Infectious Complications and Prognostic Factors of Mortality in Patients with Lupus Nephritis Admitted to Intensive Care Units

<b>Objective:</b> To determine infectious complications and explore potential prognostic factors associated with mortality in patients with lupus nephritis (LN) admitted to the intensive care unit (ICU). <b>Methods:</b> We conducted a retrospective analytical study of 20 patients with biopsy-proven LN admitted to a tertiary ICU between 2022 and 2023. Clinical, histopathological, microbiological, and paraclinical data were collected. Associations with mortality were explored using Firth's penalized logistic regression. <b>Results:</b> The mean age was 37 ± 14 years; 85% were female. Hypertension (50%) was the most frequent comorbidity. Mean ICU stay was 13 ± 27 days; in-hospital mortality was 15%, and 60% required hospital readmission. Sepsis was the leading reason for ICU admission (55%), predominantly respiratory and gastrointestinal. In the exploratory analysis, respiratory tract infection (OR 1.43; 95% CI: 1.19-9.90; <i>p</i> = 0.04), proliferative LN (OR 2.12; 95% CI: 1.32-17.34; <i>p</i> = 0.03), and hypocomplementemia (C3) (OR 1.72; 95% CI: 1.25-10.40; <i>p</i> = 0.02) showed point estimates suggestive of higher odds of mortality. <b>Conclusions:</b> In this cohort of critically ill patients with LN, respiratory tract infection, proliferative histological class, and hypocomplementemia were associated with higher mortality. These findings require validation in larger prospective studies to determine their utility in risk stratification and ICU management.