Hydroxychloroquine Blood Levels Predict Hydroxychloroquine Retinopathy

Recent findings about antimalarials in cutaneous lupus erythematosus: What dermatologists should know

Antimalarials (AMs), particularly hydroxychloroquine (HCQ) and chloroquine (CQ), are the cornerstone of the treatment for both systemic lupus erythematosus (SLE) and cutaneous lupus erythematosus (CLE). HCQ and CQ are recommended as first-line oral agents in all CLE guidelines. Initially thought to have potential therapeutic effects against COVID-19, HCQ has drawn significant attention in recent years, highlighting concerns over its potential toxicity among patients and physicians. This review aims to consolidate current evidence on the efficacy of AMs in CLE. Our focus will be on optimizing therapeutic strategies, such as switching from HCQ to CQ, adding quinacrine to either HCQ or CQ, or adjusting HCQ dose based on blood concentration. Additionally, we will explore the potential for HCQ dose reduction or discontinuation in cases of CLE or SLE remission. Our review will focus on the existing evidence regarding adverse events linked to AM usage, with a specific emphasis on severe events and those of particular interest to dermatologists. Last, we will discuss the optimal HCQ dose and the balance between preventing CLE or SLE flares and minimizing toxicity.

Assessment of hydroxychloroquine blood levels in Sjögren's disease patients: drug adherence and clinical associations

Hydroxychloroquine (HCQ) has been used to treat Sjögren's disease (SjD) patients. However, there are no studies evaluating drug adherence through HCQ blood levels, pharmacy refill (PR) and medication adherence questionnaires. The relationship of HCQ blood levels with glandular/extraglandular disease parameters was also poorly assessed. This cross-sectional observational study included 74 adult SjD patients, who were receiving a stable HCQ dose (4-5.5 mg/kg/day, actual weight) for at least 3 months before study inclusion. HCQ blood levels were quantified by high-performance liquid chromatography coupled to mass spectrometry. Adherence was assessed by PR and Medida de Adesão aos Tratamentos (MAT) questionnaire. The following parameters were evaluated: Xerostomia Inventory, Ocular Surface Disease Index, EULAR (European League Against Rheumatism) Sjögren's Syndrome Disease Activity Index, EULAR Sjögren's Syndrome Patient Reported Index, Schirmer's I test and non-stimulated/stimulated salivary flow rates. HCQ blood levels were 775.3(25.0-2,568.6)ng/mL. Eleven patients (14.9%) had HCQ blood levels < 200ng/mL (non-adherent group); 11(14.9%), 200-499ng/mL (sub-therapeutic levels group); and 52(70.2%), ≥ 500ng/mL (adherent group). PR classified incorrectly all non-adherent/sub-therapeutic patients and 2/52(3.9%) adherent patients. Using MAT, the overall misclassification was 24/52(46.2%) in the adherent group, and were correctly identified 9/11(81.8%) patients in non-adherent and 7/11(63.6%) in sub-therapeutic groups. MAT sensitivity and specificity to identify non-adherent/sub-therapeutic patients were 72.7% and 53.9%, respectively. The three groups were comparable regarding glandular/extraglandular disease parameters (p > 0.05). The assessment of HCQ blood levels is a promising tool for evaluating drug adherence in SjD. This is particularly crucial as one-third of patients exhibited non-adherence/sub-therapeutic levels, and neither PR nor MAT reliably identified these patients.

Identification of new risk factors for hydroxychloroquine and chloroquine retinopathy in systemic lupus erythematosus patients

BACKGROUND

Long-term hydroxychloroquine (HCQ) or chloroquine (CQ) intake causes retinal toxicity in 0.3-8 % of patients with rheumatic diseases. Numerous risk factors have been described, eg, daily dose by weight, treatment duration, chronic kidney disease, concurrent tamoxifen therapy and pre-existing retinal or macular disease. However, those factors cannot explain the entire risk of developing antimalarial retinopathy.

OBJECTIVE

This study was undertaken to identify new risk factors associated with HCQ or CQ retinopathy (QRNP) in systemic lupus erythematosus (SLE) patients.

METHODS

This case-control (1:2) study compared SLE patients with QRNP (cases) to those without (controls). Controls were matched for sex and known QRNP risk factors: HCQ and/or CQ treatment duration (±1 year) and age (±5 year) at SLE diagnosis.

RESULTS

Forty-eight cases were compared to 96 SLE controls. Multivariable logistic-regression analysis retained the following as independent determinants significantly associated with QRNP: concomitant selective serotonin-reuptake inhibitor (SSRI) or serotonin- and norepinephrine-reuptake inhibitor (SNRI) intake (OR [95 % confidence interval] 6.6 [1.2 to 40.9]; p < 0.01); antiphospholipid syndrome (OR=8.9 [2.2 to 41.4] p < 0.01); blood hydroxychloroquine/desethylchloroquine concentration ([HCQ]/[DCQ]) ratio <7.2 (OR 8.4 [2.7 to 30.8]; p < 0.01) or skin phototype ≥4 (OR 5.5 [1.4 to 26.5]; p = 0.02), but not daily HCQ dose, blood [HCQ] or body mass index.

CONCLUSION

The results of this case-control study identified blood [HCQ]/[DCQ] ratio, concurrent SSRI/SNRI therapy, skin phototype ≥4 and antiphospholipid syndrome as new risk factors for QRNP.

Multidisciplinary consensus on the use of hydroxychloroquine in patients with systemic lupus erythematosus

BACKGROUND

Hydroxychloroquine (HCQ) is the first-line treatment for systemic lupus erythematosus (SLE); however, there is heterogeneity in its clinical use. This consensus aims to bridge the gap in SLE treatment by providing practical and valuable recommendations for health professionals.

METHODS

The methodology used is based on a systematic literature review and a nominal group technique (NGT). A ten-member scientific committee formulated eight clinically relevant questions. First, a systematic review was conducted to identify the available evidence, which the scientific committee evaluated to developed recommendations based on their expertise, achieving consensus through NGT.

RESULTS

1673 titles and abstracts were screened, and 43 studies were included for meeting the inclusion criteria. The scientific committee established 11 recommendations for HCQ use in initiation, maintenance, and monitoring, considering benefits and potential adverse effects of HCQ. Unanimous agreement was achieved on all recommendations.

CONCLUSIONS

The available evidence supports HCQ's effectiveness and safety for SLE. Individualized assessment of the initial HCQ dose is important, especially in situations requiring dose reduction or discontinuation. This risk-benefit assessment, specifically focusing on the balance between retinal toxicity and the risk of SLE relapse, should guide decisions regarding medication withdrawal, considering disease activity, risk factors, and HCQ potential benefits. Close monitoring is essential for optimal disease management and minimize potential risks, such as QT prolongation or retinal toxicity.

Management of systemic lupus erythematosus: a systematic literature review informing the 2023 update of the EULAR recommendations

OBJECTIVES

To analyse the new evidence (2018-2022) for the management of systemic lupus erythematosus (SLE) to inform the 2023 update of the European League Against Rheumatism (EULAR) recommendations.

