Faculty Bibliography

OBJECTIVES/OBJECTIVE:Systemic lupus erythematosus (SLE) remains a deadly disease, yet our ability to predict adverse outcomes is poor. Mitochondria are organelles recognised by the immune system when released from cells, and antimitochondrial antibodies (AMA) can be detected in people with SLE. We assessed AMA as markers of nephritis, arterial vascular events (AVE), and other outcomes including mortality. METHODS:We studied sera and data from 1114 participants of the Systemic Lupus International Collaborating Clinics inception cohort. We measured antiwhole mitochondria (AwMA), antimitochondrial DNA (AmtDNA), and antimitochondrial RNA (AmtRNA) antibodies by direct Enzyme-Linked ImmunoSorbent Assays (ELISAs). Separate multivariable Cox proportional hazards regression models estimated associations of either baseline or most recent measures of AMA with the outcomes, adjusted for biological sex, age, medications, and other clinical factors. Interactions of AMA with biological sex were tested for each outcome. RESULTS:All AMA titres were elevated in SLE vs healthy individuals. Higher AMA levels were associated with a higher hazard of nephritis, with the strongest associations for most recent AmtDNA (adjusted hazard ratio [aHR] =1.61 for increase of 1 SD, 95% CI 1.43-1.82) and AmtRNA (aHR =1.59, 1.46-1.73). Higher baseline AwMA levels predicted early mortality (aHR =1.19, 1.02-1.40). Most recent AmtDNA (aHR =1.68, 1.28-2.19) was associated with higher mortality throughout the follow-up. For AVE, the impact of higher AmtRNA was stronger in females. CONCLUSIONS:Baseline and most recent assessments of AMA levels may help identify individuals at higher risk of severe outcomes in SLE, including mortality. Integrating AMA into precision medicine strategies will allow deeper exploration of lupus heterogeneity.

BACKGROUND:Using hydroxychloroquine (HCQ) dose of 5 mg/kg/day in systemic lupus erythematosus (SLE) is associated with a higher risk of flares; HCQ blood level monitoring could be a better way to adjust HCQ dose. We studied the upper threshold for a reference range of HCQ levels to inform routine monitoring. METHODS:This observational study included patients (n=2010) across the Systemic Lupus International Collaborating Clinics (SLICC), Wisconsin, International, and French studies, who underwent HCQ blood level measurements. Using adjusted spline and logistic regression analyses on the cross-sectional data, we first identified a HCQ blood level associated with higher HCQ toxicity. Next, we tested if this upper threshold level was supratherapeutic (no further risk reduction for SLE Disease Activity Index 2000 (SLEDAI-2K ≥6). Finally, we examined associations between chronic kidney disease (CKD) stage and supratherapeutic (toxic) HCQ blood levels. RESULTS:Among 1842 patients (excluding 168 patients with very low HCQ blood levels), 4.9% had HCQ related toxicity. Odds of toxicity were 2.1-fold higher with blood levels ≥1150 ng/mL, and 1.7-fold higher with cumulative HCQ dose per 1000g increase. Blood levels ≥1150 ng/mL were associated with a saturation in therapeutic effect, indicating supratherapeutic levels. Patients with CKD stage ≥3 had 2.3-fold higher odds of having supratherapeutic levels (≥1150 ng/mL). CONCLUSION/CONCLUSIONS:The therapeutic reference range for HCQ blood level monitoring is 750-<1150 ng/ml. HCQ level monitoring could optimize HCQ use, particularly in patients with CKD stage ≥3. Future longitudinal studies are needed to validate the use of HCQ blood level monitoring in optimizing dosing.

OBJECTIVES/OBJECTIVE:This 1-year long-term extension (LTE) study (NCT04451772) followed the 48-week phase 2 SLEek study (NCT03978520) that evaluated upadacitinib (a Janus kinase inhibitor) alone or combined with elsubrutinib (a Bruton's tyrosine kinase inhibitor) in adults with moderately to severely active systemic lupus erythematosus (SLE). The objective was to evaluate the efficacy and safety of an additional 56 weeks of treatment. METHODS:Patients randomised to upadacitinib 30 mg one time per day (QD) or upadacitinib 30 mg/elsubrutinib 60 mg QD (upadacitinib/elsubrutinib) in the SLEek study continued their assigned treatment during the LTE. Patients originally receiving placebo switched to upadacitinib/elsubrutinib in the LTE. Assessments through week 104 included SLE Responder Index-4 (SRI-4), British Isles Lupus Assessment Group-based Combined Lupus Assessment (BICLA), Lupus Low Disease Activity State (LLDAS), change from baseline in glucocorticoid dose, flare events and adverse events. RESULTS:This LTE analysis included 127 patients. Efficacy responses for the groups receiving upadacitinib, upadacitinib/elsubrutinib and placebo to upadacitinib/elsubrutinib were maintained or increased from weeks 48 to 104 (week 104: SRI-4: 82.1%, 85.4% and 61.3%; BICLA: 69.2%, 78.0% and 54.8%; LLDAS: 60.0%, 78.0% and 34.4%). From weeks 48 through 104, the mean daily glucocorticoid dose was reduced, and the incidence of flares was maintained or further reduced in all treatment groups. Safety profiles were similar to those observed in the primary SLEek study. CONCLUSIONS:In this LTE study, upadacitinib monotherapy and upadacitinib/elsubrutinib combined were well tolerated and continued to demonstrate beneficial effects on SLE disease activity, glucocorticoid dose and flares through 104 weeks.

