Serum copper and caeruloplasmin are higher in seropositive than seronegative rheumatoid arthritis.

Increased serum copper (sCu) and alpha 2 caeruloplasmin (alpha 2 sCP) concentrations have been reported in patients with rheumatoid arthritis and other inflammatory conditions. Close parallel changes of sCu and alpha 2 sCP in rheumatoid arthritis have recently been observed by us in 30 subjects. The 'IgM rheumatoid factor positive (IgM-RF)' patients showed higher sCu and alpha 2 sCP concentrations when compared with 'IgM-RF negative'. Moreover a significant correlation was found between sCu alpha 2 sCP and other humoral indexes altered in rheumatoid arthritis. Therefore it seems useful, as further index of inflammation, to test both sCu and alpha 2 sCP.