Abstract
Objective: To evaluate the prognostic importance of sex in lupus nephritis (LN).
Methods: A retrospective cohort of 921 biopsy-confirmed LN patients, diagnosed between 1996 and 2018, was analyzed. Demographics, clinical characteristics, laboratory findings, and renal pathology were assessed. The primary outcome was mortality, and the secondary outcomes included doubling of serum creatinine and end-stage renal disease (ESRD). Sex-associated risks were evaluated using Cox regression models.
Results: Among the 921 patients, 157 (17%) were male and 764 (83%) were female. Male patients exhibited more aggressive features: higher blood pressure, earlier disease onset, and elevated levels of serum creatinine (Scr), uric acid, blood urea nitrogen. Intriguingly, male patients also displayed more severe histopathological alterations, such as more karyorrhexis, cellular crescents/cellular fibrous crescents formations and tubular atrophy, even when overall renal pathology was comparable between sexes. During a median follow-up of 112 months, mortality was registered in 141 patients (15.3%). Mortality rates were conspicuously higher in males (24.2% males versus 13.4% females, P = 0.0029). Secondary outcomes did not show significant sex differences. Cox regression analysis highlighted male, age on renal biopsy, Scr, and Chronicity Index (CI) as independent risk factors for survival in LN patients. Notably, infections emerged as the leading cause of mortality among LN patients, with a significant higher rate in male patients.
Conclusion: In our cohort with LN, there was a higher rate of all-cause mortality and proportion of infection-related death in male. Recognizing and further exploring these sex disparities is crucial for optimized LN patient care.