Serum ferritin and outcome in adult Still’s disease

The systemic onset of polyarthritis in adults Adult type of Still’s disease (ASD), initially described by Wissler as an inflammatory multisystem disease of unknown origin has a pleiomorphic clinical presentation and is usually diagnosed per exclusionam in the context of a specific set of symptoms. In the absence of a single diagnostic marker, clinical criteria assist in classifying patients More recently several reports confirmed the diagnostic usefulness of serum ferritin levels in identifying ASD patients and it has even been suggested that elevated serumferritin levels be included as a classification criterion. While the cause for the strong increases in serumferritin levels in ASD is unknown, similarities with malignant histiocytosis and hemophagocytic syndrome together with the associated increases in IL-6 , IL-18 and TNF-alpha levels suggest that activation of the histiocyte-macrophage system is a main feature of ASD. The outcome for patients with ASD is highly variable and more than half of all patients have a poor functional outcome, that seems mainly determined by non-remittance of the disease. As serumferritin levels may reflect basic pathophysiology in ASD, we aim to investigate whether serumferritin could serve a predictor for the disease course.