Hydroxychloroquine and Mortality Among Patients With Systemic Lupus Erythematosus in the General Population

Effect of antimalarials on clinical outcomes in lupus nephritis

OBJECTIVES

To evaluate the effect of antimalarial drugs in response to therapy, incidence of LN flares, and progression of kidney disease in a large LN cohort.

METHODS

We retrospectively studied 424 biopsy-proven LN patients followed for >3 years. We obtained demographic, clinical, laboratory, histopathological and treatment variables. Antimalarial use was approached as (i) users vs no users, (ii) according to prevalent vs incident use regarding the LN flare and (iii) according to the type of antimalarial. All outcomes were evaluated by time-to-event analyses. Adjusted hazard ratios were obtained by Cox regression.

RESULTS

The cohort included 424 patients, median age of 29 years (IQR 23-37), 96% female, with a median eGFR of 81 ml/min/1.73 m2 (IQR 48-118) and proteinuria of 3.4 g/g (IQR 1.9-5.5). Antimalarial use was associated with higher complete response (aHR 1.57, 1.08-2.27), lower incidence of kidney flares (aHR 0.63, 0.43-0.92) and lower progression to kidney failure (aHR 0.37, 0.23-0.53). The effect of antimalarials on these outcomes was modified by the presentation eGFR, histological class and/or concomitant initial immunosuppressor. These protective effects were observed in patients with prevalent or incident use regarding the LN flare and patients using hydroxychloroquine. The incidence of toxic retinopathy was 1.7%, 5.7% and 8.8% by 3, 5 and 7 years of continued antimalarial use, respectively.

CONCLUSION

The use of antimalarial drugs is associated with increased response to therapy, lower incidence of kidney flares, and lower progression to kidney failure in LN patients. Conversely, this population is at high risk of toxic maculopathy, and yearly ophthalmologic examination is recommended.

Antiplatelet effects of hydroxychloroquine in patients with systemic lupus erythematosus evaluated by the total thrombus-formation analysis system (T-TAS)

OBJECTIVES

Hydroxychloroquine (HCQ) has been shown to reduce thrombotic events in patients with SLE. However, the antiplatelet effects of HCQ are only supported by the platelet aggregation assay, which is a non-physiological test. The total thrombus-formation analysis system (T-TAS) is a microchip-based flow chamber system that mimics physiological conditions and allows for the quantitative analysis of thrombogenicity. The present study investigated the antiplatelet effects of HCQ using T-TAS.

METHODS

This was a single-centre cross-sectional study on 57 patients with SLE. We measured the area under the pressure curve for 10 min (PL-AUC10) and the time to 10 kPa (T10) in patients with SLE using T-TAS and examined their relationships with the use of HCQ. PL-AUC10 and platelet aggregation were also measured at several HCQ concentrations using blood samples from healthy donors.

RESULTS

PL-AUC10 was significantly lower in the HCQ/real body weight (RBW) ≥5 mg/kg group than in the <5 mg/kg group, while T10 was similar, indicating that HCQ inhibited overall thrombus formation rather than the initiation of thrombus formation. The antiplatelet effects of HCQ were initially detected at HCQ/RBW of approximately 4 mg/kg and reached a plateau at around 5.5 mg/kg. The administration of HCQ/RBW >4.6 mg/kg clearly exerted antiplatelet effects. Additionally, HCQ inhibited thrombus formation in T-TAS and the platelet aggregation response to epinephrine in a dose-dependent manner.

CONCLUSIONS

We demonstrated the antiplatelet effects of HCQ under conditions simulating the physiological environment by using T-TAS and identified the range of doses at which HCQ exerted antiplatelet effects.

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.

Effect of hydroxychloroquine blood concentration on the efficacy and ocular toxicity of systemic lupus erythematosus

