[Endocrine rhythms in patients with rheumatoid arthritis: possible neurohormonal influence on immunological...

Recent studies are reporting on an influence of ACTH and prolactin in physiological dosages on the intensity of the immune response in the animal model of adjuvant arthritis. Therefore, we studied the circadian secretion patterns of ACTH, cortisol and prolactin by measurements throughout a 24-hour cycle in two-hour intervals in patients with rheumatoid arthritis with different inflammatory activity of the disease. We only investigated patients who never before were treated with corticosteroids and drugs like gold, d-penicillamine or immunosuppressive drugs. The circadian secretion patterns of cortisol and ACTH were disturbed in most patients. High inflammatory activity was accompanied by severe disturbance of the circadian rhythm, whereas patients with low inflammatory activity showed a nearly normal secretion pattern. Also the measurements of prolactin showed a tendency of loss of circadian rhythm in relation to the inflammatory activity of the disease. According to the found changes of endocrine regulation of ACTH, cortisol and prolactin, an influence of mediators of inflammation on hypothalamic centers, analogous to endogenous pyrogen in fever should be discussed.