METHODS

Systematic literature reviews were performed in the Medline and the Cochrane Library databases capturing publications from 1 January 2018 through 31 December 2022, according to the EULAR standardised operating procedures. The research questions focused on five different domains, namely the benefit/harm of SLE treatments, the benefits from the attainment of remission/low disease activity, the risk/benefit from treatment tapering/withdrawal, the management of SLE with antiphospholipid syndrome and the safety of immunisations against varicella zoster virus and SARS-CoV2 infection. A Population, Intervention, Comparison and Outcome framework was used to develop search strings for each research topic.

RESULTS

We identified 439 relevant articles, the majority being observational studies of low or moderate quality. High-quality randomised controlled trials (RCTs) documented the efficacy of the type 1 interferon receptor inhibitor, anifrolumab, in non-renal SLE, and belimumab and voclosporin, a novel calcineurin inhibitor, in lupus nephritis (LN), when compared with standard of care. For the treatment of specific organ manifestations outside LN, a lack of high-quality data was documented. Multiple observational studies confirmed the beneficial effects of attaining clinical remission or low disease activity, reducing the risk for multiple adverse outcomes. Two randomised trials with some concerns regarding risk of bias found higher rates of relapse in patients who discontinued glucocorticoids (GC) or immunosuppressants in SLE and LN, respectively, yet observational cohort studies suggest that treatment withdrawal might be feasible in a subset of patients.

CONCLUSION

Anifrolumab and belimumab achieve better disease control than standard of care in extrarenal SLE, while combination therapies with belimumab and voclosporin attained higher response rates in high-quality RCTs in LN. Remission and low disease activity are associated with favourable long-term outcomes. In patients achieving these targets, GC and immunosuppressive therapy may gradually be tapered. Cite Now.

Clinical features of ocular damage in systemic lupus erythematosus and risk factors for hydroxychloroquine-related complications

Ocular damage in systemic lupus erythematosus (SLE) may cause insidious visual impairment, but its clinical features and the risk of hydroxychloroquine (HCQ)-related complications are still controversial. We performed a meta-analysis to evaluate ocular damage in SLE, the correlation between eye and systemic involvement, and the ocular side effects of treatment. The database PubMed, Embase, and Ovid were used for literature from reception to July, 2023, and the calculation was carried out with R. About 48,693 patients from 66 studies were included. The results indicated that ocular damage in SLE was insidious, appearing in 28 % of patients with no complaints. The most common symptoms and manifestations were dry eye (30 %) and keratoconjunctivitis sicca (26 %). Retinopathy was detected in 10 % of patients and was related to antiphospholipid antibodies (25 % versus 8 %). The proportion of retinopathy also significantly increased in patients with lupus nephropathy or neuropsychiatric systemic lupus erythematosus (risk ratio of 2.29 and 1.95, respectively). HCQ was used in 82 % of patients, of which 4 % suffered from ocular toxicity. HCQ-related retinopathy was dose-dependent. Dosage below 5 mg/kg/d was relatively effective and safe for long-term use, while routine examination was recommended.

Advancements on the impact of hydroxychloroquine in systemic lupus erythematosus

Hydroxychloroquine (HCQ) has gained significant attention as a therapeutic option for systemic lupus erythematosus (SLE) because of its multifaceted mechanism of action. It is a lipophilic, lysosomotropic drug, that easily traverses cell membranes and accumulates in lysosomes. Once accumulated, HCQ alkalizes lysosomes within the cytoplasm, thereby disrupting their function and interfering with processes like antigen presentation. Additionally, HCQ has shown potential in modulating T-cell responses, inhibiting cytokine production, and influencing Toll-like receptor signaling. Its immunomodulatory effects have generated interest in its application for autoimmune disorders. Despite its established efficacy, uncertainties persist regarding the optimal therapeutic concentrations and their correlation with adverse effects such as retinal toxicity. Therefore, standardized dosing and monitoring guidelines are crucial. In this study, we provide a comprehensive review of the mechanisms, efficacy, dosing variations, and retinal toxicity profiles of HCQ, which are essential to optimize SLE treatment protocols and ensure patient safety.

Skin and ophthalmic complications of chloroquine and hydroxychloroquine in patients with rheumatoid arthritis and systemic lupus erythematous

Immunosuppressive agents are routinely used to control autoimmunity. However, some adverse events are correlated to their clinical applications. The aim of this study was to study the clinical findings and ocular and cutaneous side effects of chloroquine (CQ) and hydroxychloroquine (HCQ), as current immunomodulators, in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). This descriptive study was performed on 360 individuals referred to the Rheumatology clinic during 2003-2020. Demographic characteristics and other information were collected from patients with RA and SLE. Skin and ocular complications were evaluated in patients who were on treatment with CQ and HCQ. Study populations consisted of 199 subjects with RA and 161 cases with SLE. The frequencies of skin and ocular complications in all patients treated with CQ and HCQ were 32 (17.65%) and 94 (51.9%), respectively. The prevalence of skin complications in patients with RA and SLE was 20 (10.05%) and 22 (13.66%), respectively. The frequencies of ocular complications in patients with RA and SLE were, respectively, 58 (29.4%) and 36 (22.5%). Multiple logistic regression analysis revealed that ophthalmic complications of CQ and HCQ in all patients were dependent on the effects of the duration of drug uses, disease duration, and cumulative doses (p < 0.05), unlike skin complications. Disease types had no effect on ocular complications. Based on these findings, treatment with CQ and HCQ participates in some skin and ocular complications in patients with RA and SLE which are largely associated with the duration of disease and treatment.

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.

Factors associated with early hydroxychloroquine-induced retinal toxicity in patients with systemic lupus erythematosus

PURPOSE

Hydroxychloroquine is currently recommended for the treatment of systemic lupus erythematosus (SLE), but it can cause irreversible retinal toxicity. This study aimed to identify factors associated with early hydroxychloroquine-induced retinal toxicity in patients with SLE from a single centre for 20 years.

METHODS

SLE patients diagnosed between 1998 and 2017 and followed up for at least 1 year were included. Demographic, clinical, laboratory and therapeutic data were collected from the electronic medical records and retrospectively analysed. Early hydroxychloroquine-induced retinal toxicity was defined as the development of macular toxicity within the first 5 years of hydroxychloroquine treatment.

RESULTS

A total of 345 patients followed for a median of 15 years were analysed; 337 (97.7%) patients received hydroxychloroquine, 38 (11.3%) of them presented with retinal toxicity, and 10 (3%) developed early retinal toxicity. These patients had a mean treatment duration of 3.3 years with a mean cumulative dose of 241 g. Patients were diagnosed by visual field (VF) and fundoscopy, and two were also assessed using spectral domain optical coherence tomography (SD-OCT). The median (IQR) age of patients with early toxicity was 56 (51-66) years, and 80% were female. Factors independently associated with early hydroxychloroquine-induced retinal toxicity were lupus anticoagulant positivity (OR 4.2; 95% CI 1.2-15.5) and hypercholesterolaemia (OR 5.6; 95% CI 1.5-21.5).

CONCLUSION

Our results suggest that lupus anticoagulant positivity and hypercholesterolaemia among SLE patients may be risk factors for early hydroxychloroquine-induced retinal toxicity, regardless of the dose or duration of treatment.

Balancing risks and benefits in the use of hydroxychloroquine and glucocorticoids in systemic lupus erythematosus

INTRODUCTION

Hydroxychloroquine (HCQ) and glucocorticoids (GCs) constitute the oldest and more used drugs in the treatment of systemic lupus erythematosus (SLE). Despite this long experience, both are still subject to a number of uncertainties, mainly regarding the dose.

