Epidemiology of systemic lupus erythematosus: Capturing the butterfly

Racism-Related Experiences and Adiposity: Findings From the Black Women's Experiences Living With Lupus (BeWELL) Study

INTRODUCTION

Studies suggest that higher rates of excess adiposity in Black women may in part be driven by experiences of racism. Racial microaggressions, which include unintentional and subtle slights and insults, and responses to racism such as racism-related vigilance, may contribute to adiposity in this population. This study examined these understudied racism-related facets as well as interpersonal racial discrimination in relation to adiposity in a cohort of Black women with systemic lupus erythematosus.

METHODS

Data are from the Black Women's Experiences Living with Lupus (BeWELL) Study (2015-2017; n = 432). Linear regression was used to examine adiposity measures (body mass index [BMI], percent body fat, and waist-to-hip ratio), measured during a physical examination, in relation to self-reported measures of racial microaggressions, racism-related vigilance, and interpersonal racial discrimination.

RESULTS

Compared with infrequent microaggressions, very frequent experiences of microaggressions were associated with 2.9 kg/m2 higher BMI (95% confidence [CI], 0.63-5.21) and 2.6% higher body fat (95% CI, 0.32-4.80) after adjusting for covariates. Racism-related vigilance, measured continuously, was positively associated with BMI (b = 0.84; 95% CI-0.08, 1.61) and percent body fat (b = 0.89; 95% CI, 0.14-1.64). Very frequent experiences of everyday discrimination were associated with a higher BMI (b = 2.70; 95% CI, 0.58-4.83) and waist-to-hip ratio (b = 0.32; 95% CI, 0.09-0.55) compared with less frequent everyday discrimination.

CONCLUSIONS

Our results suggest that various dimensions of racism are associated with excess adiposity. Efforts to address obesity among Black women with systemic lupus erythematosus should consider these multiple aspects to decrease racial inequities in adiposity.

Racial Discrimination, Disease Activity, and Organ Damage: The Black Women's Experiences Living With Lupus (BeWELL) Study

Black women are disproportionately affected by systemic lupus erythematosus (SLE), a chronic, potentially debilitating autoimmune disease, and they also experience more rapid progression and worse outcomes compared with other groups. We examined if racial discrimination is associated with disease outcomes among 427 black women with a validated diagnosis of SLE, who live in the Atlanta, Georgia, metropolitan area, and were recruited to the Black Women's Experiences Living with Lupus Study (2015-2017). Frequency of self-reported experiences of racial discrimination in domains such as employment, housing, and medical settings was assessed using the Experiences of Discrimination measure. SLE activity in the previous 3 months, including symptoms of fatigue, fever, skin rashes, and ulcers, was measured using the Systemic Lupus Activity Questionnaire; irreversible damage to an organ or system was measured using the Brief Index of Lupus Damage. Results of multivariable linear regression analyses examining the Systemic Lupus Activity Questionnaire and log-transformed Brief Index of Lupus Damage scores indicated that increasing frequency of racial discrimination was associated with greater SLE activity (b = 2.00, 95% confidence interval: 1.32, 2.68) and organ damage (b = 0.08, 95% confidence interval: 0.02, 0.13). Comprehensive efforts to address disparities in SLE severity should include policies that address issues of racial discrimination.

Vicarious Racism Stress and Disease Activity: the Black Women's Experiences Living with Lupus (BeWELL) Study

BACKGROUND

Indirect or vicarious exposure to racism (e.g., hearing about or observing acts of racism or discrimination) is a salient source of stress for African Americans. Emerging research suggests that these "secondhand" experiences of racism may contribute to racial health inequities through stress-mediated pathways. Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease that disproportionately impacts African American women and is characterized by racial disparities in severity. Health outcomes in this population may be susceptible to vicarious racism given that SLE is shown to be sensitive to psychosocial stress.

