Ferritin is an iron deposition protein and a commonly ordered clinical test. While high levels may signify iron deposition, the majority are due to metabolic, inflammatory, infectious, and malignant disorders. The association between ferritin elevations < 1000 μg/L and long-term mortality is well demonstrated. The association between extreme ferritin elevations, namely ferritin levels over 10,000 μg/L, and short-term mortality, as well as predictors of mortality, has not been defined.

A retrospective chart study was designed in an academic hospital to analyze the clinical, laboratory, and mortality characteristics of patients whose ferritin is over 10,000 μg/L. Patients from 2012 to 2023 in a large academic center’s electronic medical records were analyzed. Demographics, underlying disorders, laboratory values, mortality status, and days to mortality were acquired. Multivariate logistic regression analysis was used to define predictors of mortality. The Kaplan–Meier survival curve was used to analyze survival.

Sixty-seven patients were identified to have ferritin levels over 10,000 μg/L. The most common underlying disorders were infectious diseases and malignancies. Predictors of mortality in the multivariate logistic regression model were also infectious disease (odds ratio (OR) = 5.35), and malignancy (OR = 6.56), as well as age (OR = 1.05). The area under the curve of the model was .86. 1-year mortality was 62%. Of the patients who died, median survival was 5 days; 30- and 90-day mortality were 80% and 92%, respectively.

Extreme hyperferritinemia is associated with high short-term mortality. Ferritin can be used as a marker of poor prognosis, particularly among patients with infection and malignancy.