Association between hydroxychloroquine levels and disease activity in a predominantly Hispanic systemic lupus erythematosus cohort

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.

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.

The presumable effects of hydroxychloroquine and its metabolites in the treatment of systemic lupus erythematosus

OBJECTIVE

Hydroxychloroquine (HCQ) is an essential drug in the treatment of systemic lupus erythematosus (SLE). This study aimed to detect the concentrations of HCQ and its metabolites from peripheral blood of SLE patients and to investigate the relationship between those concentrations and SLE disease activity.

METHODS

176 SLE patients treated with HCQ were enrolled in this study. The concentrations of HCQ and its metabolites in their peripheral blood were measured by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Patients' disease activity was evaluated with the systemic lupus erythematosus disease activity index (SLEDAI). The variables between different concentrations or treatments were statistically analyzed. Linear regression was employed to explore relationships between the concentrations of HCQ and its metabolites with the disease activity.

RESULTS

The SLEDAI was lower in patients with higher concentrations of HCQ, desethylhydroxychloroquine (DHCQ), and desethylchloroquine (DCQ) (P = 0.024, P = 0.018, and P = 0.003, respectively). There were no significant differences in SLEDAI and the concentrations of HCQ and its metabolites among groups with different treatments (P > 0.05). After adjusting age, gender, disease duration, HCQ dose adjusted to actual body weight, and glucocorticoid (GC) dose, the SLEDAI was negatively correlated with the concentrations of HCQ, DHCQ, DCQ and bisdesethylchloroquine (BDCQ) (P = 0.007, P = 0.011, P = 0.029, and P = 0.008, respectively). After grouping analysis, in patients treated with HCQ and GC, the SLEDAI was negatively correlated with concentrations of HCQ, DHCQ and BDCQ (P = 0.011, P = 0.035, and P = 0.036, respectively).

CONCLUSIONS

The concentrations of HCQ and metabolites were correlated with the SLE disease activity after adjusting possible confounding factors, indicating that HCQ and its metabolites might play certain immunoregulatory roles in SLE treatment. Moreover, GC might have a synergistic effect with HCQ. It is helpful in clinical management and follow-up to monitor the concentrations of HCQ and its metabolites in SLE patients.

Whole blood hydroxychloroquine: Does genetic polymorphism of cytochrome P450 enzymes have a role?

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a wide range of clinical manifestations and multifactorial etiologies ranging from environmental to genetic. SLE is associated with dysregulated immunological reactions, with increased immune complex formation leading to end-organ damages such as lupus nephritis, cutaneous lupus, and musculoskeletal disorders. Lupus treatment aims to reduce disease activity, prevent organ damage, and improve long-term patient survival and quality of life. Antimalarial, hydroxychloroquine (HCQ) is used as a first-line systemic treatment for lupus. It has shown profound efficacy in lupus and its associated conditions. However, wide variation in terms of clinical response to this drug has been observed among this group of patients. This variability has limited the potential of HCQ to achieve absolute clinical benefits. Several factors, including genetic polymorphisms of cytochrome P450 enzymes, have been stipulated as key entities leading to this inter-individual variation. Thus, there is a need for more studies to understand the role of genetic polymorphisms in CYP450 enzymes in the clinical response to HCQ. Focusing on the role of genetic polymorphism on whole blood HCQ in lupus disorder, this review aims to highlight up-to-date pathophysiology of SLE, the mechanism of action of HCQ, and finally the role of genetic polymorphism of CYP450 enzymes on whole blood HCQ level as well as clinical response in lupus.

Association Between Severe Nonadherence to Hydroxychloroquine and Systemic Lupus Erythematosus Flares, Damage, and Mortality in 660 Patients From the SLICC Inception Cohort

OBJECTIVE

The goals of this study were to assess the associations of severe nonadherence to hydroxychloroquine (HCQ), objectively assessed by HCQ serum levels, and risks of systemic lupus erythematosus (SLE) flares, damage, and mortality rates over five years of follow-up.

METHODS

The Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort is an international multicenter initiative (33 centers throughout 11 countries). The serum of patients prescribed HCQ for at least three months at enrollment were analyzed. Severe nonadherence was defined by a serum HCQ level <106 ng/mL or <53 ng/mL for HCQ doses of 400 or 200 mg/day, respectively. Associations with the risk of a flare (defined as a Systemic Lupus Erythematosus Disease Activity Index 2000 increase ≥4 points, initiation of prednisone or immunosuppressive drugs, or new renal involvement) were studied with logistic regression, and associations with damage (first SLICC/American College of Rheumatology Damage Index [SDI] increase ≥1 point) and mortality with separate Cox proportional hazard models.