METHODS

Data are from 431 African American women with SLE living in Atlanta, Georgia in the Black Women's Experiences Living with Lupus (BeWELL) Study (2015-2017). Vicarious racism stress was measured with four items assessing distress from (1) hearing about racism in the news; (2) experiences of racism among friends or family; (3) witnessing racism in public; and (4) racism depicted in movies and television shows. Multivariable linear regression was used to examine associations with disease activity measured using the Systemic Lupus Activity Questionnaire.

RESULTS

Adjusting for sociodemographic and health-related covariates, vicarious racism stress was associated with greater disease activity (b = 2.15; 95% CI = 1.04-3.27). This association persisted even after adjustment for personal experiences of racial discrimination (b = 1.80; 95% CI = 0.67-2.92).

CONCLUSIONS

Vicarious racism may result in heightened disease activity and contribute to racial disparities in SLE. Our findings suggest that acts of racism committed against members of one's racial group may have distinct health consequences beyond the immediate victim or target.

Epidemiology and burden of systemic lupus erythematosus in a Southern European population: data from the community-based lupus registry of Crete, Greece

OBJECTIVES

Several population-based studies on systemic lupus erythematosus (SLE) have been reported, yet community-based, individual-case validated, comprehensive reports are missing. We studied the SLE epidemiology and burden on the island of Crete during 1999-2013.

METHODS

Multisource case-finding included patients ≥15 years old. Cases were ascertained by the ACR 1997, SLICC 2012 criteria and rheumatologist diagnosis, and validated through synthesis of medical charts, administrative and patient-generated data.

RESULTS

Overall age-adjusted/sex-adjusted incidence was 7.4 (95% CI 6.8 to 7.9) per 100 000 persons/year, with stabilising trends in women but increasing in men, and average (±SD) age of diagnosis at 43 (±15) years. Adjusted and crude prevalence (December 2013) was 123.4 (113.9 to 132.9) and 143 (133 to 154)/105 (165/105 in urban vs 123/105 in rural regions, p<0.001), respectively. Age-adjusted/sex-adjusted nephritis incidence was 0.6 (0.4 to 0.8) with stable trends, whereas that of neuropsychiatric SLE was 0.5 (0.4 to 0.7) per 100 000 persons/year and increasing. Although half of prevalent cases had mild manifestations, 30.5% developed organ damage after 7.2 (±6.6) years of disease duration, with the neuropsychiatric domain most frequently afflicted, and 4.4% of patients with nephritis developed end-stage renal disease. The ACR 1997 and SLICC 2012 classification criteria showed high concordance (87%), yet physician-based diagnosis occurred earlier than criteria-based in about 20% of cases.

CONCLUSIONS

By the use of a comprehensive methodology, we describe the full spectrum of SLE from the community to tertiary care, with almost half of the cases having mild disease, yet with significant damage accrual. SLE is not rare, affects predominantly middle-aged women and is increasingly recognised in men. Neuropsychiatric disease is an emerging frontier in lupus prevention and care.

The Incidence and Prevalence of Systemic Lupus Erythematosus in San Francisco County, California: The California Lupus Surveillance Project

OBJECTIVE

Estimates of the incidence and prevalence of systemic lupus erythematosus (SLE) in the US have varied widely. The purpose of this study was to conduct the California Lupus Surveillance Project (CLSP) to determine credible estimates of SLE incidence and prevalence, with a special focus on Hispanics and Asians.

METHODS

The CLSP, which is funded by the Centers for Disease Control and Prevention, is a population-based registry of individuals with SLE residing in San Francisco County, CA, from January 1, 2007 through December 31, 2009. Data sources included hospitals, rheumatologists, nephrologists, commercial laboratories, and a state hospital discharge database. We abstracted medical records to ascertain SLE cases, which we defined as patients who met ≥4 of the 11 American College of Rheumatology classification criteria for SLE. We estimated crude and age-standardized incidence and prevalence, which were stratified by sex and race/ethnicity.