In the absence of evidence-based guidance on the impact of hydroxychloroquine (HCQ) blood concentration on efficacy and ocular toxicity in systemic lupus erythematosus (SLE), the clinical monitoring of HCQ blood concentration is not yet widely performed, which raised concerns about the necessity of conducting HCQ blood concentration monitoring. In this retrospective study, we consecutively enrolled 135 patients with SLE who received HCQ treatment for more than 6 months from July 2022 to December 2022. Ocular toxicity was evaluated by collecting relevant retinal parameters using optical coherence tomography angiography (OCTA). Therapeutic efficacy was evaluated using the SLE disease activity index (SLEDAI) and relevant clinical parameters. HCQ blood concentration was determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Spearman correlation analysis revealed that the cumulative dose of HCQ was positively correlated with the foveal avascular zone (FAZ) perimeter and FAZ area (r = 0.734, P < 0.001; r = 0.784, P < 0.001). Meanwhile, the treatment duration of HCQ was positively correlated with FAZ perimeter and FAZ area (r = 0.761, P < 0.001; r = 0.882, P < 0.001). The univariate and multivariate logistic regression analyses indicated that HCQ blood concentration was associated with the disease activity of patients with SLE (odds ratio 0.994, 95% CI 0.990-0.999). HCQ blood concentration may be an important factor in assessing the therapeutic effectiveness of SLE patients. The HCQ-related ocular toxicity was a long-term effect related to long term exposure, rather than the blood concentration of HCQ at the time of testing. More importantly, when addressing HCQ-related ocular toxicity, it may be crucial to pay attention to the cumulative dose and treatment duration of HCQ.

The effect of antimalarials on the safety and persistence of treatment with biologic agents or Janus kinase inhibitors in rheumatoid arthritis

OBJECTIVES

To test the association of use of antimalarials with the overall safety of treatment in RA patients receiving one or multiple courses of biologic (b)DMARDs or a Janus kinase inhibitor (JAKi).

METHODS

BiobadaBrasil is a multicentric registry-based cohort study of Brazilian patients with rheumatic diseases starting their first bDMARD or JAKi. The present analysis includes RA patients recruited from January 2009 to October 2019, followed up over one or multiple (up to six) courses of treatment (latest date, 19 November 2019). The primary outcome was the incidence of serious adverse events (SAEs). Total and system-specific adverse events (AEs) and treatment interruption served as secondary outcomes. Negative binomial regression with generalized estimating equations (to estimate multivariate incidence rate ratios, mIRR) and frailty Cox proportional hazards models were used for statistical analyses.

RESULTS

The number of patients enrolled was 1316 (2335 treatment courses, 6711 patient-years [PY]; 1254.5 PY on antimalarials). The overall incidence of SAEs was 9.2/100 PY. Antimalarials were associated with reduced risk of SAEs (mIRR: 0.49; 95% CI: 0.36, 0.68; P < 0.001), total AEs (0.68; 95% CI: 0.56, 0.81; P < 0.001), serious infections (0.53; 95% CI: 0.34, 0.84; P = 0.007) and total hepatic AEs (0.21; 95% CI: 0.05, 0.85; P = 0.028). Antimalarials were also related to better survival of treatment course (P = 0.003). There was no significant increase in the risk of cardiovascular AEs.

CONCLUSION

Among RA patients on treatment with bDMARDs or JAKi, concomitant use of antimalarials was associated with reduced the incidence of serious and total AEs and with longer treatment course survival.

The impact of traditional cardiovascular risk factor control on 7-year follow-up atherosclerosis progression in systemic lupus erythematosus

OBJECTIVES

The 2022 EULAR recommendations for cardiovascular risk management in patients with rheumatic disorders, including SLE, call for rigorous management of cardiovascular risk factors (CVRF). The impact of CVRF target attainment on atherosclerotic plaque progression hasn't been previously evaluated in prospective ultrasound studies.

METHODS

A total of 115 patients with SLE and 1:1 age and sex-matched healthy controls who had a baseline carotid and femoral ultrasound examination in our cardiovascular research unit were invited for a 7-year follow-up assessment of new plaque development. We aimed to compare the incidence of plaque progression between SLE patients and controls and reveal the extent to which it is affected by the attainment of European Society of Cardiology (ESC) targets for modifiable CVRFs (blood pressure, smoking status, body weight, lipids and physical activity), and disease-related features (disease duration, disease activity, autoantibodies, treatments).

RESULTS

Eighty-six SLE patients and 42 controls had a 7-year follow-up carotid and femoral plaque examination. New plaque development was observed in 32/86 patients vs 8/42 controls (P = 0.037). Patients with SLE had a 4-fold higher risk for plaque progression than controls (OR: 4.16, CI: 1.22, 14.19, P = 0.023), adjusting for potential confounders. Multivariate regression analyses showed a 50% decrease in plaque progression for every modifiable CVRF fulfilling ESC targets (OR: 0.56, CI: 0.34, 0.93, P = 0.026).

CONCLUSION

Patients with SLE develop a rapid progression of atherosclerotic plaques which may be drastically reduced by CVRF target attainment according to ESC guidelines.

EULAR recommendations for the management of systemic lupus erythematosus: 2023 update

OBJECTIVES

To update the EULAR recommendations for the management of systemic lupus erythematosus (SLE) based on emerging new evidence.