RESULTS

Of the 1,849 cohort participants, 660 patients (88% women) were included. Median (interquartile range) serum HCQ was 388 ng/mL (244-566); 48 patients (7.3%) had severe HCQ nonadherence. No covariates were clearly associated with severe nonadherence, which was, however, independently associated with both flare (odds ratio 3.38; 95% confidence interval [CI] 1.80-6.42) and an increase in the SDI within each of the first three years (hazard ratio [HR] 1.92 at three years; 95% CI 1.05-3.50). Eleven patients died within five years, including 3 with severe nonadherence (crude HR 5.41; 95% CI 1.43-20.39).

CONCLUSION

Severe nonadherence was independently associated with the risks of an SLE flare in the following year, early damage, and five-year mortality.

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.

Sex and Racial Differences in Systemic Lupus Erythematosus Among US Adults in the All of Us Research Program

OBJECTIVE

Men with systemic lupus erythematosus (SLE) are an understudied population. The present study characterized differences between men and women with SLE.

METHODS

We examined cross-sectionally participants with SLE in the All of Us Research Program, a US cohort with a participant survey at enrollment (May 2018 to June 2022) and linked electronic health record (EHR) data. We described and compared characteristics of men and women with SLE encompassing disease manifestations and prescribed medications from EHR data and socioeconomic factors, including health literacy and health care access and utilization, from surveys. We reported racial variations stratified by sex.

RESULTS

Of 1,462 participants with SLE, 126 (9%) were male. Men reported lower educational attainment and less fatigue than women. Myocardial infarction was significantly more common in men. Men had significantly less confidence in completing medical forms than women and exhibited a trend toward requiring more help in reading health-related materials. Barriers to health care access and utilization were common in both men and women (40% versus 47%, respectively, reporting some reason for delay in care; P = 0.35). Women of race other than Black or African American or White more often reported delaying care due to cultural differences between patient and provider.

CONCLUSION

Our study demonstrated major clinical and health literacy differences in men and women with SLE. Socioeconomic factors were significant barriers to health care in both sexes. Our study suggests men have disproportionately poorer health literacy, which may exacerbate preexisting disparities. Further large prospective studies, focusing on recruiting men, are needed to better characterize racial differences in men with SLE.

Development and validation of a Systemic Sclerosis Health Literacy Scale

Background and aim

Health literacy levels are strongly associated with clinical outcomes and quality of life in patients with chronic diseases, and patients with limited health literacy often require more medical care and achieve poorer clinical outcomes. Among the large number of studies on health literacy, few studies have focused on the health literacy of people with systemic sclerosis (SSc), and there is no specific tool to measure health literacy in this group. Therefore, this study plans to develop a health literacy scale for patients with SSc.

Methods

This study included 428 SSc patients from the outpatient and inpatient departments of the Department of Rheumatology and Immunology, the first affiliated Hospital of Anhui Medical University and the first affiliated Hospital of University of Science and Technology of China. The formulation of the scale was completed by forming the concept of health literacy of SSc patients, establishing the item pool, screening items, and evaluating reliability and validity. Classical measurement theory was used to screen items, factor analysis was used to explore the construct validity of the scale, and Cronbach's alpha coefficient was used to assess the internal consistency.

Results

Our study population was predominantly middle-aged women, with a male to female ratio of 1:5.7 and a mean age of 51.57 ± 10.99. A SSc Health Literacy scale with 6 dimensions and 30 items was developed. The six dimensions are clinic ability, judgment/evaluation information ability, access to information ability, social support, treatment compliance and application information ability. The Cronbach's alpha coefficient of the scale is 0.960, retest reliability is 0.898, split-half reliability is 0.953, content validity is 0.983, which has good reliability and validity.

Conclusion

The Systemic Sclerosis Health Literacy Scale may become a valid tool to evaluate the health literacy level of patients with SSc.

