Plasma and Total Blood Cell Copper in Rheumatoid Arthritis

The results summarized above confirm that copper increases in the plasma and in the cell fraction of blood of RA patients, as reported in a previously published work [3]. In RA patients, the plasma copper concentration values may barely discriminate patients in remission, whereas total blood cell copper concentration seems to be more strictly correlated with the severity of the disease. Similar data were obtained studying the copper concentration in plasma and total blood cells in complete-adjuvant tail-injected female rats during the symptomatic phase of the disease [1]. In fact plasma copper concentration was found unable to discriminate severe (high score) from moderate (low score) arthritic rats, whereas the concentration of the metal in the cell fraction of blood of high score rats was found significantly higher not only when compared with control animals but also when compared with the low score group. This statistically significant increase of total blood cell copper may be the expression of an increase of the intra-cellular enzyme superoxide dismutase (SOD) although some authors have actually found a decrease of erythrocyte SOD activity in this disease [5]. Alternatively it may indicate an increase of the non-SOD-bound fraction of red cell copper, which may, in turn, suggest an increase in the non-cerulo-plasmin-bound fraction of plasma copper, which is possibly in equilibrium with the former [6].