeneity across multiple SARDs and future directions for implementing stratification approaches for SARD treatment in the clinic.

Should Renal Inflammation Be Targeted While Treating Hypertension?

Despite extensive research and a plethora of therapeutic options, hypertension continues to be a global burden. Understanding of the pathological roles of known and underexplored cellular and molecular pathways in the development and maintenance of hypertension is critical to advance the field. Immune system overactivation and inflammation in the kidneys are proposed alternative mechanisms of hypertension, and resistant hypertension. Consideration of the pathophysiology of hypertension in chronic inflammatory conditions such as autoimmune diseases, in which patients present with autoimmune-mediated kidney inflammation as well as hypertension, may reveal possible contributors and novel therapeutic targets. In this review, we 1) summarize current therapies used to control blood pressure and their known effects on inflammation; 2) provide evidence on the need to target renal inflammation, specifically, and especially when first-line and combinatory treatment efforts fail; and 3) discuss the efficacy of therapies used to treat autoimmune diseases with a hypertension/renal component. We aim to elucidate the potential of targeting renal inflammation in certain subsets of patients resistant to current therapies.

Genetic Polymorphisms and the Clinical Response to Systemic Lupus Erythematosus Treatment Towards Personalized Medicine

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a broad spectrum of clinical manifestations, an aberrant autoimmune response to self-antigens, which affect organs and tissues. There are several immune-pathogenic pathways, but the exact one is still not well known unless it is related to genetics. SLE and other autoimmune diseases are known to be inseparable from genetic factors, not only pathogenesis but also regarding the response to therapy. Seventy-one human studies published in the last 10 years were collected. Research communications, thesis publication, reviews, expert opinions, and unrelated studies were excluded. Finally, 32 articles were included. A polymorphism that occurs on the genes related to drugs pharmacokinetic, such as CYP, OATP, ABC Transporter, UGT, GST or drug-target pharmacodynamics, such as FCGR, TLR, and BAFF, can change the level of gene expression or its activity, thereby causing a variation on the clinical response of the drugs. A study that summarizes gene polymorphisms influencing the response to SLE therapy is urgently needed for personalized medicine practices. Personalized medicine is an effort to provide individual therapy based on genetic profiles, and it gives better and more effective treatments for SLE and other autoimmune disease patients.

Clinical Significance of Raynaud Phenomenon in Systemic Lupus Erythematosus

OBJECTIVE

There are limited reports of the clinical significance of Raynaud phenomenon (RP) in systemic lupus erythematosus (SLE), with some suggesting RP is associated with less severe lupus. Since most prior studies were small and/or focused on a specific race/ethnic demographic, it is unclear if those results are generalizable. We evaluated whether RP was associated with demographic and clinical factors in a large multiethnic SLE cohort.

METHODS

We studied Montreal General Hospital SLE cohort patients who are followed with standardized annual assessments. We included patients with at least 1 visit across 2011-2018 and assessed demographic and clinical variables (using the 1997 American College of Rheumatology criteria and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index) at their first visit. We present multivariate logistics regression analyses of cross-sectional associations between these variables and RP in SLE.

RESULTS

Of 489 SLE patients, most were female (n = 445, 91%). Mean age at SLE diagnosis was 31.5 (standard deviation, 13.5) years, and 169 (34.6%) had RP. In our fully adjusted model, female sex (odds ratio [OR], 2.43; 95% confidence interval [CI], 1.07-6.03), White race/ethnicity (OR, 1.85; 95% CI, 1.10-3.17), neurological/neuropsychiatric manifestations (OR, 1.98; 95% CI, 1.10-3.56), and anti-RNP antibodies (OR, 3.03; 95% CI, 1.73-5.38) were positively associated with RP, whereas hemolytic anemia and cellular casts were negatively associated.

CONCLUSIONS/DISCUSSION

Over one third of our large multiethnic North American SLE cohort had RP. This study confirmed associations between RP and a specific SLE phenotype.

Description of damage in different clusters of patients with antiphospholipid syndrome

OBJECTIVE

To identify the different clinical phenotypes of antiphospholipid syndrome (APS) by using cluster analysis and describe cumulative damage of disease clusters.

METHODS

This retrospective study includes patients with APS (±systemic lupus erythematosus (SLE)). Two-step cluster analysis was applied by considering clinical data. Damage was calculated for all patients by applying damage index for APS (DIAPS).

RESULTS

A total of 237 patients (198 females; median age of 43 years; median follow-up of 9.5 years) were classified into four clusters. Cluster 1 (n = 74) consisted of older patients with arterial-predominant thrombosis, livedo reticularis, and increased cardiovascular risk; cluster 2 (n = 70) of SLE+APS patients with thrombocytopenia and heart valve disease; cluster 3 (n = 59) of patients with venous-predominant thrombosis, less extra-criteria manifestations; and cluster 4 (n = 34) of patients with only pregnancy morbidity with lower frequency of extra-criteria features and cardiovascular risk. Patients with SLE+APS (n = 123) had the highest mean DIAPS. Regarding clusters, 1 and 2 had high cumulative damage. While cumulative survival rates of clusters did not differ, cluster 2 and 3 had lower survival rates at further years. There was no correlation between DIAPS and mortality.

CONCLUSION

SLE+APS patients with extra-criteria manifestations and older APS patients with arterial thrombosis and increased cardiovascular risk have higher cumulative damage. Effective treatment of SLE disease activity and control of cardiovascular risk may help to reduce cumulative damage in these patients.

High titers of antinuclear antibody and the presence of multiple autoantibodies are highly suggestive of systemic lupus erythematosus

The aim of this study is to evaluate the relationship between antinuclear antibody (ANA) titer and specificity, as well as the relationship between the number of positive-autoantibodies (AAbs) in antinuclear antibodies (ANAs) and specificity for systemic lupus erythematosus (SLE), so as to explore their significance in the diagnosis of SLE. A total of 1297 patients with ANA results was enrolled in this study, including 148 patients with SLE patients. The sensitivity, specificity, sensitive likelihood ratio and specific likelihood ratio of indicators in SLE were determined by receiver–operator characteristic (ROC) curve after measurement of ANA and ANAs by indirect immunofluorescence (IIF) and immunoblotting, respectively. ROC analysis showed that the specificity of ANA titer ≥ 1 +, ≥ 2 + and ≥ 3 + for SLE was estimated to be 81.29%, 90.69% and 96.52% respectively, with a increased titer-specific likelihood ratio (5.16, 9.29 and 19.60, respectively). The specificity of the number of positive-AAbs ≥ 1, ≥ 2 and ≥ 3 in ANAs for SLE was estimated to be 80.42%, 94.95% and 99.3% respectively, with a increased number-specific likelihood ratio (4.8, 15.26 and 72.48, respectively). The estimated sensitivity of the number of positive-AAbs ≥ 3, AnuA and anti-rRNP was higher than that of anti-Sm (p < 0.01) (50.68%, 41.89% and 31.76% vs. 16.89%, respectively), while there was no significant difference in their specificity (99.3%, 99.74% and 99.56% vs. 99.74%, respectively) (p > 0.05). High titers of ANA and the presence of multiple AAbs in ANAs are highly specific for SLE and highly suggestive of SLE. The likelihood of SLE can be assessed by ANA titer and the number of positive-AAbs in ANAs.

