Faculty Bibliography

Background Mitochondria are intracellular organelles derived from the endosymbiosis between an a-proteobacterium and a primitive eukaryotic cell. Mitochondria thus display proinflammatory and antigenic properties, when released into the extracellular milieu. Several cross-sectional studies reported increased levels of anti-mitochondrial antibodies (AMAs) in patients with systemic lupus erythematosus (SLE) and the antiphospholipid syndrome (APS). These autoantibodies also displayed correlations with the SLE disease activity index 2000 (SLEDAI-2K) and associations with various clinical manifestations (e.g. lupus nephritis, thromboses, carotid plaque). In the present study, we aim to detect AMAs against either whole organelles (AwMA), mitochondrial DNA (mtDNA) or RNA (mtRNA) through time in samples from patients included in the SLICC cohort. Methods Clinically relevant variables (e.g., sociodemographic variables, disease-specific outcomes including death and arterial vascular events (AVE)) were documented and biosamples were harvested upon patient enrolment in the SLICC cohort, as well as at each follow-up visit. AMA levels were measured by in-house direct ELISAs whereas SLE autoantibodies were detected by clinical laboratories. Healthy individuals, defined as having no known illnesses and infectious symptoms at the time of the blood draw, were recruited. 90% confidence intervals were calculated for both limits of the 95% nonparametric two-sided reference intervals for values measured in healthy donors. AMA values were segregated into 3 categories: Normal values were determined as within the inner limits of the range while values outside this range were characterized as abnormal, either lower or higher than the reference interval. (figure 1). Marginal Cox models with AMAs in 3 categories were adjusted for covariables and are presented as [hazard ratio (95% CI)]. Interactions with sex were tested in models with the AMAs as continuous variables. Results Sera from healthy individuals (n=126) or SLE patients included in the SLICC cohort, from their inclusion, up to 7 years of follow-up (n=1114 patients at baseline, 3577 samples in total). AwMA displayed lower correlations with antibodies to mitochondrial nucleic acids (versus AmtDNA: rs=0.37, and vs AmtRNA: rs=0.38), while antibodies to mitochondrial DNA or RNA shown higher correlations (rs=0.59). During our preliminary analyses on the distribution of the variables, We made intriguing observations regarding patients with AMA levels that were either lower or higher than those of healthy individuals. This information led us to categorize SLE patients as described in the methods and in figure 1. For each of the three antibodies assessed, SLE patients displayed more abnormal AMA levels at baseline than controls. The percentage of patients with higher levels of AwMA and AmtRNA increased at subsequent follow-up visits, while a slight decrease was observed for AmtDNA (figure 2). SLE patients with higher levels of AwMA showed higher risks of death [2.12 (1.18-3.83)]. It is of interest that an inverse relationship was found between AmtRNA and AVEs, with a small subset of patients with low levels of AmtRNA (n = 4), this autoantibody was associated with increased risks of this manifestation [4.46 (1.71-11.66)]. Additionally, patients with higher levels of AmtDNA and AmtRNA displayed increased risks of lupus nephritis [respectively: 3.05(2.05-4.54), and 1.56(1.12-2.18)]. Interestingly, there was an interaction with sex for AmtRNA levels effect on AVEs [males: 0.32 (0.11-0.99). Females: 1.56 (1.11-2.19)], and AmtDNA association with nephritis was only significant in female patients [4.00 (2.51-6.36)] (table 1). Conclusion These results show that AMAs display different associations with disease manifestations in various clusters of patients. These results prompt for further analyses by machine-learning in order to delineate clusters of clinical interests by adding AMAs in the routine serological assessment of SLE autoantibodies. Acknowledgements We acknowledge the contribution of the study participants, individual center support staff as well as investigators of the Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort project who for the past 20 years have made this study possible. LAY ABSTRACT The mitochondrion is a part of the cell that controls various biological mechanisms (e.g., energy supply, whether the cell should live or die, control, or produce various cellular components). They are derived, through evolution, from a microbe. Mitochondria may sometimes be jettisoned out of their host cell and subsequently elicit immune reactions - including the production of antibodies. Previous studies indicated that patients with autoimmune conditions such as systemic lupus erythematosus (SLE) and the antiphospholipid syndrome (APS) have antibodies against mitochondria in their blood stream. Presence of these antibodies was associated with increased disease activity and clinical manifestations of these diseases (e.g. kidney disease, arterial vessel disease). In this study, we studied blood samples harvested by an international group dedicated to the study of SLE [i.e., the SLE International Collaborating Clinics (SLICC) cohort] and observed that patients may be clustered into groups, upon their levels of antibodies and/or sex, allowing to have a better appreciation of their risks of death, vascular events, and kidney disease. These results might lead to improved diagnosis and/or prognosis in SLE and thus, in improved care and quality of life for the people living with lupus

