Circadian relationships between interleukin (IL)-6 and hypothalamic- pituitary-adrenal axis hormones: failure of IL-6 to cause sustained hypercortisolism in patients with early untreated rheumatoid arthritis. - Crofford,LJ.; Kalogeras,KT.; Mastorakos,G. (J Clin Endocrinol Metab, 1997)