Pattern of risks of systemic lupus erythematosus among statin users: a population-based cohort study

Changes in the incidence and prevalence of systemic lupus erythematosus between 1990 and 2020: an observational study using the Clinical Practice Research Datalink (CPRD)

OBJECTIVE

To obtain updated estimates on the incidence and prevalence of systemic lupus erythematosus (SLE) in the UK, over the period 1990-2020, using the Clinical Practice Research Datalink (CPRD).

METHODS

This was a retrospective cohort study using the CPRD covering the period 1990-2020. A case ascertainment algorithm was developed in line with best practice recommendations for observational research. Incidence was calculated per 100 000 person-years and point prevalence (at the mid-year point) calculated per 100 000. Results were stratified by sex.

RESULTS

9443 SLE cases were identified. 5278 incident cases were identified (4538 women, 740 men). The overall incidence rate was 5.47 (95% CI 5.33 to 5.62) cases per 100 000 person-years. Incidence rates decreased slightly across the study period, which was more pronounced for women than men. Point prevalence increased over time, from 21.4 (95% CI 17.68 to 25.67) per 100 000 in 1990 to 107.14 (95% CI 103.26 to 111.12) per 100 000 in 2020.

CONCLUSIONS

The observed fivefold increase in prevalence of SLE over the last 30 years, in the context of a modest decline in incidence rate, may suggest improved outcomes in SLE and has important implications for healthcare service delivery and planning in the UK.

Possible link between statin and iron deficiency anemia: A South Korean nationwide population-based cohort study

An extensive evaluation of disease occurrence after statin use based on a "hypothesis-free" approach remains scarce. To examine the effect of statin use on the potential risk of developing diseases, a propensity score-matched cohort study was executed using data from the National Sample Cohort in South Korea. A total of 7847 statin users and 39,235 nonstatin users were included in the final analysis. The period of statin use was defined as our main time-dependent exposure and was divided into three periods: current, recent, and past. The main outcomes were defined as new-onset diseases with ≥100 events based on the International Statistical Classification of Diseases, 10th Revision. We calculated the adjusted hazard ratios and 95% confidence intervals (CIs) using Cox regression. We found that statin use significantly increased the risk of developing iron deficiency anemia up to 5.04 times (95% CI, 2.11 to 12.03). Therefore, the iron levels of patients using statins should be monitored carefully.

Lipid metabolism in regulation of B cell development and autoimmunity

B cells play an important role in adaptive immunity and participate in the process of humoral immunity mainly by secreting antibodies. The entire development and differentiation process of B cells occurs in multiple microenvironments and is regulated by a variety of environmental factors and immune signals. Differentiation biases or disfunction of B cells participate in the process of many autoimmune diseases. Emerging studies report the impact of altered metabolism in B cell biology, including lipid metabolism. Here, we discuss how extracellular lipid environment and metabolites, membrane lipid-related components, and lipid synthesis and catabolism programs coordinate B cell biology and describe the crosstalk of lipid metabolic programs with signal transduction pathways and transcription factors. We conclude with a summary of therapeutic targets for B cell lipid metabolism and signaling in autoimmune diseases and discuss important future directions.

Association between statin use and the risk of gout in patients with hyperlipidemia: A population-based cohort study

Objective: To investigate the association between statin use and risk of gout in patients with hyperlipidemia. Methods: In this population-based retrospective cohort study, patients ≥20 years and diagnosed as having incident hyperlipidemia between 2001 and 2012 were identified from the 2000 Longitudinal Generation Tracking Database in Taiwan. Regular statin users (incident statin use, having 2 times and ≥90 days of prescription for the first year) and two active comparators [irregular statin use and other lipid-lowering agent (OLLA) use] were compared; the patients were followed up until the end of 2017. Propensity score matching was applied to balance potential confounders. Time-to-event outcomes of gout and dose- and duration-related associations were estimated using marginal Cox proportional hazard models. Results: Regular statin use non-significantly reduced gout risk compared with irregular statin use (aHR, 0.95; 95% CI, 0.90-1.01) and OLLA use (aHR, 0.94; 95% CI, 0.84-1.04). However, a protective effect was noted for a cumulative defined daily dose (cDDD) of >720 (aHR, 0.57; 95% CI, 0.47-0.69 compared with irregular statin use and aHR, 0.48; 95% CI, 0.34-0.67 compared with OLLA use) or a therapy duration of >3 years (aHR, 0.76; 95% CI, 0.64-0.90 compared with irregular statin use and aHR, 0.50; 95% CI, 0.37-0.68 compared with OLLA use). Dose- and duration-dependent associations were consistent in the 5-year sensitivity analyses. Conclusion: Although statin use was not associated with a reduction in gout risk, the protective benefit was observed in those receiving higher cumulative doses or with a longer therapy duration.

