Association of albumin to urea nitrogen ratio with 30-day mortality in adult hemophagocytic lymphohistiocytosis: a retrospective cohort study

Hemophagocytic lymphohistiocytosis (HLH) is a severe disease with a grim prognosis. This study aims to investigate the potential role of albumin to urea nitrogen ratio (AUR) as a predictor of 30-day mortality in adult HLH patients. This retrospective analysis involved patients admitted to the hospital with a first-time diagnosis of HLH between January 2015 and September 2021. The primary outcome was defined as 30-day all-cause mortality. Patients were categorized as survivors and non-survivors, as well as test and validation cohorts. Clinical signs and laboratory biomarkers on admission were picked up. A total of 467 patients were included in the study, with a 30-day mortality rate of 31.0% (n = 145). There were no significant differences observed between the test and validation cohorts. Surviving patients exhibited significantly higher levels of AUR. Multivariate analysis indicated that an AUR < 3.40 was deemed to be an independent risk factor (test cohort: HR: 3.663, P < 0.001; validation cohort: 2.475, P = 0.013; total cohort: 2.976, P < 0.001). The area under the receiver operating characteristic curve (AUC) values were 0.734 in the test cohort, 0.690 in the validation cohort, and 0.711 in the total cohort. AUR emerged as an independent and reliable risk indicator for 30-day mortality in adults with HLH, offering clinicians a tool to identify high-risk patients efficiently.