AREAS COVERED

We review the main mechanisms of action, the clinical and toxic effects of HCQ and GCs and analyze the recommendations for the use of both in guidelines published since 2018. We offer a set of recommendations based on the pharmacology, mechanisms of action and clinical evidence.

EXPERT OPINION

HCQ is the backbone therapy for SLE, and a judicious use must be accomplished, using doses that allow a good control of lupus without compromising the safety of treatments very much prolonged over the time. Stable doses of 200 mg/day seem to accomplish both conditions. GCs should be used more judiciously, with methyl-prednisolone pulses as the main therapy for inducing rapid remission and doses ≤5-2.5 mg/day be never exceeded in long-term maintenance treatments.

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.

Reference Range of Hydroxychloroquine Blood Levels That Can Reduce Odds of Active Lupus and Prevent Flares

OBJECTIVE

Recent data show that lower hydroxychloroquine (HCQ) doses are associated with a two- to six-fold higher risk of lupus flares. Thus, establishing an effective reference range of HCQ blood levels with upper and lower bounds for efficacy may support individualizing HCQ dosing to prevent flares.

METHODS

HCQ levels in whole blood and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) were measured during the baseline visit and again during a standard of care routine follow-up visit. Active cross-sectional lupus at baseline was defined as SLEDAI ≥6; a within subject flare was defined as a subsequent three-point increase in SLEDAI with clinical symptoms requiring therapy change. We examined associations between active lupus and HCQ blood levels at baseline and flares and HCQ levels during 6 to 12-month routine lupus follow-up visits using mixed regression analysis.

RESULTS

Among 158 baseline patient visits, 19% had active lupus. Odds of active lupus were 71% lower in patients with levels within a 750 to 1,200 ng/mL range (adjusted odds ratio 0.29, 95% confidence interval 0.08-0.96). Using convenience sampling strategy during a pandemic, we longitudinally followed 42 patients. Among those patients, 17% flared during their follow-up visit. Maintaining HCQ levels within 750 to 1,200 ng/mL reduced the odds of a flare by 26% over a nine-month median follow-up.

CONCLUSION

An effective reference range of HCQ blood levels, 750 to 1,200 ng/mL, was associated with 71% lower odds of active lupus, and maintaining levels within this range reduced odds of flares by 26%. These findings could guide clinicians to individualize HCQ doses to maintain HCQ levels within this range to maximize efficacy.

Evaluation of early retinal changes in patients on long-term hydroxychloroquine using optical coherence tomography angiography

Background

Connective tissue diseases (CTD), including systemic lupus erythematosus and rheumatoid arthritis (RA), have long been treated with hydroxychloroquine (HCQ). However, prolonged HCQ use poses a risk of adverse effects, particularly retinopathy.

Objective

To detect early retinal changes assessed by optical coherence tomography angiography (OCTA) in CTD patients with long-term HCQ treatment and to explore the relationship between OCTA parameters and the concentrations of HCQ and its metabolites.

Design

A cross-sectional study conducted from March 2020 to October 2021 at the First Affiliated Hospital of Anhui Medical University.

Methods

The area and perimeter of the foveal avascular zone (FAZ), the thickness of the fovea and parafovea, and the vascular density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in each area of the macula were measured by OCTA in 43 CTD patients treated with HCQ for over 6 months. Meantime, blood concentrations of HCQ and its metabolites were determined by high-performance liquid chromatography-tandem mass spectrometry, and the clinical documents of all 43 involved patients were collected.

Results

There is no significant correlation between OCTA outcomes and the patient's age, disease duration, and weight-dependent dose. HCQ cumulative duration positively correlated with FAZ area and perimeter (r = 0.419, p = 0.005 and r = 0.407, p = 0.007, respectively) and negatively correlated with the foveal vessel density in DCP (r = -0.378, p = 0.012). HCQ cumulative dose had a positive correlation with FAZ area and perimeter (r = 0.445, p = 0.003 and r = 0.434, p = 0.004, respectively) and had a negative correlation with foveal vessel density in SCP and DCP (r = -0.383, p = 0.011 and r = -0.424, p = 0.005, respectively). OCTA outcomes did not correlate with HCQ and its metabolite concentrations.

Conclusion

OCTA could be used to detect microvascular changes in the macula of CTD patients with long-term HCQ therapy. It was not found the concentrations of HCQ and its metabolites were associated with retinal vascular changes.

Therapeutic Drug Monitoring in Patients with Systemic Lupus Erythematosus: Utility and Gaps

Despite advances in the treatment of patients with systemic lupus erythematous (SLE), outcomes have remained suboptimal. Persistent disease activity, patient comorbidities and drug toxicities contribute to the accrual of progressive irreversible damage and high rates of morbidity and mortality. Currently, similar drug doses and regimens are promulgated in the treatment guidelines for all SLE patients, despite the vast differences in patient and environmental factors that affect the drugs' metabolism and blood concentrations. This causes a disconnect between drug dosing and drug blood concentrations, which can then result in unpredictability in drug toxicities and therapeutic effects. In this review, we discuss commonly used oral immunosuppressive medications in SLE, their pharmacogenomics, and factors affecting their metabolism and blood concentrations. Further, we highlight the role of therapeutic drug monitoring in SLE, which is the first accessible step to individualising therapy.

Cutaneous Lupus Erythematosus: Review and Considerations for Older Populations

Though more common earlier in life, increasing attention is being focused on the development of cutaneous lupus erythematosus (CLE) in patients with advancing age. Studies show that CLE is more common in older populations than previously thought, and all CLE subtypes are possible in this group. Just like patients in the third or fourth decade of life, CLE may appear alongside or independent of systemic lupus erythematosus. Older populations manifesting CLE for the first time seem to have a lower risk of progression to systemic disease than younger peers, and are more commonly White. CLE must be carefully distinguished from other skin conditions that have a predilection for presentation in older populations, including rosacea, lichen planus, and other autoimmune conditions such as dermatomyositis or pemphigus/pemphigoid. It is thought that most CLE in older populations is drug-induced, with drug-induced subacute cutaneous lupus erythematosus being the most common subtype. Management of CLE in older patients focuses on eliminating unnecessary medications known to induce CLE, and otherwise treatment proceeds similarly to that in younger patients, with a few special considerations.

Genotype-guided new approach for dose optimisation of hydroxychloroquine administration in Chinese patients with SLE

OBJECTIVES

The study aims to investigate the impact of gene polymorphisms on blood hydroxychloroquine (HCQ) concentrations in patients with SLE and provide guidelines for individualised care.

METHODS

489 Chinese patients with SLE taking HCQ for more than 3 months were collected in this study. The blood HCQ, desethylhydroxychloroquine (DHCQ) and desethylchloroquine concentrations were measured. The optimal blood concentration of HCQ was determined by receiver operating characteristic curve analysis. Single nucleotide polymorphisms of metabolic enzymes involved in HCQ metabolism were genotyped and the associations with treatment effects were investigated.

