Superoxide dismutase isoenzymes, glutathione peroxidase and selenium in blood from HLA-B27-positive and -negative subjects.

We studied the activity of superoxide dismutase (SOD) isoenzymes (CuZnSOD, cyanide-resistant MnSOD and extracellular SOD), the concentration of plasma selenium (P-Se), and the activities of CuZnSOD and glutathione peroxidase (GSHPx) in erythrocytes of 10 HLA-B27-positive and 10 HLA-B27-negative subjects whose sera had shown high and low chemokinetic activity, respectively, on migration of polymorphonuclear leukocytes (PMN) in vitro. No significant difference was found between the groups, suggesting that the enhanced chemokinetic activity of HLA-B27-positive sera does not derive from an aberration in serum anti-oxidant potentials. The results were also analysed on the basis of HLA-DR specificities; HLA-DR4-positive plasma samples had significantly lower levels of Se than HLA-DR4-negative ones. We therefore carried out a second series of experiments with sera of 37 subjects; the levels of P-Se in HLA-DR4-positive and -negative groups were much the same, as were the activities of GSHPx. The data suggest that there is no gross aberration in P-Se concentration in HLA-DR4-positive subjects.