Four Systemic Lupus Erythematosus Subgroups, Defined by Autoantibodies Status, Differ Regarding HLA-DRB1 Genotype Associations and Immunological and Clinical Manifestations

Objective

The heterogeneity of systemic lupus erythematosus (SLE) constitutes clinical and therapeutical challenges. We therefore studied whether unrecognized disease subgroups can be identified by using autoantibody profiling together with HLA‐DRB1 alleles and immunological and clinical data.

Methods

An unsupervised cluster analysis was performed based on detection of 13 SLE‐associated autoantibodies (double‐stranded DNA, nucleosomes, ribosomal P, ribonucleoprotein [RNP] 68, RNPA, Smith [Sm], Sm/RNP, Sjögren's syndrome antigen A [SSA]/Ro52, SSA/Ro60, Sjögren's syndrome antigen B [SSB]/La, cardiolipin [CL]‐Immunoglobulin G [IgG], CL–Immunoglobulin M [IgM], and β₂ glycoprotein I [β₂GPI]–IgG) in 911 patients with SLE from two cohorts. We evaluated whether each SLE subgroup is associated with HLA‐DRB1 alleles, clinical manifestations (n = 743), and cytokine levels in circulation (n = 446).

Results

Our analysis identified four subgroups among the patients with SLE. Subgroup 1 (29.3%) was dominated by anti‐SSA/Ro60/Ro52/SSB autoantibodies and was strongly associated with HLA‐DRB1*03 (odds ratio [OR] = 4.73; 95% confidence interval [CI] = 4.52‐4.94). Discoid lesions were more common for this disease subgroup (OR = 1.71, 95% CI = 1.18‐2.47). Subgroup 2 (28.7%) was dominated by anti‐nucleosome/SmRNP/DNA/RNPA autoantibodies and associated with HLA‐DRB1*15 (OR = 1.62, 95% CI = 1.41‐1.84). Nephritis was most common in this subgroup (OR = 1.61, 95% CI = 1.14‐2.26). Subgroup 3 (23.8%) was characterized by anti‐ß₂GPI‐IgG/anti‐CL–IgG/IgM autoantibodies and a higher frequency of HLA‐DRB1*04 compared with the other patients with SLE. Vascular events were more common in Subgroup 3 (OR = 1.74, 95% CI = 1.2‐2.5). Subgroup 4 (18.2%) was negative for the investigated autoantibodies, and this subgroup was not associated with HLA‐DRB1. Additionally, the levels of eight cytokines significantly differed among the disease subgroups.

Conclusion

Our findings suggest that four fairly distinct subgroups can be identified on the basis of the autoantibody profile in SLE. These four SLE subgroups differ regarding associations with HLA‐DRB1 alleles and immunological and clinical features, suggesting dissimilar disease pathways.

Antiphospholipid antibodies and the risk of autoimmune hemolytic anemia in patients with systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

According to criteria for the classification of Systemic Lupus Erythematosus (SLE), autoimmune hemolytic anemia is one of the disease-defining hematologic disorders together with thrombocytopenia. Since the recognition of Antiphospholipid Syndrome (APS), hemolytic anemia was frequently reported but several studies yielded contradictory results on the association between antiphospholipid antibodies (aPL) and hemolytic anemia. Therefore, we evaluated the association of aPL and autoimmune hemolytic anemia in SLE patients by conducting a systematic review and meta-analysis of available literature.

METHODS

MEDLINE, EMBASE, Cochrane Library, congress abstracts, and reference lists of eligible studies were searched from 1987 to 2020. Studies were selected if they included SLE patients with descriptions of exposure to aPL and occurrence of hemolytic anemia. Three reviewers extracted study characteristics and association data from published reports. Risk estimates were pooled using random effects models and sensitivity analyses. We followed the PRISMA guidelines for all stages of the meta-analysis (Supplemental Table). PROSPERO registration number: CRD42015027376.

RESULTS

From 3555 articles identified, 38 studies met inclusion criteria and included 8286 SLE patients. 20.5% of aPL-positive SLE patients had hemolytic anemia compared to 8.7% in aPL-negative SLE patients. The overall pooled Odds Ratio (OR) for hemolytic anemia in aPL positive patients was 2.83 (95% CI; 2.12-3.79). Among aPL subtypes, the risk of hemolytic anemia was highest for lupus anticoagulant (OR = 3.37 [95% CI; 2.26-5.04]) and, antiβ₂Glycoprotein I antibodies (OR = 3.21 [95% CI; 1.54-6.72]), especially IgM antiβ₂Glycoprotein I (OR = 3.01 [95% CI; 1.26, 7.24]).

CONCLUSIONS

The occurrence of hemolytic anemia was strongly associated with presence of aPL in SLE patients. Interestingly, IgM isotypes indicate an increased risk of hemolytic anemia in SLE.

Characteristics and Management of Autoimmune Disease-Associated Cerebral Venous Sinus Thrombosis

Cerebral venous sinus thrombosis (CVST) is a central nervous system disease characterised by thrombosis in cerebral venous or dural sinuses. Autoimmune diseases, a series of diseases caused by immune responses to autoantigens, are important causes of CVST. The most common diseases that lead to CVST are Behçet’s syndrome, systemic lupus erythematosus, antiphospholipid syndrome, and Sjögren’s syndrome. Each of these diseases have different clinical and imaging manifestations and treatment for CVST varies by aetiology. This review summarises the characteristics and the current management strategies for autoimmune disease-associated CVST and emphasises controversial therapeutic strategies to provide informative reference information for diagnosis and treatment. Risk factors of autoimmune antigens should not be neglected when unconventional CVST occurs, and both drugs and interventional therapy need further standardisation and discussion with more prospective clinical studies.

