Increased ferritin response in adult Still's disease: specificity and relationship to outcome

Background: The disproportionate ferritin response encountered in some patients with adult Still's disease (ASD) may reflect a fundamental aspect in the pathophysiology of ASD.Methods: An observational case–control study of 22 ASD patients followed for 63 months. Baseline laboratory data were compared with age‐ and gender‐matched controls with new‐onset rheumatoid arthritis (RA). Serum levels of ferritin and C‐reactive protein (CRP) and the ferritin/CRP ratio were related to clinical outcome in ASD through nonparametric statistical analyses.Results: Compared to RA patients, haemoglobin levels were lower (11.8 vs. 13.5 g/dL; p = 0.009) and leucocyte counts (17.1 vs. 8.6 109/mL; p<0.001), erythrocyte sedimentation rate (ESR) (84 vs. 38 mm; p = 0.001), CRP (154 vs. 27 mg/L; p<0.001), aspartate aminotransferase (ASAT) (52 vs. 23 U/l; p = 0.004), serum ferritin (8750 vs. 62 µg/L; p<0.001) and ferritin/CRP ratios (9.7 vs. 1.7; p<0.001) were higher in ASD patients at baseline. Six patients (27%) achieved sustain...