RESULTS

The cut-off value of HCQ was 559.67 ng/mL, with sensitivity and specificity values of 0.51 and 0.89, respectively. The TC and CC genotypes of CYP2C8 (rs7910936) were significantly related to the increase in blood HCQ concentrations, and the CYP2C8 (rs10882521) TT genotype was associated with lower blood HCQ concentrations. The DHCQ:HCQ ratio was highest in patients with the GG genotype of the CYP2D6*10 (rs1065852) polymorphism and lowest in those with the AA genotype. Patients with the CYP2C8 (rs7910936) CC genotype were more likely to achieve the optimal blood concentration (p=0.030) in HCQ 200 mg/day group and patients with the CYP2D6*10 (rs1065852) GG genotype were more likely to reach the optimal blood concentration (p=0.049) in 400 mg/day group.

CONCLUSIONS

Our results suggest that the optimal blood concentration of HCQ measured approximately 12-18 hours after the last dosage may be between 500 and 600 ng/mL in Chinese patients with SLE. The observed variations in HCQ concentrations between individuals can potentially be attributed to genetic polymorphisms in CYP2D6*10 (rs1065852) and CYP2C8 (rs7910936 and rs10882521). Genotypical testing of patients and regular monitoring of blood levels are recommended for optimising HCQ dosage management in Chinese patients with SLE.

TRIAL REGISTRATION NUMBER

ChiCTR2300070628.

Hydroxychloroquine in nephrology: current status and future directions

Hydroxychloroquine is one of the oldest disease-modifying anti-rheumatic drugs in clinical use. The drug interferes with lysosomal activity and antigen presentation, inhibits autophagy, and decreases transcription of pro-inflammatory cytokines. Owing to its immunomodulatory, anti-inflammatory, anti-thrombotic effect, hydroxychloroquine has been an integral part of therapy for systemic lupus erythematosus and lupus nephritis for several decades. The therapeutic versatility of hydroxychloroquine has led to repurposing it for other clinical conditions, with recent studies showing reduction in proteinuria in IgA nephropathy. Research is also underway to investigate the efficacy of hydroxychloroquine in primary membranous nephropathy, Alport's syndrome, systemic vasculitis, anti-GBM disease, acute kidney injury and for cardiovascular risk reduction in chronic kidney disease. Hydroxychloroquine is well-tolerated, inexpensive, and widely available and therefore, should its indications expand in the future, it would certainly be welcomed. However, clinicians should be aware of the risk of irreversible and progressive retinal toxicity and rarely, cardiomyopathy. Monitoring hydroxychloroquine levels in blood appears to be a promising tool to evaluate compliance, individualize the dose and reduce the risk of retinal toxicity, although this is not yet standard clinical practice. In this review, we discuss the existing knowledge regarding the mechanism of action of hydroxychloroquine, its utility in lupus nephritis and other kidney diseases, the main adverse effects and the evidence gaps that need to be addressed in future research. Created with Biorender.com. HCQ, hydroxychloroquine; GBM, glomerular basement membrane; mDC, myeloid dendritic cell; MHC, major histocompatibility complex; TLR, toll-like receptor.

Pharmacokinetics of hydroxychloroquine in Japanese systemic lupus erythematosus patients with renal impairment

OBJECTIVES

Reduction of the hydroxychloroquine (HCQ) dosage is recommended in systemic lupus erythematosus (SLE) patients with renal impairment, but a pharmacokinetics (PK) study of patients with renal impairment has not yet been performed.

METHODS

We investigated the PK of both single and multiple doses of HCQ and its metabolites in SLE patients with renal impairment who newly started HCQ at a daily dose of 300 mg based on an ideal body weight dosage of 6.5 mg/kg. Population PK analysis was performed using a non-linear mixed-effects model.

RESULTS

In total, 219 samples from 21 patients were analysed. The PK of HCQ in blood after single and multiple oral administrations followed the two-compartment model. At steady state, the concentration ratio of HCQ to each metabolite was HCQ:desethylhydroxychloroquine:desethylchloroquine:bisdesethylchloroquine = 1:0.28:0.1:0.06. The HCQ concentration correlated positively with that of each metabolite. The estimated values (relative standard error) of the population PK parameters were the total clearance at 110 l/h (31%) and a central volume of distribution of 398 l (19%). Co-administration of prednisolone and age, but not renal impairment, were factors affecting the total clearance of HCQ.

CONCLUSIONS

From the PK perspective, a dosage reduction is unnecessary in SLE patients with impaired renal function.

Unmet needs and future perspectives in hydroxychloroquine retinopathy

Retinopathy is a well-recognized toxic effect of hydroxychloroquine treatment. As hydroxychloroquine retinopathy is potentially a vision-threatening condition, early detection is imperative to minimize vision loss due to drug toxicity. However, early detection of hydroxychloroquine retinopathy is still challenging even with modern retinal imaging techniques. No treatment has been established for this condition, except for drug cessation to minimize further damage. In this perspective article, we aimed to summarize the knowledge gaps and unmet needs in current clinical practice and research in hydroxychloroquine retinopathy. The information presented in this article may help guide the future directions of screening practices and research in hydroxychloroquine retinopathy.

Hydroxychloroquine-induced Retinal Toxicity

Long-term use of hydroxychloroquine can cause retinopathy, which may result in severe and progressive visual loss. In the past decade, hydroxychloroquine use has markedly increased and modern retinal imaging techniques have enabled the detection of early, pre-symptomatic disease. As a consequence, the prevalence of retinal toxicity in long-term hydroxychloroquine users is known to be higher than was previously estimated. The pathophysiology of the retinopathy is incompletely characterised, although significant advances have been made in understanding the disease from clinical imaging studies. Hydroxychloroquine retinopathy elicits sufficient public health concern to justify the implementation of retinopathy screening programs for patients at risk. Here, we describe the historical background of hydroxychloroquine retinopathy and summarize its current understanding. We review the utility and limitations of each of the mainstream diagnostic tests used to detect hydroxychloroquine retinopathy. The key considerations towards a consensus on the definition of hydroxychloroquine retinopathy are outlined in the context of what is known of the natural history of the disease. We compare the current screening recommendations for hydroxychloroquine retinopathy, identifying where additional evidence is required, and the management of proven cases of toxicity. Finally, we highlight the areas for further investigation, which may further reduce the risk of visual loss in hydroxychloroquine users.

Low estimated glomerular filtration rate is an independent risk factor for higher hydroxychloroquine concentration

BACKGROUND

The aim of this study was to analyze the relationship of the estimated glomerular filtration rate (eGFR) to hydroxychloroquine (HCQ) blood concentrations in systemic lupus erythematosus (SLE) patients.

METHOD

Patients with SLE who had been taking HCQ for more than 12 months were recruited. All subjects gave written informed consent. Various clinical characteristics and laboratory values were examined. The blood concentration of HCQ was measured by high-performance liquid chromatography, and the relationship of eGFR to HCQ blood concentration was mainly investigated.

RESULT

In total, 115 patients with SLE receiving long-term HCQ therapy were included in the study. The median concentration of HCQ was 1096 ng/ml (range 116-8240 ng/ml). The eGFR was strongly associated with blood concentration of HCQ (P = 0.011, P < 0.05), when adjusted for age, sex, body mass index (BMI), weight-adjusted dose, prednisone use and immunosuppressive drug use. No statistically significant association were found between age, duration, BMI, weight-adjusted HCQ dose, corticosteroid use, immunosuppressant use and blood concentrations of HCQ.

CONCLUSION

We provided novel evidence that impaired renal function influenced the blood concentration of HCQ. Patients with low eGFR need to adjust the HCQ dosage according to the monitoring results of HCQ blood concentrations.