Persistent thrombocytopenia predicts poor long-term survival in patients with antiphospholipid syndrome: a 38-year follow-up study

OBJECTIVES

To investigate the impact of thrombocytopenia on survival in patients with antiphospholipid syndrome (APS).

METHODS

Thrombocytopenia and other predictors of outcome were retrospectively evaluated in an antiphospholipid-antibody (aPL)-positive and APS cohort with 38-year follow-up (1980-2018). Thrombocytopenia was defined as < 150 × 109 platelets/l. Hazard ratios (HR) of mortality were calculated using Cox-regression models.

RESULTS

Among 114 patients, 64% had primary APS, 25% secondary APS, and 10% asymptomatic aPL. Mean follow-up was 19 (5-38) years. ANA (HR 1.8, p= 0.10, 95%CI 0.8-3.6), arterial thrombotic events (HR 7.0, p= 0.016, 95%CI 1.4-3.5), myocardial infarction (HR 8.3, p= 0.03, 95%CI 1.1-59), intracardiac thrombosis (HR 17, p= 0.04, 95%CI 1-279), and thrombocytopenia (HR 2.9, p= 0.004, 95%CI 1.4-6.1) were risk factors for all-cause mortality but in multivariate analysis only thrombocytopenia (HR 2.7, p= 0.01, 95%CI 1.3-6.0) remained significant. Persistent (HR 4.4, p= 0.001, 95%CI 2.1-9.2) and low-moderate thrombocytopenia (HR 2.8, p= 0.01, 95%CI 1.2-6.4) were associated with a significant increase in mortality compared with acute (HR 1.6, p= 0.40, 95%CI 0.5-5.3) and severe forms (HR 2.1, p= 0.30, 95%CI 0.5-9.2). APS patients with vs without thrombocytopenia were more frequently male (58% vs 24%, p= 0.001) with arterial thrombosis (55% vs 32%, p= 0.04), LA positivity (100% vs 87%, p= 0.04), type I aPL profile (89% vs 71%, p= 0.05), and anticoagulant treatment (89% vs 63%, p= 0.01). Thrombosis caused 13% of deaths in thrombocytopenic patients and 1% in those without (p= 0.01).

CONCLUSION

Thrombocytopenia is an aPL-related manifestation that identifies patients with severe disease phenotype and high thrombotic risk. Persistent low-moderate thrombocytopenia is associated with a reduced long-term survival.

Predicting the Risk of Pulmonary Arterial Hypertension in Systemic Lupus Erythematosus: A Chinese Systemic Lupus Erythematosus Treatment and Research Group Cohort Study

OBJECTIVE

Pulmonary arterial hypertension (PAH) is a life-threatening complication of systemic lupus erythematosus (SLE). However, there is no algorithm to identify those at high risk. This study was undertaken to develop a prediction model for PAH in patients with lupus that provides individualized risk estimates.

METHODS

A multicenter, longitudinal cohort study was undertaken from January 2003 to January 2020. The study collected data on 3,624 consecutively evaluated patients diagnosed as having SLE. The diagnosis of PAH was confirmed by right-sided heart catheterization. Cox proportional hazards regression and least absolute shrinkage and selection operator were used to fit the model. Model discrimination, calibration, and decision curve analysis were performed for validation.

RESULTS

Ninety-two lupus patients (2.54%) developed PAH during a median follow-up of 4.84 years (interquartile range 2.42-8.84). The final prediction model included 5 clinical variables (acute/subacute cutaneous lupus, arthritis, renal disorder, thrombocytopenia, and interstitial lung disease) and 3 autoantibodies (anti-RNP, anti-Ro/SSA and anti-La/SSB). A 10-year PAH probability-predictive nomogram was established. The model was internally validated by Harrell's concordance index (0.78), the Brier score (0.03), and a satisfactory calibration curve. According to the net benefit and predicted probability thresholds, we recommend annual screening in high-risk (>4.62%) lupus patients.

CONCLUSION

We developed a risk stratification model using routine clinical assessments. This new tool may effectively predict the future risk of PAH in patients with SLE.

Lymphocyte subset clustering analysis in treatment-naive patients with systemic lupus erythematosus

OBJECTIVES

The aim of the study is to identify clusters of lymphocyte subsets within treatment-naive systemic lupus erythematosus (SLE) patients and evaluate the potential association of these clusters with disease activities.

METHODS

We conducted a cross-sectional study of consecutive 143 treatment-naive SLE patients in the Affiliated Hospital of Nantong University, China. We used hierarchical cluster analysis to classify individuals into clusters based on circulating lymphocyte subset proportions (CD3⁺CD4⁺T cell, CD3⁺CD8⁺T cell, CD19⁺B cell, and CD3-CD16 + CD56 NK cell) via R software. Demographic variables, clinical manifestations, laboratory variables, and disease activities were compared among clusters.

RESULTS

The SLE patients (median age 35 (26-48) years, 90.9% female) were divided into four clusters. The clustering features were as follows: cluster 1 (B high), cluster 2 (CD4 high), cluster 3 (CD8 high), and cluster 4 (NK high). SLE patients in cluster 1 showed the highest incidence of arthritis (70.6%, 34.2%, 48.3%, and 42.9% in clusters 1, 2, 3, and 4, respectively; P = 0.046), and patients in cluster 3 and cluster 4 showed significantly a higher incidence of nephritis (35.3%, 25.0%, 48.3%, and 61.9% in in clusters 1, 2, 3, and 4, respectively; P = 0.008). Patients in cluster 2 suffered from lower SLE Disease Activity Index (SLEDAI) score (12.1 ± 5.0, 10.3 ± 5.6, 12.2 ± 4.6, and 14.4 ± 7.3 in clusters 1, 2, 3, and 4, respectively; P = 0.046). Regression analysis indicated that, compared with patients in cluster 2, patients in cluster 1 exhibited higher rate of arthritis (OR 4.53, 95% CI 1.38-14.86, P = 0.013), while patients in cluster 3 (OR 2.85, 95%CI 1.15-7.08, P = 0.024) and cluster 4 (OR 4.93, 95%CI 1.76-13.85, P = 0.002) exhibited higher rate of nephritis.

CONCLUSION

This study supports the existence of lymphocyte subset clusters with different clinical features in treatment-naive SLE patients, which could help to differentiate between various subsets of SLE. Key Points • Lymphocyte subsets may occur in a pattern of cluster in treatment-naive SLE patients.

