Race, Ethnicity, and Disparities in the Risk of End-Organ Lupus Manifestations Following a Systemic Lupus Erythematosus Diagnosis in a Multiethnic Cohort

Abstract

Objective: Data on the onset of lupus manifestations across multiple organ domains and in diverse populations are limited. The objective was to analyze racial and ethnic differences in the risk of end-organ lupus manifestations following systemic lupus erythematosus (SLE) diagnosis in a multiethnic cohort.

Methods: The California Lupus Epidemiology Study (CLUES) is a longitudinal study of SLE. Data on major end-organ lupus manifestations were collected and categorized by organ system: renal, hematologic, neurologic, cardiovascular, and pulmonary. Multiorgan disease was defined as manifestations in ≥2 of these distinct organ systems. Kaplan-Meier curves assessed end-organ disease-free survival, and Cox proportional hazards regression estimated the rate of end-organ disease following SLE diagnosis, adjusting for age at diagnosis, sex, and self-reported race and ethnicity (White, Hispanic, Black, and Asian).

Results: Of 326 participants, 89% were female; the mean age was 45 years. Self-reported race and ethnicity were 30% White, 23% Hispanic, 11% Black, and 36% Asian. Multiorgan disease occurred in 29%. Compared to White participants, Hispanic and Asian participants had higher rates, respectively, of renal (hazard ratio [HR] 2.9 [95% confidence interval (95% CI) 1.8-4.7], HR 2.9 [95% CI 1.9-4.6]); hematologic (HR 2.7 [95% CI 1.3-5.7], HR 2.1 [95% CI 1.0-4.2]); and multiorgan disease (HR 3.3 [95% CI 1.8-5.9], HR 2.5 [95% CI 1.4-4.4]) following SLE diagnosis.

Conclusion: We found heightened risks of developing renal, hematologic, and multiorgan disease following SLE diagnosis among Hispanic and Asian patients with SLE, as well as a high burden of multiorgan disease among CLUES participants.

Figure 1:. Proportion of participants diagnosed with end-organ disease by the first year and by the fifth year of SLE diagnosis, by organ system domain.

Graph depicts the proportion of participants diagnosed with renal, hematologic, neurologic, cardiovascular, pulmonary, and multiorgan disease by the first year and by the fifth year of SLE diagnosis, including participants diagnosed with end-organ disease prior to SLE diagnosis. Categories of end-organ disease were defined by specific manifestations as follows: renal disease (lupus nephritis), hematologic disease (immune thrombocytopenic purpura, autoimmune hemolytic anemia, thrombotic thrombocytopenic purpura), neurologic disease (seizure, stroke, peripheral/cranial neuropathy, mononeuritis multiplex, myelitis), cardiovascular disease (heart failure, myocardial ischemia/infarction, cardiac arrythmia, Libman-Sacks endocarditis), pulmonary disease (interstitial lung disease, pulmonary hypertension), and multiorgan disease (manifestations in ≥2 of the following distinct end-organ domains: renal, hematologic, neurologic, cardiovascular, and pulmonary disease).

Figure 2:. Time to onset of end-organ disease following SLE diagnosis in the CLUES cohort by race and ethnicity.

Kaplan-Meier curves depict time to onset of end-organ disease following SLE diagnosis, stratified by race and ethnicity. 2A) renal disease (lupus nephritis); 2B) hematologic disease (immune thrombocytopenic purpura, autoimmune hemolytic anemia, thrombotic thrombocytopenic purpura); 2C) neurologic disease (seizure, stroke, peripheral/cranial neuropathy, mononeuritis multiplex, myelitis); 2D) and cardiovascular disease (heart failure, myocardial ischemia/infarction, cardiac arrythmia, Libman-Sacks endocarditis).

Figure 3:. Time to onset of multiorgan disease following SLE diagnosis in the CLUES cohort by race and ethnicity.

The Kaplan-Meier curve depicts time to onset of multiorgan disease following SLE diagnosis, stratified by race and ethnicity. Multiorgan disease was defined as manifestations in ≥2 of the following distinct end-organ domains: renal, hematologic, neurologic, cardiovascular, and pulmonary disease.