Objectives We previously reported in a single centre prevalent SLE cohort that antibodies against the cytokinesis-associated protein M-Phase Phosphoprotein 1 (anti-MPP-1) were associated with SLE-related cranial neuropathy (CN), a rare manifestation of neuropsychiatric SLE (NPSLE). The purpose of this study was to assess whether anti-MPP-1 is a biomarker for CN or other NPSLE manifestations using an international SLE inception cohort. Methods SLE patients fulfilling the updated 1997 ACR classification criteria for SLE were included. Anti-MPP-1 antibody testing was performed on baseline samples (within 15 months of diagnosis) or first annual assessment using an addressable laser bead immunoassay (ALBIA) with purified recombinant human protein with results expressed as median florescence units (MFU). Based on healthy controls, a dilution of >=1:500 MFU was considered positive. NPSLE manifestations occurring over the first 5 years of follow up were documented annually based on ACR case definitions using published NPSLE attribution rules1). The frequency of anti-MPP-1 positivity between patients with versus without each of the 19 NPSLE manifestations was compared using univariate logistic regression. For any NPSLE manifestations where anti-MPP-1 positivity differed between patients with versus without the manifestation, baseline demographic and clinical characteristics were compared using t-tests and twosample tests of proportions. For NPSLE manifestations associated with anti-MPP-1 positivity in the univariate analysis, multivariable logistic regression analysis using penalized maximum likelihood estimates was then performed to assess the relationship between anti-MPP-1 and the NPSLE manifestation, adjusting for age at anti-MPP-1 testing, female, White race/ethnicity, and significantly different baseline clinical characteristics. Results Seven hundred and ninety-five SLE patients were assessed; 29.8% were anti-MPP-1 positive, 88.7% female, and 52.1% White. The frequency of anti-MPP-1 positivity differed only for those with versus without CN (70.0% vs. 29.3%; odds ratio [OR] 5.16, 95%CI 1.44, 18.54) (table 1). Compared to patients without CN (n=785), patients with CN (n=10) were more likely to fulfill the ACR hematologic (difference: 23.9%, 95%CI 5.0%, 42.8%) and antinuclear antibody criteria (difference: 4.3%, 95%CI 2.9%, 5.8%) (table 2). (Table Presanted)In the multivariate analysis, anti-MPP-1 remained associated with CN (OR 5.24, 95%CI 1.44, 19.09) after adjusting for age at anti-MPP-1 testing, female, White race/ethnicity, hematologic disorder, and antinuclear antibody (table 3). Conclusion Anti-MPP-1 is a potential biomarker for CN. Although anti-MPP-1 is differentially expressed in a variety of neurological cells and tissues, the link to a pathogenic role requires further study

OBJECTIVES/OBJECTIVE:A perception derived from cross-sectional studies of small systemic lupus erythematosus (SLE) cohorts is that there is a marked discrepancy between antinuclear antibody (ANA) assays, which impacts on clinicians' approach to diagnosis and follow-up. We compared three ANA assays in a longitudinal analysis of a large international incident SLE cohort retested regularly and followed for 5 years. METHODS:Demographic, clinical and serological data was from 805 SLE patients at enrolment, year 3 and 5. Two HEp-2 indirect immunofluorescence assays (IFA1, IFA2), an ANA ELISA, and SLE-related autoantibodies were performed in one laboratory. Frequencies of positivity, titres or absorbance units (AU), and IFA patterns were compared using McNemar, Wilcoxon and kappa statistics, respectively. RESULTS:At enrolment, ANA positivity (≥1:80) was 96.1% by IFA1 (median titre 1:1280 (IQR 1:640-1:5120)), 98.3% by IFA2 (1:2560 (IQR 1:640-1:5120)) and 96.6% by ELISA (176.3 AU (IQR 106.4 AU-203.5 AU)). At least one ANA assay was positive for 99.6% of patients at enrolment. At year 5, ANA positivity by IFAs (IFA1 95.2%; IFA2 98.9%) remained high, while there was a decrease in ELISA positivity (91.3%, p<0.001). Overall, there was >91% agreement in ANA positivity at all time points and ≥71% agreement in IFA patterns between IFA1 and IFA2. CONCLUSION/CONCLUSIONS:In recent-onset SLE, three ANA assays demonstrated commutability with a high proportion of positivity and titres or AU. However, over 5 years follow-up, there was modest variation in ANA assay performance. In clinical situations where the SLE diagnosis is being considered, a negative test by either the ELISA or HEp-2 IFA may require reflex testing.

