SCARF1-Induced Efferocytosis Plays an Immunomodulatory Role in Humans, and Autoantibodies Targeting SCARF1 Are Produced in Patients with Systemic Lupus Erythematosus.

Deficiency in the clearance of cellular debris is a major pathogenic factor in the emergence of autoimmune diseases. We previously demonstrated that mice deficient for scavenger receptor class F member 1 (SCARF1) develop a lupus-like autoimmune disease with symptoms similar to human systemic lupus erythematosus (SLE), including a pronounced accumulation of apoptotic cells (ACs). Therefore, we hypothesized that SCARF1 will be important for clearance of ACs and maintenance of self-tolerance in humans, and that dysregulation of this process could contribute to SLE. In this article, we show that SCARF1 is highly expressed on phagocytic cells, where it functions as an efferocytosis receptor. In healthy individuals, we discovered that engagement of SCARF1 by ACs on BDCA1+ dendritic cells initiates an IL-10 anti-inflammatory response mediated by the phosphorylation of STAT1 and STAT3. Unexpectedly, there was no significant difference in SCARF1 expression in samples of patients with SLE compared with healthy donor samples. However, we detected anti-SCARF1 autoantibodies in 26% of patients with SLE, which was associated with dsDNA Ab positivity. Furthermore, our data show a direct correlation of the levels of anti-SCARF1 in the serum and defects in the removal of ACs. Depletion of Ig restores efferocytosis in SLE serum, suggesting that defects in the removal of ACs are partially mediated by SCARF1 pathogenic autoantibodies. Our data demonstrate that human SCARF1 is an AC receptor in dendritic cells and plays a role in maintaining tolerance and homeostasis.

Hydroxychloroquine Dose and Risk for Incident Retinopathy : A Cohort Study.

BACKGROUND: Hydroxychloroquine is recommended for all patients with systemic lupus erythematosus and is often used for other inflammatory conditions, but a critical long-term adverse effect is vision-threatening retinopathy. OBJECTIVE: To characterize the long-term risk for incident hydroxychloroquine retinopathy and examine the degree to which average hydroxychloroquine dose within the first 5 years of treatment predicts this risk. DESIGN: Cohort study. SETTING: U.S. integrated health network. PARTICIPANTS: All patients aged 18 years or older who received hydroxychloroquine for 5 or more years between 2004 and 2020 and had guideline-recommended serial retinopathy screening. MEASUREMENTS: Hydroxychloroquine dose was assessed from pharmacy dispensing records. Incident hydroxychloroquine retinopathy was assessed by central adjudication of spectral domain optical coherence tomography with severity assessment (mild, moderate, or severe). Risk for hydroxychloroquine retinopathy was estimated over 15 years of use according to hydroxychloroquine weight-based dose (>6, 5 to 6, or ≤5 mg/kg per day) using the Kaplan-Meier estimator. RESULTS: Among 3325 patients in the primary study population, 81 developed hydroxychloroquine retinopathy (56 mild, 17 moderate, and 8 severe), with overall cumulative incidences of 2.5% and 8.6% at 10 and 15 years, respectively. The cumulative incidences of retinopathy at 15 years were 21.6% for higher than 6 mg/kg per day, 11.4% for 5 to 6 mg/kg per day, and 2.7% for 5 mg/kg per day or lower. The corresponding risks for moderate to severe retinopathy at 15 years were 5.9%, 2.4%, and 1.1%, respectively. LIMITATION: Possible misclassifications of dose due to nonadherence to filled prescriptions. CONCLUSION: In this large, contemporary cohort with active surveillance retinopathy screening, the overall risk for hydroxychloroquine retinopathy was 8.6% after 15 years, and most cases were mild. Higher hydroxychloroquine dose was associated with progressively greater risk for incident retinopathy. PRIMARY FUNDING SOURCE: National Institutes of Health.

Exploration of machine learning methods to predict systemic lupus erythematosus hospitalizations.