Persistence of Depression and Anxiety despite Short-Term Disease Activity Improvement in Patients with Systemic Lupus Erythematosus: A Single-Centre, Prospective Study

Mental disorders such as anxiety and depression are prevalent in systemic lupus erythematosus (SLE) patients, yet their association with the underlying disease activity remains uncertain and has been mostly evaluated at a cross-sectional level. To examine longitudinal trends in anxiety, depression, and lupus activity, a prospective observational study was performed on 40 adult SLE outpatients with active disease (SLE Disease Activity Index [SLEDAI]-2K ≥ 3 [excluding serology]) who received standard-of-care. Anxiety and depression were determined at baseline and 6 months by the Hospital Anxiety and Depression Scale. Treatment adherence was assessed with the Morisky Medication Adherence Scale-4. Increased anxiety (median [interquartile range] HADS-A: 11.0 [7.8]) and depression (HADS-D: 8.0 [4.8]) were found at inclusion, which remained stable and non-improving during follow-up (difference: 0.0 [4.8] and −0.5 [4.0], respectively) despite reduced SLEDAI-2K by 2.0 (4.0) (p < 0.001). Among possible baseline predictors, paid employment—but not disease activity—correlated with reduced HADS-A and HADS-D with corresponding standardized beta-coefficients of −0.35 (p = 0.017) and −0.27 (p = 0.093). Higher anxiety and depression correlated with lower treatment adherence (p = 0.041 and p = 0.088, respectively). These results indicate a high-mental disease burden in active SLE that persists despite disease control and emphasize the need to consider socioeconomic factors as part of comprehensive patient assessment.

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.

Prescription strategy of antimalarials in cutaneous and systemic lupus erythematosus: an international survey

Background:

Antimalarial agents (AMs), mainly hydroxychloroquine (HCQ) and chloroquine, are the cornerstone of treatment of cutaneous and systemic lupus erythematosus. However, many aspects of AM prescription remain empirical. The aim of this study was to assess the modalities of AM prescription among physicians treating patients with lupus and to verify the assumption that AM use is heterogeneous and frequently at variance with international guidelines.

Methods:

We performed an international cross-sectional study among physicians involved in lupus care, using a web-based survey (from September 2019 to July 2020) addressing the main controversial aspects of AM prescription.

Results:

A total of 298 physicians [median age: 42 (interquartile range: 17) years, mainly internists and rheumatologists] from 35 countries participated to the study. A total of 93% used HCQ as the first-line AM, 69.5% used fixed doses of AMs (mainly 400 mg/day for HCQ) and only 37.9% adjusted the dose in case of renal failure. The main reasons for measuring HCQ blood levels were suspected non-adherence (55.7%) and failure of AM treatment (34.1%). In case of AM failure, 58.0% added an immunosuppressive agent. In case of remission, 49.7% maintained the same dose of AM, whereas 48.3% reduced the dose. One-third of respondents reported not following the American screening guidelines on AM retinal toxicity and 40.9% started retinal screening from the first year of treatment.

Conclusion:

This study highlights the strong heterogeneity of AM prescription in lupus, as well as several key unmet needs regarding AMs. This may be improved by developing more comprehensive recommendations and favoring dissemination among physicians.

Association of antimalarial drugs with decreased overall and cause specific mortality in systemic lupus erythematosus

OBJECTIVE

To evaluate the association and dose-response pattern between antimalarial drugs and overall and cause specific mortality in SLE patients.

METHODS

Medical records including information on HCQ/chloroquine (CQ) prescription were extracted from Jiangsu Lupus database. The database was designed to collect data from SLE patients that first-hospitalized during 1999-2009 in Jiangsu province, China, and a follow-up for survival status was performed in 2010 and 2015. Cox and restricted cubic spline models were used to estimate the hazard ratio and 95% CI.

RESULTS

We identified 221 deaths among 2446 SLE patients in total. Compared with non-users, decreased overall mortality was associated with either HCQ or CQ users, with adjusted hazard ratio (95% CI) of 0.49 (0.35, 0.67) and 0.49 (0.27, 0.87), respectively. The association between HCQ/CQ and overall mortality was similar across subgroups, such as patients with comorbidities and organ involvements. Interestingly, both the time and the daily dosage of HCQ/CQ use were related to decreased mortality of SLE in a linear dose-response relationship. In cause specific analyses, HCQ/CQ was inversely associated with death from renal insufficiency and other organ (cardiopulmonary, gastrointestinal and haematological) involvements, with adjusted hazard ratio (95% CI) of 0.23 (0.09, 0.55) and 0.25 (0.10, 0.62), respectively, yet it was not significantly associated with mortality from infection and neuropsychiatric involvements.