Validation of the adjusted global antiphospholipid syndrome score in systemic lupus erythematosus patients in Argentina

INTRODUCTION

Assessment of risk both for pregnancy morbidity and thrombosis in the presence of anti-phospholipid antibodies (aPL) is still a challenge in Systemic Lupus Erythematosus (SLE) patients. The Global Antiphospholipid Syndrome Score (GAPSS) takes into account the aPL profile (criteria and non-criteria aPL), the conventional cardiovascular risk factors and the autoimmune antibody profile. An adjusted model of the score (aGAPSS) excluding anti-phosphatidylserine/Prothrombin (aPS/PT), suggests that the score is able to stratify patients for their rate of events making it widely applicable in daily clinical practice.

OBJECTIVE

To validate the aGAPSS in a multicentric cohort of SLE patients in Argentina.

PATIENTS AND METHODS

consecutive SLE patients with and with andwithout thrombotic events from seven Rheumatologist centers were included. Traditional cardiovascular risk factors, aPL antibodies and medications received (aspirin, hydroxychloroquine and anticoagulation) were collected. The score aGAPSS was calculated for each patient at the last visit by adding together the points corresponding to the risk factors: 1 for hypertension, 3 for dyslipidemia, 4 for LA and B2GPI (IgM or IgG) antibodies and 5 for aCL (IgM or IgG) antibodies. The discriminative ability of the aGAPSS was calculated by measuring the area under the receiver operating characteristic curve (AUC). Multivariate logistic regression analysis was performed to examine the impact of multiple cardiovascular risk factors and laboratory parameters on the occurrence of thrombosis.

RESULTS

Two hundred and ninety-six SLE patients were included. One-hundred and twenty-one patients (40.9%) presented thrombotic and/or pregnancy complications. Median aGAPSS was significantly higher in patients who experienced an event (thrombosis and/or pregnancy morbidity) compared with those without [4 (IQR 1-9) versus 1 (IQR 0-5); p < 0.001]. The best cut off point for the diagnosis of thrombosis and/or pregnancy complications was aGAPSS ≥4. Multivariate logistic regression analysis showed that aCL antibodies [OR 2.1 (95% CI 1.16-3.90); p = 0.015] were an independent risk factors for thrombotic events.

CONCLUSIONS

This score is a simple tool, easy to apply to SLE patients in daily practice. The use of the aGAPSS could change the non-pharmacologic and pharmacologic treatment in higher risk patients to improve their survival.

Antiphospholipid syndrome (APS) in patients with systemic lupus erythematosus (SLE) implies a more severe disease with more damage accrual and higher mortality

INTRODUCTION

Antiphospholipid antibodies (aPL) have been associated with organ damage and certain features in systemic lupus erythematosus(SLE) patients. Our aim was to investigate the differences between SLE patients according to the presence of aPL and/or clinical antiphospholipid syndrome (APS).

MATERIALS AND METHODS

Patients from the RELESSER-T registry were included. RELESSER-T is a Spanish multicenter, hospital-based, retrospective, SLE registry.

RESULTS

We included 2398 SLE patients, 1372 of whom were positive for aPL. Overall 1026 patients were classified as SLE, 555 as SLE-APS and817 as SLE-aPL. Regarding cardiovascular risk factors, SLE-APS patients had higher rates of hypertension, dyslipidemia and diabetes than those with SLE-aPL and SLE (p < 0.001). SLE-APS patients showed higher rates of neuropsychiatric, cardiac, pulmonary, renal and ophthalmological manifestations than the other groups (p < 0.001). SLE-APS patients presented greater damage accrual with higher SLICC values (1.9 ± 2.2 in SLE-APS, 0.9 ± 1.4 in SLE-aPL and 1.1 ± 1.6 in SLE, p < 0.001) and more severe disease as defined by the Katz index (3 ± 1.8 in SLE-APS, 2.7 ± 1.7 in SLE-aPL and 2.6 ± 1.6 in SLE, p  < 0.001). SLE-APS patients showed higher mortality rates (p < 0.001).

CONCLUSIONS

SLE-APS patients exhibited more severe clinical profiles with higher frequencies of major organ involvement, greater damage accrual and higher mortality than SLE-aPL and SLE patients.

Validation of the adjusted global antiphospholipid syndrome score in a single centre cohort of APS patients from Turkey

The adjusted global antiphospholipid syndrome score (aGAPSS) is a recently developed thrombotic risk assessment score that considers the antiphospholipid antibody (aPL) profile and conventional cardiovascular risk factors. In this retrospective study, we aimed to evaluate the validity of the aGAPSS in predicting clinical manifestations (criteria and extra-criteria) of antiphospholipid syndrome (APS) in a single centre cohort of patients. Ninety-eight patients with APS ± systemic lupus erythematosus (SLE) were classified according to clinical manifestations as vascular thrombosis (VT), pregnancy morbidity (PM) or both (VT + PM). The aGAPSS was calculated for each patient as previously defined. Mean aGAPSS of the cohort was calculated as 10.2 ± 3.8. Significantly higher aGAPSS values were seen in VT (n = 58) and VT + PM (n = 29) groups when compared to PM (n = 11) group (10.6 ± 3.7 vs 7.4 ± 2.9, P = 0.005; 10.7 ± 4 vs 7.4 ± 2.9, P = 0.008, respectively), mainly due to lower frequencies of cardiovascular risk factors in PM. Higher aGAPPS values were also associated with recurrent thrombosis (11.6 ± 3.7 vs 9.9 ± 3.6, P = 0.04). Regarding extra-criteria manifestations, patients with livedo reticularis (n = 11) and APS nephropathy (n = 9) had significantly higher aGAPSS values (12.9 ± 3.4 vs 9.9 ± 3.7, P = 0.02; 12.4 ± 2.9 vs 10 ± 3.8, P = 0.04, respectively). The computed AUC demonstrated that aGAPSS values ≥10 had the best diagnostic accuracy for thrombosis. Our results suggest that patients with higher aGAPSS values are at higher risk for developing vascular thrombosis (either first event or recurrence) and extra-criteria manifestations, especially livedo reticularis and APS nephropathy.

Non-histologic factors discriminating proliferative lupus nephritis from membranous lupus nephritis

BACKGROUND

To investigate non-histologic factors that can discriminate proliferative lupus nephritis (LN) from membranous LN in patients with systemic lupus erythematosus with renal manifestations.

METHODS

Patients with biopsy-proven proliferative LN (class III ± V and class IV ± V) and membranous LN (class V) were included. Non-histologic factors were compared between the two groups. A logistic regression analysis was performed to identify the factors associated with proliferative LN. To assess the accuracy of these factors in discriminating between proliferative LN and membranous LN, we performed a receiver-operating characteristic analysis.

