Extrarenal symptoms associate with worse quality of life in patients enrolled in the AMP RA/SLE Lupus Nephritis Network.

OBJECTIVE: Lupus nephritis (LN) can occur as an isolated component of disease activity or be accompanied by diverse extrarenal manifestations. Whether isolated renal disease is sufficient to decrease health related quality of life (HRQOL) remains unknown. This study compared Patient-Reported Outcomes Measurement Information System 29-Item (PROMIS-29) scores in LN patients with isolated renal disease to those with extrarenal symptoms to evaluate the burden of LN on HRQOL and inform future LN clinical trials incorporating HRQOL outcomes. METHODS: A total of 181 LN patients consecutively enrolled in the multicentre multi-ethnic/racial Accelerating Medicines Partnership completed PROMIS-29 questionnaires at the time of a clinically indicated renal biopsy. Raw PROMIS-29 scores were converted to standardized T scores. RESULTS: Seventy-five (41%) patients had extrarenal disease (mean age 34, 85% female) and 106 (59%) had isolated renal (mean age 36, 82% female). Rash (45%), arthritis (40%) and alopecia (40%) were the most common extrarenal manifestations. Compared with isolated renal, patients with extrarenal disease reported significantly worse pain interference, ability to participate in social roles, physical function, and fatigue. Patients with extrarenal disease had PROMIS-29 scores that significantly differed from the general population by > 0.5 SD of the reference mean in pain interference, physical function, and fatigue. Arthritis was most strongly associated with worse scores in these three domains. CONCLUSION: Most patients had isolated renal disease and extrarenal manifestations associated with worse HRQOL. These data highlight the importance of comprehensive disease management strategies that address both renal and extrarenal manifestations to improve overall patient outcomes.

Prevalence of concomitant rheumatologic diseases and autoantibody specificities among racial and ethnic groups in SLE patients.

Objective: Leveraging the Manhattan Lupus Surveillance Program (MLSP), a population-based registry of cases of systemic lupus erythematosus (SLE) and related diseases, we investigated the proportion of SLE with concomitant rheumatic diseases, including Sjögren's disease (SjD), antiphospholipid syndrome (APLS), and fibromyalgia (FM), as well as the prevalence of autoantibodies in SLE by sex and race/ethnicity. Methods: Prevalent SLE cases fulfilled one of three sets of classification criteria. Additional rheumatic diseases were defined using modified criteria based on data available in the MLSP: SjD (anti-SSA/Ro positive and evidence of keratoconjunctivitis sicca and/or xerostomia), APLS (antiphospholipid antibody positive and evidence of a blood clot), and FM (diagnosis in the chart). Results: 1,342 patients fulfilled SLE classification criteria. Of these, SjD was identified in 147 (11.0%, 95% CI 9.2-12.7%) patients with women and non-Latino Asian patients being the most highly represented. APLS was diagnosed in 119 (8.9%, 95% CI 7.3-10.5%) patients with the highest frequency in Latino patients. FM was present in 120 (8.9%, 95% CI 7.3-10.5) patients with non-Latino White and Latino patients having the highest frequency. Anti-dsDNA antibodies were most prevalent in non-Latino Asian, Black, and Latino patients while anti-Sm antibodies showed the highest proportion in non-Latino Black and Asian patients. Anti-SSA/Ro and anti-SSB/La antibodies were most prevalent in non-Latino Asian patients and least prevalent in non-Latino White patients. Men were more likely to be anti-Sm positive. Conclusion: Data from the MLSP revealed differences among patients classified as SLE in the prevalence of concomitant rheumatic diseases and autoantibody profiles by sex and race/ethnicity underscoring comorbidities associated with SLE.

Longitudinal patterns and predictors of response to standard-of-care therapy in lupus nephritis: data from the Accelerating Medicines Partnership Lupus Network.