RESULTS

The overall age-standardized annual incidence rate was 4.6 per 100,000 person-years. The average annual period prevalence was 84.8 per 100,000 persons. The age-standardized incidence rate in women and men was 8.6 and 0.7 per 100,000 person-years, respectively. This rate was highest among black women (30.5), followed by Hispanic women (8.9), Asian women (7.2), and white women (5.3). The age-standardized prevalence in women per 100,000 persons was 458.1 in blacks, 177.9 in Hispanics, 149.7 in Asians, and 109.8 in whites. Capture-recapture modeling estimated 33 additional incident cases and 147 additional prevalent cases.

CONCLUSION

Comprehensive methods that include intensive case-finding provide more credible estimates of SLE in Hispanics and Asians, and confirm racial and ethnic disparities in SLE. The disease burden of SLE is highest in black women, followed by Hispanic women, Asian women, and white women.

Incidence of End-Stage Renal Disease Among Newly Diagnosed Systemic Lupus Erythematosus Patients: The Georgia Lupus Registry

OBJECTIVE

To estimate and identify factors associated with the incidence of all-cause end-stage renal disease (ESRD) among newly diagnosed systemic lupus erythematosus (SLE) patients.

METHODS

Data from a national registry of treated ESRD were linked to data from a lupus registry of SLE patients who were newly diagnosed and living in Atlanta, Georgia, 2002-2004 (median followup 7.8 years). Cumulative incidence and incidence rates (ESRD treatment initiations per 1,000 patient-years) were calculated, and age- and race-adjusted Poisson models were used to calculate incidence rate ratios (IRRs).

RESULTS

Among 344 newly diagnosed SLE patients, 29 initiated ESRD treatment over 2,603.8 years of followup. Incidence rates were 13.8 (95% confidence interval [95% CI] 9.4-20.3) among black patients and 3.3 (95% CI 0.8-13.0) among white patients, per 1,000 patient-years; corresponding 5-year cumulative incidence was 6.4% and 2.5% among black and white patients, respectively. Lupus nephritis documented prior to 2005, which occurred in 80% of those who progressed to ESRD, was the strongest risk factor for incident ESRD (IRR 6.7 [95% CI 2.7-16.8]; incidence rate 27.6 per 1,000 patient-years). Results suggested that patients who were black versus white (IRR 3.9 [95% CI 0.9-16.4]) or <18 years old (versus ≥30 years old) at diagnosis (IRR 2.1 [95% CI 0.9-5.3]) may be more likely to progress to ESRD, but incidence did not differ by sex or other characteristics.

CONCLUSION

The incidence of all-cause ESRD among patients with a recent diagnosis of SLE is high in Georgia. Interventions to decrease ESRD incidence among newly diagnosed SLE patients should target young and black patients, as well as patients with lupus nephritis.

Attribution of cause of end-stage renal disease among patients with systemic lupus erythematosus: the Georgia Lupus Registry

Objective

Whether using provider-attributed end-stage renal disease (ESRD) cause of systemic lupus erythematosus (SLE) in national surveillance data captures the entire population of patients with SLE and ESRD remains uncertain. Our goal was to examine attributed cause of ESRD in US surveillance data among patients with SLE who have developed ESRD.

Methods

Data from a national registry of treated ESRD (United States Renal Data System (USRDS)) were linked to the population-based Georgia Lupus Registry (GLR). The provider-attributed cause of ESRD was extracted from the USRDS for each validated patient with SLE in the GLR (diagnosed through 2004) who initiated treatment for ESRD through 2012. The percentage of these patients with SLE whose ESRD was subsequently attributed to SLE in the USRDS was calculated, overall and by patient characteristics.

Results

Among 251 patients with SLE who progressed to ESRD, 78.9% had SLE as their attributed cause of ESRD. Of the remaining 53 patients, 43.4%, 18.9% and 15.6% had ESRD attributed to hypertension, diabetes mellitus type II and non-SLE-related glomerulonephritis, respectively. Attribution of ESRD to SLE was higher among patients aged ≤30 (87.9–93.9%) vs >30 (52.6%; p<0.001) but did not differ by sex or race. Having Medicaid (86.2%) or no insurance (93.5%) was associated with greater attribution of ESRD to SLE than having private insurance (72.5%; p=0.02), as was having two or more providers state a diagnosis of SLE (89.0% vs 73.5% with a rheumatologist diagnosis alone; p=0.008).

