Background Hyperferritinemia is associated with severe inflammatory conditions, such as rheumatic diseases with systemic inflammatory responses, and multiorgan dysfunction syndromes.
Objectives To determine which diseases are associated with hyperferritinemia in a tertiary hospital; to compare ferritin levels between these different entities and to evaluate relationship between levels of ferritin and mortality in these patients.
Methods A retrospective study was carried out in which all patients over 18 years with at least one determination of serum ferritin equal to or greater than 1000 ng/ml were identified in the laboratory database of our hospital between 1/1/2006 and 6/30/2016. Corresponding electronic medical records were reviewed and demographic data and clinical data were collected. Mortality was assessed at the end of follow-up. Descriptive statistical analysis and logistic regression analysis were performed in order to identify variables associated with mortality.
Results A total of 1979 patients were included, 1235 men (62.4%) with a mean age of 63.2 years (SD 17.2). Only 36 patients (1.8%) presented a rheumatologic diagnosis as the only cause of high levels of ferritin, with Still's disease (n=8) and systemic Vasculitis (n=9) being the main diagnoses. Table 1 shows patients' characteristics grouped according to whether the elevation of ferritin was associated with a rheumatic disease or not. Median serum ferritin and transferrin saturation in both groups were similar (see Table 1). Mortality was lower for rheumatologic causes (5.9% vs 37.2%, p<0.001). Variables that were associated with mortality in multivariable logistic regression analysis were: maximum ferritin value (OR 1,0004, 95% CI 1,0003–1,0004, p<0.001) and age (OR 1.03, 95% CI 1.02–1.04, p<0.001), whereas the diagnosis of a rheumatic disease was a protective factor (OR 0.11, 95% CI 0.03–0.47, p=0.003). ROC curve for ferritin and mortality showed an area under the curve of 0.59 (95% CI 0.58–0.62). Ferritin levels greater than 3000 ng/ml showed a specificity of 89.2% and a sensitivity of 19.7% for mortality, regardless of cause of ferritin elevation.
Conclusions Rheumatic diseases, represents a very small percentage of the causes of elevation of ferritin above 1000 ng/ml, and were associated with lower mortality than the non-rheumatic causes. Serum ferritin levels were significantly associated with increased mortality regardless of the underlying cause.
Disclosure of Interest None declared