While the risk of developing lupus nephritis (LN) is higher among younger, non-White patients, overall survival rates among those with systemic lupus erythematosus (SLE) may be improving over time, according to study results published in Rheumatology (Oxford).
The aim of the study was to assess the effect of patient factors on risk for mortality and LN among patients with SLE.
The retrospective survival analysis included patients with SLE at a single center in the United Kingdom, all of whom had available data on follow-up duration, year of death, year of LN diagnosis, and censor date where applicable. The study population was grouped by sex, age at start of follow-up, time period of diagnosis, and ethnicity, namely, groups 1 (1978-1989), 2 (1990-1999), 3 (2000-2005), and 4 (2006-2011). Differences between the groups were examined using Kaplan-Meier analysis.
A total of 496 patients with SLE (group 1, n=89; group 2, 155; group 3, n=112; group 4, n=140) were included in the study. Among the study population, 18.3% (n=91) died, 33.3% (n=165) developed LN, and 7.1% (n=35) developed both LN and died. A total of 4 patients died from only LN. The rate of end-stage kidney disease was 6.7% among patients with LN.
The development of LN was significantly less likely among White patients compared with patients of other ethnicities (P <.0001), though the likelihood of death was similar (P >.05). Diagnosis before the median age of 28 years was significantly associated with LN development (P <.0001) and a lower likelihood of death (P =.0039). The likelihood of survival was found to have significantlyimproved significantly over time (intergroup difference between groups 1 and 4, 38.2% vs 2.9%, respectively; P =.0186). The diagnosis of LN also increased significantly in group 3 compared with other groups (P <.05).
Limitations to this study included the use of a single study center, changes in care practices during the course of the study period, and the possibility that individuals with advanced kidney failure and LN may not have been referred.
The study researchers concluded, “[M]ortality does seem to be improving in patients diagnosed more recently.” They also noted, “Greater mortality in [Black] patients with SLE may be a specific USA finding related to socioeconomic factors.”
Luo W, Farinha F, Isenberg DA, Rahman A. Survival analysis of mortality and development of lupus nephritis in patients with systemic lupus erythematosus up to 40-years of follow-up. Published online April 12, 2022. Rheumatology. doi:10.1093/rheumatology/keac218