OBJECTIVES: Systemic lupus erythematosus (SLE) is a heterogeneous disease characterized by disease flares which can require hospitalization. Our objective was to apply machine learning methods to predict hospitalizations for SLE from electronic health record (EHR) data. METHODS: We identified patients with SLE in a longitudinal EHR-based cohort with ≥2 outpatient rheumatology visits between 2012 and 2019. We applied multiple machine learning methods to predict hospitalizations with a primary diagnosis code for SLE, including decision tree, random forest, naive Bayes, logistic regression, and an ensemble method. Candidate predictors were derived from structured EHR features, including demographics, laboratory tests, medications, ICD-9/10 codes for SLE manifestations, and healthcare utilization. We used two approaches to assess these variables over longitudinal follow-up, including the incorporation of lagged features to capture changes over time of clinical data. The performance of each model was evaluated by overall accuracy, the F statistic, and the area under the receiver operator curve (AUC). RESULTS: We identified 1996 patients with SLE. 4.6% were hospitalized for SLE in their most recent year of follow-up. Random forest models had highest performance in predicting SLE hospitalizations, with AUC 0.751 and AUC 0.772 for two approaches (averaging and progressive), respectively. The leading predictors of SLE hospitalizations included dsDNA positivity, C3 level, blood cell counts, and inflammatory markers as well as age and albumin. CONCLUSION: We have demonstrated that machine learning methods can predict SLE hospitalizations. We identified key predictors of these events including known markers of SLE disease activity; further validation in external cohorts is warranted.

Coronavirus disease 2019 outcomes among patients with rheumatic diseases 6 months into the pandemic.

OBJECTIVE: In earlier studies, patients with rheumatic and musculoskeletal disease (RMD) who got infected with COVID-19 had a higher risk of mechanical ventilation than comparators. We sought to determine COVID-19 outcomes among patients with RMD 6 months into the pandemic. METHODS: We conducted a cohort study at Mass General Brigham in Boston, Massachusetts, of patients with RMD matched to up to five comparators by age, sex and COVID-19 diagnosis date (between 30 January 2020 and 16 July 2020) and followed until last encounter or 18 August 2020. COVID-19 outcomes were compared using Cox regression. Risk of mechanical ventilation was compared in an early versus a recent cohort of patients with RMD. RESULTS: We identified 143 patients with RMD and with COVID-19 (mean age 60 years; 76% female individuals) and 688 comparators (mean age 59 years; 76% female individuals). There were no significantly higher adjusted risks of hospitalisation (HR: 0.87, 95% CI: 0.68-1.11), intensive care unit admission (HR: 1.27, 95% CI: 0.86-1.86), or mortality (HR: 1.02, 95% CI: 0.53-1.95) in patients with RMD versus comparators. There was a trend towards a higher risk of mechanical ventilation in the RMD cohort versus comparators, although not statistically significant (adjusted HR: 1.51, 95% CI: 0.93-2.44). There was a trend towards improvement in mechanical ventilation risk in the recent versus early RMD cohort (10% vs 19%, adjusted HR: 0.44, 95% CI: 0.17-1.12). CONCLUSIONS: Patients with RMD and comparators had similar risks of poor COVID-19 outcomes after adjusting for race, smoking and comorbidities. The higher risk of mechanical ventilation in the early RMD cohort was no longer detected in a recent cohort, suggesting improved management over time.

Comparison of an administrative algorithm for SLE disease severity to clinical SLE Disease Activity Index scores.

Systemic lupus erythematosus (SLE) severity, reflecting both disease intensity and duration, is heterogeneous making it challenging to study in administrative databases where severity may confound or mediate associations with outcomes. Garris et al. developed an administrative claims-based algorithm employing claims over a 1-year period to classify SLE severity as mild, moderate or severe. We sought to compare this administrative algorithm to a measure of SLE activity, the SLE Disease Activity Index-2000 (SLEDAI-2K) score at clinical visits. We identified 100 SLE patients followed in the Brigham and Women's Hospital (BWH) Lupus Center (in 2008-2010) with SLEDAI-2K scores at each visit over a 1-year period per person. We obtained data for the Garris algorithm for the same year per subject. We compared Garris SLE severity to the highest SLEDAI-2K in that year, with SLEDAI-2K categories of mild < 3, moderate 3-6, and severe > 6. We compared classification using weighted kappa statistics, and positive and negative predictive values (PPV, NPV). We also assessed the binary comparison of mild vs. moderate/severe. We calculated sensitivity, specificity, and McNemar's test. We analyzed 377 SLEDAI-2K assessments (mean 3.8 [SD 2.6] per subject/year). For classifying moderate/severe vs. mild SLE severity, the sensitivity was 85.7%, specificity 67.6%, PPV 81.8% and NPV 73.5%. The Garris algorithm for classifying SLE severity in administrative datasets had moderate agreement for classification of mild vs. moderate/severe SLE activity assessed by SLEDAI-2K assessments in an academic lupus center. It may be a useful tool for classifying SLE severity in administrative database studies.

