Clinical characteristics, outcome and prognostic factors in critically ill patients with lupus nephritis

Objective To describe the clinical characteristics and outcome of patients with lupus nephritis (LN) in intensive care unit (ICU), identify prognostic factors and construct a predictive model of in-ICU survival. Methods A total of 505 ICU admissions of lupus patients were screened and LN patients confirmed by renal biopsy were enrolled. Clinical characteristics and outcome of patients in ICU were collected. A logistic regression analysis was performed to identify independent prognostic factors and a nomogram was plotted to construct a predictive model. Results A total of 70 patients with LN were enrolled. The median age of the patients was 28.5 years, and the median course of LN was two months. Renal pathology classes indicated that 38 patients were class IV, 11 were class IV+V, and 10 were class III. The most common primary cause of ICU admission was infection in 40 patients, followed by LN in 11 patients. Forty-one patients died in ICU. The multivariate analyses revealed that lactic acid (OR 1.682 [2.130-17.944], p=0.001), gamma-glutamyl transpeptidase (OR 1.057 [1.009-1.107], p=0.020), APACHE II (OR 3.852 [1.176-12.618], p=0.026), vasopressor (OR 10.571 [1.615-69.199], p=0.014) and platelet count (OR 0.967 [0.941-0.993], p=0.013) were independently associated with ICU survival of critical LN patients. A predictive model was constructed and validated. Conclusion This study is the first to elucidate the features and identify prognostic factors in critically ill patients with LN. These findings could help clinicians to early identify high-risk patients of mortality, which consequently may reduce the mortality of critically ill patients with LN.