METHODS

An international Task Force formed the questions for the systematic literature reviews (January 2018-December 2022), followed by formulation and finalisation of the statements after a series of meetings. A predefined voting process was applied to each overarching principle and recommendation. Levels of evidence and strengths of recommendation were assigned, and participants finally provided their level of agreement with each item.

RESULTS

The Task Force agreed on 5 overarching principles and 13 recommendations, concerning the use of hydroxychloroquine (HCQ), glucocorticoids (GC), immunosuppressive drugs (ISDs) (including methotrexate, mycophenolate, azathioprine, cyclophosphamide (CYC)), calcineurin inhibitors (CNIs, cyclosporine, tacrolimus, voclosporin) and biologics (belimumab, anifrolumab, rituximab). Advice is also provided on treatment strategies and targets of therapy, assessment of response, combination and sequential therapies, and tapering of therapy. HCQ is recommended for all patients with lupus at a target dose 5 mg/kg real body weight/day, considering the individual's risk for flares and retinal toxicity. GC are used as 'bridging therapy' during periods of disease activity; for maintenance treatment, they should be minimised to equal or less than 5 mg/day (prednisone equivalent) and, when possible, withdrawn. Prompt initiation of ISDs (methotrexate, azathioprine, mycophenolate) and/or biological agents (anifrolumab, belimumab) should be considered to control the disease and facilitate GC tapering/discontinuation. CYC and rituximab should be considered in organ-threatening and refractory disease, respectively. For active lupus nephritis, GC, mycophenolate or low-dose intravenous CYC are recommended as anchor drugs, and add-on therapy with belimumab or CNIs (voclosporin or tacrolimus) should be considered. Updated specific recommendations are also provided for cutaneous, neuropsychiatric and haematological disease, SLE-associated antiphospholipid syndrome, kidney protection, as well as preventative measures for infections, osteoporosis, cardiovascular disease.

CONCLUSION

The updated recommendations provide consensus guidance on the management of SLE, combining evidence and expert opinion.

Hydroxychloroquine use is associated with reduced mortality risk in older adults with rheumatoid arthritis

BACKGROUND

There is little robust data about the cardiovascular safety of hydroxychloroquine in patients with rheumatoid arthritis (RA), who often have cardiovascular comorbidities. We examined the association between use of hydroxychloroquine (HCQ) in patients with RA and major adverse cardiovascular events (MACE).

METHODS

In a retrospective cohort of Medicare beneficiaries aged ≥ 65 years with RA, we identified patients who initiated HCQ (users) and who did not initiate HCQ (non-users) between January 2015-June 2017. Each HCQ user was matched to 2 non-users of HCQ using propensity score derived from patient baseline characteristics. The primary outcome was the occurrence of MACE, defined as acute admissions for stroke, myocardial infarction, or heart failure. Secondary outcomes included all-cause mortality and the composite of MACE and all-cause mortality. Cox proportional hazards model was used to compare outcomes between HCQ users to non-users.

RESULTS

The study included 2380 RA patients with incident HCQ use and matched 4633 HCQ non-users over the study period. The mean follow-up duration was 1.67 and 1.63 years in HCQ non-users and users, respectively. In multivariable models, use of HCQ was not associated with the risk of MACE (hazard ratio 1.1; 95% CI: 0.832-1.33). However, use of HCQ was associated with a lower risk of all-cause mortality (HR: 0.54; 95% CI: 0.45-0.64) and the composite of all-cause mortality and MACE (HR 0.67; 95% CI: 0.58-0.78).

CONCLUSION

HCQ use was independently associated with a lower risk of mortality in older adults with RA but not with incidence of MACE events. Key Points • Using an incident user design (to avoid the biases of a prevalent user design) and a population-based approach, we examined the effect of hydroxychloroquine (HCQ) on the risk of major cardiovascular events (MACE) in older patients with RA. • We did not find an association between HCQ use and incident MACE. We did, however, find a significant association with the composite outcome (MACE and all-cause mortality) driven by a significant reduction in all-cause mortality with HCQ use.