Unchanging premature mortality trends in systemic lupus erythematosus: a general population-based study (1999-2014).

Objective: Patients with SLE have increased morbidity and premature mortality. Whether this mortality gap has improved in recent years, as in RA, is unknown. Methods: We conducted a population-based cohort study using a medical records database representative of the general population of the UK. We identified incident SLE cases and matched non-SLE controls between 1999 and 2014, divided into two subgroups based on year of SLE diagnosis, forming the early cohort (1999-2006) and late cohort (2007-14). We compared the mortality rates and hazard ratios, adjusting for potential confounders. Results: We identified 1470 and 1666 incident SLE cases in the early and late cohorts, respectively. In both cohorts, SLE patients had similar levels of excess mortality compared with their matched comparators [15.9 vs 7.9 deaths/1000 person-years (PY) in the early cohort and 13.8 vs 7.0 deaths/1000 PY in the late cohort]. The corresponding mortality hazard ratios were 2.15 (95% CI 1.63, 2.83) and 2.12 (95% CI 1.61, 2.80) in the early and late cohorts, respectively (P-value for interaction = 0.95). The absolute mortality differences were 8.0 (95% CI 4.3, 11.8) and 6.8 (95% CI 3.5, 10.0) deaths/1000 PY, respectively (P-value for interaction = 0.61). Conclusion: This general population-based cohort study suggests that excess mortality has not improved among SLE patients in recent years, remaining greater than double that of comparators, unlike RA during the same period. This highlights a critical unmet need for the development of new therapeutic agents and improved management strategies for SLE and its comorbidities.

Hydroxychloroquine Dose per Ophthalmology Guidelines and the Risk of Systemic Lupus Erythematosus Flares.

This study of an academic medical center patient cohort with systemic lupus erythematosus (SLE) investigates the association between hydroxychloroquine dose based on current guidelines and risk of lupus flares.

Risk Factors for Hydroxychloroquine Retinopathy and Its Subtypes.

Importance: The major toxic effect of hydroxychloroquine is retinopathy. Thus, current guidelines recommend limiting the dose and screening annually for retinopathy among all long-term users, but individual patient factors may be associated with retinopathy risk. Objective: To identify risk factors beyond hydroxychloroquine dose and duration of use for hydroxychloroquine retinopathy. Design, Setting, and Participants: This cohort study of 4677 patients in the Kaiser Permanente Northern California integrated health network who initiated hydroxychloroquine, continued treatment, and underwent retinopathy screening after 5 years of use was conducted from July 1, 1997, to December 31, 2020, with up to 15 years of follow-up. Statistical analysis was performed in August 2023. Exposure: Candidate risk factors included age at hydroxychloroquine initiation, sex, race and ethnicity, indications, chronic kidney disease (CKD), liver disease, diabetes, tamoxifen use, and medications that interact with hydroxychloroquine metabolism. Hydroxychloroquine dose was assessed from pharmacy dispensing records. Main Outcome and Measures: Incident hydroxychloroquine retinopathy was adjudicated from masked review of guideline-recommended screening studies and classified as parafoveal or pericentral pattern. Multivariable Cox proportional hazards regression was used to assess potential risk factors for hydroxychloroquine retinopathy within 15 years of initiation. Results: Of 4677 long-term hydroxychloroquine users (mean [SD] age at initiation, 52.4 [14.1] years; 3877 women [82.9%]), 125 patients developed hydroxychloroquine retinopathy within 15 years (102 parafoveal, 23 pericentral). Older age at time of hydroxychloroquine initiation was associated with retinopathy risk, with adjusted hazard ratios (HRs) of 2.48 (95% CI, 1.28-4.78) for those aged 45 to 54 years, 3.82 (95% CI, 2.05-7.14) for those aged 55 to 64 years, and 5.68 (95% CI, 2.99-10.79) for those aged 65 years or older compared with those younger than 45 years. The risk of retinopathy was higher among females than males (HR, 3.83 [95% CI, 1.86-7.89]), among patients with CKD stage 3 or greater (HR, 1.95 [95% CI, 1.25-3.04]), and among individuals with tamoxifen use (HR, 3.43 [95% CI, 1.08-10.89]). The likelihood of pericentral retinopathy was higher among Asian patients (HR, 15.02 [95% CI, 4.82-46.87]) and Black patients (HR, 5.51 [95% CI, 1.22-24.97]) compared with non-Hispanic White patients. Conclusions and Relevance: This study suggests that increasing age, female sex, CKD stage 3 or greater, and tamoxifen use were associated with a higher risk of hydroxychloroquine retinopathy, whereas being younger than 45 years at hydroxychloroquine initiation and male sex were associated with a lower risk. Race and ethnicity were also associated with the pattern of retinopathy. These factors should be incorporated into hydroxychloroquine dosing decisions.

