Serum and urinary ferritin levels in patients with rheumatoid arthritis.

The serum and urinary ferritin levels in 52 RA patients were measured by the 2-site immunoradiometric assay method. Serum ferritin levels in RA patients correlated with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) but not with serum iron levels and hemoglobin concentrations, although they were within the normal range. High serum ferritin levels were associated with sera with hyper gamma-globulin and rheumatoid factors. In sequential studies, serum ferritin changed in parallel with ESR, CRP and disease activity in a majority of the patients. The urinary ferritin levels and u/s ratios in some RA patients were higher than control values. Higher values were found particularly in the group of patients under gold therapy but not in groups under other treatments.