Risk factors for cardiovascular diseases in patients with systemic lupus erythematosus: an umbrella review

Cardiovascular disease in patients with systemic lupus erythematosus (SLE) remains one of the most common causes of death and is caused by several factors, including both traditional and disease-specific risk factors. We aimed to systematically appraise the evidence of cardiovascular disease risk factors focusing on the SLE population. The protocol for this umbrella review is registered in PROSPERO (registration no. CRD42020206858). A systematic literature search was conducted in PubMed, Embase, and the Cochrane Library from database inception to June 22, 2022, for systematic reviews and meta-analyzes that examined cardiovascular disease risk factors in patients with SLE. Two reviewers independently extracted data and assessed the quality of the included studies using the "Assessing the Methodological Quality of Systematic Reviews 2 (AMSTER 2)" tool. Of the 102 identified articles, nine systematic reviews were included in this umbrella review. All included systematic reviews were assessed as critically low quality according to the AMSTER 2 tool. The traditional risk factors identified in this study were older age, male sex, hypertension, dyslipidemia, smoking, and a family history of cardiovascular disease. SLE-specific risk factors were long-term disease duration, lupus nephritis, neurological disorders, high disease activity, organ damage, use of glucocorticoids, azathioprine, and antiphospholipid antibodies, including anticardiolipin antibodies and lupus anticoagulant. This umbrella review identified some cardiovascular disease risk factors in patients with SLE; however, the study quality of all included systematic reviews was critically low. Key Points • We examined the evidence of cardiovascular disease risk factors focusing on patients with systemic lupus erythematosus. • We found that long-term disease duration, lupus nephritis, neurological disorders, high disease activity, organ damage, use of glucocorticoids, azathioprine, and antiphospholipid antibodies, including anticardiolipin antibodies and lupus anticoagulant, were cardiovascular disease risk factors among patients with systemic lupus erythematosus. • The review indicates the need for well-validated and high-quality future reviews that assess major adverse cardiovascular events as an outcome in patients with systemic lupus erythematosus.

Advances in the management of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a severe multisystem autoimmune disease that can cause injury in almost every body system. While considered a classic example of autoimmunity, it is still relatively poorly understood. Treatment with immunosuppressive agents is challenging, as many agents are relatively non-specific, and the underlying disease is characterized by unpredictable flares and remissions. This State of The Art Review provides a comprehensive current summary of systemic lupus erythematosus based on recent literature. In basic and translational science, this summary includes the current state of genetics, epigenetics, differences by ancestry, and updates about the molecular and immunological pathogenesis of systemic lupus erythematosus. In clinical science, the summary includes updates in diagnosis and classification, clinical features and subphenotypes, and current guidelines and strategies for treatment. The paper also provides a comprehensive review of the large number of recent clinical trials in systemic lupus erythematosus. Current knowns and unknowns are presented, and potential directions for the future are suggested. Improved knowledge of immunological pathogenesis and the molecular differences that exist between patients should help to personalize treatment, minimize side effects, and achieve better outcomes in this difficult disease.

Researchers in rheumatology should avoid categorization of continuous predictor variables

BACKGROUND

Rheumatology researchers often categorize continuous predictor variables. We aimed to show how this practice may alter results from observational studies in rheumatology.

METHODS

We conducted and compared the results of two analyses of the association between our predictor variable (percentage change in body mass index [BMI] from baseline to four years) and two outcome variable domains of structure and pain in knee and hip osteoarthritis. These two outcome variable domains covered 26 different outcomes for knee and hip combined. In the first analysis (categorical analysis), percentage change in BMI was categorized as ≥ 5% decrease in BMI, < 5% change in BMI, and ≥ 5% increase in BMI, while in the second analysis (continuous analysis), it was left as a continuous variable. In both analyses (categorical and continuous), we used generalized estimating equations with a logistic link function to investigate the association between the percentage change in BMI and the outcomes.

RESULTS

For eight of the 26 investigated outcomes (31%), the results from the categorical analyses were different from the results from the continuous analyses. These differences were of three types: 1) for six of these eight outcomes, while the continuous analyses revealed associations in both directions (i.e., a decrease in BMI had one effect, while an increase in BMI had the opposite effect), the categorical analyses showed associations only in one direction of BMI change, not both; 2) for another one of these eight outcomes, the categorical analyses suggested an association with change in BMI, while this association was not shown in the continuous analyses (this is potentially a false positive association); 3) for the last of the eight outcomes, the continuous analyses suggested an association of change in BMI, while this association was not shown in the categorical analyses (this is potentially a false negative association).

CONCLUSIONS

Categorization of continuous predictor variables alters the results of analyses and could lead to different conclusions; therefore, researchers in rheumatology should avoid it.

Hydroxychloroquine Use and Cardiovascular Events Among Patients With Systemic Lupus Erythematosus and Rheumatoid Arthritis

OBJECTIVE

We evaluated the potential temporal association between hydroxychloroquine (HCQ) use and cardiovascular (CV) events among patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA).