OBJECTIVE:The Systemic Lupus International Collaborating Clinics (SLICC) frailty index (FI) predicts mortality and damage accrual in SLE, but its association with hospitalizations has not been described. We estimated the association of baseline SLICC-FI values with future hospitalizations in the SLICC inception cohort. METHODS:Baseline SLICC-FI scores were calculated. The number and duration of inpatient hospitalizations during follow-up were recorded. Negative binomial regression was used to estimate the association between baseline SLICC-FI values and the rate of hospitalizations per patient-year of follow-up. Linear regression was used to estimate the association of baseline SLICC-FI scores with the proportion of follow-up time spent in hospital. Multivariable models were adjusted for relevant baseline characteristics. RESULTS:The 1549 SLE patients eligible for this analysis were mostly female (88.7%) with mean (SD) age 35.7 (13.3) years and median (IQR) disease duration 1.2 (0.9-1.5) years at baseline. Mean (SD) baseline SLICC-FI was 0.17 (0.08). During mean (SD) follow-up of 7.2 (3.7) years, 614 patients (39.6%) experienced 1570 hospitalizations. Higher baseline SLICC-FI values (per 0.05 increment) were associated with more frequent hospitalizations during follow-up (Incidence Rate Ratio 1.21; 95%CI 1.13-1.30), adjusting for baseline age, sex, corticosteroid use, immunosuppressive use, ethnicity/location, SLE disease activity index 2000 (SLEDAI-2K), SLICC/ACR damage index (SDI), and disease duration. Among patients with ≥1 hospitalization, higher baseline SLICC-FI values predicted a greater proportion of follow-up time spent hospitalized (Relative Rate 1.09; 95%CI 1.02-1.16). CONCLUSION/CONCLUSIONS:The SLICC-FI predicts future hospitalizations among incident SLE patients, further supporting the SLICC-FI as a valid health measure in SLE.

Non-white people are more likely to develop systemic lupus erythematosus (SLE), yet are underrepresented in SLE clinical trials. The efficacy and safety of drugs may be influenced by ancestry, and ancestrally diverse study populations are necessary to optimize treatments across the full spectrum of patients. However, barriers to entry into clinical trials are amplified in non-white populations. To address these issues, a conference was held in Bethesda, Maryland from October 15^th -16^th , 2019 entitled "Increasing Ancestral Diversity in Systemic Lupus Erythematosus Clinical Studies: Overcoming the Barriers." Participants included people with lupus, lupus physicians, lupus clinical trialists, treatment developers from biotechnology, social scientists, patient advocacy groups, and United States government representatives (the Office of Minority Health, Centers for Disease Control and Prevention, National Institutes of Health, and the Food and Drug Administration). For all of these groups, the organizers purposefully included people of non-white ancestry. Decreased participation of non-white SLE patients in clinical research was evaluated through historical, societal, experiential, and pragmatic perspectives, and several interventional programs to increase non-white patient participation in SLE and non-SLE research were described and discussed. The presentations and discussions highlighted the need for changes at the societal, institutional, research team, referring physician, and patient education levels to achieve equitable ancestral representation in SLE clinical studies.