BACKGROUND: Leveraging the Accelerating Medicines Partnership (AMP) Lupus Nephritis (LN) dataset, we evaluated longitudinal patterns, rates, and predictors of response to standard-of-care therapy in patients with lupus nephritis. METHODS: Patients from US academic medical centers with class III, IV, and/or V LN and a baseline urine protein/creatinine (UPCR) ratio ≥ 1.0 (n = 180) were eligible for this analysis. Complete response (CR) required the following: (1) UPCR < 0.5; (2) normal serum creatinine (≤ 1.3 mg/dL) or, if abnormal, ≤ 125% of baseline; and (3) prednisone ≤ 10 mg/day. Partial response (PR) required the following: (1) > 50% reduction in UPCR; (2) normal serum creatinine or, if abnormal, ≤ 125% of baseline; and (3) prednisone dose ≤ 15 mg/day. RESULTS: Response rates to the standard of care at week 52 were CR = 22.2%; PR = 21.7%; non-responder (NR) = 41.7%, and not determined (ND) = 14.4%. Only 8/180 (4.4%) patients had a week 12 CR sustained through week 52. Eighteen (10%) patients attained a week 12 PR or CR and sustained their responses through week 52 and 47 (26.1%) patients achieved sustained PR or CR at weeks 26 and 52. Week 52 CR or PR attainment was associated with baseline UPCR > 3 (ORadj = 3.71 [95%CI = 1.34-10.24]; p = 0.012), > 25% decrease in UPCR from baseline to week 12 (ORadj = 2.61 [95%CI = 1.07-6.41]; p = 0.036), lower chronicity index (ORadj = 1.33 per unit decrease [95%CI = 1.10-1.62]; p = 0.003), and positive anti-dsDNA antibody (ORadj = 2.61 [95%CI = 0.93-7.33]; p = 0.069). CONCLUSIONS: CR and PR rates at week 52 were consistent with the standard-of-care response rates observed in prospective registrational LN trials. Low sustained response rates underscore the need for more efficacious therapies and highlight how critically important it is to understand the molecular pathways associated with response and non-response.

Clinical and Serologic Phenotyping and Damage Indices in Patients With Systemic Lupus Erythematosus With and Without Fibromyalgia.

OBJECTIVE: Given fibromyalgia (FM) frequently co-occurs with autoimmune disease, this study was initiated to objectively evaluate FM in a multiracial/ethnic cohort of patients with systemic lupus erythematosus (SLE). METHODS: Patients with SLE were screened for FM using the 2016 FM classification criteria during an in-person rheumatologist visit. We evaluated hybrid Safety of Estrogens in Lupus National Assessment (SELENA)-SLE Disease Activity Index (SLEDAI) scores, SLE classification criteria, and Systemic Lupus International Collaborating Clinics damage index. We compared patients with and without FM and if differences were present, compared patients with FM with patients with non-FM related chronic pain. RESULTS: 316 patients with SLE completed the FM questionnaire. 55 (17.4%) met criteria for FM. The racial composition of patients with FM differed from those without FM (P = 0.023), driven by fewer Asian patients having FM. There was no difference in SLE disease duration, SELENA-SLEDAI score, or active serologies. There was more active arthritis in the FM group (16.4%) versus the non-FM group (1.9%) (P < 0.001). The Widespread Pain Index and Symptom Severity Score did not correlate with degree of SLE activity (r = -0.016; 0.107) among patients with FM or non-FM chronic pain (r = 0.009; -0.024). Regarding criteria, patients with FM had less nephritis and more malar rash. Systemic Lupus International Collaborating Clinics damage index did not differ between groups. CONCLUSION: Except for arthritis, patients with SLE with FM are not otherwise clinically or serologically distinguishable from those without FM, and Widespread Pain Index and Symptom Severity Score indices do not correlate with SLEDAI. These observations support the importance of further understanding the underlying biology of FM in SLE.

Urine proteomic signatures of histological class, activity, chronicity, and treatment response in lupus nephritis.

Lupus nephritis (LN) is a pathologically heterogenous autoimmune disease linked to end-stage kidney disease and mortality. Better therapeutic strategies are needed as only 30%-40% of patients completely respond to treatment. Noninvasive biomarkers of intrarenal inflammation may guide more precise approaches. Because urine collects the byproducts of kidney inflammation, we studied the urine proteomic profiles of 225 patients with LN (573 samples) in the longitudinal Accelerating Medicines Partnership in RA/SLE cohort. Urinary biomarkers of monocyte/neutrophil degranulation (i.e., PR3, S100A8, azurocidin, catalase, cathepsins, MMP8), macrophage activation (i.e., CD163, CD206, galectin-1), wound healing/matrix degradation (i.e., nidogen-1, decorin), and IL-16 characterized the aggressive proliferative LN classes and significantly correlated with histological activity. A decline of these biomarkers after 3 months of treatment predicted the 1-year response more robustly than proteinuria, the standard of care (AUC: CD206 0.91, EGFR 0.9, CD163 0.89, proteinuria 0.8). Candidate biomarkers were validated and provide potentially treatable targets. We propose these biomarkers of intrarenal immunological activity as noninvasive tools to diagnose LN and guide treatment and as surrogate endpoints for clinical trials. These findings provide insights into the processes involved in LN activity. This data set is a public resource to generate and test hypotheses and validate biomarkers.