METHODS

We conducted a nested case-control study within inception cohorts of SLE and RA patients using administrative health databases including the entire population of British Columbia, Canada. We identified cases with incident CV events, including myocardial infarction (MI), stroke, or venous thromboembolism (VTE). We matched each case with up to 3 controls on age, sex, and rheumatic disease. HCQ exposure was categorized by the time between the last HCQ prescription date covered and the index date as current use, recent use, remote use, or never used. We used conditional logistic regression to assess the association between HCQ exposure and CV events, using remote use as the reference group.

RESULTS

We identified 10,268 cases and 29,969 controls. Adjusted conditional odd ratios (cORs) and 95% confidence intervals (95% CIs) for current HCQ use relative to remote use were 0.86 (0.77-0.97) for combined CV events, 0.88 (0.74-1.05) for MI, 0.87 (0.74-1.03) for stroke, and 0.74 (0.59-0.94) for VTE. Recent HCQ users and nonusers had similar odds of combined CV events as remote users (cORs 0.93, 95% CI 0.77-1.13 and 0.96, 95% CI 0.88-1.04, respectively).

CONCLUSION

In this nested case-control study of patients with SLE and RA, we found a reduced risk of overall CV events associated with current HCQ use, including reductions in VTE and trends toward reductions in MI and stroke. These findings suggest a possible cardiovascular preventative benefit of HCQ use.

Predictors of severe hemolytic anemia and its impact on major outcomes in systemic lupus erythematosus: Data from a multiethnic Latin American cohort

OBJECTIVE

To determine the predictors of the occurrence of severe autoimmune hemolytic anemia (AIHA) and its impact on damage accrual and mortality in SLE patients.

METHODS

Factors associated with time to severe AIHA (hemoglobin level ≤7 g/dL) occurring from the onset of SLE symptoms were examined by Cox proportional hazards regressions. The association of severe AIHA with mortality was examined by logistic regression analyses while its impact on damage was by negative binomial regression.

RESULTS

Of 1,349 patients, 49 (3.6%) developed severe AIHA over a mean (SD) follow-up time of 5.4 (3.8) years. The median time from the first clinical manifestation to severe AIHA was 111 days (IQR 43-450). By multivariable analysis, male sex (HR 2.26, 95% CI 1.02-4.75, p = 0.044), and higher disease activity at diagnosis (HR 1.04, 95% CI 1.01-1.08, p = 0.025) were associated with a shorter time to severe AIHA occurrence. Of the SLEDAI descriptors, only hematologic (leukopenia and/or thrombocytopenia) showed a certain trend toward significance in the multivariable analysis (HR 2.36, 95% CI 0.91-6.13, p = 0.0772). Severe AIHA contributed neither to damage nor to mortality.

CONCLUSIONS

Severe AIHA occurs during the early course of SLE. Male sex and higher disease activity at diagnosis emerged as independent predictors of a shorter time to severe AIHA occurrence. Although not statistically significant, hematological abnormalities at SLE diagnosis could predict the occurrence of severe AIHA in a shorter time. Damage and mortality did not seem to be impacted by the occurrence of severe AIHA.

Risk of Arrhythmia Among New Users of Hydroxychloroquine in Rheumatoid Arthritis and Systemic Lupus Erythematosus: A Population-Based Study

OBJECTIVES

We assessed the association between hydroxychloroquine (HCQ) initiation and risk of arrhythmia among patients with incident rheumatoid arthritis (RA) or with incident systemic lupus erythematosus (SLE).

METHODS

All patients with incident RA or SLE and no arrhythmic events, not receiving antiarrhythmic medications, and not receiving HCQ prior to the index date of disease in British Columbia, Canada, between January 1996 and December 2014 were identified from administrative databases. We identified patients who were dispensed HCQ prescriptions (HCQ initiators) or were not dispensed HCQ prescriptions (HCQ noninitiators) during each study year; groups were matched 1:1 by propensity scores using baseline confounders on demographics, comorbidities, medications, and health care utilization. Outcomes were any new arrhythmias, atrial fibrillation, abnormal electrocardiograms, including long QT syndrome and conduction disorder, and other unspecified arrhythmias during follow-up. We used cause-specific Cox proportional hazards models with death as a competing event to assess the association between HCQ initiation and the outcomes.