RESULTS

Of the total 168 patients with biopsy-proven LN, 150 patients (89.3%) had proliferative LN, and 18 patients (10.7%) had membranous LN. In the multivariable logistic regression analysis, positive anti-double-stranded DNA (anti-dsDNA) antibody (adjusted OR = 11.200, 95% CI = 2.202-56.957, p = 0.004) was associated with proliferative LN, while positive anti-U1RNP antibody (adjusted OR = 0.176, 95% CI = 0.040-0.769, p = 0.021) and higher glomerular filtration rate (GFR) (adjusted OR = 0.973, 95% CI = 0.951-0.994, p = 0.013) were inversely associated with proliferative LN. Among these covariates, the anti-dsDNA antibody (area under the curve = 0.806, 95% CI = 0.695-0.916) had the highest accuracy in discriminating between proliferative LN and membranous LN.

CONCLUSION

The positivity of anti-dsDNA antibody was associated with proliferative LN, while the positivity of anti-U1RNP antibody and GFR were inversely associated with proliferative LN. The anti-dsDNA antibody had a good accuracy in discriminating proliferative LN from membranous LN.

Antiphospholipid Antibodies and Autoimmune Haemolytic Anaemia: A Systematic Review and Meta-Analysis

The relationship between antiphospholipid antibodies (aPL) and autoimmune haemolytic anaemia (AIHA) has never been systematically addressed. The aim of this study is to assess the link between aPL and AIHA in adult systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). This study performed an EMBASE/PubMed search from inception to June 2019 and meta-analysis using Peto’s odds ratios. The pooled prevalence (PP) of IgG/IgM anticardiolipin (aCL) and lupus anticoagulant (LA) was greater in AIHA +ve than AIHA −ve patients (34.7% vs. 27.6%, p = 0.03; 33.3% vs. 21.8%, p < 0.0001; 20.9% vs. 8.3%, p = 0.01). The PP of AIHA was greater in: (1) IgG and IgM aCL +ve than −ve patients (21.8% vs. 11.1%, p = 0.001 and 18.7% vs. 6.3%, p < 0.0001), (2) in SLE related APS than in primary APS patients (22.8% vs. 3.9% p < 0.0001), (3) in APS +ve than APS −ve SLE patients (23.2% vs. 8.4%, p = 0.01), and (4) in thrombotic APS than non-thrombotic APS/SLE patients (26.8% vs. 10%, p = 0.03). The PP of IgG/IgM aCL and LA was greater in DAT +ve than DAT −ve patients (42.4% vs. 12.8%, p < 0.0001; 26.2% vs. 12.8%, p = 0.03 and 29.2% vs. 15.7%, p = 0.004 respectively). It was found that AIHA prevalence is maximal in SLE with aPL/APS, low-moderate in SLE without aPL and minimal in PAPS. Moreover, AIHA is rightly included among the classification criteria for SLE but not for APS/aPL. The significance of an isolated DAT positivity remains unclear in this setting

Clusters in Pediatric Rheumatic Diseases

PURPOSE OF THE REVIEW

Rheumatic diseases usually have very diverse and complex pathophysiology resulting in different clinical phenotypes. Some certain phenotypes cluster together with a common presentation, course, and outcome. Our primary aim is to review the known disease clusters in certain rheumatological conditions.

RECENT FINDINGS

Cluster analysis has been reported in several rheumatic diseases, Behcet disease being the most common. Five individual clusters together with some clinical associations have been reported in Behcet patients. Certain antibody-phenotype associations and damage clusters have been reported in systemic lupus erythematosus (SLE) patients as well. Although there is no proper cluster analysis, two distinct phenotypes are evident in deficiency of ADA2 (DADA2): those with a polyarteritis nodosa-like vasculopathy and hematological involvement with pure red cell aplasia or bone marrow failure. The variants are claimed to be different regions of this gene for these 2 phenotypes. Lastly, there is a recent paper grouping ANCA-associated vasculitis according to disease phenotype and antibody associations. There are distinct clusters in certain rheumatic diseases which might help us to predict comorbidities, disease course, and treatment response.

The antiphospholipid syndrome - often overlooked cause of vascular occlusions?

The antiphospholipid syndrome (APS) was fully recognized as a clinical entity in the early 1980s. Still, more than 30 years later, the epidemiology of APS is not well described, and furthermore, APS remains a challenge in terms of both diagnostic issues and clinical praxis involving a wide range of specialties. To date, there are no diagnostic criteria for APS. The present classification criteria rely on a combination of clinical manifestations and persistently positive tests for antiphospholipid antibodies (aPL). Clinical symptoms comprise vascular thrombosis, which can affect any vascular bed, including venous, microvascular and arterial vessels, and a set of pregnancy morbidities including early and late miscarriages, foetal death and preeclampsia. APS is more frequent among patients with other autoimmune diseases, and it is especially common in systemic lupus erythematosus (SLE). Importantly, APS symptoms can present in almost any medical specialty, but general knowledge and most previous clinical studies have essentially been confined to haematology, rheumatology and obstetrics/gynaecology. However, recent data demonstrate a relatively high prevalence of aPL also in patients from the general population who suffer from vascular occlusions or pregnancy complications. It is important that these patients are recognized by the general health care since APS is a treatable condition. This review aims to summarize the present knowledge on the history, pathogenesis, clinical manifestations and treatment of APS in order to urge a wide range of clinicians to consider comprehensive assessment of all patients where the diagnosis APS may be conceivable.

Adults with systemic lupus exhibit distinct molecular phenotypes in a cross-sectional study

BACKGROUND

The clinical and pathologic diversity of systemic lupus erythematosus (SLE) hinders diagnosis, management, and treatment development. This study addresses heterogeneity in SLE through comprehensive molecular phenotyping and machine learning clustering.

METHODS

Adult SLE patients (n = 198) provided plasma, serum, and RNA. Disease activity was scored by modified SELENA-SLEDAI. Twenty-nine co-expression module scores were calculated from microarray gene-expression data. Plasma soluble mediators (n = 23) and autoantibodies (n = 13) were assessed by multiplex bead-based assays and ELISAs. Patient clusters were identified by machine learning combining K-means clustering and random forest analysis of co-expression module scores and soluble mediators.

