Association of Race and Risk of Future Scleroderma Renal Crisis at Systemic Sclerosis Diagnosis

Objective Scleroderma renal crisis (SRC) is a rare and severe manifestation of systemic sclerosis (SSc). Although it is well documented that Blacks with SSc have worse morbidity and mortality than non-Blacks, racial predilection for SRC is underreported. We examine the association of race and future development of SRC in an SSc cohort. Methods Using the electronic health record of the United States Military Health System, we conducted a comprehensive chart review of each patient with SSc from 2005 to 2016. The final study cohort was comprised of 31 SRC cases and 322 SSc without SRC controls. We conducted logistic regression of SRC as the outcome variable and race (Black vs. non-Black) as the primary predictor variable, adjusted for age, estimated glomerular filtration rate, hypertension and proteinuria at SSc diagnosis. Results Out of 353 patients, 294 had identifiable race (79 Black, 215 non-Black). Thirteen out of 79 Blacks (16.5%) vs. 16/215 (7.4%) non-Blacks developed SRC (p=0.02). On adjusted analysis, Blacks had a significantly higher risk of developing SRC than non-Blacks (odds ratio 6.4, 95% CI 1.3-31.2, p=0.02). Anti-Ro antibody was present in a higher proportion of Black SRC patients vs. Blacks without SRC [45% vs. 14%, p=0.01]. Conversely, older age, thrombocytopenia, and anti-RNA polymerase III antibody at SSc diagnosis were significantly associated with future SRC in the non-Black cohort. Conclusion Black race was independently associated with a higher risk of future SRC. Further studies are needed to elucidate the mechanisms that underlie this important association. This article is protected by copyright. All rights reserved.