RESULTS

We identified 11,518 propensity score-matched patients with RA or SLE in each group. Over the mean follow-up of 8 years, there were 1,610 and 1,646 incident arrhythmias in the HCQ initiator group and the noninitiator group, respectively, with crude incidence rates of arrhythmia of 17.5 and 18.1 in 1,000 persons per year, respectively. The adjusted cause-specific hazard ratio (cHR) for patients who received HCQ was 0.96 (95% confidence interval [95% CI] 0.89-1.03) compared with HCQ noninitiators, and the cHRs for patients who took HCQ and had arrhythmia subtypes of atrial fibrillation, abnormal electrocardiograms, and other unspecified arrhythmias were 0.93 (95% CI 0.83-1.04), 0.98 (95% CI 0.87-1.11), and 0.95 (95% CI 0.84-1.07), respectively.

CONCLUSION

Risk of any type of arrhythmia was not increased among new users of HCQ.

Venous Thromboembolism in the Inflammatory Rheumatic Diseases

Venous thromboembolism (VTE), which includes deep venous thrombosis and pulmonary embolism, is a cardiovascular event whose risk is increased in most inflammatory rheumatic diseases (IRDs). Mechanisms that increase VTE risk include antiphospholipid antibodies (APLs), particularly anticardiolipin antibodies, anti-beta2glycoprotein I antibodies and lupus anticoagulant present together, and inflammation-mediated endothelial injury. Patients with IRDs should receive long-term anticoagulation drugs when the risk of VTE recurrence is high. In the light of recent warnings from regulatory agencies regarding heightened VTE risk with Janus kinase inhibitors, these drugs should be initiated only after a careful assessment of VTE risk in those with IRDs.

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.

Hydroxychloroquine and Risk of Long QT Syndrome in Rheumatoid Arthritis: A Veterans Cohort Study With Nineteen-Year Follow-up

OBJECTIVE

Recent evidence suggests that hydroxychloroquine use is not associated with higher 1-year risk of long QT syndrome (LQTS) in patients with rheumatoid arthritis (RA). Less is known about its long-term risk, the examination of which was the objective of this study.

METHODS

We conducted a propensity score-matched active-comparator safety study of hydroxychloroquine in 8,852 veterans (mean age 64 ± 12 years, 14% women, 28% Black) with newly diagnosed RA. A total of 4,426 patients started on hydroxychloroquine and 4,426 started on another nonbiologic disease-modifying antirheumatic drug (DMARD) and were balanced on 87 baseline characteristics. The primary outcome was LQTS during 19-year follow-up through December 31, 2019.

RESULTS

Incident LQTS occurred in 4 (0.09%) and 5 (0.11%) patients in the hydroxychloroquine and other DMARD groups, respectively, during the first 2 years. Respective 5-year incidences were 17 (0.38%) and 6 (0.14%), representing 11 additional LQTS events in the hydroxychloroquine group (number needed to harm 403; [95% confidence interval (95% CI)], 217-1,740) and a 181% greater relative risk (95% CI 11%-613%; P = 0.030). Although overall 10-year risk remained significant (hazard ratio 2.17; 95% CI 1.13-4.18), only 5 extra LQTS occurred in hydroxychloroquine group over the next 5 years (years 6-10) and 1 over the next 9 years (years 11-19). There was no association with arrhythmia-related hospitalization or all-cause mortality.

CONCLUSIONS

Hydroxychloroquine use had no association with LQTS during the first 2 years after initiation of therapy. There was a higher risk thereafter that became significant after 5 years of therapy. However, the 5-year absolute risk was very low, and the absolute risk difference was even lower. Both risks attenuated during longer follow-up. These findings provide evidence for long-term safety of hydroxychloroquine in patients with RA.

Outcomes following antimalarial withdrawal in patients with quiescent systemic lupus erythematosus

OBJECTIVE

Antimalarial medications (AMs) are central to the management of SLE. We investigated the rate of flare in lupus patients who withdrew AM after achieving clinical remission for at least one year, compared to those who continued therapy and compared flare rates in cases who tapered AM versus abruptly withdrew.

METHODS

Cases achieved clinical remission for at least one year then ceased their AM. Index date was defined as the date of complete AM cessation. Controls achieved clinical remission for at least one year and continued AM. Controls were matched according to the duration of AM before remission and the duration of therapy from remission date to case index date. All patients had ≥ 2 years of follow up.

RESULTS

Of 1573 patients on AM, 165 achieved a one-year remission and then ceased their AM. 96 had adequate follow-up, 88 were successfully matched to one control and 85 to 2 controls for a total of 173 controls. Flare occurred in 61.4% of cases and 45.1% of controls (p = 0.002). 52.3% patients who withdrew AM later restarted it due to disease flare. 88% recaptured control or improved, while 12% did not. Patients who tapered had significantly fewer flares (45.9% vs. 72.6%; p = 0.01).