Clinical diagnosis typically incorporates physical examination, patient history, various laboratory tests, and imaging studies but makes limited use of the human immune system's own record of antigen exposures encoded by receptors on B cells and T cells. We analyzed immune receptor datasets from 593 individuals to develop MAchine Learning for Immunological Diagnosis, an interpretive framework to screen for multiple illnesses simultaneously or precisely test for one condition. This approach detects specific infections, autoimmune disorders, vaccine responses, and disease severity differences. Human-interpretable features of the model recapitulate known immune responses to severe acute respiratory syndrome coronavirus 2, influenza, and human immunodeficiency virus, highlight antigen-specific receptors, and reveal distinct characteristics of systemic lupus erythematosus and type-1 diabetes autoreactivity. This analysis framework has broad potential for scientific and clinical interpretation of immune responses.

OBJECTIVE:The 48-week, phase 2 SLEek study (NCT03978520) evaluated the efficacy and safety of upadacitinib (JAK inhibitor) and elsubrutinib (BTK inhibitor) alone or in combination (ABBV-599) in adults with moderately to severely active systemic lupus erythematosus (SLE). METHODS:Patients were randomized 1:1:1:1:1 to elsubrutinib 60 mg and upadacitinib 30 mg once daily (ABBV-599 high dose), elsubrutinib 60 mg and upadacitinib 15 mg once daily (ABBV-599 low dose), elsubrutinib 60 mg once daily (QD), upadacitinib 30 mg QD, or placebo QD. The primary endpoint was the proportion of patients achieving both Systemic Lupus Erythematosus Responder Index 4 (SRI-4) and glucocorticoid dose ≤10 mg QD at week 24. Additional assessments through week 48 included British Isles Lupus Assessment Group-Based Composite Lupus Assessment (BICLA) and Lupus Low Disease Activity State (LLDAS) responses, number of flares, time to first flare, and adverse events. RESULTS:The study enrolled 341 patients. The ABBV-599 low dose and elsubrutinib arms were discontinued after a planned interim analysis showed lack of efficacy (no safety concerns). More patients achieved the primary endpoint with upadacitinib (54.8%; P = 0.028) and ABBV-599 high dose (48.5%; P = 0.081) versus placebo (37.3%). SRI-4, BICLA, and LLDAS response rates were higher for both upadacitinib and ABBV-599 high dose versus placebo at weeks 24 and 48. Flares were reduced, and time to first flare through week 48 was substantially delayed with both upadacitinib and ABBV-599 high dose versus placebo. No new safety signals were observed beyond those previously reported for upadacitinib or elsubrutinib. CONCLUSION/CONCLUSIONS:Upadacitinib 30 mg alone or in combination with elsubrutinib (ABBV-599 high dose) demonstrated significant improvements in SLE disease activity and reduced flares and were well tolerated through 48 weeks.