Thrombosis recurrence and major bleeding in non-anticoagulated thrombotic antiphospholipid syndrome patients: Prospective study from antiphospholipid syndrome alliance for clinical trials and international networking (APS ACTION) clinical database and repository ("Registry").

BACKGROUND: Long-term anticoagulant therapy is generally recommended for thrombotic antiphospholipid syndrome (TAPS) patients, however it may be withdrawn or not introduced in routine practice. OBJECTIVES: To prospectively evaluate the risk of thrombosis recurrence and major bleeding in non-anticoagulated TAPS patients, compared to anticoagulated TAPS, and secondly, to identify different features between those two groups. PATIENTS/METHODS: Using an international registry, we identified non-anticoagulated TAPS patients at baseline, and matched them with anticoagulated TAPS patients based on gender, age, type of previous thrombosis, and associated autoimmune disease. Thrombosis recurrence and major bleeding were prospectively analyzed using Kaplan-Meier method and compared using a marginal Cox's regression model. RESULTS: As of June 2022, 94 (14 %) of the 662 TAPS patients were not anticoagulated; and 93 of them were matched with 181 anticoagulated TAPS patients (median follow-up 5 years [interquartile range 3 to 8]). The 5-year thrombosis recurrence and major bleeding rates were 12 % versus 10 %, and 6 % versus 7 %, respectively (hazard ratio [HR] 1.38, 95 % confidence interval [CI] 0.53 to 3.56, p = 0.50 and HR 0.53; 95 % CI 0.15 to 1.86; p = 0.32, respectively). Non-anticoagulated patients were more likely to receive antiplatelet therapy (p < 0.001), and less likely to have more than one previous thrombosis (p < 0.001) and lupus anticoagulant positivity (p = 0.01). CONCLUSION: Fourteen percent of the TAPS patients were not anticoagulated at recruitment. Their recurrent thrombosis risk did not differ compared to matched anticoagulated TAPS patients, supporting the pressing need for risk-stratified secondary thrombosis prevention trials in APS investigating strategies other than anticoagulation.

Damage measured by Damage Index for Antiphospholipid Syndrome (DIAPS) in antiphospholipid antibody-positive patients included in the APS ACTION registry.

OBJECTIVES: Our primary objective was to quantify damage burden measured by Damage Index for Antiphospholipid Syndrome (DIAPS) in aPL-positive patients with or without a history of thrombosis in an international cohort (the APS ACTION cohort). Secondly, we aimed to identify clinical and laboratory characteristics associated with damage in aPL-positive patients. METHODS: In this cross-sectional study, we analysed the baseline damage in aPL-positive patients with or without APS classification. We excluded patients with other autoimmune diseases. We analysed the demographic, clinical and laboratory characteristics based on two subgroups: (i) thrombotic APS patients with high vs low damage; and (ii) non-thrombotic aPL-positive patients with vs without damage. RESULTS: Of the 826 aPL-positive patients included in the registry as of April 2020, 586 with no other systemic autoimmune diseases were included in the analysis (412 thrombotic and 174 non-thrombotic). In the thrombotic group, hyperlipidaemia (odds ratio [OR] 1.82; 95% CI 1.05, 3.15; adjusted P = 0.032), obesity (OR 2.14; 95% CI 1.23, 3.71; adjusted P = 0.007), aß2GPI high titres (OR 2.33; 95% CI 1.36, 4.02; adjusted P = 0.002) and corticosteroid use (ever) (OR 3.73; 95% CI 1.80, 7.75; adjusted P < 0.001) were independently associated with high damage at baseline. In the non-thrombotic group, hypertension (OR 4.55; 95% CI 1.82, 11.35; adjusted P = 0.001) and hyperlipidaemia (OR 4.32; 95% CI 1.37, 13.65; adjusted P = 0.013) were independent predictors of damage at baseline; conversely, single aPL positivity was inversely correlated with damage (OR 0.24; 95% CI 0.075, 0.77; adjusted P = 0.016). CONCLUSIONS: DIAPS indicates substantial damage in aPL-positive patients in the APS ACTION cohort. Selected traditional cardiovascular risk factors, steroids use and specific aPL profiles may help to identify patients more prone to present with a higher damage burden.

