The study: Plantinga LC, Yazdany J, Pearce BD, et al. Fluid cognition among individuals with systemic lupus erythematosus. Arthritis Care Res (Hoboken). 2024 Mar 25.
Prevalence of SLE & Severe Restrictive Lung Disease in Hispanic Patients with SSc
By Bochra Jandali, MD, & Shervin Assassi, MD, MS
Why was this study done? It is well known that systemic sclerosis (SSc) manifestations vary in different ethnic groups around the world. In the U.S., previous studies have shown that patients who are Black have earlier disease onset and overall worse disease outcomes when compared with patients who are white. Few studies have examined disease characteristics in Hispanic patients, and those had conflicting results. Our prospective, observational study focused on SSc disease features and outcomes in Hispanic Americans in comparison with non-Hispanic white and Black American patients.
What were the study methods? We enrolled patients who fulfilled the classification criteria for SSc and had a disease duration less than five years who self-identified as white, Black or Hispanic. Demographics, disease duration, autoantibodies and comorbidities were captured at the baseline visit. Longitudinal clinical characteristics were collected prospectively every six months for three years, then annually. Autoantibodies were determined using reference methods in our research laboratory. Generalized linear mixed models for the longitudinal analysis and Cox proportional hazards regression for the mortality analysis were used.
What were the key findings? A cohort of 427 patients, comprising 124 Hispanic, 220 non-Hispanic white, and 83 non-Hispanic Black participants was examined. We found that Hispanic patients were significantly younger, but had longer disease duration at enrollment, higher frequency of U1-RNP positivity and more frequent concurrent systemic lupus erythematosus (SLE) diagnosis. They also had lower income and educational levels in comparison with non-Hispanic white patients. In the longitudinal analysis, Hispanic patients had significantly lower forced vital capacity percent predicted (average 9.3% lower FVC% over time) than non-Hispanic white, but not Black patients. Hispanic patients also had higher mortality rates than white Americans, even after adjustment for age, gender and socioeconomic status.
What were the main conclusions? Hispanic American patients differ in disease characteristics from white patients. They are younger at diagnosis, more likely to have U1-RNP positivity and overlap with SLE. Moreover, Hispanic patients have more severe restrictive lung disease and higher mortality even after adjustment for demographic and socioeconomic factors.
What are the implications for patients and clinicians? Our study revealed significant differences in demographics, SSc clinical presentation and severity in Hispanic patients when compared with white patients. These results support the importance of enhancing physician awareness of the higher prevalence of SLE overlap in Hispanic SSc patients and the tendency to have more severe restrictive lung disease. This may help risk stratify patients to receive more aggressive monitoring/treatment strategies, with the ultimate goal of improving disease outcomes and survival.