FINDINGS

SLEDAI scores correlated with interferon, plasma cell, and select cell cycle modules, and with circulating IFN-α, IP10, and IL-1α levels. Co-expression modules and soluble mediators differentiated seven clusters of SLE patients with unique molecular phenotypes. Inflammation and interferon modules were elevated in Clusters 1 (moderately) and 4 (strongly), with decreased T cell modules in Cluster 4. Monocyte, neutrophil, plasmablast, B cell, and T cell modules distinguished the remaining clusters. Active clinical features were similar across clusters. Clinical SLEDAI trended highest in Clusters 3 and 4, though Cluster 3 lacked strong interferon and inflammation signatures. Renal activity was more frequent in Cluster 4, and rare in Clusters 2, 5, and 7. Serology findings were lowest in Clusters 2 and 5. Musculoskeletal and mucocutaneous activity were common in all clusters.

INTERPRETATION

Molecular profiles distinguish SLE subsets that are not apparent from clinical information. Prospective longitudinal studies of these profiles may help improve prognostic evaluation, clinical trial design, and precision medicine approaches.

FUNDING

US National Institutes of Health.

Autoantibody clustering of lupus-associated pulmonary hypertension

Objective

To define the SLE phenotype associated with pulmonary hypertension using multiple autoantibodies.

Methods

207 (8%) patients with SLE with pulmonary hypertension, defined as a right ventricular systolic pressure greater than 40 mm Hg on transthoracic echocardiogram or as pulmonary artery dilatation on CT of the chest, were identified from the Hopkins Lupus Cohort (94.2% female; 56.5% African–American, 39% Caucasian; mean age 45.6 years). 53 patients were excluded from the clustering analysis due to incomplete autoantibody profiles. Agglomerative hierarchical clustering algorithm with Ward’s method was used to cluster the patients with pulmonary hypertension, based on their autoantibodies. Autoantibodies used in the clustering analysis included lupus anticoagulant, anticardiolipin, anti-beta 2 glycoprotein I, antidouble-stranded DNA, anti-Sm (anti-Smith), antiribonucleoprotein, false positive-rapid plasma reagin, anti-Ro, anti-La and hypocomplementaemia (C3 ever low or C4 ever low). The Dunn index was used to internally validate the clusters. Bootstrap resampling derived the mean Jaccard coefficient for each cluster. All analyses were performed in R V.3.6.1 using the packages cluster, fpc and gplots.

Results

A significantly higher prevalence of pulmonary hypertension in African–American patients with SLE, compared with Caucasian patients with SLE (11.5% vs 5.9%, p<0.0001), was found. Based on equivalent Dunn indices, the 154 patients with SLE-associated pulmonary hypertension with complete autoantibody data were divided into five clusters, three of which had mean Jaccard coefficients greater than 0.6. Hypocomplementaemia, renal disorder and age at diagnosis significantly differed across clusters. One cluster was defined by antiphospholipid antibodies. One cluster was defined by anti-Ro and anti-La. One cluster had low frequencies of all antibodies.

Conclusion

SLE-associated pulmonary hypertension disproportionately affects African–American patients. Pulmonary hypertension in SLE is defined by five autoantibody clusters. Antiphospholipid antibodies, anti-Ro and anti-La positivity, serological activity, and age at pulmonary hypertension diagnosis significantly differed across clusters, possibly indicating different pathophysiological mechanisms.

Identifying damage clusters in patients with systemic lupus erythematosus

AIM

Systemic lupus erythematosus (SLE) causes irreversible damage to organ systems. Recently, evidence has been obtained for subphenotypes of SLE. This study aimed to identify damage clusters and compare the associated clinical manifestations, SLE disease activity, mortality, and genetic risk scores (GRS).

METHODS

The study was conducted on the Hanyang BAE lupus cohort. Patients with disease duration <5 years were excluded to minimize confounding effects of disease duration. They were grouped into 3 clusters based on the Systemic Lupus International Collaborating Clinics Damage Index using k-means cluster analysis.

RESULTS

Among the 1130 analyzed patients, musculoskeletal damage was most prevalent (20.2%), followed by ocular (11.4%), renal (10.5%), and neuropsychiatric damage (10.2%). Three significantly different damage clusters were identified. Patients in cluster 1 (n = 824) showed the least damage. Cluster 2 (n = 195) was characterized by frequent renal (55.4%) and ocular (58.0%) damage, and cluster 3 (n = 111) was dominated by neuropsychiatric (100%) and musculoskeletal damage (35.1%). Cluster 2 had the highest adjusted mean AMS (adjusted mean SLE Disease Activity Index score; mean ± SD: 5.4 ± 2.9), while cluster 3 had the highest mortality (14.4%). Weighted GRS did not differ significantly between the clusters.

CONCLUSION

Patients in prevalent renal and ocular damage cluster had the highest AMS scores, while the cluster with frequent neuropsychiatric damage had the highest mortality.

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.

Autoimmune haemolytic anaemia and thrombocytopaenia in a single-centre cohort of patients with systemic lupus erythematosus from Turkey: clinical associations and effect on disease damage and survival

Introduction

Thrombocytopaenia and autoimmune haemolytic anaemia (AIHA) have considerable impact on prognosis in systemic lupus erythematosus (SLE). We investigated the frequencies of these haemocytopaenias, along with their associations and effect on outcome in a single-centre cohort of patients with SLE.

Methods

Demographic characteristics, clinical features, autoantibody profiles, damage and mortality data were compared between patients with and without each haematological abnormality. Variables displaying significant differences between the groups were entered into logistic regression.

Results

Ninety-three patients had AIHA and 215 had thrombocytopaenia. Both were associated with neuropsychiatric (NP) involvement, with each other, leucopaenia, antiphospholipid syndrome (APS) and antiphospholipid antibodies. More patients in both groups had organ damage, and their damage scores were higher. Association to NP damage was discernible. In addition, cardiovascular and renal damage and diabetes were more pronounced in patients with thrombocytopaenia. At logistic regression analysis, younger age, anticardiolipin antibody IgM positivity, leucopaenia and thrombocytopaenia were associated with AIHA whilst lupus anticoagulant activity, AIHA, leucopaenia, APS and NP involvement were associated with thrombocytopaenia. Among damage items, peripheral vascular damage, diabetes, NP damage, renal and ocular damage displayed significant associations with thrombocytopaenia, whereas none of the items did with AIHA. Patients with AIHA had significantly reduced survival rates at 10 and 20 years.

Conclusions

We observed that AIHA and thrombocytopaenia were associated with severe lupus, affecting major organs and causing end organ damage. Thus, they may be considered as prognostic markers. Furthermore, AIHA and especially thrombocytopaenia may also be a marker for a subgroup of lupus patients who have or may develop APS.