How toxic is an old friend? A review of the safety of hydroxychloroquine in clinical practice

Hydroxychloroquine (HCQ) and its close relative chloroquine (CQ) were initially used as antimalarial agents but are now widely prescribed in rheumatology, dermatology and immunology for the management of autoimmune diseases. HCQ is considered to have a better long-term safety profile than CQ and is therefore more commonly used. HCQ has a key role in the treatment of connective tissue diseases including systemic lupus erythematosus (SLE), where it provides beneficial immunomodulation without clinically significant immunosuppression. HCQ can also assist in managing inflammatory arthritis, including rheumatoid arthritis (RA). Debate around toxicity of HCQ in COVID-19 has challenged those who regularly prescribe HCQ to discuss its potential toxicities. Accordingly, we have reviewed the adverse effect profile of HCQ to provide guidance about this therapeutic agent in clinical practice.

Systemic Lupus Erythematosus May Be a Risk Factor for Antimalarial-Induced Retinopathy Compared With Other Rheumatologic Diseases

OBJECTIVE

To describe the pattern and risk factors for antimalarial (AM)-induced retinopathy in patients with rheumatic diseases.

METHODS

A retrospective chart review was conducted at an urban Canadian center for patients with AM use of more than 3 months and documented retinopathy screening. Univariate and multivariate regression analyses were performed to determine risk factors for retinopathy. Sensitivity analyses included stratification of analysis by method of screening and by hydroxychloroquine (HCQ) versus chloroquine (CQ).

RESULTS

A total of 613 patients were included in the final analysis, with systemic lupus erythematosus (SLE) (n = 259) as the most common diagnosis. Definite AM-induced retinal toxicity was observed in 12 patients, 11 of whom had SLE. The earliest diagnosis of toxicity occurred after 5.4 years of AM therapy, and the prevalence beyond 5 years was 3.1%. In univariate analysis, a diagnosis of SLE (P = 0.009; odds ratio [OR]: 15.66; 95% confidence interval [CI]: 2.01-122.05), the daily weight-based dose of HCQ (P = 0.044; OR: 1.49; 95% CI: 1.01-2.20), cumulative CQ dose (P = 0.014; OR: 4.80; CI: 1.37-16.84), and daily CQ weight-based dose (P = 0.0001; OR: 5.70; 95% CI: 2.41-13.49) were significantly associated with toxicity. In multivariate analysis, diagnosis of SLE (P = 0.022; OR: 12.14; 95% CI: 1.44-102.44) and daily CQ weight-based dose (P = 0.005; OR: 1.83; 95% CI: 1.83-26.75) were significant after adjusting for standard covariates.

CONCLUSION

The risk of AM-induced retinopathy increases after 5 years of therapy. There may be higher rates of toxicity in patients with SLE because of longer duration of treatment, higher weight-based dosages, and more CQ use in this population, and SLE may be an independent risk factor.

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.

Systemic Lupus Erythematosus: New Diagnostic and Therapeutic Approaches

Systemic lupus erythematosus (SLE) is a devastating autoimmune disease that can result in substantial morbidity and mortality. Diagnosis and treatment of SLE are clinical challenges. Patient presentation and response to therapy are heterogeneous because of the complex immune dysregulation that results in SLE disease pathogenesis. An intricate interplay between genetic risk and skewing of adaptive and innate immune system responses leads to overproduction of type I interferons and other cytokines, complement activation, immune-complex deposition, and ultimately inflammation and tissue damage. Here, we review the classification criteria as well as standard and emerging diagnostic tools available to identify patients with SLE. We then focus on medical management, including novel therapeutics, nonpharmacologic interventions, and comorbidity management.

Characteristics and Potential Risk Factors of Hydroxychloroquine Retinopathy in Patients with Systemic Lupus Erythematosus: Focusing on Asian Population

Purpose: Hydroxychloroquine (HCQ) would cause irreversible retinal damage, despite its pivotal role in treatment of systemic lupus erythematosus (SLE). This study aims to reassess the characteristics and risk factors of HCQ retinopathy. Methods: This study included patients with SLE who had used HCQ for >5 years and received ophthalmologic examinations during November 2017 to December 2020 in a tertiary hospital in Taiwan. Spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) were performed in all patients. Visual field assessment and/or multifocal electroretinography were done if suspicious findings were noted by SD-OCT or FAF. Clinical features and dosing details of HCQ were recorded by chart review. Results: Ninety-two patients were included, with the median duration of drug exposure of 11.2 years [interquartile range (IQR) 9.4-12.7 years], median daily dose of 6.9 mg/kg (IQR 6.1-7.7 mg/kg), and cumulative dose of 1,503.6 g (IQR 1,257.7-1,805.9 g). HCQ retinopathy was diagnosed in 10.9% of patients (10 of 92), and in 20.8% of patients (5 of 24) who complained about blurred vision. High myopia [odds ratio (OR) 5.03; 95% confidence interval (CI) 1.29-24.79; P = 0.03] and lower body weight (OR 0.88; 95% CI 0.78-0.97; P = 0.03) were significantly associated with HCQ retinopathy. Conclusions: Long-term HCQ users may suffer from retinal toxicity. Since there is no optimal substitute for HCQ, careful retinal evaluation is needed to avoid unnecessary drug discontinuation. In addition, an association between high myopia and HCQ retinopathy was noted. More investigation is needed to clarify this association.

Machine Learning-Based Automated Detection of Hydroxychloroquine Toxicity and Prediction of Future Toxicity Using Higher-Order OCT Biomarkers

OBJECTIVE

Despite guidelines for hydroxychloroquine (HCQ) toxicity screening, there are clear challenges to accurate detection and interpretation. In the current report, the feasibility of automated machine learning (ML)-based detection of HCQ retinopathy and prediction of progression to toxicity in eyes without preexisting toxicity has been described.

DESIGN

Retrospective, longitudinal cohort study.

SUBJECTS

Subjects on HCQ therapy.

METHODS

This was an institutional review board-approved, retrospective, longitudinal image analysis of 388 subjects on HCQ. Multilayer, compartmental, retinal segmentation with ellipsoid zone (EZ) mapping was used to harvest quantitative spectral-domain (SD)-OCT biomarkers. Using a combination of clinical features (i.e., cumulative HCQ dose and the duration of therapy) and quantitative imaging biomarkers (e.g., volumetric EZ integrity and compartmental measurements), ML models were created to detect toxicity and predict progression based on ground-truth OCT-based toxicity readings by 2 masked retina specialists. Furthermore, 10-fold cross-validation was performed.

MAIN OUTCOME MEASURES

The model performance was visualized using receiver operator curves and calculating the area under the curve (AUC). The corresponding sensitivity and specificity values were evaluated for the feasibility of HCQ toxicity screening and prediction.

RESULTS

The prevalence of HCQ toxicity in this cohort of 388 patients was 9.8% (n = 38). Twenty-one eyes progressed to toxicity during follow-up. OCT-based features (i.e., partial EZ attenuation, EZ volume, outer nuclear layer volume, and compartmental thicknesses) and clinical features (i.e., HCQ daily dose, HCQ cumulative dose, and duration of therapy) showed significant differences between the toxic and nontoxic groups. Percentage area with partial EZ attenuation (i.e., percentage of the macula with an EZ-retinal pigment epithelium thickness of ≤ 20 μm) was the most discriminating single feature (toxic, 35.7 ± 46.5%; nontoxic, 1.8 ± 4.4%; P < 0.0001). Using a random forest model, high-performance, automated toxicity detection was achieved, with a mean AUC of 0.97, sensitivity of 95%, and specificity of 91%. Furthermore, the toxicity progression prediction model had a mean AUC of 0.89, with a sensitivity and specificity of 90% and 80%, respectively.

