Access and Cost-Related Nonadherence to Prescription Medications Among Lupus Patients and Controls: The Michigan Lupus Epidemiology and Surveillance Program

Effects of Demographic Identities on Psychosocial Burdens of Patients Living in the United States With Systemic Lupus Erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease predominantly affecting women, particularly in African American populations. While its physical health impacts are well-documented, patients also face significant psychosocial burdens, including barriers to healthcare access, financial constraints, mental health challenges, and inadequate social support.

STUDY GOAL

This cross-sectional study surveyed 294 SLE patients recruited from Facebook and Reddit social media forums to examine how demographic factors such as age, race/ethnicity, and geographic location influence these burdens.  Results: Findings revealed that although most participants had health insurance and access to rheumatology care, the majority were not able to be evaluated by their specialist until at least a week later after inquiring about an appointment, especially urban respondents. This does not appear to be a major limitation as such appointments may take in some cases months. Limited access to a pharmacy was reported more by respondents who are either rural residents, live in the Midwest region of the United States, or are older than 61 years old. Additionally, SLE is shown to impact patients financially. About 20.1% of the respondents indicated that they are unable to afford their co-pay for all of their monthly medications in general. Indian Asians were noted to pay more out-of-pocket medical expenses compared to other race/ethnicity groups. Respondents older than 61 years old were more likely to spend more than $200 a month on prescriptions for all their medical conditions than their younger counterparts. Regarding mental health, higher rates of anxiety and depression were reported across all groups, especially in a higher percentage of younger respondents under the age of 45. Despite this, there were no major differences in mental health changes between race/ethnicity and geographic location groups. Additionally, most respondents reported having some kind of social support for their SLE diagnosis, notably in the older than 61 age group. Suburban and urban respondents also reported receiving more support than rural ones.  Conclusion: Overall, this study highlights the complex interplay of socioeconomic factors and demographic identities in shaping the experiences of SLE patients, emphasizing the need for healthcare providers to consider these nonphysical aspects when developing treatment plans. Tailored interventions are essential to address the unique needs of diverse patient populations and enhance the management of SLE.

Using linked electronic medical record-pharmacy data to examine lupus medication adherence: A retrospective cohort study

INTRODUCTION

Medication nonadherence is common in systemic lupus erythematosus (SLE) and associated with morbidity and mortality. We explored the reliability of pharmacy data within the electronic medical record (EMR) to examine factors associated with nonadherence to SLE medications.

METHODS

We included patients with SLE who were prescribed ≥1 SLE medication for ≥90 days. We compared two datasets of pharmacy fill data, one within the EMR and another from the vendor who obtained this information from pharmacies and prescription benefit managers. Adherence was defined by medication possession ratio (MPR) ≥80%. In addition to MPR for each SLE medication, we evaluated the weighted-average MPR and the proportion of patients adherent to ≥1 SLE medication and to all SLE medications. We used logistic regression to examine factors associated with adherence.

RESULTS

Among 181 patients (median age 36, 96% female, 58% Black), 98% were prescribed hydroxychloroquine, 34% azathioprine, 33% mycophenolate, 18% methotrexate, and 7% belimumab. Among 1276 pharmacy records, 74% overlapped between linked EMR-pharmacy data and data obtained directly from the vendor. Only 9% were available from the vendor but not through linked EMR-pharmacy data. The weighted-average MPR was 57%; 45% were adherent to hydroxychloroquine, 46% to ≥1 SLE medication, and 32% to all SLE medications. Older age was associated with adherence in univariable and multivariable analyses.

DISCUSSION

Our study showed that obtaining linked EMR-pharmacy data is feasible with minimal missing data and can be leveraged in future adherence research. Younger patients were more likely to be nonadherent and may benefit from targeted intervention.

Immune-mediating and immunosuppressive pharmacotherapies for proliferative lupus nephritis

INTRODUCTION

Proliferative lupus nephritis is a common and severe complication of systemic lupus erythematosus. Affected patients are at an increased risk of developing chronic kidney disease, end-stage kidney disease, and extra-renal comorbidities. In recent years, the prognosis for patients with proliferative lupus nephritis has improved thanks to advancements in management regimens. Despite these advances, lupus nephritis continues to present therapeutic complexities and unmet needs.