Sjögren Syndrome in Systemic Lupus Erythematosus: A Subset Characterized by a Systemic Inflammatory State

OBJECTIVE

An often-neglected subset of patients with systemic lupus erythematosus (SLE) is those with secondary Sjögren syndrome (SLE-sSS). Further, primary SS overlaps and can be difficult to delineate from SLE. To shed light on the SLE-sSS subset, we investigated a large and well-characterized SLE cohort, comparing patients with SLE-sSS and SLE patients without SS (SLE-nonsSS) and controls.

METHODS

We included 504 consecutive patients with SLE, fulfilling the 1982 revised American College of Rheumatology criteria, and 319 controls from the general population, matched for age and sex to the first 319 patients. SLE-sSS was defined according to the American-European Consensus Criteria (AECC). A thorough clinical examination, including subjective and objective quantifications of sicca symptoms, was performed in all participants. Autoantibodies and 20 selected cytokines were measured by luminex and multiplex analysis, respectively.

RESULTS

SLE-sSS, as defined by AECC, occurred in 23% of the patients with SLE. In comparison to SLE-nonsSS, the SLE-sSS group was older and more frequently female. Leukopenia and peripheral neuropathy were more frequent and nephritis less frequent. Circulating levels of 6/20 investigated proinflammatory cytokines [tumor necrosis factor-α, interleukin (IL) 6, monocyte chemoattractant protein 4, macrophage inflammatory protein 1β, IL-12/IL-23p40, and interferon γ-induced protein 10], total IgG, anti-SSA/Ro52, anti-SSA/Ro60, anti-SSB/La antibodies, and rheumatoid factor (IgM and IgA) were higher in the SLE-sSS group (p < 0.05 for all comparisons).

CONCLUSION

The frequency of SLE-sSS increased with age and affected roughly one-quarter of all patients with SLE. Despite less internal organ involvement, a systemic inflammatory state with high levels of proinflammatory cytokines is present in the SLE-sSS subgroup. This is a novel observation that may affect future understanding and treatment of the SLE-sSS subset.

Identification of 6 dermatomyositis subgroups using principal component analysis-based cluster analysis

OBJECTIVE

Dermatomyositis (DM) is a heterogeneous disease with a wide range of clinical manifestations. The aim of the present study was to identify the clinical subtypes of DM by applying cluster analysis.

METHODS

We retrospectively reviewed the medical records of 720 DM patients and selected 21 variables for analysis, including clinical characteristics, laboratory findings, and comorbidities. Principal component analysis (PCA) was first conducted to transform the 21 variables into independent principal components. Patient classification was then performed using cluster analysis based on the PCA-transformed data. The relationships among the clinical variables were also assessed.

RESULTS

We transformed the 21 clinical variables into nine independent principal components by PCA and identified six distinct subgroups. Cluster A was composed of two sub-clusters of patients with classical DM and classical DM with minimal organ involvement. Cluster B patients were older and had malignancies. Cluster C was characterized by interstitial lung disease (ILD), skin ulcers, and minimal muscle involvement. Cluster D included patients with prominent lung, muscle, and skin involvement. Cluster E contained DM patients with other connective tissue diseases. Cluster F included all patients with myocarditis and prominent myositis and ILD. We found significant differences in treatment across the six clusters, with clusters E, C and D being more likely to receive aggressive immunosuppressive therapy.

CONCLUSION

We applied cluster analysis to a large group of DM patients and identified 6 clinical subgroups, underscoring the need for better phenotypic characterization to help develop individualized treatments and improve prognosis.

Diagnostic value of serum high-mobility group box-1 in pediatric systemic lupus erythematosus

BACKGROUND

High-mobility group box-1 (HMGB1) acts as a damage-associated molecular pattern or as an alarmin and it stimulates inflammatory and immunological activities.

AIM

We sought to investigate serum HMGB1 protein expression in patients with pediatric systemic lupus erythematosus (pSLE) in relation to the disease characteristics and activity.

PATIENTS AND METHODS

This is a controlled cross-sectional study which comprised 50 children and adolescents with Systemic lupus erythematosus (SLE) and 50 age- and sex-matched healthy subjects who served as a control group. Study measurements included clinical assessment, laboratory workup for SLE (complete blood count, erythrocyte sedimentation rate, serum creatinine, creatinine clearance and 24-hour urinary protein, C3 and anti-double-stranded DNA, lupus anticoagulant and anticardiolipin antibodies) and measurement of serum HMGB1 by enzyme-linked immunosorbent assay in patients and controls.

RESULTS

Serum HMGB1 expression was significantly higher in the pSLE patients than the control group (P < 0.001). Patients with lupus nephritis (LN) had significantly higher serum HMGB1 as compared to those with normal kidneys (P < 0.04). Serum HMGB1 in LN patients correlated positively to the SLE Disease Activity Index (P < 0.0001), and 24 hours urinary proteins and negatively to creatinine clearance (P < 0.001). At a cut-off point of ≥40 µg/L, serum HMGB1 showed good diagnostic value for pSLE with sensitivity and specificity of 98% and 95%, respectively.

CONCLUSION

Serum HMGB1 seems to be a reliable biomarker for diagnosis of pSLE and monitoring disease status, especially in LN. HMBG1 might prove to be a potential therapeutic target in LN.

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.

Two subgroups in systemic lupus erythematosus with features of antiphospholipid or Sjögren's syndrome differ in molecular signatures and treatment perspectives

Background

Previous studies and own clinical observations of patients with systemic lupus erythematosus (SLE) suggest that SLE harbors distinct immunophenotypes. This heterogeneity might result in differences in response to treatment in different subgroups and obstruct clinical trials. Our aim was to understand how SLE subgroups may differ regarding underlying pathophysiology and characteristic biomarkers.

Methods

In a cross-sectional study, including 378 well-characterized SLE patients and 316 individually matched population controls, we defined subgroups based on the patients’ autoantibody profile at inclusion. We selected a core of an antiphospholipid syndrome-like SLE (aPL+ group; positive in the lupus anticoagulant (LA) test and negative for all three of SSA (Ro52 and Ro60) and SSB antibodies) and a Sjögren’s syndrome-like SLE (SSA/SSB+ group; positive for all three of SSA (Ro52 and Ro60) and SSB antibodies but negative in the LA test). We applied affinity-based proteomics, targeting 281 proteins, together with well-established clinical biomarkers and complementary immunoassays to explore the difference between the two predefined SLE subgroups.