Clinical implications of discordance between anti-dsDNA antibodies by multiplex flow immunoassay and Crithidia luciliae assay in a multiethnic racial cohort of patients with SLE.

OBJECTIVE: Anti-dsDNA antibodies (anti-dsDNA) are a component of all classification schemes in SLE and comprise one of the domains in validated activity indices. Anti-dsDNA is frequently measured commercially by an enzyme immunoassay (EIA) or Crithidia luciliae immunofluorescence test (CLIFT). To address the clinical impact of measuring these antibodies by two different assays, this study leveraged a well-phenotyped multiethnic/racial cohort. METHODS: All patients fulfilled the classification criteria for SLE by at least one of the validated schemes: American College of Rheumatology, Systemic Lupus Erythematosus International Collaborating Clinics and/or American College of Rheumatology/European League Against Rheumatism classification criteria. Patients with one or more simultaneously paired anti-dsDNA by multiplex EIA and CLIFT were identified. Analysis of concordance or discordance, titre comparability of assays and association with hybrid SLE Disease Activity Index score, prevalence of lupus nephritis (LN), ability to predict a flare and classification criteria was performed. RESULTS: 207 patients were simultaneously tested by EIA and CLIFT at least once for anti-dsDNA, generating 586 paired results. 377 pairs were concordant and 209 were discordant. 41 of 207 patients always had discordant paired results and 39 patients always had results with titre discordance. In 100 patients with LN, 60 were positive by EIA and 72 by CLIFT. Sensitivities and specificities for patients with LN versus patients without LN were EIA 60% and 47%, and CLIFT 72% and 37%, respectively. 42 patients had flare assessment within 90 days of their paired result. Six of seven patients with mild flares and all four patients with severe flares had concordant positive results. CONCLUSION: Our data demonstrate that discordance of positivity between both assays for anti-dsDNA is relatively common, occurring in a fifth of patients overall and a third of visits. EIA positivity is associated with LN less often than CLIFT positivity. With the significant discordance of results between anti-dsDNA assays, obtaining both CLIFT and EIA assays may be beneficial for classification and routine monitoring of SLE.

Microvascular C5b-9 deposition in non-lesional skin in patients with SLE and its correlation with active lupus nephritis: a prospective observational study.

OBJECTIVE: Tissue damage in lupus nephritis (LN) is mediated by activation of the classical complement pathway. Complement-mediated upregulation of endothelial cell adhesion molecules is seen in dermal blood vessels of non-lesional skin of patients with active lupus. In diseases with systemic complement activation, extensive microvascular C5b-9 deposition is seen in non-lesional skin. In this study, we assess the presence of systemic complement pathway activation as determined by non-lesional skin microvascular C5b-9 deposition in patients with LN. METHODS: Eight patients with active LN and eight patients without active LN underwent non-lesional skin biopsies. Using a diaminobenzidine technique, specimens were evaluated for microvascular C5b-9 consistent with systemic complement pathway activation. RESULTS: Five of eight patients with active LN and one of eight patients without active LN demonstrated positive C5b-9 staining in non-lesional skin (p=0.04). Positive non-lesional C5b-9 staining has greater specificity, 87.5%, for active LN than pyuria, low complements, elevated double-stranded DNA (dsDNA) and proteinuria. Urine protein creatinine ratio was significantly higher in patients with positive non-lesional C5b-9 deposition (5.18 vs 1.20; p=0.04). C5b-9 deposition was not associated with a higher NIH Activity Index, interstitial fibrosis, dsDNA or lower complements. CONCLUSION: This is the first study to demonstrate evidence in non-lesional skin of microvascular C5b-9 indicative of systemic complement pathway activation in LN. C5b-9 deposition is statistically more common and demonstrated greater specificity than most historical biomarkers for active LN. The findings support a potential role for microvascular C5b-9 assessment in non-lesional skin as a biomarker for LN activity.

The 2023 ACR/EULAR Antiphospholipid Syndrome Classification Criteria.