CONCLUSION

Antimalarial drugs were associated with lower risk of SLE mortality, especially renal insufficiency- and other organ involvement-related death. The protective effects for survival might be augmented by adherence and full dosage of these drugs.

Clinical Significance of Monitoring Hydroxychloroquine Levels in Patients With Systemic Lupus Erythematosus: A Systematic Review and Meta-Analysis

OBJECTIVE

Despite the pivotal role that hydroxychloroquine (HCQ) plays in treating systemic lupus erythematosus (SLE), less than 50% of patients take HCQ as prescribed. Measurement of HCQ blood levels can help clinicians distinguish nonadherence versus lack of efficacy of HCQ. Our objective was to systematically review publications and perform a meta-analysis to examine the correlation between HCQ levels and 1) nonadherence and 2) Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores, in SLE.

METHODS

A comprehensive search was performed. We included observational and interventional studies that measured HCQ levels and assessed adherence or SLEDAI scores in adults with SLE. Forest plots compared pooled estimates of correlations between HCQ levels and reported nonadherence or SLEDAI scores.

RESULTS

Among 604 studies screened, 17 were reviewed. We found 3-times higher odds of reported nonadherence in patients with low HCQ levels (odds ratio 2.95 [95% confidence interval (95% CI) 1.63, 5.35], P < 0.001). The mean SLEDAI score was 3.14 points higher in groups with below-threshold HCQ levels on a priori analysis (δ = 3.14 [95% CI -0.05, 6.23], P = 0.053), and 1.4 points higher in groups with HCQ levels of <500 ng/ml (δ = 1.42 [95% CI 0.07, 2.76], P = 0.039). Among 1,223 patients, those with HCQ levels ≥750 ng/ml had a 58% lower risk of active disease, and their SLEDAI score was 3.2 points lower.

CONCLUSION

We found a strong association between low HCQ levels and reported nonadherence. Our results suggest that HCQ levels of ≥750 ng/ml might be a potential therapeutic target.

Low health numeracy is associated with higher disease activity in systemic lupus erythematosus

OBJECTIVE

Evidence suggests low health literacy is prevalent in the United States and associated with worse clinical outcomes, yet few studies have investigated health literacy in systemic lupus erythematosus (SLE). The objective of this study was to determine the prevalence of low health literacy and numeracy in lupus patients and to examine its association with disease characteristics.

METHODS

Patients with SLE were recruited from an academic center clinic. Participants completed in-person assessments of health literacy (Rapid Estimate of Adult Literacy in Medicine, REALM) and numeracy (Numeracy Understanding in Medicine Instrument Shortened Version, S-NUMi). Clinical disease activity measures were obtained, including urine protein to creatinine ratio (UPC), Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and physician global assessment (PhGA) scores.

RESULTS

Ninety-five SLE patients participated in the study; 13% had low health literacy and 73% had limited health numeracy. Patients with lower health literacy and numeracy were more likely to be Black, have Medicaid insurance, and earn income <$50 K annually. In linear regression models, patients with limited health numeracy had, on average, PhGA scores 0.31 points higher (95% CI: 0.02, 0.60) than patients with adequate numeracy, after adjusting for race and age. No clinical outcomes were associated with health literacy.

CONCLUSION

In this exploratory study, we found SLE patients with low numeracy had higher disease activity. Our findings indicate that lower health literacy and numeracy are more common among Black and socioeconomically disadvantaged patients. Additional research will be needed to investigate the impact of health literacy on other outcomes and racial disparities in SLE.

American College of Rheumatology Guidance for the Management of Rheumatic Disease in Adult Patients During the COVID-19 Pandemic: Version 3

OBJECTIVE

To provide guidance to rheumatology providers on the management of adult rheumatic disease in the context of the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

A task force, including 10 rheumatologists and 4 infectious disease specialists from North America, was convened. Clinical questions were collated, and an evidence report was rapidly generated and disseminated. Questions and drafted statements were reviewed and assessed using a modified Delphi process. This included asynchronous anonymous voting by email and webinars with the entire panel. Task force members voted on agreement with draft statements using a 1-9-point numerical scoring system, and consensus was determined to be low, moderate, or high based on the dispersion of votes. For approval, median votes were required to meet predefined levels of agreement (median values of 7-9, 4-6, and 1-3 defined as agreement, uncertainty, or disagreement, respectively) with either moderate or high levels of consensus.