AREAS COVERED

Research was conducted across major databases to identify the most relevant articles pertaining to immune-mediating and immunosuppressive therapies in lupus nephritis.

EXPERT OPINION

The prognosis for patients with proliferative lupus nephritis remains severe. Some drugs used in this disease may be unable to control activity, and most of them have a low therapeutic index and may cause severe and life-threatening side effects. Nonetheless, better management of traditional drugs and the introduction of novel therapies have improved renal prognosis and reduced local and systemic adverse events in patients with proliferative lupus nephritis.

Cost-Related Medication Behaviors for Patients With and Without Systemic Autoimmune Rheumatic Diseases

OBJECTIVE

Medication nonadherence challenges the management of systemic autoimmune rheumatic diseases (SARDs). We investigated cost-related medication behaviors among patients with SARDs, and compared them to those of patients without SARDs, in a large diverse cohort across the United States.

METHODS

As part of the All of Us (version 7), a nationwide diverse adult cohort with linked electronic health records begun in 2017, participants completed questionnaires concerning cost-related medication behaviors. Chi-square tests compared responses between patients with SARDs, by disease and medication type, and to those without SARDs. Logistic regression analyses were used to calculate odds ratios (95% confidence intervals [CIs]).

RESULTS

We analyzed data from 3,997 patients with SARDs and 73,990 participants without SARDs. After adjustment, patients with versus without SARDs had 1.56 times increased odds of reporting unaffordability of prescription medicines (95% CI 1.43-1.70), 1.43 times increased odds of cost-related medication nonadherence (95% CI 1.31-1.56), and 1.23 times increased odds of using cost-reducing strategies (95% CI 1.14-1.32). Patients with SARDs who reported unaffordability were 16.5% less likely to receive a disease-modifying drug (95% CI 0.70-0.99) but 18.1% more likely to receive glucocorticoids (95% CI 0.99-1.42). In addition, unaffordability of prescription medicines was likely to have 1.27 times increased odds of one to two emergency room visits per year (95% CI 1.03-1.57) and 1.38-fold increased odds of three or more emergency room visits per year (95% CI 0.96-1.99).

CONCLUSION

In this large diverse cohort, patients with versus without SARDs had more self-reported cost-related medication behaviors, and those who reported medication unaffordability received fewer disease-modifying drugs and had more emergency room visits.

Association between self-perceived consultation time and understanding of the prescribed treatment: An analysis of a national survey in Peru

OBJECTIVE

To assess the relationship between the self-perceived consultation time and the knowledge of the proposed treatment.

METHODS

Secondary data from a 2015 national survey of health services in Peru were analyzed. The self-perceived consultation time was calculated by asking how long it took from when you entered the consultation until you departed. It was then categorized as low, medium, and high. Five self-reported questions were used to construct a knowledge of the prescribed treatment. Adjusted regression models from the Poisson family models were used to evaluate the relationship. We report adjusted prevalence ratios (aPR) with their 95% confidence intervals (95%CI).

RESULTS

A total of 9939 outpatients were analyzed, with 58% women; the average age was 44 years; and 45.4% had higher education. Using low self-perceived consultation time as references, medium and high consultation times were associated with understanding the prescribed treatment (aPR=1.17; 95%CI, 1.04-1.33 and aPR=1.30; 95%CI, 1.20-1.40, respectively).

CONCLUSION

Patients who reported a medium and high self-perceived consultation time better understood the prescribed treatment.

IMPLICATIONS FOR PRACTICE

Healthcare professionals should strive to maximize consultation time to ensure effective communication and improve patient knowledge of treatments, improving overall patient satisfaction and health outcomes.