OBJECTIVE: To develop new antiphospholipid syndrome (APS) classification criteria with high specificity for use in observational studies and trials, jointly supported by the American College of Rheumatology (ACR) and EULAR. METHODS: This international multidisciplinary initiative included 4 phases: 1) Phase I, criteria generation by surveys and literature review; 2) Phase II, criteria reduction by modified Delphi and nominal group technique exercises; 3) Phase III, criteria definition, further reduction with the guidance of real-world patient scenarios, and weighting via consensus-based multicriteria decision analysis, and threshold identification; and 4) Phase IV, validation using independent adjudicators' consensus as the gold standard. RESULTS: The 2023 ACR/EULAR APS classification criteria include an entry criterion of at least one positive antiphospholipid antibody (aPL) test within 3 years of identification of an aPL-associated clinical criterion, followed by additive weighted criteria (score range 1-7 points each) clustered into 6 clinical domains (macrovascular venous thromboembolism, macrovascular arterial thrombosis, microvascular, obstetric, cardiac valve, and hematologic) and 2 laboratory domains (lupus anticoagulant functional coagulation assays, and solid-phase enzyme-linked immunosorbent assays for IgG/IgM anticardiolipin and/or IgG/IgM anti-ß2 -glycoprotein I antibodies). Patients accumulating at least 3 points each from the clinical and laboratory domains are classified as having APS. In the validation cohort, the new APS criteria versus the 2006 revised Sapporo classification criteria had a specificity of 99% versus 86%, and a sensitivity of 84% versus 99%. CONCLUSION: These new ACR/EULAR APS classification criteria were developed using rigorous methodology with multidisciplinary international input. Hierarchically clustered, weighted, and risk-stratified criteria reflect the current thinking about APS, providing high specificity and a strong foundation for future APS research.

2023 ACR/EULAR antiphospholipid syndrome classification criteria.

OBJECTIVE: To develop new antiphospholipid syndrome (APS) classification criteria with high specificity for use in observational studies and trials, jointly supported by the American College of Rheumatology (ACR) and EULAR. METHODS: This international multidisciplinary initiative included four phases: (1) Phase I, criteria generation by surveys and literature review; (2) Phase II, criteria reduction by modified Delphi and nominal group technique exercises; (3) Phase III, criteria definition, further reduction with the guidance of real-world patient scenarios, and weighting via consensus-based multicriteria decision analysis, and threshold identification; and (4) Phase IV, validation using independent adjudicators' consensus as the gold standard. RESULTS: The 2023 ACR/EULAR APS classification criteria include an entry criterion of at least one positive antiphospholipid antibody (aPL) test within 3 years of identification of an aPL-associated clinical criterion, followed by additive weighted criteria (score range 1-7 points each) clustered into six clinical domains (macrovascular venous thromboembolism, macrovascular arterial thrombosis, microvascular, obstetric, cardiac valve, and hematologic) and two laboratory domains (lupus anticoagulant functional coagulation assays, and solid-phase enzyme-linked immunosorbent assays for IgG/IgM anticardiolipin and/or IgG/IgM anti-ß2-glycoprotein I antibodies). Patients accumulating at least three points each from the clinical and laboratory domains are classified as having APS. In the validation cohort, the new APS criteria vs the 2006 revised Sapporo classification criteria had a specificity of 99% vs 86%, and a sensitivity of 84% vs 99%. CONCLUSION: These new ACR/EULAR APS classification criteria were developed using rigorous methodology with multidisciplinary international input. Hierarchically clustered, weighted, and risk-stratified criteria reflect the current thinking about APS, providing high specificity and a strong foundation for future APS research.

Risk Assessment Model for Postpartum Venous Thromboembolism Prevention in Patients with Systemic Lupus Erythematosus.