Increased Risk of COVID-19 in Patients With Rheumatoid Arthritis: A General Population-Based Cohort Study.

OBJECTIVE: Patients with rheumatoid arthritis (RA) are at an increased risk of acquiring infections owing to immunologic dysfunction and use of potent immunomodulatory medications; however, few data are available on their risk of COVID-19. We estimated the rate of COVID-19 among RA participants and compared it with that of the general population. METHODS: Using the Health Improvement Network, we identified RA patients before February 2020 and followed them to September 2020. We calculated the rate of COVID-19 among participants with RA and compared it with that of the general population using a Cox proportional hazards model, adjusting for potential confounders using overlap weighting of exposure score. We repeated the same analysis among participants with osteoarthritis, a nonautoimmune rheumatic disease, as a negative control exposure. RESULTS: We identified 225 cases of suspected and confirmed COVID-19 among 17,268 RA patients, and 14,234 cases among 1,616,600 participants in the general population (1.4 versus 0.9/1,000 person-months), with the adjusted hazard ratio (HRadj ) being 1.19 (95% confidence interval [95% CI] 1.04-1.36). Confirmed COVID-19 cases developed in 46 RA participants and in 2,249 in the general population (0.3 versus 0.1/1,000 person-months), with the HRadj being 1.42 (95% CI 1.01-1.95). No statistically significant difference was observed for suspected and confirmed (HR 1.00 [95% CI 0.93-1.07]) or confirmed (HR 1.08 [95% CI 0.92-1.27]) COVID-19 rates between participants with osteoarthritis and the general population. CONCLUSION: RA, but not osteoarthritis, was associated with an increased risk of COVID-19. Our findings provide timely evidence to support recommendations that booster vaccines and priority access to anti-SARS-CoV-2 monoclonal antibody treatments should be encouraged for RA patients.

The Effect of Statin Use on Mortality in Systemic Autoimmune Rheumatic Diseases.

OBJECTIVE: Systemic autoimmune rheumatic diseases (SARD) are associated with an increased risk of premature cardiovascular disease (CVD) and all-cause mortality. We examined the potential survival benefit of statin use among patients with SARD in a general population setting. METHODS: We conducted an incident user cohort study using a UK general population database. Our population included patients with a SARD as determined by Read code diagnoses of systemic lupus erythematosus, systemic sclerosis, Sjögren syndrome, dermatomyositis, polymyositis, mixed connective tissue disease, Behçet disease, or antineutrophil cytoplasmic antibodies-associated vasculitis between January 1, 2000, and December 31, 2014. We compared propensity score-matched cohorts of statin initiators and noninitiators within 1-year cohort accrual blocks to account for potential confounders, including disease duration, body mass index, lifestyle factors, comorbidities, and medication use. RESULTS: Of 2305 statin initiators, 298 died during the followup period (mean 5.1 yrs), whereas among 2305 propensity score-matched noninitiators, 338 died during the followup period (mean 4.8 yrs). This corresponded to mortality rates of 25.4/1000 and 30.3/1000 person-years, respectively. Statin initiation was associated with reduced all-cause mortality (HR 0.84, 95% CI 0.72-0.98). When we compared the unmatched cohorts, the statin initiators (n = 2863) showed increased mortality (HR 1.85, 95% CI 1.58-2.16) compared with noninitiators (n = 2863 randomly selected within 1-year cohort accrual blocks) because of confounding by indication. CONCLUSION: In this general population-based study, statin initiation was shown to reduce overall mortality in patients with SARD after adjusting for relevant determinates of CVD risk.

Statin use and mortality in gout: A general population-based cohort study.