CONCLUSIONS

This report described the feasibility of high-performance automated classification models that used a combination of clinical and quantitative SD-OCT biomarkers to detect HCQ retinal toxicity and predict progression to toxicity in cases without toxicity. Future work is needed to validate these findings in an independent dataset.

Prescribing Patterns of Hydroxychloroquine and Glucocorticoids Among Lupus Patients After New-Onset End-Stage Renal Disease

OBJECTIVE

Optimal strategies for managing lupus medications after end-stage renal disease (ESRD) have not been addressed. The objective was to identify the current US-wide prescribing patterns of hydroxychloroquine (HCQ) and oral glucocorticoids (GS) among systemic lupus erythematosus (SLE) patients with incident ESRD enrolled in the US Renal Data System (USRDS) registry.

METHODS

We identified incident ESRD patients age ≥18 years with SLE as a primary cause of ESRD between January 2006 and June 2013. Patients who were started on dialysis at ESRD onset and enrolled in Medicare Part D within 93 days as required by Medicare were included.

RESULTS

Among the 2,654 new-onset ESRD patients with Part D, the median duration of follow-up was 761 days (interquartile range [IQR] 374-1,375). At baseline, 1,076 patients (41%) were not receiving HCQ or GS, 220 (8%) were prescribed HCQ alone, 509 (19%) were prescribed both HCQ and GS, and 849 (32%) were prescribed GS alone. Of the 1,983 patients who either never received or discontinued HCQ after ESRD onset, 667 (34%) continued GS to the end of the follow-up period. The median GS dose was lower for patients taking HCQ (14 mg [IQR 9-21]) compared to patients who were never prescribed HCQ (15 mg [IQR 9-27]) or patients who discontinued HCQ after ESRD (17 mg [IQR 10-27]; P = 0.001).

CONCLUSION

Approximately one-third of patients with lupus nephritis and new-onset ESRD received GS monotherapy at high doses. As GS-related complications contribute to hospitalizations and deaths in SLE ESRD, changing these prescribing practices may improve morbidity and mortality outcomes.

Retinal toxicity in a multinational inception cohort of patients with systemic lupus on hydroxychloroquine

OBJECTIVE

To evaluate hydroxychloroquine (HCQ)-related retinal toxicity in the Systemic Lupus International Collaborating Clinics (SLICC) inception cohort.

METHODS

Data were collected at annual study visits between 1999 and 2019. We followed patients with incident SLE from first visit on HCQ (time zero) up to time of retinal toxicity (outcome), death, loss-to-follow-up or end of study. Potential retinal toxicity was identified from SLICC Damage Index scores; cases were confirmed with chart review. Using cumulative HCQ duration as the time axis, we constructed univariate Cox regression models to assess if covariates (ie, HCQ daily dose/kg, sex, race/ethnicity, age at SLE onset, education, body mass index, renal damage, chloroquine use) were associated with HCQ-related retinal toxicity.

RESULTS

We studied 1460 patients (89% female, 52% white). Retinal toxicity was confirmed in 11 patients (incidence 1.0 per 1000 person-years, 0.8% overall). Average cumulative time on HCQ in those with retinal toxicity was 7.4 (SD 3.2) years; the first case was detected 4 years after HCQ initiation. Risk of retinal toxicity was numerically higher in older patients at SLE diagnosis (univariate HR 1.05, 95% CI 1.01 to 1.09).

CONCLUSIONS

This is the first assessment of HCQ and retinal disease in incident SLE. We did not see any cases of retinopathy within the first 4 years of HCQ. Cumulative HCQ may be associated with increased risk. Ophthalmology monitoring (and formal assessment of cases of potential toxicity, by a retinal specialist) remains important, especially in patients on HCQ for 10+ years, those needing higher doses and those of older age at SLE diagnosis.

Rapid Onset and Resolution of Hydroxychloroquine Cardiomyopathy: A Case Report

Systemic lupus erythematosus (SLE) is an autoimmune, chronic, and heterogenous disease with organ damage resulting from immune complex deposition and inflammatory infiltrates. Antimalarial drugs, such as hydroxychloroquine (HCQ), are cornerstone immunomodulators for the treatment of SLE. Rarely, HCQ toxicity can occur, leading to devastating outcomes. We report a case of a patient with SLE on HCQ who presented with a rapid onset of large pericardial effusion and a dramatically decreased left ventricular ejection fraction. Endomyocardial biopsy was positive for curvilinear bodies, confirming the diagnosis of hydroxychloroquine cardiotoxicity. Hydroxychloroquine cardiomyopathy is a rare but life-threatening medication side effect. It is important to consider it in any patient taking the medication who presents with a new onset or worsening symptoms of heart failure.

Risk of hydroxychloroquine retinopathy in the community

OBJECTIVES

We aimed to estimate the risk of HCQ retinopathy and its risk factors among incident users in the community.

METHODS

Using the Rochester Epidemiology Project, a record-linkage system, a cohort of incident users of HCQ was identified from 27 counties in the American upper Midwest. HCQ retinopathy was defined based on characteristic paracentral automated 10-2 visual field (10-2 AVF) defects and parafoveal retinal photoreceptor layer changes on spectral domain optical coherence tomography. Cumulative incidence rates were estimated adjusting for competing risk of death. Risk factors for HCQ retinopathy were examined using Cox models.

RESULTS

The study included 634 incident HCQ users (mean age at initial HCQ use was 53.7 years, 79% females, 91% white). Most common indications for HCQ were RA (57%) and SLE (19%). The average follow-up length was 7.6 years. Eleven patients developed HCQ retinopathy (91% females, 91% white). The majority used HCQ for RA (91%). The cumulative incidence rate at year 5 was 0%, which increased to 3.9% (95% CI 2.0, 7.4) by 10 years. Taking an HCQ dose ≥5 mg/kg was associated with a hazard ratio (HR) of 3.59 (95% CI 1.09, 11.84) compared with lower doses. There was a 48% increase [HR 1.48 (95% CI 1.03, 2.14)] in the risk of HCQ retinopathy for each 100 g of HCQ cumulative dose.

CONCLUSION

The risk of HCQ retinopathy at 10 years of use is lower compared with previous prevalence-based estimations. A dose ≥5 mg/kg was associated with higher HCQ retinopathy risk.

Compliance With Hydroxychloroquine Screening Guidelines at a Large Academic Medical Center

Purpose:

Long-term hydroxychloroquine use can result in irreversible maculopathy and vision loss. New screening guidelines to identify early maculopathy were issued by American Academy of Ophthalmology (AAO) in 2016; however, few studies have evaluated compliance with these updated guidelines.

Methods:

This cross-sectional study evaluated compliance with hydroxychloroquine maculopathy screening examinations at a large academic institution. Patients seen in the ophthalmology department who were prescribed hydroxychloroquine between 2011 and 2021 were included. This retrospective chart review included patients screened for hydroxychloroquine toxicity between 2011 and 2021. The main outcome measure was compliance with AAO screening guidelines (based on 2011 guidelines for patients screened between 2011 and 2015 and on 2016 guidelines for those screened in 2016 and later).