Artemisinins: Promising drug candidates for the treatment of autoimmune diseases

Autoimmune diseases are characterized by the immune system's attack on one's own tissues which are highly diverse and diseases differ in severity, causing damage in virtually all human systems including connective tissue (e.g., rheumatoid arthritis), neurological system (e.g., multiple sclerosis) and digestive system (e.g., inflammatory bowel disease). Historically, treatments normally include pain-killing medication, anti-inflammatory drugs, corticosteroids, and immunosuppressant drugs. However, given the above characteristics, treatment of autoimmune diseases has always been a challenge. Artemisinin is a natural sesquiterpene lactone initially extracted and separated from Chinese medicine Artemisia annua L., which has a long history of curing malaria. Artemisinin's derivatives such as artesunate, dihydroartemisinin, artemether, artemisitene, and so forth, are a family of artemisinins with antimalarial activity. Over the past decades, accumulating evidence have indicated the promising therapeutic potential of artemisinins in autoimmune diseases. Herein, we systematically summarized the research regarding the immunoregulatory properties of artemisinins including artemisinin and its derivatives, discussing their potential therapeutic viability toward major autoimmune diseases and the underlying mechanisms. This review will provide new directions for basic research and clinical translational medicine of artemisinins.

Sociodemographic profiles and organ damage accural in the Black Women's Experience Living with Lupus study

OBJECTIVE

Black/African American women with systemic lupus erythematosus (SLE) experience greater organ damage and at younger ages than white women. The objective of this study was to advance research on SLE inequities by identifying sociodemographic risk profiles associated with organ damage accrual specifically among Black/African American women.

METHODS

Latent profile analysis was conducted among 438 Black/African American women with SLE living in Atlanta, GA and enrolled in the Black Women's Experiences Living with Lupus (BeWELL) Study (May 2015 to April 2017). Proportional hazard and Poisson regression models examined prospective associations between sociodemographic profiles and the timing and degree of organ damage accrual over 2 years.

RESULTS

Four profiles emerged: (1) "Younger/Lower SES with Uncontrolled SLE" (44.8%), (2) "Older/Lower SES with Uncontrolled SLE" (23.3%), (3) "Mid-SES with Controlled SLE" (19.6%), and (4) "Higher SES with Controlled SLE" (11.2%). Approximately 42% of participants experienced new organ damage during the follow-up period. Proportional hazard models indicated that "Older/Lower SES with Uncontrolled SLE" participants were at greatest risk of new organ damage (HR = 2.41; 95% CI = 1.39, 4.19), followed by "Younger/Lower SES with Uncontrolled SLE" participants (HR = 1.56; 95% CI = 0.92, 2.67), compared to those in the "Higher SES with Controlled SLE" profile. Poisson regression models revealed that these two groups also exhibited greater organ damage accrual (b = 0.98, SE = 0.24, 95% CI = 0.52, 1.44 and b = 0.72, SE = 0.23, 95% CI = 0.27, 1.17, respectively).

CONCLUSIONS

Black/African American women with fewer socioeconomic resources and uncontrolled SLE are at greatest risk for increasing disease severity over time. Social inequities likely contribute to racial inequities in SLE progression.

Medication Cost Concerns and Disparities in Patient-Reported Outcomes Among a Multiethnic Cohort of Patients With Systemic Lupus Erythematosus

OBJECTIVE

Concerns about the affordability of medications are common in systemic lupus erythematosus (SLE), but the relationship between medication cost concerns and health outcomes is poorly understood. We assessed the association of self-reported medication cost concerns and patient-reported outcomes (PROs) in a multiethnic SLE cohort.

METHODS

The California Lupus Epidemiology Study is a cohort of individuals with physician-confirmed SLE. Medication cost concerns were defined as having difficulties affording SLE medications, skipping doses, delaying refills, requesting lower-cost alternatives, purchasing medications outside the United States, or applying for patient assistance programs. Linear regression and mixed effects models assessed the cross-sectional and longitudinal association of medication cost concerns and PROs, respectively, adjusting for age, sex, race and ethnicity, income, principal insurance, immunomodulatory medications, and organ damage.

RESULTS

Of 334 participants, medication cost concerns were reported by 91 (27%). Medication cost concerns were associated with worse Systemic Lupus Activity Questionnaire (SLAQ; beta coefficient [β] 5.9, 95% CI 4.3-7.6; P < 0.001), 8-item Patient Health Questionnaire depression scale (PHQ-8; β 2.7, 95% CI 1.4-4.0; P < 0.001), and Patient-Reported Outcomes Measurement Information System (PROMIS; β for physical function -4.6, 95% CI -6.7 to -2.4; P < 0.001) scores after adjusting for covariates. Medication cost concerns were not associated with significant changes in PROs over 2-year follow-up.