RESULTS

Draft guidance statements approved by the task force have been combined to form final guidance.

CONCLUSION

These guidance statements are provided to promote optimal care during the current pandemic. However, given the low level of available evidence and the rapidly evolving literature, this guidance is presented as a "living document," and future updates are anticipated.

Investigating Health Literacy in Systemic Lupus Erythematosus: a Descriptive Review

PURPOSE OF REVIEW

Inadequate health literacy is common among American adults, but little is known about the impact of health literacy in rheumatic diseases. The purpose of this article is to review studies investigating health literacy and its association with clinical outcomes in systemic lupus erythematosus (SLE).

RECENT FINDINGS

Several validated health literacy measures have been examined in SLE patients. Low health literacy is associated with worse patient-reported outcomes and lower numeracy with higher disease activity. Two studies found no association of low health literacy with medication adherence. One randomized controlled trial tested a medication decision aid among patients with low health literacy. We found a paucity of studies exploring health literacy in SLE. Low health literacy is associated with worse patient-reported outcomes and limited numeracy with higher disease activity in SLE. Further studies are needed exploring the impact of low health literacy on clinical outcomes and the effectiveness of literacy-sensitive interventions.

Rheumatologists’ perspective on hydroxychloroquine guidelines

Objective

Hydroxychloroquine (HCQ) retinal toxicity is an ongoing concern for rheumatologists. The revised 2016 American Academy of Ophthalmology (AAO) guidelines created controversy regarding the correct dosing and evaluation of HCQ toxicity. The current study was initiated to further understand rheumatologists’ practices regarding HCQ.

Methods

A questionnaire-based survey was distributed electronically to rheumatologists. We collected information on HCQ dosing, clinical decision-making processes, familiarity with the AAO 2016 guidelines, and perceived disparities between the AAO 2016 guidelines and rheumatological clinical practice.

Results

78 rheumatologists completed the survey (49% from USA, 90% academic practices, 82% self-identified as lupus experts). Only lupus expert (n=64) data were included in subsequent analysis. The mean cohort size was 747 (50–6571), a total cohort 45 612 patients. HCQ was prescribed to >75% of patients with SLE by 81.3% of SLE experts, with routine counselling about ophthalmic risks. The typical dose of HCQ used was 200–400 mg/day. 17% of rheumatologists use doses up to 600 mg/day, while 6.2% use up to 6.5 mg/kg/day. HCQ adherence is routinely assessed. 479 cases of HCQ retinal toxicity (1.05%) and 9 cases of HCQ-associated blindness (1.8 per 10 000 patients) were reported. 89.1% of respondents reported familiarity with the AAO guidelines. Those aware of the guidelines cited limited dosing options (54.7%), lack of supporting evidence (57.8%) and low patient adherence (43.8%) as obstacles to greater implementation of the guidelines.

Conclusion

These data suggest that HCQ toxicity and blindness are rare in patients with SLE. Rheumatologists treating patients with SLE are aware of the guidelines and appreciate the importance of partnering with ophthalmologists in preventing retinal toxicity.

Hydroxychloroquine levels in patients with systemic lupus erythematosus: whole blood is preferable but serum levels also detect non-adherence

Background

Hydroxychloroquine (HCQ) levels can be measured in both serum and whole blood. No cut-off point for non-adherence has been established in serum nor have these methods ever been compared. The aims of this study were to compare these two approaches and determine if serum HCQ cut-off points can be established to identify non-adherent patients.

Methods

HCQ levels were measured in serum and whole blood from 573 patients with systemic lupus erythematosus (SLE). The risk factors for active SLE (SLEDAI score > 4) were identified by multiple logistic regression. Serum HCQ levels were measured in 68 additional patients known to be non-adherent, i.e. with whole-blood HCQ < 200 ng/mL.

Results

The mean (± SD) HCQ levels were 469 ± 223 ng/mL in serum and 916 ± 449 ng/mL in whole blood. The mean ratio of serum/whole-blood HCQ levels was 0.53 ± 0.15. In the multivariate analysis, low whole-blood HCQ levels (P = 0.023), but not serum HCQ levels, were independently associated with active SLE.

