Systemic lupus erythematosus (SLE) is associated with significantly reduced survival among critically ill patients admitted to intensive care units, with renal dysfunction emerging as a key mediator of this risk, according to a large retrospective study using U.S. critical care data.
Researchers analysed data from 50,920 critically ill adults included in the MIMIC-IV database between 2008 and 2019, comparing outcomes between patients with and without comorbid SLE. To reduce bias, matching techniques were used to control for known confounders, and survival outcomes were assessed using Cox regression and mediation analyses.
Lower 180-Day Survival in ICU Patients With SLE
Patients with SLE demonstrated significantly poorer 180-day survival compared with matched controls. The presence of SLE was associated with a 48% increased risk of death within 180 days of ICU admission (hazard ratio 1.485; P=0.015). While several laboratory and clinical variables were associated with mortality in univariate analyses, only markers of renal function remained significant after multivariate adjustment.
Specifically, elevated serum creatinine levels and reduced urine output were independently associated with mortality, highlighting kidney dysfunction as a central determinant of prognosis in critically ill patients with lupus.
Renal Dysfunction Identified as a Key Mediator
Mediation analysis confirmed that renal impairment, represented by creatinine levels, significantly mediated the relationship between SLE and reduced survival. This suggests that lupus-related kidney injury plays a pivotal role in driving adverse outcomes during critical illness, rather than broader haematological or inflammatory abnormalities alone.
These findings underscore the vulnerability of patients with lupus to acute and chronic renal insults in the ICU setting and highlight the importance of early identification and management of kidney dysfunction in this population.
Glucocorticoid Use May Attenuate Mortality Risk
The study also explored the impact of glucocorticoid therapy on survival outcomes. Notably, patients with SLE who received glucocorticoids did not experience a statistically significant reduction in survival compared with controls. In contrast, SLE patients not treated with glucocorticoids showed a significantly higher mortality risk.
Although observational in nature, these findings suggest that glucocorticoid therapy may partially mitigate the survival disadvantage associated with SLE in critically ill patients, potentially by modulating inflammatory or immune-mediated renal injury.
Clinical Implications
The authors conclude that SLE independently reduces ICU survival, primarily through renal dysfunction. Targeted renal monitoring and optimisation, alongside appropriate immunomodulatory therapy, may be crucial strategies to improve outcomes for critically ill patients with lupus.
Reference
Zhang H et al. Systemic lupus erythematosus reduces survival of ICU patients mediated by renal dysfunction: retrospective study of critically ill patients. BMC Rheumatol. 2025;DOI: 10.1186/s41927-025-00600-0.