CONCLUSION

More than a quarter of participants reported at least 1 medication cost concern, which was associated with worse PROs. Our results reveal a potentially modifiable risk factor for poor outcomes rooted in the unaffordability of SLE care.

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.

Association of patient copayment and medication adherence in systemic lupus erythematosus

OBJECTIVE

To investigate the association of medication copayment and treatment adherence to hydroxychloroquine and immunosuppressants for SLE.

METHODS

We conducted a retrospective analysis of health claims data using Optum's de-identified Clinformatics Data Mart Database. Individuals with SLE continuously enrolled for 180 days from 1 July 2010 to 31 December 2019 were included. Adherence was defined as the proportion of days covered ≥80%. Copayment for a 30-day supply of medication was dichotomised as high (≥$10) or low (<$10). We examined the association between copayment and odds of adherence in multivariable-adjusted logistic regression models, including age, sex, race or ethnicity, comorbidities, educational attainment and household income.

RESULTS

We identified 12 510 individuals (age 54.2±15.5 years; 88.2% female sex), of whom 9510 (76%) were prescribed hydroxychloroquine and 1880 (15%) prescribed hydroxychloroquine and an additional immunosuppressant (azathioprine, methotrexate or mycophenolate mofetil). Median (IQR) 30-day copayments were $8 (4-10) for hydroxychloroquine, $7 (2-10) for azathioprine, $8 (3-11) for methotrexate and $10 (5-20) for mycophenolate mofetil. High copayments were associated with OR of adherence of 0.61 (95% CI 0.55 to 0.68) for hydroxychloroquine, OR 0.44 (95% CI 0.30 to 0.66) for azathioprine and OR 0.69 (95% CI 0.49 to 0.96) for mycophenolate mofetil. For methotrexate, the association was not significant.

CONCLUSION

In a large, administrative health claims database, we identified that high copayments were associated with reduced adherence to commonly prescribed medications for SLE. Incorporating awareness of the burden of copayments and its consequences into healthcare is essential to promote optimal medication adherence.

Disparities in Lupus and the Role of Social Determinants of Health: Current State of Knowledge and Directions for Future Research

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease. The complex relationships between race and ethnicity and social determinants of health (SDOH) in influencing SLE and its course are increasingly appreciated. Multiple SDOH have been strongly associated with lupus incidence and outcomes and contribute to health disparities in lupus. Measures of socioeconomic status, including economic instability, poverty, unemployment, and food insecurity, as well as features of the neighborhood and built environment, including lack of safe and affordable housing, crime, stress, racial segregation, and discrimination, are associated with race and ethnicity in the US and are risk factors for poor outcomes in lupus. In this scientific statement, we aimed to summarize current evidence on the role of SDOH in relation to racial and ethnic disparities in SLE and SLE outcomes, primarily as experienced in the U.S. Lupus Foundation of America's Health Disparities Advisory Panel, comprising 10 health disparity experts, including academic researchers and patients, who met 12 times over the course of 18 months in assembling and reviewing the data for this study. Sources included articles published from 2011 to 2023 in PubMed, Centers for Disease Control and Prevention data, and bibliographies and recommendations. Search terms included lupus, race, ethnicity, and SDOH domains. Data were extracted and synthesized into this scientific statement. Poorer neighborhoods correlate with increased damage, reduced care, and stress-induced lupus flares. Large disparities in health care affordability, accessibility, and acceptability exist in the US, varying by region, insurance status, and racial and minority groups. Preliminary interventions targeted social support, depression, and shared-decision-making, but more research and intervention implementation and evaluation are needed. Disparities in lupus across racial and ethnic groups in the US are driven by SDOH, some of which are more easily remediable than others. A multidimensional and multidisciplinary approach involving various stakeholder groups is needed to address these complex challenges, address these diminish disparities, and improve outcomes.