Results:

Of the 419 patients included, 239 were evaluated between 2011 and 2015 and 357 between 2016 and 2021. Only 60.7% of patients screened before 2016 met the recommended screening examination frequency, while 40.6% received adequate visual field screenings. Of patients screened after 2016, 55.3% met the recommended examination screening frequency, 46.4% received screening with macula ocular coherence tomography at the recommended interval, and 21.0% received appropriate visual field screening. One third of patients were prescribed higher than the recommended 5 mg/kg/day of hydroxychloroquine. Ten patients developed definite macular toxicity; most had concomitant risk factors for toxicity.

Conclusions:

Despite clear guidelines set forth by AAO in 2011 and 2016, compliance with screening was suboptimal. Hydroxychloroquine prescribers and eye care providers must collaborate to ensure patients are not overdosed and that they receive appropriate maculopathy screening.

Hydroxychloroquine Blood Concentrations Can Be Clinically Relevant Also After Drug Discontinuation

BACKGROUND AND OBJECTIVE

Hydroxychloroquine was widely used during the severe acute respiratory syndrome coronavirus 2 pandemic as an antiviral drug. Most previous pharmacokinetic/pharmacodynamic studies on hydroxychloroquine were conducted on healthy volunteers or patients receiving long-term therapy. There are no studies on the elimination of hydroxychloroquine after short-term treatments. Hydroxychloroquine is known to have a pro-arrhythmic effect through QT interval prolongation, but data in this setting are not conclusive. Our aims were to estimate the time needed for hydroxychloroquine concentrations (CHCQ) to drop to a safe concentration (500 ng/mL) after a short-term therapeutic cycle and to correlate the corrected QT interval with CHCQ.

METHODS

We collected blood samples and electrocardiograms of patients who underwent short-term therapy with hydroxychloroquine during drug intake and after discontinuation. Hydroxychloroquine concentrations were determined by high-performance liquid chromatography-tandem mass spectrometry and analysed with a linear regression model to estimate the elimination time of the drug after its discontinuation. We conducted a multivariate analysis of the corrected QT interval correlation with CHCQ.

RESULTS

Our data suggest that short-term hydroxychloroquine courses can generate significant CHCQ persisting above 500 ng/mL up to 16 days after discontinuation of treatment. Corrected QT interval prolongation significantly correlates with CHCQ.

CONCLUSIONS

The study confirms the long half-life of hydroxychloroquine and its effect on the corrected QT interval even after short-term courses of the drug. This can inform the clinician using hydroxychloroquine treatments that it would be safer to start or re-initiate treatments with corrected QT interval-prolonging potential 16 days after hydroxychloroquine discontinuation.

Rapid Macular Thinning is an Early Indicator of Hydroxychloroquine Retinal Toxicity

PURPOSE

To demonstrate rapid macular thinning as an early and objective sign of hydroxychloroquine (HCQ) retinopathy.

DESIGN

Retrospective case cohort.

SUBJECTS

Cohort of 301 long-term HCQ therapy patients at Kaiser Permanente Northern California who had a minimum of four optical coherence tomography (OCT) studies which included Early Treatment Diabetic Retinopathy Study (ETDRS) retinal thickness values over a minimum interval of four years.

METHODS

Creation of sequential retinal thickness plots to show the rate of change in macular thickness within ETDRS regions.

MAIN OUTCOME MEASURES

1) Identification of rapid macular thinning, 2) Comparison of patients with rapid thinning to those with stable macular thickness, and 3) Comparison of rapid thinning patients with and without conventional OCT or 10-2 visual field signs of HCQ toxicity.

RESULTS

Retina thinning in 219 stable patients on long-term HCQ therapy averaged 0.62 ± 0.45 (mean ± standard deviation) microns per year, while 82 patients showed a period of relatively linear rapid thinning with a loss of 3.75 ± 1.34 microns per year. Of the patients with rapid thinning, 38 eventually developed conventional OCT or 10-2 visual field signs of HCQ retinal toxicity. The cumulative retinal thinning in these patients was 25.1 ± 6.2 microns compared to 15.7 ± 4.0 microns in those without conventional toxicity (p < 0.01).

CONCLUSIONS

Retinal thickness remains stable for many years in most patients on long-term HCQ therapy, but after a critical point the retina may begin to thin rapidly. Sequential plots of inner and outer ETDRS ring macular thickness provide objective evidence of this early structural change several years before conventional signs appear. This approach can alert patients and prescribing physicians to potential retinal damage and uses readily available OCT measurements that could be automated by manufacturers for use in comprehensive eyecare settings.

Advances in the clinical use of hydroxychloroquine levels

PURPOSE OF REVIEW

This review summarizes the recent literature exploring hydroxychloroquine levels and their relationship with disease activity and risk of toxicity.

RECENT FINDINGS

There is no clear correlation between weight-based dosing of hydroxychloroquine and the resulting blood levels of the medication. Recent studies have shown that increased hydroxychloroquine levels are associated with lower lupus disease activity and likely also increased risk of medication toxicity.

SUMMARY

Mounting evidence supports use of hydroxychloroquine levels in clinical practice to document adherence and ensure safety.

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.

Prevalence of ECG testing and characteristics among new hydroxychloroquine and chloroquine users within a multi-center tertiary care center

COVID-19 raised concern regarding cardiotoxicity and QTc prolongation of hydroxychloroquine (HCQ) and chloroquine (CQ). We examined the frequency and patient factors associated with ECG testing and the detection of prolonged QTc among new HCQ/CQ users in a large academic medical system. 10,248 subjects with a first HCQ/CQ prescription (1/2015–3/2020) were included. We assessed baseline (1 year prior to and including day of initiation of HCQ/CQ through 2 months after initial HCQ/CQ prescription) and follow-up (10 months after the baseline period) patient characteristics and ECGs obtained from electronic health records. Among 8384 female HCQ/CQ new users, ECGs were obtained for 22.3%, 14.3%, and 7.6%, at baseline, follow, and both periods, respectively. Among 1864 male HCQ/CQ new users, ECGs were obtained more frequently at baseline (29.7%), follow-up (18.0%), and both periods (11.3%). Female HCQ/CQ users with a normal QTc at baseline but prolonged QTc (> 470 ms) at follow-up (13.1%) were older at HCQ/CQ initiation [mean 64.7 (SD 16.5) vs. 58.7 (SD 16.9) years, p = 0.004] and more likely to have history of myocardial infarction (41.0% vs. 21.6%, p = 0.0003) compared to those who had normal baseline and follow-up QTc. The frequency of prolonged QTc development was similar (12.4%) among male HCQ/CQ new users (> 450 ms). Prior to COVID-19, ECG testing before and after HCQ/CQ prescription was infrequent, particularly for females who are disproportionately affected by rheumatic diseases and were just as likely to develop prolonged QTc (> 1/10 new users). Prospective studies are needed to guide future management of HCQ/CQ therapy in rheumatic populations.