Mechanistic insight into premature atherosclerosis and cardiovascular complications in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is associated with a significant risk of cardiovascular disease (CVD), which substantially increases disease mortality and morbidity. The overall mechanisms associated with the development of premature atherosclerosis and CVD in SLE remain unclear, but has been considered as a result of an intricate interplay between the profound immune dysregulation and traditional CVD risk factors. Aberrant systemic inflammation in SLE may lead to an abnormal lipid profile and dysfunction, which can further fuel the pro-atherosclerotic environment. The existence of a strong imbalance between endothelial damage and vascular repair/angiogenesis promotes vascular injury, which is the early step in the progression of atherosclerotic CVD. Profound innate and adaptive immune dysregulation, characterized by excessive type I interferon burden, aberrant macrophage, platelet and complements activation, neutrophil dysregulation and neutrophil extracellular traps formation, uncontrolled T cell activation, and excessive autoantibody production and immune complex formation, have been proposed to promote accelerated CVD in SLE. While designing targeted therapies to correct the dysregulated immune activation may be beneficial in the treatment of SLE-related CVD, much additional work is needed to determine how to translate these findings into clinical practice. Additionally, a number of biomarkers display diagnostic potentials in improving CVD risk stratification in SLE, further prospective studies will help understand which biomarker(s) will be the most impactful one(s) in assessing SLE-linked CVD. Continued efforts to identify novel mechanisms and to establish criteria for assessing CVD risk as well as predicting CVD progression are in great need to improve CVD outcomes in SLE.

The role of environmental exposures and gene-environment interactions in the etiology of systemic lupus erythematous

Systemic lupus erythematosus (SLE) is a complex, chronic autoimmune disease, whose etiology includes both genetic and environmental factors. Individual genetic risk factors likely only account for about one-third of observed heritability among individuals with a family history of SLE. A large portion of the remaining risk may be attributable to environmental exposures and gene-environment interactions. This review focuses on SLE risk associated with environmental factors, ranging from chemical and physical environmental exposures to lifestyle behaviors, with the weight of evidence supporting positive associations between SLE and occupational exposure to crystalline silica, current smoking, and exogenous estrogens (e.g., oral contraceptives and postmenopausal hormones). Other risk factors may include lifestyle behaviors (e.g., dietary intake and sleep) and other exposures (e.g., ultraviolet [UV] radiation, air pollution, solvents, pesticides, vaccines and medications, and infections). Alcohol use may be associated with decreased SLE risk. We also describe the more limited body of knowledge on gene-environment interactions and SLE risk, including IL-10, ESR1, IL-33, ITGAM, and NAT2 and observed interactions with smoking, UV exposure, and alcohol. Understanding genetic and environmental risk factors for SLE, and how they may interact, can help to elucidate SLE pathogenesis and its clinical heterogeneity. Ultimately, this knowledge may facilitate the development of preventive interventions that address modifiable risk factors in susceptible individuals and vulnerable populations.

Health-care utilization and costs in adults with systemic lupus erythematosus in the United Kingdom: a real-world observational retrospective cohort analysis

Objective

The aim was to describe direct health-care costs for adults with SLE in the UK over time and by disease severity and encounter type.

Methods

Patients aged ≥18 years with SLE were identified using the linked Clinical Practice Research Datalink-Hospital Episode Statistics database from January 2005 to December 2017. Patients were classified as having mild, moderate or severe disease using an adapted claims-based algorithm based on prescriptions and co-morbid conditions. We estimated all-cause health-care costs and incremental costs associated with each year of follow-up compared with a baseline year, adjusting for age, sex, disease severity and co-morbid conditions (2017 UK pounds).

