Letter: Significance of plasma copper and caeruloplasmin concentrations in rheumatoid arthritis

Changes in zinc, copper and selenium status during adjuvant-induced arthritis in rats

Trace elements such as zinc, copper and selenium are involved in the pathogenesis of inflammatory diseases. In order to obtain more information about the overall movements of these minerals during the evolution of an experimental chronic inflammatory process, trace element levels were determined in five body compartments of the rat at several time intervals after induction of adjuvant arthritis. Rapid and significant changes in plasma zinc and copper levels and in liver zinc levels were observed. These modifications occurred as early as those in biochemical parameters of inflammation such as serum fibrinogen and ceruloplasmin, and preceded the appearance of any clinical symptom of the disease. Inverse correlations were found between plasma zinc levels and these two biochemical indices. Other modifications in trace element levels were observed two weeks after disease induction, the most important being a considerable increase in liver copper levels. Although food intake of affected animals decreased with the progression of the disease, there was no evidence of depletion in zinc and copper levels over the study period. A redistribution of body zinc between different biological compartments (mainly plasma and liver) occurred simultaneously with an accumulation of copper in several organs. The decreasing selenium status of animals was not clearly related to the inflammatory process.

Copper and inflammation--a possible rationale for the pharmacological manipulation of inflammatory disorders

Acute and chronic inflammations are characterized, among other features, by changes in the metabolism of copper and by a widespread responsiveness to the therapy with copper-containing molecules. The exact map of inflammation-induced copper movements as well as the role played by the metal in the pathogenesis of inflammatory disorders are, however, far from being clear, and this is especially true in the case of chronic processes. Nevertheless the present knowledge suggests that the "copper approach' may provide a new way for coping with the problem of anti-inflammatory/anti-arthritic therapies. The administration of exogenous copper, and the in vivo manipulation of the endogenous metal levels are proposed as two possible therapeutic strategies, not necessarily mutually exclusive. For a better understanding of the value of such an approach, further research work is needed, especially to attain a more detailed know-how on the involved chemical forms, distribution and functions of copper in both normal as well as inflamed organisms.

Serum copper and ceruloplasmin in preterm infants: prospective study

The postnatal time courses in preterm infants (30.0 weeks mean gestational age) of serum copper and ceruloplasmin (Cp) are described and compared. Serum copper was measured by nonflame atomic absorption spectrophotometry and serum Cp was measured by both immunodiffusion (Cpi) and enzyme assay (Cpe). With the exception of Cpe between 7 and 11 weeks of age, correlations among the three laboratory parameters were excellent. Following an early rise in all values, a plateau was seen in copper and Cpi between 5 and 11 weeks; Cpe showed a discordant fall at 7 to 11 weeks of age. After 11 weeks a secondary and definitive rise in all values was seen. Examination of individual time courses indicates the existence of a subgroup of infants with falling values between 5 and 11 weeks of age. Preterm infants had significantly higher serum copper (0.53 +/- 0.05 micrograms/ml) at a mean postnatal age of 10 weeks (39-41 weeks postconception) than did full-term infants (0.44 +/- 0.04 microns/ml) of similar postconceptional age. Low serum copper values were correlated with parenteral nutrition deficient in copper, with increased growth rates, and with twin pregnancies. It is concluded that extrauterine life in preterm infants is associated with precocious rises in serum copper and Cp values. The subgroup of infants with falling values may represent subclinically copper-deficient infants. This subgroup may bias the results of grouped data downwards. A role for nutritional factors in the delayed postnatal rise of serum copper and Cp values in preterm infants cannot be excluded on the basis of current knowledge.

An evaluation of the use of electrophoresis and carbon furnace atomic absorption spectrometry to determine the copper level in separated serum protein fractions

The results of an evaluation of the use of atomic absorption spectrometry with carbon furnace atomisation to analyse the copper content of individual protein fractions separated by electrophoresis is reported. Albumin copper levels in patients with rheumatoid arthritis were found to be about 1 to 2% of the total serum copper. Both albumin and alpha 2 levels are affected by contamination from residual copper present on the strip. An investigation of this contamination indicated very low blank copper levels in the areas of the strip containing alpha 1 and beta proteins. These results, and the results of analysis of copper in the ultrafiltrate from the same serum samples, are combined to define the copper distribution in a group of patients with rheumatoid arthritis. The determinations that can most readily be carried out by this technique are discussed.