Conclusions

These estimates indicate that USRDS-based studies may underreport ESRD among US patients with SLE. However, observed patterns of differential attribution of ESRD cause, particularly by age, suggest that providers may be correctly attributing ESRD to causes other than SLE among some patients with SLE.

The incidence and prevalence of systemic lupus erythematosus in Thrace, 2003–2014: A 12-year epidemiological study

Background

We estimated the prevalence and incidence, clinical features, treatment, and prognosis of systemic lupus erythematosus (SLE) patients in the Thrace region of Turkey.

Methods

We retrospectively evaluated 331 patients (307 female, 24 male, mean age 38.5 years) diagnosed with SLE between 2003 and 2014. Clinical features, treatments, and response to various treatment modalities were recorded. Our hospital has been the only tertiary referral center for rheumatological diseases for a mixed rural and urban population of 620,477 people (306,036 females, 314,411 males) for more than 16 years.

Results

The mean annual incidence of SLE was 4.44/100,000 (females, 8.4/100,000; males, 0.6/100,000). The overall prevalence of SLE was 51.7/100,000 (females, 97.7/100,000; males, 7/100,000). Major organ involvement was present in the following percentages: neurologic involvement: 20.1%; renal involvement: 28.2%; autoimmune hemolytic anemia: 9.6%; thrombocytopenia: 14.7%. Seventeeen SLE patients (13 females, four males) died at a median follow-up of 48 months. The five-year survival was 94.5%, and the ten-year survival was 89.9%. According to Kaplan–Meier survival analysis, poor prognostic factors were: male gender ( p = 0.015); smoking ( p = 0.02); pleural involvement ( p = 0.011); thrombocytopenia ( p = 0.021); myocarditis ( p = 0.028); renal involvement ( p = 0.037); treatment with cyclophosphamide ( p = 0.011); and an initial high SLEDAI score (>4) ( p = 0.02). Lymphopenia at the time of diagnosis appeared as a favorable prognostic factor ( p = 0.008). Cox regression analysis revealed myocarditis (OR: 20.4, p = 0.018) and age at diagnosis (OR: 1.11, p = 0.035) to be poor, and lymphopenia at the time of diagnosis to be good prognostic factors (OR:0.13, p = 0.031).

Conclusions

The annual incidence and prevalence of SLE in the Thrace region of Turkey is lower than those reported in North America, however they are similar to those reported for European countries. Clinical manifestations appear to be milder, whereas survival was similar to those recorded in Western countries.

Prevalence and incidence of systemic lupus erythematosus in a population-based registry of American Indian and Alaska Native people, 2007-2009

OBJECTIVE

Few studies have investigated the epidemiology of systemic lupus erythematosus (SLE) in American Indian and Alaska Native populations. The objective of this study was to determine the prevalence and incidence of SLE in the Indian Health Service (IHS) active clinical population in 3 regions of the US.

METHODS

For this population-based registry within the IHS, the denominator consisted of individuals in the IHS active clinical population in 2007, 2008, and/or 2009 and residing in a community in 1 of 3 specified regions. Potential SLE cases were identified based on the presence of a diagnostic code for SLE or related disorder in the IHS National Data Warehouse. Detailed medical record abstraction was performed for each potential case. The primary case definition was documentation in the medical record of ≥4 of the revised American College of Rheumatology criteria for the classification of SLE. Prevalence was calculated for 2007, and the mean annual incidence was calculated for the years 2007 through 2009.

RESULTS

The age-adjusted prevalence and incidence of SLE according to the primary definition were 178 per 100,000 person-years (95% confidence interval [95% CI] 157-200) and 7.4 per 100,000 person-years (95% CI 5.1-10.4). Among women, the age-adjusted prevalence was 271, and the age-adjusted incidence was 10.4. The prevalence was highest in women ages 50-59 years and in the Phoenix Area IHS.

