Psoriatic arthritis: clinical improvement and correlation with hormone axes in etanercept-treated patients.

In a chronic inflammatory disease, such as rheumatoid arthritis (RA), the hypothalamic-pituitary-adrenal axis is altered in three ways: (1) the inflammation-related spontaneous and stimulated secretion of cortisol is inadequate; (2) the inflammation-related secretion of adrenocorticotropic hormone (ACTH) is low; and (3) the levels of adrenal androgens decrease. In patients with RA, long-term therapy with anti-TNF therapy sensitizes the pituitary gland and improves adrenal androgen secretion. We have recently found that the mean serum levels of ACTH, cortisol, 17-hydroxyprogesterone (17OHP), and androstenedione (ASD) in 11 prednisolone-naïve patients with psoriatic arthritis did not markedly change during 12 weeks of etanercept treatment, nor did the serum cortisol/ACTH ratio. However, the greater increase in serum cortisol in comparison with serum 17OHP or ASD was related to clinical improvement, which indicates that the improvement was more related to the higher cortisol levels.