BACKGROUND:Cranial neuropathies (CN) are a rare neuropsychiatric SLE (NPSLE) manifestation. Previous studies reported that antibodies to the kinesin family member 20B (KIF20B) (anti-KIF20B) protein were associated with idiopathic ataxia and CN. We assessed anti-KIF20B as a potential biomarker for NPSLE in an international SLE inception cohort. METHODS:Individuals fulfilling the revised 1997 American College of Rheumatology (ACR) SLE classification criteria were enrolled from 31 centres from 1999 to 2011 and followed annually in the Systemic Lupus Erythematosus International Collaborating Clinics inception cohort. Anti-KIF20B testing was performed on baseline (within 15 months of diagnosis or first annual visit) samples using an addressable laser bead immunoassay. Logistic regression (penalised maximum likelihood and adjusting for confounding variables) examined the association between anti-KIF20B and NPSLE manifestations (1999 ACR case definitions), including CN, occurring over the first 5 years of follow-up. RESULTS:Of the 1827 enrolled cohort members, baseline serum and 5 years of follow-up data were available on 795 patients who were included in this study: 29.8% were anti-KIF20B-positive, 88.7% female, and 52.1% White. The frequency of anti-KIF20B positivity differed only for those with CN (n=10) versus without CN (n=785) (70.0% vs 29.3%; OR 5.2, 95% CI 1.4, 18.5). Compared with patients without CN, patients with CN were more likely to fulfil the ACR haematological (90.0% vs 66.1%; difference 23.9%, 95% CI 5.0%, 42.8%) and ANA (100% vs 95.7%; difference 4.3%, 95% CI 2.9%, 5.8%) criteria. In the multivariate analysis adjusting for age at baseline, female, White race and ethnicity, and ACR haematological and ANA criteria, anti-KIF20B positivity remained associated with CN (OR 5.2, 95% CI 1.4, 19.1). CONCLUSION/CONCLUSIONS:Anti-KIF20B is a potential biomarker for SLE-related CN. Further studies are needed to examine how autoantibodies against KIF20B, which is variably expressed in a variety of neurological cells, contribute to disease pathogenesis.

OBJECTIVES/OBJECTIVE:To assess the associations of severe non-adherence to HCQ, objectively assessed by HCQ serum levels, and risks of SLE flares, damage, and mortality over 5 years of follow-up. METHODS:The SLICC Inception Cohort is an international multicenter initiative (33 centers; 11 countries). Serum of patients prescribed HCQ for at least 3 months at enrollment were analyzed. Severe non-adherence was defined by a serum HCQ level <106 ng/ml or <53 ng/ml, for HCQ doses of 400 or 200 mg/d, respectively. Associations with the risk of a flare (defined as a SLEDAI-2K increase ≥4 points, initiation of prednisone or immunosuppressive drugs, or new renal involvement) were studied with logistic regression, and associations with damage (first SLICC/ACR Damage Index (SDI) increase ≥1 point) and mortality with separate Cox proportional hazard models. RESULTS:Of 1849 cohort subjects, 660 patients (88% women) were included. Median (interquartile range) serum HCQ was 388 ng/ml (244-566); 48 patients (7.3%) had severe HCQ non-adherence. No covariates were clearly associated with severe non-adherence, which was however independently associated with both flare (OR 3.38; 95% CI 1.80-6.42) and an increase in the SDI within each of the first 3 years (HR 1.92 at 3 years; 95% CI 1.05-3.50). Eleven patients died within 5 years, including 3 with severe non-adherence (crude HR 5.41; 95% CI 1.43-20.39). CONCLUSION/CONCLUSIONS:Severe non-adherence was independently associated with the risks of an SLE flare in the following year, early damage, and 5-year mortality.

OBJECTIVE:To estimate direct and indirect costs associated with neuropsychiatric (NP) events in the Systemic Lupus International Collaborating Clinics inception cohort. METHODS:NP events were documented annually using American College of Rheumatology definitions for NP events and attributed to systemic lupus erythematosus (SLE) or non-SLE causes. Patients were stratified into 1 of 3 NP states (no, resolved, or new/ongoing NP event). Change in NP status was characterized by interstate transition rates using multistate modeling. Annual direct costs and indirect costs were based on health care use and impaired productivity over the preceding year. Annual costs associated with NP states and NP events were calculated by averaging all observations in each state and adjusted through random-effects regressions. Five- and 10-year costs for NP states were predicted by multiplying adjusted annual costs per state by expected state duration, forecasted using multistate modeling. RESULTS:A total of 1,697 patients (49% White race/ethnicity) were followed for a mean of 9.6 years. NP events (n = 1,971) occurred in 956 patients, 32% attributed to SLE. For SLE and non-SLE NP events, predicted annual, 5-, and 10-year direct costs and indirect costs were higher in new/ongoing versus no events. Direct costs were 1.5-fold higher and indirect costs 1.3-fold higher in new/ongoing versus no events. Indirect costs exceeded direct costs 3.0 to 5.2 fold. Among frequent SLE NP events, new/ongoing seizure disorder and cerebrovascular disease accounted for the largest increases in annual direct costs. For non-SLE NP events, new/ongoing polyneuropathy accounted for the largest increase in annual direct costs, and new/ongoing headache and mood disorder for the largest increases in indirect costs. CONCLUSION/CONCLUSIONS:Patients with new/ongoing SLE or non-SLE NP events incurred higher direct and indirect costs.

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

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.