CONCLUSION

The first population-based lupus registry in the US American Indian and Alaska Native population has demonstrated that the prevalence and incidence of SLE are high. Our estimates are as high as or higher than the rates reported in the US black population.

Observation period effects on estimation of systemic lupus erythematosus incidence and prevalence in Quebec

OBJECTIVE

To determine how duration of observation affects estimation of incidence and prevalence of systemic lupus erythematosus (SLE).

METHODS

SLE incidence and prevalence estimates from data periods as brief as 3 years (2001-2003) were compared to estimates from a 15-year period (1989-2003).

RESULTS

The 15-year period incidence was 5.6/100,000 (95% CI 5.0-6.1) and the prevalence was 59.1/100,000 (95% CI 57.4-60.8). When a 3-year period was used, incidence was overestimated by 238.1% and prevalence underestimated by 66.0%.

CONCLUSION

SLE incidence and prevalence estimates vary considerably according to the observation period; more than 5 years of data is likely required.

Geoepidemiology, gender and autoimmune disease

Autoimmune diseases include more than 70 different disorders affecting over 5% of the population of the Western countries. They are mainly characterized by female predominance and have great impact on the quality of life of affected subjects. It is generally accepted that ADs are the result of a complex interaction between genetic and environmental factors; however the mechanisms involved in the loss of tolerance remain unknown. Studying the distribution of these conditions across various global regions and ethnic groups by means of geoepidemiology might readily provide epidemiological data and also advance our understanding of their pathogenesis. Indeed, geoepidemiology demonstrates that genetic susceptibility interacts with lifestyle and environmental factors, which include socioeconomic status, infectious agents (triggering or protective agents), environmental pollutants, and vitamin D (dependent on sunlight exposure), in determining the risk of developing autoimmunity and in the understanding of their female prevalence. To properly understand the geoepidemiology of human autoimmunity, it is important to consider the many pleiotropic factors which lead to its initiation. In most studies the focus has been on genetics and environment. However, in this review the focus is primarily on gender. Overall, autoimmune diseases are well known to have female predominance, but there is significant variation in geographic area. Further, the mechanisms that influence female predominance are relatively unknown. Hence the attempt in this review is to focus on these critical issues.

Maternal and fetal factors associated with mortality and morbidity in a multi-racial/ethnic registry of anti-SSA/Ro-associated cardiac neonatal lupus

BACKGROUND

Cardiac manifestations of neonatal lupus include conduction disease and, rarely, an isolated cardiomyopathy. This study was initiated to determine the mortality and morbidity of cardiac neonatal lupus and associated risk factors in a multi-racial/ethnic US-based registry to provide insights into the pathogenesis of antibody-mediated injury and data for counseling.

METHODS AND RESULTS

Three hundred twenty-five offspring exposed to maternal anti-SSA/Ro antibodies with cardiac neonatal lupus met entry criteria. Maternal, fetal echocardiographic, and neonatal risk factors were assessed for association with mortality. Fifty-seven (17.5%) died, 30% in utero. The probability of in utero death was 6%. The cumulative probability of survival at 10 years for a child born alive was 86%. Fetal echocardiographic risk factors associated with increased mortality in a multivariable analysis of all cases included hydrops and endocardial fibroelastosis. Significant predictors of in utero death were hydrops and earlier diagnosis, and of postnatal death were hydrops, endocardial fibroelastosis, and lower ventricular rate. Isolated heart block was associated with a 7.8% case fatality rate, whereas the concomitant presence of dilated cardiomyopathy or endocardial fibroelastosis quadrupled the case fatality rate. There was a significantly higher case fatality rate in minorities compared with whites, who were at a lower risk of hydrops and endocardial fibroelastosis. Pacing was required in 70%; cardiac transplantation was required in 4 children.

CONCLUSION

Nearly one fifth of fetuses who develop cardiac neonatal lupus die of complications predicted by echocardiographic abnormalities consistent with antibody-associated disease beyond the atrioventricular node. The disparity in outcomes observed between minorities and whites warrants further investigation.