OBJECTIVE: This article assesses the application of the Royal College of Obstetricians and Gynaecologists (RCOG) venous thromboembolism (VTE) risk model on a cohort of postpartum patients with a history of systemic lupus erythematosus (SLE). STUDY DESIGN: This is a secondary analysis of an ongoing patient registry of women with SLE from 2016 to 2022. There were 49 SLE patients with 55 pregnancies using the Definitions of Remission in SLE (DORIS) criteria to determine SLE disease activity. RCOG risk assessment model scoring was calculated for each patient prior to and after delivery. The primary outcome was the qualification of "active SLE" by standard rheumatologic criteria and assessment of recommendations for VTE prophylaxis based on RCOG VTE risk assessment scoring. Data were analyzed using Fisher's exact test, chi-square test, and Mann-Whitney U test with significance defined as p < 0.05. RESULTS: In the study cohort, 34 pregnancies (61.8%) were in DORIS remission at delivery. Twenty-one pregnancies (38.2%) were not and scored 3 points on the RCOG VTE risk model. Of these pregnancies, only 19% (n = 4) were recommended for VTE prophylaxis by the obstetrical provider despite RCOG score ≥3. Only 35.7% (n = 5) of pregnancies in DORIS remission, but with 3 points for non-SLE-related VTE risk factors (n = 14), were recommended for VTE prophylaxis. Of the 20 pregnancies in remission with an RCOG score < 3 after assessing all risk factors, 15% (n = 3) were nevertheless recommended for VTE prophylaxis. No patients had a postpartum VTE regardless of therapy. CONCLUSION: These data reveal a need to improve upon providing postpartum VTE prophylaxis to SLE patients not in remission while also recognizing a diagnosis of SLE alone should not equate with active disease. Moreover, SLE patients in remission may still warrant VTE prophylaxis if other non-SLE-related risk factors are present. KEY POINTS: · Those with SLE are at increased risk for VTE postpartum.. · VTE prophylaxis should be instituted when clinically appropriate.. · Caution should be exercised in broadly assigning disease activity for SLE diagnosis only.. · This study supports VTE prophylaxis use in postpartum patients with SLE..

Associations Among Antiphospholipid Antibody Types, Isotypes, and Titers: An AntiPhospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking (APS ACTION) Study.

Several antiphospholipid antibody (aPL) profiles ("triple" and lupus anticoagulant [LA] positivity) are associated with a higher risk for clinical manifestations of antiphospholipid syndrome (APS). Further risk is correlated with higher levels of anticardiolipin antibody (aCL) and anti-ß2 glycoprotein-I antibody (aß2GPI), and with aPL persistence. Given that the 3 aPL tests detect partially overlapping sets of antibodies, the primary goal of this study was to characterize the associations among aPL tests using AntiPhospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking (APS ACTION) core laboratory data. The APS ACTION Registry includes annually followed adult patients with positive aPL based on the Revised Sapporo Classification Criteria. We analyzed baseline and prospective core laboratory data of the registry for associations among aPL tests using the Spearman rank correlation with Bonferroni-adjusted significance level for multiple comparisons. An aPL Load was calculated based on 6 tests (aCL IgG/IgM/IgA and aß2GPI IgG/IgM/IgA); a receiver operating characteristic curve was used to evaluate the diagnostic performance of the aPL Load in predicting LA positivity. In 351 patients simultaneously tested for LA, aCL, and aß2GPI, the frequency of moderate-to-high (≥40 U) titers of aCL and aß2GPI IgG/IgM/IgA was higher in patients who were positive for LA vs those who were negative. An aPL Load was calculated for each patient to assess the overall aPL burden. For every 1-point increase in the aPL Load, the possibility of a positive LA test increased by 32% (odds ratio, 1.32; 95% CI, 1.2-1.5; P < .001). Based on core laboratory data from a large international registry, most aPL enzyme-linked immunosorbent assay ≥40 U and a high calculated aPL Load combining 6 aPL enzyme-linked immunosorbent assays were predictive of a positive LA. These data suggest that the combined quantitative burden of aPL may provide a mechanistic explanation of a positive LA.

Modeling of clinical phenotypes in systemic lupus erythematosus based on the platelet transcriptome and FCGR2a genotype.

BACKGROUND: The clinical heterogeneity of SLE with its complex pathogenesis remains challenging as we strive to provide optimal management. The contribution of platelets to endovascular homeostasis, inflammation and immune regulation highlights their potential importance in SLE. Prior work from our group showed that the Fcγ receptor type IIa (FcγRIIa)-R/H131 biallelic polymorphism is associated with increased platelet activity and cardiovascular risk in SLE. The study was initiated to investigate the platelet transcriptome in patients with SLE and evaluate its association across FcγRIIa genotypes and distinct clinical features. METHODS: Fifty-one patients fulfilling established criteria for SLE (mean age = 41.1 ± 12.3, 100% female, 45% Hispanic, 24% black, 22% Asian, 51% white, mean SLEDAI = 4.4 ± 4.2 at baseline) were enrolled and compared with 18 demographically matched control samples. The FCGR2a receptor was genotyped for each sample, and RNA-seq was performed on isolated, leukocyte-depleted platelets. Transcriptomic data were used to create a modular landscape to explore the differences between SLE patients and controls and various clinical parameters in the context of FCGR2a genotypes. RESULTS: There were 2290 differentially expressed genes enriched for pathways involved in interferon signaling, immune activation, and coagulation when comparing SLE samples vs controls. When analyzing patients with proteinuria, modules associated with oxidative phosphorylation and platelet activity were unexpectedly decreased. Furthermore, genes that were increased in SLE and in patients with proteinuria were enriched for immune effector processes, while genes increased in SLE but decreased in proteinuria were enriched for coagulation and cell adhesion. A low-binding FCG2Ra allele (R131) was associated with decreases in FCR activation, which further correlated with increases in platelet and immune activation pathways. Finally, we were able to create a transcriptomic signature of clinically active disease that performed significantly well in discerning SLE patients with active clinical disease form those with inactive clinical disease. CONCLUSIONS: In aggregate, these data demonstrate the platelet transcriptome provides insight into lupus pathogenesis and disease activity, and shows potential use as means of assessing this complex disease using a liquid biopsy.

