Serum levels of pregnenolone and 17-hydroxypregnenolone in patients with rheumatoid arthritis and systemic lupus erythematosus: relation to other adrenal hormones

OBJECTIVE: In patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), low levels of adrenal steroids have been repeatedly demonstrated, but the site of alteration has not been exactly described because measurements of serum pregnenolone and 17-hydroxypregnenolone (17OHPreg) together with other adrenal steroids have never been performed. METHODS: We measured serum levels of adrenal hormones such as pregnenolone, 17OHPreg, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), progesterone (P), 17-hydroxyprogesterone (17OHP), androstenedione (ASD), and cortisol in 24 healthy controls, 24 patients with RA, and 24 patients with SLE. RESULTS: Serum levels of pregnenolone were similar in RA and SLE patients as compared to healthy controls irrespective of prior prednisolone therapy. In all RA and SLE patients (including those with prior prednisolone treatment), serum levels of all measured hormones except pregnenolone were significantly lower as compared to controls. In RA patients without prior prednisolone treatment, serum levels of 17OHPreg, DHEA, cortisol, and ASD were similar to controls, and serum levels of P, 17OHP, and DHEAS were significantly lower as compared to controls. In SLE patients without prior prednisolone treatment, serum levels of 17OHPreg and cortisol were similar, and serum levels of P, 17OHP, ASD, DHEA, and DHEAS were significantly lower as compared to controls. CONCLUSION: The primary hormone of the adrenal steroid cascade, pregnenolone, is almost normal in RA and SLE irrespective of corticosteroid treatment. In patients with RA, we believe that there is a near normal P450scc reaction and a normal double step P450c17 reaction. In SLE patients, the P450scc reaction also seems normal but the second step of the P450c17 reaction seems to be inhibited. In both diseases, cortisol levels remain relatively stable at the expense of other adrenal hormones. This study revealed distinct changes of steroid pathways that are related to the disease entities.