Results

We identified 802 patients; 369 (46.0%) with mild, 345 (43.0%) moderate and 88 (11.0%) severe disease. The mean all-cause cost increased in the 3 years before diagnosis, peaked in the first year after diagnosis and remained high. The adjusted total mean annual increase in costs per patient was £4476 (95% CI: £3809, £5143) greater in the year of diagnosis compared with the baseline year (P < 0.0001). The increase in costs per year was 4.7- and 1.6-fold higher among patients with severe SLE compared with those with mild and moderate SLE, respectively. Primary care utilization was the leading component of costs during the first year after diagnosis.

Conclusion

The health-care costs for patients with SLE in the UK are substantial, remain high after diagnosis and increase with increasing severity. Future research should assess whether earlier diagnosis and treatment might reduce disease severity and associated high health-care costs.

Disease severity, flares and treatment patterns in adults with systemic lupus erythematosus in the UK: a real-world observational retrospective cohort analysis

Objectives

The aim was to characterize disease severity, clinical manifestations, treatment patterns and flares in a longitudinal cohort of adults with SLE in the UK.

Methods

Adults with SLE were identified in the Clinical Practice Research Datalink–Hospital Episode Statistics database (1 January 2005–31 December 2017). Patients were required to have ≥12 months of data before and after the index date (earliest SLE diagnosis date available). SLE disease severity and flares were classified using adapted claims-based algorithms, which are based on SLE-related conditions, medications and health-service use.

Results

Of 802 patients, 369 had mild, 345 moderate and 88 severe SLE at baseline. A total of 692 initiated treatment in the first year after diagnosis. Five hundred and fifty-seven received antimalarials, 203 immunosuppressants and 416 oral CSs. Information on biologic use in hospitals was unavailable. The mean (S.d.) time to initiating any medication was 177 (385.3) days. The median time to first flare was 63 days (95% CI: 57, 71). At least one flare was experienced by 750 of 802 patients during follow-up; the first flare was mild for 549 of 750, moderate for 116 of 750 and severe for 85 of 750. The mean (S.d.) annual overall flare rate (year 1) was 3.5 (2.5). A shorter median time to first flare was significantly associated with moderate/severe disease (P < 0.001) and clinical manifestations (P < 0.001).

Conclusion

Our findings suggest some delay in the initiation of SLE treatment. Most patients experience a flare within 2 months of diagnosis. Early treatment might delay or reduce the severity of the first SLE flare and might translate to slower disease progression, lower accrual of organ damage and better outcomes.

Proprotein convertase subtilisin kexin 9 is associated with disease activity and is implicated in immune activation in systemic lupus erythematosus

BACKGROUND

Low-density lipoprotein (LDL) levels are increased by proprotein convertase subtilisin kexin 9 (PCSK9) which targets the LDL receptor. We recently reported that PCSK9 ameliorates dendritic cell (DC) activation by oxidized LDL (OxLDL), which is abundant in atherosclerotic plaques and is also associated with cardiovascular disease (CVD) in systemic lupus erythematosus (SLE). Here, we investigated the role of PCSK9 in SLE.

METHODS

PCSK9 levels were determined by ELISA among SLE patients (N = 109) and age- and sex-matched population-based controls (N = 91). Common carotid intima-media thickness (IMT) and plaque occurrence were determined by B-mode ultrasound. Plaques were graded by echogenicity. Human peripheral blood monocytes from SLE patients or controls were differentiated into DCs. The effects of PCSK9 and its inhibition by silencing were studied.

RESULTS

PCSK9 levels were non-significantly higher among SLE-patients compared to controls but significantly associated with SLE disease activity, as determined by the Systemic Lupus Activity Measure (p = 0.020) or the SLE Disease Activity Index (p = 0.0178). There was no association between PCSK9 levels and atherosclerosis as determined by IMT, prevalence of plaques or echolucent (potentially vulnerable) plaques. PCSK9 levels were significantly associated with CVD among SLE patients but not after adjusting for age. OxLDL induced PCSK9 in DCs and DC maturation with increased expression of CD86 and HLA-DR. The effects were significantly stronger in DCs from SLE patients than from controls. Silencing of PCSK9 abolished OxLDL-induced DC maturation.