Cost-related prescription non-adherence and patient-reported outcomes in systemic lupus erythematosus: The Michigan Lupus Epidemiology & Surveillance program

OBJECTIVES

Medication access and adherence play key roles in determining patient outcomes. We investigated whether cost-related non-adherence (CRNA) to prescription medications was associated with worse patient-reported outcomes in a population-based systemic lupus erythematosus (SLE) cohort.

METHODS

Sociodemographic and prescription data were collected by structured interviews in 2014-2015 from patients meeting SLE criteria in the established Michigan Lupus Epidemiology & Surveillance (MILES) Cohort. We examined the associations between CRNA and potential confounders such as sociodemographics and health insurance coverage, and outcome measures of SLE activity and damage using multivariable linear regression.

RESULTS

462 SLE participants completed the study visit: 430 (93.1%) female, 208 (45%) Black, and mean age 53.3 years. 100 (21.6%) participants with SLE reported CRNA in the preceding 12 months. After adjusting for covariates, CRNA was associated with both higher levels of current SLE disease activity [SLAQ: β coeff 2.7 (95% CI 1.3, 4.1), p < 0.001] and damage [LDIQ β coeff 1.4 (95% CI 0.5, 2.4), p = 0.003]. Race, health insurance status, and fulfilling Fibromyalgia (FM) Survey Criteria were independently associated with both higher (worse) SLAQ and LDIQ scores; female sex was further associated with higher SLAQ scores.

CONCLUSION

Patients with SLE who reported CRNA in the previous 12 months had significantly worse self-reported current disease activity and damage scores compared to those not reporting CRNA. Raising awareness and addressing barriers or concerns related to financial implications and accessibility issues in care plans may help to improve these outcomes.

Adherence with mycophenolate mofetil in patients with autoimmune inflammatory rheumatic diseases in coventry: Signs of progress but challenges remain

OBJECTIVE

The study investigated adherence with MMF treatment among patients attending rheumatology clinics at University Hospitals Coventry and Warwickshire NHS Trust (UHCW) with Autoimmune inflammatory rheumatic diseases (AIIRDs).

METHODS

This retrospective study collated hospital pharmacy data in patients who requested the prescription for MMF between January 2015 and December 2018. Clinical data were obtained from paper and electronic notes. Data were analysed using Microsoft Excel. Ethical approval was obtained through Coventry University.

RESULTS

We recruited 144 patients into this study with age range from 18 to 91 years, including 100 females and 44 males. There were 112 White patients, 22 of South Asian origin, 3 East Asian and 4 black patients. SLE (56), scleroderma (18), mixed connective tissue disease (15), myositis (13), vasculitis (13) were the commonest diagnoses. Overall adherence with Mycophenolate mofetil was 62%. The adherence rates were below 80% for all age groups with ∼60% of patients having adherence levels of >60%. Poor adherence with MMF correlated with 3-fold increase in risk of flares compared to good adherence (p = 0.002). We also found a significant difference between Asian patients (mean adherence 47%) and White patients (mean adherence 65%, p < 0.001).

CONCLUSION

Adherence with MMF has improved considerably compared to historical studies, although these remain suboptimal. Certain population groups such as young adults, elderly and Asian patients continue to have lower adherence and higher risk of flares. Strategies are needed to improve adherence levels overall and specifically in the high-risk groups to reduce risk of flares and organ damage.

Researchers in rheumatology should avoid categorization of continuous predictor variables

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pilot Intervention to Improve Medication Adherence Among Patients With Systemic Lupus Erythematosus Using Pharmacy Refill Data

OBJECTIVE

Despite high rates of medication nonadherence among patients with systemic lupus erythematosus (SLE), effective interventions to improve adherence in SLE are limited. We aimed to assess the feasibility of a pilot intervention and explore its effect on adherence.

METHODS

The intervention used pharmacy refill data to monitor nonadherence and prompt discussions surrounding SLE medications during clinic encounters. Over 12 weeks, the intervention was delivered through routine clinic visits by providers to patients with SLE who take SLE-specific medications. We measured acceptability, appropriateness, and feasibility using provider surveys. We also measured acceptability by patient surveys and feasibility by medical record documentation. We explored change in adherence by comparing percent of patients with medication possession ratio (MPR) ≥80% 3 months before and after the intervention visit using the McNemar's test.

