RELATIONSHIP BETWEEN BLOOD AND JOINT TISSUE DHEAS LEVELS IN RHEUMATOID-ARTHRITIS AND OSTEOARTHRITIS

To assess the relationship between blood and tissue steroid levels, co rtisol and dehydroepiandrosterone sulphate (DHEAS) were measured by ra dioimmunoassay (RIA) in blood and joint tissues from a group of patien ts with RA (N = 29) ranging in age from 26 to 80 years (mean 63, SD: 1 3) and another group with secondary osteoarthritis (OA; N = 23), rangi ng in age from 47 to 86 years (mean 66, SD: 9), all of whom were sched uled for surgical correction of joint dysfunction. Seventeen of the RA patients were on steroid treatment at the time of the study. Assessin g all the patients together, it was found that the tissue concentratio ns of DHEAS very closely paralleled the blood levels (r = 0.875; p < 0 .001). The mean blood and tissue concentrations of DHEAS were found to be significantly reduced in RA, compared to those in OA (geometric me ans 540 vs. 2100 nmol/l blood, respectively, and 160 vs. 420 nmol/kg t issue, p < 0.001). Individual data indicated, however, that: (a) 3/29 patients with RA exhibited normal levels; (b) the reduction was more a ccentuated in those patients on steroid treatment; and (c) 5123 patien ts with OA, who were treated for cardiovascular disorders, also had re duced DHEAS levels. Significant differences were not found between the mean cortisol levels in RA and those in OA, nor was there a correlati on between the blood and tissue levels of this steroid. The possible i nfluence of reduced DHEAS levels on immune-mediated diseases and/or pa thophysiology is unknown, and needs to be investigated.