CONCLUSIONS

PCSK9 is associated with disease activity in SLE. One underlying cause could be OxLDL promoting DC activation which depends on PCSK9. OxLDL induces PCSK9 - an effect which is higher among SLE patients. PCSK9 could play an unexpected immunological role in SLE.

Cardiovascular disease in systemic lupus erythematosus: an update

PURPOSE OF REVIEW

The mechanisms leading to the development of premature atherosclerosis and vascular injury in systemic lupus erythematosus (SLE) remain to be fully elucidated. This is a comprehensive review of recent research developments related to the understanding of cardiovascular disease (CVD) in lupus.

RECENT FINDINGS

SLE patients with lupus nephritis display significantly increased risk of myocardial infarction and CVD mortality than SLE patients without lupus nephritis. SLE disease-related parameters could be taken into consideration when calculating CVD risks. The type I interferon pathway is detrimental to the vasculature and may contribute to the development of insulin resistance. The level of low-density granulocytes, a distinct subset of proinflammatory neutrophils present in SLE, was independently associated with coronary plaque burden and endothelial dysfunction. Invariant natural killer T cells may promote an atheroprotective effect in SLE patients with asymptomatic atherosclerotic plaques. Oxidized lupus high-density lipoprotein promotes proinflammatory responses in macrophages.

SUMMARY

Recent discoveries have further strengthened the critical role of SLE-related immune dysregulation and metabolic disturbances in promoting accelerated CVD. Understanding how these pathogenic factors promote vascular injury may provide better molecular candidates for therapeutic targeting, and ultimately to improve CVD outcomes.

Drug-induced lupus: Traditional and new concepts

Drug-induced lupus (DIL) includes a spectrum of drug-induced reactions often characterised by a clinical phenotype similar to that of idiopathic systemic lupus eruthematosus (SLE) but usually lacking major SLE complications. Different drugs may be associated with distinct clinical and serological profiles, and early recognition is crucial. Drugs traditionally associated with DIL include procainamide, hydralazine, quinidine and others, but strong associations with newer agents, such as TNF α (TNFα) inhibitors, are increasingly recognised. The pathogenic mechanisms explaining how drugs that have heterogeneous chemical structure and function lead to autoimmunity are only partially understood. However, it is likely that traditional DIL-associated agents can boost innate immune responses, particularly neutrophil responses, with neutrophil extracellular trap (NET) formation and exposure of autoantigens. Research in the field of DIL is evolving and may provide interesting models for the study of autoimmunity.

Pattern of risks of rheumatoid arthritis among patients using statins: A cohort study with the clinical practice research datalink

We examined the association between statin use and the risk of rheumatoid arthritis (RA), with special focus on describing the patterns of risks of RA during statin exposure in a large population-based cohort in the United Kingdom. In the Clinical Practice Research Datalink, patients aged ≥40 years with at least one prescription of statins (1995–2009) were selected, and matched by age (+/-5 years), sex, practice and date of first prescription of statins to non-users. The follow-up period of statin use was divided into periods of current, recent and past exposure, with patients moving between these three exposure categories over time. Time-dependent Cox models were used to derive hazard ratios (HRs) of RA, adjusted for disease history and previous drug use. The study population included 1,023,240 patients, of whom 511,620 were statin users. No associations were found between RA and current (HR_adj,1.06;99%CI:0.88–1.27) or past statin users (HR_adj,1.18;99%CI:0.88–1.57). However, in patients who currently used statins, hazard rates were increased shortly after the first prescription of statins and then gradually decreased to baseline level. The risk of developing RA was increased in recent statin users, as compared to non-users (HR_adj,1.39;99%CI:1.01–1.90). The risk of RA is substantially increased in the first year after the start of statins and then diminishes to baseline level. These findings may suggest that statins might accelerate disease onset in patients susceptible to develop RA, but in other patients, statins are probably safe and well tolerated, even after prolonged use. Alternatively, we cannot rule out that confounding by cardiovascular risk factors and ascertainment bias may have influenced the findings.