Results

The aPL+ group comprised 66 and the SSA/SSB+ group 63 patients. The protein with the highest prediction power (receiver operating characteristic (ROC) area under the curve = 0.89) for separating the aPL+ and SSA/SSB+ SLE subgroups was integrin beta-1 (ITGB1), with higher levels present in the SSA/SSB+ subgroup. Proteins with the lowest p values comparing the two SLE subgroups were ITGB1, SLC13A3, and CERS5. These three proteins, rheumatoid factor, and immunoglobulin G (IgG) were all increased in the SSA/SSB+ subgroup. This subgroup was also characterized by a possible activation of the interferon system as measured by high KRT7, TYK2, and ETV7 in plasma. In the aPL+ subgroup, complement activation was more pronounced together with several biomarkers associated with systemic inflammation (fibrinogen, α-1 antitrypsin, neutrophils, and triglycerides).

Conclusions

Our observations indicate underlying pathogenic differences between the SSA/SSB+ and the aPL+ SLE subgroups, suggesting that the SSA/SSB+ subgroup may benefit from IFN-blocking therapies while the aPL+ subgroup is more likely to have an effect from drugs targeting the complement system. Stratifying SLE patients based on an autoantibody profile could be a way forward to understand underlying pathophysiology and to improve selection of patients for clinical trials of targeted treatments.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1836-8) contains supplementary material, which is available to authorized users.

Pulmonary arterial hypertension in systemic lupus erythematosus based on a CSTAR-PAH study: Baseline characteristics and risk factors

AIM

Pulmonary arterial hypertension (PAH) is a complex and devastating complication of systemic lupus erythematosus (SLE). We sought to describe the baseline characteristics of right heart catheterization (RHC)-confirmed SLE-associated PAH and identify risk factors for PAH in SLE patients.

METHODS

A multicenter, cross-sectional study was conducted using the Chinese SLE Treatment and Research group (CSTAR) registry. Baseline data for patients with SLE-associated PAH and SLE patients without PAH were collected and compared. Risk factors for PAH among patients with SLE were identified.

RESULTS

A total of 292 patients with SLE-associated PAH were enrolled. RHC was used to reveal hemodynamic features, including mean pulmonary arterial pressure (46.2 ± 12.0 mm Hg), pulmonary arterial wedge pressure (7.84 ± 3.92 mm Hg), pulmonary vascular resistance (10.86 ± 5.57 Wood units), and cardiac index (2.77 ± 0.91 L/min × m² ). A multivariate logistic regression analysis showed that serositis (odds ratio [OR] = 5.524, 95% CI 3.605-8.465, P < 0.001), anti-ribonucleoprotein (RNP) antibody positivity (OR = 13.332, 95% CI 9.500-18.710, P < 0.001), and diffusion capacity of carbon monoxide in the lung (DLCO)/%Pred <70% (OR = 10.018, 95% CI 6.619-15.162, P < 0.001) were independent predictors of PAH. We recommend using transthoracic echocardiography (TTE) to perform early screening of SLE patients who have serositis, anti-RNP antibody positivity, or DLCO/%Pred <70%. RHC is suggested for patients suspected of having PAH. Once a diagnosis of SLE-PAH is confirmed, evaluation and treatment should immediately begin.

CONCLUSION

Overall, we recommend performing early screening using TTE in SLE patients with serositis, anti-RNP antibodies, or a DLCO/%Pred <70%, even for patients in a relatively stable condition according to SLE disease activity index.

Phenome-wide association study identifies dsDNA as a driver of major organ involvement in systemic lupus erythematosus

In systemic lupus erythematosus (SLE), dsDNA antibodies are associated with renal disease. Less is known about comorbidities in patients without dsDNA or other autoantibodies. Using an electronic health record (EHR) SLE cohort, we employed a phenome-wide association study (PheWAS) that scans across billing codes to compare comorbidities in SLE patients with and without autoantibodies. We used our validated algorithm to identify SLE subjects. Autoantibody status was defined as ever positive for dsDNA, RNP, Smith, SSA and SSB. PheWAS was performed in antibody positive vs. negative SLE patients adjusting for age and race and using a false discovery rate of 0.05. We identified 1097 SLE subjects. In the PheWAS of dsDNA positive vs. negative subjects, dsDNA positive subjects were more likely to have nephritis ( p = 2.33 × 10^-9) and renal failure ( p = 1.85 × 10^-5). After adjusting for sex, race, age and other autoantibodies, dsDNA was independently associated with nephritis and chronic kidney disease. Those patients negative for dsDNA, RNP, SSA and SSB negative subjects were all more likely to have billing codes for sleep, pain and mood disorders. PheWAS uncovered a hierarchy within SLE-specific autoantibodies with dsDNA having the greatest impact on major organ involvement.

Cytokine profiling in active and quiescent SLE reveals distinct patient subpopulations

BACKGROUND

Patients with SLE display marked clinical and immunlogical heterogeneity. The purpose of the study was to investigate patterns of serum cytokines in patients with active and stable systemic lupus erythematosus (SLE) and to determine how they relate to clinical phenotype.

METHODS

Serum levels of 10 cytokines were measured retrospectively in a cohort of patients with SLE and in healthy controls using a high-sensitivity multiplex bead array. Disease activity was determined using the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) and British Isles Lupus Assessment Group (BILAG-2004) indices. Logistic regression models were used to determine the association between cytokine levels and active SLE. Principal component analysis (PCA) and cluster analysis was then used to identify subgroups of patients on the basis of cytokine levels.

RESULTS

Serum chemokine (C-X-C motif) ligand 10 (CXCL10) and CXCL13 were significantly higher in patients with SLE compared to healthy controls. Two cytokines (pentraxin-related protein (PTX3) and CXCL10) were significantly higher in patients with active disease after adjustment for potential confounding factors. Measurement of four cytokines (CXCL10, IL-10, IL-21 and PTX3) significantly improved the performance of a model to identify patients with clinically active disease. Cluster analysis revealed that the patients formed 3 distinct groups, characterised by higher levels of interferon alpha (IFNα) and B lymphocyte stimulator (BLyS) (group 1), increased CXCL10 and CXCL13 (group 2) or low levels of cytokines (group 3). Group 2 had significantly lower serum complement and higher anti-double-stranded DNA antibodies and increased prevalence of inflammatory arthritis.

CONCLUSIONS

Multiplex analysis has identified a serum cytokine signature for active SLE. Within the SLE population distinct cytokine subgroups were identified, with differing clinical and immunological phenotypes that appeared stable over time. Assessment of cytokine profiles may reveal unique insights into disease heterogeneity.