Influence of hydroxychloroquine blood levels on adhesion molecules associated with endothelial dysfunction in patients with systemic lupus erythematosus

Background

Patients with SLE have an endothelial dysfunction (ED), which is considered the earliest marker of cardiovascular (CV) disease. Endothelial cell activation induced by proinflammatory cytokines is defined by the endothelial expression of cell-surface adhesion molecules, such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin. The aim of this study was to investigate whether serum endothelial adhesion molecule levels are influenced by blood hydroxychloroquine (HCQ) levels in SLE.

Methods

Consecutive patients with SLE taking a stable dose of HCQ were investigated. At study entry and 6 months later HCQ blood levels were quantified by tandem mass spectrometry. Serum levels of P-selectin, E-selectin, ICAM-1 and VCAM-1 were also measured using a Luminex 200 instrument. Comparison of endothelial soluble adhesion molecules in groups with different HCQ blood levels was performed by t-test.

Results

83 patients with SLE were enrolled. Correlation were demonstrated between mean blood HCQ concentrations and endothelial soluble adhesion molecules (E-selectin, ICAM-1 and VCAM-1). Moreover, serum levels of ICAM-1 and VCAM-1 were significantly lower in the patients with SLE with HCQ blood levels >500 ng/mL (83.67±52.8 ng/mL vs 158.81±125.1 ng/mL and 8.9±2.2 ng/mL vs 10.4±2.3 ng/mL). Serum levels of E-selectin were nearly significantly lower in the patients with SLE with HCQ blood levels >500 ng/mL (64.7±30.2 ng/mL vs 71.6±42.2 ng/mL, p=0.06). No significant difference in concentration of P-selectin was detected.

Conclusions

In the present study, there was a trend towards higher adhesion molecules levels with lower HCQ blood levels in patients with SLE. Further longitudinal studies will determine whether changes in endothelial biomarkers reflect decreased clinical CV events.

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.

Hydroxychloroquine administration exacerbates acute kidney injury complicated by lupus nephritis

Background

Hydroxychloroquine (HCQ) has been recommended as a basic treatment for lupus nephritis (LN) during this decade based on its ability to improve LN-related renal immune-mediated inflammatory lesions. As a classical lysosomal inhibitor, HCQ may inhibit lysosomal degradation and disrupt protective autophagy in proximal tubular epithelial cells (PTECs). Therefore, the final renal effects of HCQ on LN need to be clarified.

Method

HCQ was administered on spontaneous female MRL/lpr LN mice with severe proteinuria daily for 4 weeks. Moreover, the MRL/lpr mice with proteinuric LN were subjected to cisplatin-induced or unilateral ischemia/reperfusion (I/R)-induced acute kidney injury (AKI) after 2 weeks of HCQ preadministration.

Results

As expected, HCQ treatment increased the survival ratio and downregulated the levels of serum creatinine in the mice with LN, ameliorated renal lesions, and inhibited renal interstitial inflammation. Unexpectedly, HCQ preadministration significantly increased susceptibility to and delayed the recovery of AKI complicated by LN, as demonstrated by an increase in PTEC apoptosis and expression of the tubular injury marker KIM-1 as well as the retardation of PTEC replenishment. HCQ preadministration suppressed the proliferation of PTECs by arresting cells in G1/S phase and upregulated the expression of cell cycle inhibitors. Furthermore, HCQ preadministration disrupted the PTEC autophagy-lysosomal pathway and accelerated PTEC senescence.

Conclusion

HCQ treatment may increase susceptibility and delay the recovery of AKI complicated by LN despite its ability to improve LN-related renal immune-mediated inflammatory lesions. The probable mechanism involves accelerated apoptosis and inhibited proliferation of PTECs via autophagy-lysosomal pathway disruption and senescence promotion.

New Insights Into Systemic Lupus Erythematosus Therapies: 2010-2020

ABSTRACT

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that may affect every organ. The multiple pathogenic mechanisms and heterogeneous phenotypes of SLE present unique challenges in the management of this complex disease. This article discusses new SLE therapies from the last 10 years. We will address new information in the realms of lifestyle interventions, antimalarials, nonsteroidal anti-inflammatory drugs, glucocorticoids, immunosuppressive disease modifying antirheumatic drugs, biological therapies, and other modalities as they pertain to SLE.

American College of Rheumatology White Paper on Antimalarial Cardiac Toxicity

Hydroxychloroquine (HCQ) and chloroquine (CQ) are well-established medications used in treating systemic lupus erythematosus and rheumatoid arthritis, as well as skin conditions such as cutaneous lupus erythematosus. In rare cases, arrhythmias and conduction system abnormalities, as well as cardiomyopathy, have been reported in association with HCQ/CQ use. Recently, however, the corrected QT interval (QTc)-prolonging potential of these medications, and risk of torsade de pointes (TdP) in particular, have been highlighted in the setting of their experimental use for COVID-19 infection. This report was undertaken to summarize the current understanding of HCQ/CQ cardiac toxicity, describe QTc prolongation and TdP risks, and discuss areas of priority for future research. A working group of experts across rheumatology, cardiology, and dermatology performed a nonsystematic literature review and offered a consensus-based expert opinion. Current data clearly indicate that HCQ and CQ are invaluable medications in the management of rheumatic and dermatologic diseases, but they are associated with QTc prolongation by directly affecting cardiac repolarization. Prescribing clinicians should be cognizant of this small effect, especially in patients taking additional medications that prolong the QTc interval. Long-term use of HCQ/CQ may lead to a cardiomyopathy associated with arrhythmias and heart failure. Risk and benefit assessment should be considered prior to initiation of any medication, and both initial and ongoing risk-benefit assessments are important with regard to prescription of HCQ/CQ. While cardiac toxicity related to HCQ/CQ treatment of rheumatic diseases is rarely reported, it can be fatal. Awareness of the potential adverse cardiac effects of HCQ and CQ can increase the safe use of these medications. There is a clear need for additional research to allow better understanding of the cardiovascular risk and safety profile of these therapies used in the management of rheumatic and cutaneous diseases.

Risk versus Benefit of Using Hydroxychloroquine to Treat Patients with COVID-19

Hydroxychloroquine (HCQ), also known by its trade name Plaquenil®, has been used for over 50 years as a treatment for malaria, systemic lupus erythematosus, and rheumatoid arthritis. As the COVID-19 pandemic emerged in the United States and globally in early 2020, HCQ began to garner attention as a potential treatment and as prophylaxis against COVID-19. Preliminary data indicated that HCQ as well as chloroquine (CQ) possessed in vitro antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Early clinical data from China and France reported that HCQ and CQ were associated with viral load reduction and clinical improvement in patients with COVID-19 compared to control groups; however, an overwhelming number of randomized controlled trials, meta-analyses, and systematic reviews have since concluded that HCQ used alone, or in combination with azithromycin (AZ), provides no mortality or time-to-recovery benefit in hospitalized patients with COVID-19. Additionally, these same trials reported adverse events including cardiac, neuropsychiatric, hematologic, and hepatobiliary manifestations in patients with COVID-19 whom had been treated with HCQ. This review article summarizes the available data pertaining to the adverse events associated with HCQ use, alone or in combination with azithromycin, in patients with COVID-19 in order to fully assess the risk versus benefit of treating COVID-19 patients with these agents. The results of this review lead us to conclude that the risks of adverse events associated with HCQ use (with or without AZ) outweigh the potential clinical benefits and thus recommend against its use in the treatment or prevention of COVID-19.