OBJECTIVES: Gout is associated with a higher risk of cardiovascular disease and premature mortality. We examined the potential survival benefit of statin use among gout patients in the general population. METHODS: We performed an incident user cohort study with time-stratified propensity score matching using a database representative of the UK general population between January 1999 and December 2014. To account for potential confounders, we compared propensity score-matched cohorts of statin initiators and non-initiators within 1-year cohort accrual blocks. We estimated the hazard ratio (HR) for mortality using a Cox proportional hazard model and the mortality rate difference using an additive hazard model. We examined potential subgroup effects stratified by key factors, including circulatory disease history. RESULTS: Among 17,018 statin initiators, 2025 deaths occurred during the follow-up (mean = 5.0 years) with a mortality rate of 24.0/1000 person-years (PY). The number of deaths and all-cause mortality rate among matched comparators during the follow-up (mean = 4.6 years) were 2503 and 31.7/1000 PY respectively. Compared with non-initiators, statin initiators experienced a 16% lower relative risk of all-cause mortality (HR = 0.84, 95% CI: 0.79-0.89) and 7.7 (95% CI: 6.1-9.3) fewer deaths per 1000 PY. This protective association was stronger among those without prior circulatory disease (HRs = 0.65 vs. 0.85; p for interaction = 0.02). CONCLUSION: In this general population-based cohort study, statin initiation was associated with a lower risk of mortality in gout, potentially with greater benefits among those without prior circulatory disease. The proper use of statins may help to substantially improve the premature mortality in gout.

Sharp decline in hydroxychloroquine dosing-analysis of 17,797 initiators from 2007 to 2016.

We aimed to assess the impact of ophthalmology weight-based hydroxychloroquine (HCQ) dosing guidelines on prescribing patterns. We examined initial HCQ prescription dosing between 2007 and 2016 and determined independent predictors for HCQ dosing above the previous (2011) recommended ≤ 6.5 mg/kg of ideal body weight (IBW)/day and the latest (2016) recommended ≤ 5.0 mg/kg of actual body weight (ABW)/day using logistic regression. Among 17,797 patients (82% female), the proportion of 400 mg prescribed daily dosing declined sharply from 80% in 2007-2011 to nearly 40% in 2014, whereas the proportions of 200- and 300-mg daily doses showed the opposite trends during the same periods. Accordingly, the risk of HCQ dosing above the guideline recommendations declined by more than 60%. While 36% of normal body mass index (BMI) individuals were classified as dosing above the IBW-based guideline, 66% would have received dosing above the latest ABW-based guideline. The risk of excess dosing was associated with female patients and dermatology prescribers (adjusted odds ratios ≥ 2 according to IBW- or ABW-based guidelines). There has been a sharp decline in HCQ dosing following ophthalmology weight-based guidelines in recent years. While this trend is likely helpful in reducing the risk of retinopathy, its potential impact on HCQ efficacy remains to be clarified.

Hydroxychloroquine prescription trends and predictors for excess dosing per recent ophthalmology guidelines.

BACKGROUND: Hydroxychloroquine (HCQ) retinopathy may be more common than previously recognized; recent ophthalmology guidelines have revised recommendations from ideal body weight (IBW)-based dosing to actual body weight (ABW)-based dosing. However, contemporary HCQ prescribing trends in the UK remain unknown. METHODS: We examined a UK general population database to investigate HCQ dosing between 2007 and 2016. We studied trends of excess HCQ dosing per ophthalmology guidelines (defined by exceeding 6.5 mg/kg of IBW and 5.0 mg/kg of ABW) and determined their independent predictors using multivariable logistic regression analyses. RESULTS: Among 20,933 new HCQ users (78% female), the proportions of initial HCQ excess dosing declined from 40% to 36% using IBW and 38% to 30% using ABW, between 2007 and 2016. Among these, 47% of women were excess-dosed (multivariable OR 12.52; 95% CI 10.99-14.26) using IBW and 38% (multivariable OR 1.98; 95% CI,1.81-2.15) using ABW. Applying IBW, 37% of normal and 44% of obese patients were excess-dosed; however, applying ABW, 53% of normal and 10% of obese patients were excess-dosed (multivariable ORs = 1.61 and 0.1 (reference = normal); both p < 0.01). Long-term HCQ users showed similar excess dosing. CONCLUSION: A substantial proportion of HCQ users in the UK, particularly women, may have excess HCQ dosing per the previous or recent weight-based guidelines despite a modest decline in recent years. Over half of normal-BMI individuals were excess-dosed per the latest guidelines. This implies the potential need to reduce dosing for many patients but also calls for further research to establish unifying evidence-based safe and effective dosing strategies.