Anti-Neutrophil Extracellular Trap Antibodies in Antiphospholipid Antibody-Positive Patients: Results From the Antiphospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking Clinical Database and Repository.

OBJECTIVE: This study aimed to elucidate the presence, antigen specificities, and potential clinical associations of anti-neutrophil extracellular trap (anti-NET) antibodies in a multinational cohort of antiphospholipid (aPL) antibody-positive patients who did not have lupus. METHODS: Anti-NET IgG/IgM levels were measured in serum samples from 389 aPL-positive patients; 308 patients met the classification criteria for antiphospholipid syndrome. Multivariate logistic regression with best variable model selection was used to determine clinical associations. For a subset of the patients (n = 214), we profiled autoantibodies using an autoantigen microarray platform. RESULTS: We found elevated levels of anti-NET IgG and/or IgM in 45% of the aPL-positive patients. High anti-NET antibody levels are associated with more circulating myeloperoxidase (MPO)-DNA complexes, which are a biomarker of NETs. When considering clinical manifestations, positive anti-NET IgG was associated with lesions affecting the white matter of the brain, even after adjusting for demographic variables and aPL profiles. Anti-NET IgM tracked with complement consumption after controlling for aPL profiles; furthermore, patient serum samples containing high levels of anti-NET IgM efficiently deposited complement C3d on NETs. As determined by autoantigen microarray, positive testing for anti-NET IgG was significantly associated with several autoantibodies, including those recognizing citrullinated histones, heparan sulfate proteoglycan, laminin, MPO-DNA complexes, and nucleosomes. Anti-NET IgM positivity was associated with autoantibodies targeting single-stranded DNA, double-stranded DNA, and proliferating cell nuclear antigen. CONCLUSION: These data reveal high levels of anti-NET antibodies in 45% of aPL-positive patients, where they potentially activate the complement cascade. While anti-NET IgM may especially recognize DNA in NETs, anti-NET IgG species appear to be more likely to target NET-associated protein antigens.

Fluctuation of Anti-Domain 1 and Anti-ß2 -Glycoprotein I Antibody Titers Over Time in Patients With Persistently Positive Antiphospholipid Antibodies.

OBJECTIVE: The present study was undertaken to longitudinally evaluate titers of antibodies against ß2 -glycoprotein I (anti-ß2 GPI) and domain 1 (anti-D1), to identify predictors of variations in anti-ß2 GPI and anti-D1 titers, and to clarify whether antibody titer fluctuations predict thrombosis in a large international cohort of patients who were persistently positive for antiphospholipid antibodies (aPL) in the APS ACTION Registry. METHODS: Patients with available blood samples from at least 4 time points (at baseline [year 1] and at years 2-4 of follow-up) were included. Detection of anti-ß2 GPI and anti-D1 IgG antibodies was performed using chemiluminescence (BIO-FLASH; INOVA Diagnostics). RESULTS: Among 230 patients in the study cohort, anti-D1 and anti-ß2 GPI titers decreased significantly over time (P < 0.0001 and P = 0.010, respectively). After adjustment for age, sex, and number of positive aPL tests, we found that the fluctuations in anti-D1 and anti-ß2 GPI titer levels were associated with treatment with hydroxychloroquine (HCQ) at each time point. Treatment with HCQ, but not immunosuppressive agents, was associated with 1.3-fold and 1.4-fold decreases in anti-D1 and anti-ß2 GPI titers, respectively. Incident vascular events were associated with 1.9-fold and 2.1-fold increases in anti-D1 and anti-ß2 GPI titers, respectively. Anti-D1 and anti-ß2 GPI titers at the time of thrombosis were lower compared to titers at other time points. A 1.6-fold decrease in anti-D1 titers and a 2-fold decrease in anti-ß2 GPI titers conferred odds ratios for incident thrombosis of 6.0 (95% confidence interval [95% CI] 0.62-59.3) and 9.4 (95% CI 1.1-80.2), respectively. CONCLUSION: Treatment with HCQ and incident vascular events in aPL-positive patients predicted significant anti-D1 and anti-ß2 GPI titer fluctuations over time. Both anti-D1 and anti-ß2 GPI titers decreased around the time of thrombosis, with potential clinical relevance.

