Investigators have identified risk factors for development of end-stage kidney disease (ESKD) after a systemic lupus erythematosus (SLE) diagnosis, according to a recent report.
These risk factors include proteinuria within the first year of diagnosis, Black race, younger age at diagnosis, and low C3 level.
In the Hopkins Lupus Cohort, 151 of 2528 patients with SLE progressed to dialysis or renal transplantation. The estimated risk of kidney failure was 2.7% within 5 years, 4.8% within 10 years, and 8.4% within 20 years of SLE diagnosis, Michelle Petri, MD, MPH, of Johns Hopkins University School of Medicine in Baltimore, Maryland, and colleagues reported in the Journal of Rheumatology. However, the 10- and 20-year risk of ESKD increased to 10.8% and 20.0%, respectively, for patients who had proteinuria within the first year of diagnosis.
In a multivariable Cox proportional hazards model, proteinuria at diagnosis significantly correlated with a 2.8-fold increased risk of kidney failure. Ever having a low C3 level significantly doubled the risk of ESKD. Low C3 was significantly associated with a 7% and 11.1% risk of kidney failure within 10 and 20 years of diagnosis, respectively, even after adjustment for confounding variables.
A strength of the study was the relatively large proportion of Black adults. Black individuals made up 39% of cohort, and White individuals 53%. Black patients had a significant 1.8-fold greater risk of requiring renal replacement therapy compared with White patients, the investigators reported. Conversely, being diagnosed at age 40 years or older was significantly associated with a 49% lower risk of kidney failure than being diagnosed at an age younger than 30 years.
“We think these predictors of renal failure in SLE will be immediately useful in clinical practice to identify patients who might benefit from more aggressive treatment,” Dr Petri’s team wrote. “In particular, those with [lupus nephritis] in the first year after diagnosis have a greatly increased risk of later renal failure that would justify more aggressive induction therapy.”
Petri M, Barr E, Magder LS, et al. Risk of renal failure within 10 or 20 years of systemic lupus erythematosus diagnosis. Journal of Rheumatology. 2021;48:222-7. doi:10.3899/jrheum.191094