CONCLUSION

AMs aid in preventing disease flare even in patients who have achieved prolonged clinical remission. Tapering AM results in lower flare rates. Hence, except in the setting of toxicity, cessation of antimalarial therapy in patients with prolonged disease quiescence is feasible using a slow taper.

Asymptomatic coronary artery disease assessed by coronary computed tomography in patients with systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

Coronary artery disease (CAD) assessed by coronary computed tomography (CT) in patients with systemic lupus erythematosus (SLE) has been investigated in several studies, but with conflicting results. The aim of this systematic review and meta-analysis of the literature was synthesize the evidence on this topic.

METHODS

The relevant literature was identified and evaluated from inception until January 2021 in PubMed, Embase, Web of Science and Cochrane library. Studies reporting coronary artery calcification (CAC), and its prevalence and extent using the coronary calcium score (CCS) were included. Data extracted from eligible studies were used to calculate effect estimates (ESs) and 95% confidence intervals (95%CI) and weighted mean differences (WMD) with 95%CI.

RESULTS

Twenty-four studies were eligible for inclusion. For the CAC prevalence, 11 studies were included (918 SLE patients and 3952 controls) and the pooled prevalence for the random effect was 29.8% (95%CI 25.7-32.9%) for SLE patients and 11.8% (95%CI 16.2-20.4%) in controls (RR 2.22, 95%CI 1.42 to 3.48; p= 0.0005) and no significant increase in the WMD for CCS (MD= 0.32, 95%CI -5.55 to 6.20, p= 0.91) compared with controls in seven studies. Greater organ damage and glucocorticoid use has been associated with a higher CCS. According to two studies, the coronary CT angiography calcified and non-calcified plaque burden were increased in SLE patients compared with controls.

CONCLUSIONS

In SLE, asymptomatic CAD by CAC is more prevalent and there is more multivessel disease compared with controls without lupus. However, the extent of CAC was not increased in SLE patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021228710.

Drug monitoring in systemic lupus erythematosus

Therapeutic drug monitoring (TDM) is not yet accepted by systemic lupus erythematosus (SLE) treatment guidelines. Studies in SLE, however, have proven benefit in three areas: identification of non-adherence or poor adherence; targets for clinical benefit; and ranges of toxicity. This review covers the data on three medications commonly used for SLE, drawing on studies from both the SLE and non-SLE literature.

Whole blood drug levels do not correlate with QTc intervals in hydroxychloroquine-treated systemic lupus erythematosus patients

OBJECTIVES

HCQ is recommended for all patients with SLE, but reports of cardiac toxicity in severe acute respiratory syndrome coronavirus 2 patients raised concerns. We aimed to study the relationship between HCQ blood levels and QTc intervals.

METHODS

A retrospective review of 90 SLE patients (cohort 1) was conducted with data collected regarding demographics, QTc interval and chronic kidney disease (CKD). A prospective study of 84 SLE patients (cohort 2) was conducted with data collected regarding demographics, dose of HCQ, duration of HCQ treatment, presence of echocardiographic abnormalities and CKD simultaneous with whole blood HCQ levels measured by HPLC. Statistical analysis utilized one-way analysis of variance, Pearson's correlation coefficient and t tests.

RESULTS

In cohort 1 there was no significant difference in mean QTc based on 75 HCQ-treated [437.91 msec (s.d. 20.02)] as compared with 15 untreated patients [434.6 msec (s.d. 27.49)]. In patients with CKD, the mean QTc in HCQ users [448 (s.d. 23.37)] as compared with non-users [444.5 msec (s.d. 24.61)] also had no significant difference. In cohort 2, HCQ levels did not correlate with QTc interval (r = 0.017) and this applied regardless of the dose prescribed (r = 0.113 for 400 mg and r = 0.06 for 200 mg), duration of exposure (P = 0.36 for 0-5, >5-10 or >10 years), CKD (r = 0.482) or underlying cardiac abnormalities (r = 0.430).

CONCLUSIONS

This is the first study relying on measured blood levels demonstrating the absence of a clinically consequential increase in QTc levels in HCQ-treated SLE patients.

RetINal Toxicity And HydroxyChloroquine Therapy (INTACT): protocol for a prospective population-based cohort study

PURPOSE

Hydroxychloroquine (HCQ) is an important medication for patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and other rheumatic diseases. Although it is well-tolerated and cost-effective, the risk of HCQ retinal toxicity is of increasing concern. The aim of this study is to re-examine the HCQ retinal toxicity incidence rate, risk factors and clinical course after discontinuation.