Population-based prevalence and incidence estimates of mixed connective tissue disease from the Manhattan Lupus Surveillance Program.

OBJECTIVE: Epidemiological data for MCTD are limited. Leveraging data from the Manhattan Lupus Surveillance Program (MLSP), a racially/ethnically diverse population-based registry of cases with SLE and related diseases including MCTD, we provide estimates of the prevalence and incidence of MCTD. METHODS: MLSP cases were identified from rheumatologists, hospitals and population databases using a variety of International Classification of Diseases, Ninth Revision codes. MCTD was defined as one of the following: fulfilment of our modified Alarcon-Segovia and Kahn criteria, which required a positive RNP antibody and the presence of synovitis, myositis and RP; a diagnosis of MCTD and no other diagnosis of another CTD; and a diagnosis of MCTD regardless of another CTD diagnosis. RESULTS: Overall, 258 (7.7%) cases met a definition of MCTD. Using our modified Alarcon-Segovia and Kahn criteria for MCTD, the age-adjusted prevalence was 1.28 (95% CI 0.72, 2.09) per 100 000. Using our definition of a diagnosis of MCTD and no other diagnosis of another CTD yielded an age-adjusted prevalence and incidence of MCTD of 2.98 (95% CI 2.10, 4.11) per 100 000 and 0.39 (95% CI 0.22, 0.64) per 100 000, respectively. The age-adjusted prevalence and incidence were highest using a diagnosis of MCTD regardless of other CTD diagnoses and were 16.22 (95% CI 14.00, 18.43) per 100 000 and 1.90 (95% CI 1.49, 2.39) per 100 000, respectively. CONCLUSIONS: The MLSP provided estimates for the prevalence and incidence of MCTD in a diverse population. The variation in estimates using different case definitions is reflective of the challenge of defining MCTD in epidemiologic studies.

Platelet LGALS3BP as a Mediator of Myeloid Inflammation in Systemic Lupus Erythematosus.

OBJECTIVE: Platelets are mediators of inflammation with immune effector cell properties and have been implicated in the pathogenesis of systemic lupus erythematosus (SLE). This study investigated the role of platelet-associated lectin, galactoside-binding, soluble 3 binding protein (LGALS3BP) as a mediator of inflammation in SLE and as a potential biomarker associated with clinical phenotypes. METHODS: We performed RNA sequencing on platelets from patients with SLE (n = 54) and on platelets from age-, sex-, and race/ethnicity-matched healthy controls (n = 18) and measured LGALS3BP levels in platelet releasate and in circulating serum. We investigated the association between LGALS3BP levels and the prevalence, disease severity, and clinical phenotypes of SLE and studied platelet-mediated effects on myeloid inflammation. RESULTS: Platelets from patients with SLE exhibited increased expression of LGALS3BP (fold change 4.0, adjusted P = 6.02 × 10-11 ). Platelet-released LGALS3BP levels were highly correlated with circulating LGALS3BP (R = 0.69, P < 0.0001), and circulating LGALS3BP levels were correlated with the severity of disease according to the SLE Disease Activity Index (r = 0.32, P = 0.0006). Specifically, circulating LGALS3BP levels were higher in SLE patients with lupus nephritis than in patients with inactive disease (4.0 µg/ml versus 2.3 µg/ml; P < 0.001). Interferon-α induced LGALS3BP transcription and translation in a megakaryoblastic cell line (MEG-01) in a dose-dependent manner. Recombinant LGALS3BP and platelet releasates from SLE patients enhanced proinflammatory cytokine production by macrophages. CONCLUSIONS: Our results support that platelets act as potent effector cells that contribute to the pathogenesis of SLE by secreting proinflammatory LGALS3BP, which also represents a novel biomarker of SLE clinical activity.