RESULTS

Six rheumatologists participated; 130 patients were included in the analysis (median age 43, 95% female, and 59% racial and ethnic minorities). Implementation of the intervention was documented in 89% of clinic notes. Provider surveys showed high scores for feasibility (4.7/5), acceptability (4.4/5), and appropriateness (4.6/5). Among patient surveys, the most common reactions to the intervention visit were feeling determined (32%), empowered (32%), and proud (19%). Proportion of patients with MPR ≥80% increased from 48% to 58% (P = 0.03) after the intervention visit.

CONCLUSION

Our intervention showed feasibility, acceptability, and appropriateness and led to a statistically significant improvement in adherence. Future work should refine the intervention, assess its efficacy in a controlled setting, and adapt its use among other clinic settings.

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.

Screening Biomarkers for Systemic Lupus Erythematosus Based on Machine Learning and Exploring Their Expression Correlations With the Ratios of Various Immune Cells

Background

Systemic lupus erythematosus (SLE) is an autoimmune illness caused by a malfunctioning immunomodulatory system. China has the second highest prevalence of SLE in the world, from 0.03% to 0.07%. SLE is diagnosed using a combination of immunological markers, clinical symptoms, and even invasive biopsy. As a result, genetic diagnostic biomarkers for SLE diagnosis are desperately needed.

Method

From the Gene Expression Omnibus (GEO) database, we downloaded three array data sets of SLE patients' and healthy people's peripheral blood mononuclear cells (PBMC) (GSE65391, GSE121239 and GSE61635) as the discovery metadata (n_SLE = 1315, n_normal = 122), and pooled four data sets (GSE4588, GSE50772, GSE99967, and GSE24706) as the validate data set (n_SLE = 146, n_normal = 76). We screened the differentially expressed genes (DEGs) between the SLE and control samples, and employed the least absolute shrinkage and selection operator (LASSO) regression, and support vector machine recursive feature elimination (SVM-RFE) analyze to discover possible diagnostic biomarkers. The candidate markers' diagnostic efficacy was assessed using the receiver operating characteristic (ROC) curve. The reverse transcription quantitative polymerase chain reaction (RT-qPCR) was utilized to confirm the expression of the putative biomarkers using our own Chinese cohort (n_SLE = 13, n_normal = 10). Finally, the proportion of 22 immune cells in SLE patients was determined using the CIBERSORT algorithm, and the correlations between the biomarkers' expression and immune cell ratios were also investigated.

Results

We obtained a total of 284 DEGs and uncovered that they were largely involved in several immune relevant pathways, such as type І interferon signaling pathway, defense response to virus, and inflammatory response. Following that, six candidate diagnostic biomarkers for SLE were selected, namely ABCB1, EIF2AK2, HERC6, ID3, IFI27, and PLSCR1, whose expression levels were validated by the discovery and validation cohort data sets. As a signature, the area under curve (AUC) values of these six genes reached to 0.96 and 0.913, respectively, in the discovery and validation data sets. After that, we checked to see if the expression of ABCB1, IFI27, and PLSCR1 in our own Chinese cohort matched that of the discovery and validation sets. Subsequently, we revealed the potentially disturbed immune cell types in SLE patients using the CIBERSORT analysis, and uncovered the most relevant immune cells with the expression of ABCB1, IFI27, and PLSCR1.

Conclusion

Our study identified ABCB1, IFI27, and PLSCR1 as potential diagnostic genes for Chinese SLE patients, and uncovered their most relevant immune cells. The findings in this paper provide possible biomarkers for diagnosing Chinese SLE patients.

Lupus Cohorts

Large cohorts with diverse ethnic backgrounds and heterogenous clinical features have provided the real-life data about the safety and efficacy of various treatment regimens for systemic lupus erythematosus (SLE). There are multiple well-established regional, national, and international lupus cohorts that have made significant contributions to the understanding of SLE. Using social media for cohort-based studies can significantly increase the outreach in a short time period for studying rare diseases such as SLE. Lack of strict inclusion criteria allows study of a broad range of patients but selection bias and incomplete data are possible in long-term cohort studies.