METHODS

We designed a prospective population-based cohort study in adult patients with SLE or RA, currently receiving HCQ for five or more years, who are residents of British Columbia (BC), Canada. Based on administrative data, we identified 5508 eligible participants (1346 SLE and 4162 RA). They will participate in annual or biannual retinal screening over 5 years in alignment with the recently revised American Academy of Ophthalmology guidelines. To standardise procedures for retinal screening, imaging, diagnostic criteria, severity staging and data transfer, a consensus meeting was convened in December 2019 with participation of BC retinal specialists and the research team. Agreement was attained on: use of spectral domain-optical coherence tomography as the primary objective screening modality; classification of images into categories of normal, equivocal or abnormal; and transferring the equivocal and abnormal images plus corresponding subjective test results via cloud-based server from each clinic to a reading centre. Confirmation of HCQ retinal toxicity diagnoses and severity staging will be performed by three independent and masked reviewers. The incidence of HCQ retinal toxicity will be calculated, accounting for the competing risk of death. Hazard ratios for each risk factor will be calculated for the risk of HCQ retinopathy, after adjusting for confounders. We will also estimate the risk of HCQ retinal toxicity progression over 5 years.

ETHICS AND DISSEMINATION

This study has received approval from the University of British Columbia Clinical Research Ethics Board (H20-00736) and the Vancouver Coastal Health Research Institute.

Hydroxychloroquine in systemic lupus erythematosus: overview of current knowledge

The antimalarial hydroxychloroquine (HCQ) has demonstrated several crucial properties for the treatment of systemic lupus erythematosus (SLE). Herein, we reviewed the main HCQ pharmacologic features, detailed its mechanism of action, and summarized the existing guidelines and recommendations for HCQ use in rheumatology with a systematic literature search for the randomized controlled trials focused on lupus. HCQ has been shown to decrease SLE activity, especially in mild and moderate disease, to prevent disease flare and to lower the long-term glucocorticoid need. The numerous benefits of HCQ are extended to pregnancy and breastfeeding period. Based on cohort studies, antithrombotic and metabolic HCQ’s effects were shown, including lipid-lowering properties, which might contribute to an improved cardiovascular risk. Moreover, early HCQ use in antinuclear antibodies positive individuals might delay the progression to SLE. Finally, HCQ has a significant favorable impact on long-term outcomes such as damage accrual and mortality in SLE. Based on these multiple benefits, HCQ is now the mainstay long-term treatment in SLE, recommended by current guidelines in all patients unless contraindications or side effects. The daily dose associated with the best compromise between efficacy and safety is matter of debate. The concern regarding retinal toxicity rather than proper efficacy data is the one that dictated the daily dosage of ⩽5 mg/kg/day actual body weight currently agreed upon.

Update on antimalarials and systemic lupus erythematosus

PURPOSE OF REVIEW

The purpose of this review is highlighting the most recent evidence on the clinical efficacy and toxicity of antimalarials in systemic lupus erythematosus (SLE).

RECENT FINDINGS

New data confirm the effects of antimalarials in preventing SLE activity, damage and infections and in decreasing mortality. An important reduction in use of health resources is related to continued antimalarial use. Hydroxychloroquine (HCQ) may prevent preeclampsia in pregnant women with SLE. HCQ ocular toxicity is infrequent and could be associated with blood levels. Gastrointestinal and skin toxicity are underrecognized and could influence adherence. Prolongation of QT interval is extremely unusual with HCQ. Doses of HCQ of 200 mg/day seem to offer a good efficacy/toxicity balance. HCQ protection against herpes zoster and Pneumocystis jirovecii infection has been shown. On the contrary, HCQ prescription by doctors and adherence by patients are both under recommended standards. The recent coronavirus disease 2019 pandemic has resulted in a significant shortage of HCQ in many countries with possible consequences in the correct treatment of lupus patients.

SUMMARY

Recent evidence reinforces the central role of HCQ in SLE therapy. The reduction in activity, damage accrual and mortality is consistent across studies, countries and ethnical groups. On the contrary, and despite the well established beneficial effects of prolonged regular HCQ therapy, many SLE patients do never take this drug or it is eventually stopped in the setting of severe flares, pregnancy or presumed toxicity. Every effort must be made to assure the correct prescription of HCQ and not to withdraw the drug unless unequivocal signs of toxicity are present.