From the mean serum/whole-blood level ratio, a serum HCQ level of 106 ng/mL was extrapolated as the corresponding cut-off to identify non-adherent patients with a sensitivity of 0.87 (95% CI 0.76–0.94) and specificity of 0.89 (95% CI 0.72–0.98).

All serum HCQ levels of patients with whole-blood HCQ below the detectable level (< 20 ng/mL) were also undetectable (< 20 ng/mL).

Conclusions

These data suggest that whole blood is better than serum for assessing the pharmacokinetic/pharmacodynamic relation of HCQ. Our results support the use of serum HCQ levels to assess non-adherence when whole blood is unavailable.

COVID-19 prevention and treatment: A critical analysis of chloroquine and hydroxychloroquine clinical pharmacology

Nicholas White and coauthors discuss chloroquine and hydroxychloroquine pharmacology in the context of possible treatment of SARS-CoV-2 infection.

American College of Rheumatology Guidance for the Management of Rheumatic Disease in Adult Patients During the COVID-19 Pandemic: Version 2

OBJECTIVE

To provide guidance to rheumatology providers on the management of adult rheumatic disease in the context of the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

A task force, including 10 rheumatologists and 4 infectious disease specialists from North America, was convened. Clinical questions were collated, and an evidence report was rapidly generated and disseminated. Questions and drafted statements were reviewed and assessed using a modified Delphi process. This included asynchronous anonymous voting by e-mail and webinars with the entire panel. Task force members voted on agreement with draft statements using a 1-9-point numerical scoring system, and consensus was determined to be low, moderate, or high based on the dispersion of votes. For approval, median votes were required to meet predefined levels of agreement (median values of 7-9, 4-6, and 1-3 defined as agreement, uncertainty, or disagreement, respectively) with either moderate or high levels of consensus.

RESULTS

To date, the task force has approved 80 guidance statements: 36 with moderate and 44 with high consensus. These were combined, resulting in 27 final guidance statements.

CONCLUSION

These guidance statements are provided to promote optimal care during the current pandemic. However, given the low level of available evidence and the rapidly evolving literature, this guidance is presented as a "living document," and future updates are anticipated.

Understanding the dynamics of hydroxychloroquine blood levels in lupus nephritis

Objectives

It is unknown if hydroxychloroquine blood level dynamics impact flare rates in lupus nephritis patients. We prospectively evaluated hydroxychloroquine levels to determine which blood-based patterns are more associated with disease activity.

Methods

In total, 82 lupus nephritis patients under a prescribed hydroxychloroquine dose of 4–5.5 mg/kg actual body weight (maximum 400 mg/day) for ≥3 months were evaluated at baseline and 7 months. Hydroxychloroquine blood levels were determined by liquid chromatography-tandem mass spectrometry. Flare was defined as increase ≥3 in the Systemic Lupus Erythematosus Disease Activity Index 2000 score and/or a change or increase in therapy.

Results

Overall, 9/82(11%) patients had flares during follow-up and had lower baseline hydroxychloroquine blood levels than those without flares (220.4 (53.5–1471.1) vs. 1006.3 (53.5–2137.8) ng/ml, p = 0.013). The hydroxychloroquine blood level cut-off that best predicted flares was 613.5 ng/ml (odds ratio = 8.67, 95% confidence interval: 1.66–45.18, p = 0.006). For 77 (94%) patients, the 7-month hydroxychloroquine level dynamics was evaluated and revealed: 59/77 (77%) had a persistent pattern of adequate (41/77(53%)) or fluctuating (18/77 (23%)) levels, with a low and comparable risk of flares (2/41 (5%) vs. 1/18 (5%), p = 1.000). The remaining group had persistent low levels (18/77 (23%)) and their flare frequency was significantly higher than the adequate group (5/18 (28%) vs. 2/41 (5%), p = 0.023). The frequencies of adequate/inadequate hydroxychloroquine blood levels in patients were comparable at baseline and 7 months (McNemar’s test, p = 0.480).

Conclusion

We provide novel evidence that hydroxychloroquine blood-level patterns (persistently low, adequate, or intermittent) have distinct impacts on flare rates in lupus nephritis patients. These findings reinforce the need of routine hydroxychloroquine measurements to maintain the appropriate blood levels.