Background Prior studies of SLE clusters based on autoantibodies have utilized cross-sectional data from single centers. We applied clustering techniques to longitudinal and comprehensive autoantibody data from a large multinational, multiethnic inception cohort of well characterized SLE patients to identify clusters associated with disease outcomes. Methods We used demographic, clinical, and serological data at enrolment and follow-up visits years 3 and 5 from 805 patients who fulfilled the 1997 Updated ACR SLE criteria and were enrolled within 15 months of diagnosis. For each visit, ANA, dsDNA, Sm, U1-RNP, SSA/Ro60, SSB/La, Ro52/ TRIM21, histones, ribosomal P, Jo-1, centromere B, PCNA, anti-DFS70, lupus anticoagulant (LAC), IgG and IgM for anticardiolipin, anti-b2GP1, and aPS/PT, and IgG anti-b2GP1 D1 were performed at a single lab (except LAC). K-means clustering algorithm on principal component analysis (10 dimensions) transformed longitudinal ANA/autoantibody profiles was used. We compared cluster demographic/clinical outcomes, including longitudinal disease activity (total and adjusted mean SLEDAI- 2K), SLICC/ACR damage index and organ-specific domains, SLE therapies, and survival, using one-way ANOVA test and a Benjamini-Hochberg correction with false discovery rate alpha=0.05. Results were visualized using t-distributed stochastic neighbor embedding. Results Four unique patient clusters were identified (table 1). Cluster 1, characterized by high frequency of anti-Sm and anti-RNP over time, was the youngest group at disease onset with a high proportion of subjects of Asian and African ancestry. At year 5, they had the highest disease activity, were more likely to have active hematologic and mucocutaneous involvement, and to be on/exposed to immunosuppressants/ biologics. Cluster 2, the largest cluster, had low frequency of anti-dsDNA, were oldest at disease onset, and at year 5, had the lowest disease activity, and were least likely to have nephritis and be on/exposed to immunosuppressants/biologics. Cluster 3 had the highest frequency of antiphospholipid antibodies over time, were more likely to be of European ancestry, have an elevated BMI, be former smokers, and by year 5, to have nephritis, neuropsychiatric involvement, including strokes and seizures (SLICC/ACR damage index). Cluster 4 was characterized by anti-SSA/Ro60, SSB/La, Ro52/TRIM21, histone antibodies, and low complements at year 5. Overall, survival of the 805 subjects was 94% at 5 years, and none of the clusters predicted survival. Conclusions Four SLE patient clusters associated with disease activity, organ involvement, and treatment were identified in this analysis of longitudinal ANA/autoantibody profiles in relation to SLE outcomes, suggesting these subsets might be identifiable based on extended autoantibody profiles early in disease and carry prognostic information

Background Little is known about the economic burden of NP lupus. We estimated direct and indirect costs (DC, IC) associated with NP events attributed to SLE and non-SLE causes using multistate modelling. Methods Patients fulfilling ACR classification criteria for SLE from 31 centres in 11 countries were enrolled within 15 months of diagnosis. NP events were documented annually using ACR NP definitions and attributed to SLE or non-SLE causes. At each assessment and for SLE and non-SLE events, patients were stratified into 1 of 3 NP states (no, resolved, or new/ongoing NP event). The change in NP status characterized by transition rates between states was analyzed using multistate modelling (doi:10.1002/art.41876). At each assessment, annual DC and IC were based on health resource use and lost work-force/non-work-force productivity over the preceding year. Resource use was costed using 2021 Canadian prices and lost productivity using Statistics Canada age-and-sex specific wages. Costs associated with SLE and non-SLE NP states were calculated by averaging all observations in each NP state. Multiple regressions adjusted for possible confounding of age at diagnosis, sex, race/ethnicity, disease duration, geographic region, education, and smoking on the association of annual DC and IC and NP state. 5 and 10-year cumulative costs for NP states were predicted by multiplying adjusted annual costs for each state by the expected state duration, forecasted using multistate modelling. Results 1697 patients (89% female, 51% non-Caucasian race/ ethnicity, mean age at enrolment 35.1 years) were followed a mean of 8.8 years. 1971 NP events occurred in 956 patients, 32% attributed to SLE. For SLE NP events, annual DC were higher in those with new/ongoing vs no events ($10,809 vs $6715) (table 1). Annual and 5-yr IC were higher in new/ ongoing vs no events and new/ongoing vs resolved events (5- yr: new/ongoing vs no: $172,674 vs $136,970). For non-SLE NP events, annual IC were higher in new/ongoing vs no events, new/ongoing vs resolved events, and resolved vs no events and 5 and 10-yr IC were higher in new/ongoing vs no events (10-yr: new/ongoing vs no: $342,434 vs $279,874). For all NP states, IC exceeded DC 2.8 to 4-fold. Conclusion IC are 1.3-fold higher in patients with new/ ongoing vs no NP events. While DC trended higher in new/ ongoing events, they were not significantly higher across all NP states and times. Impaired productivity associated with ongoing and resolved NP lupus is substantial, contributing to the previously documented reduced quality of life