IL6 and rheumatoid arthritis: Several studies have observed that serum cortisol concentrations in adults rheumatoid arthritis (RA) and other inflammatory diseases are disproportionally low relative to the level of inflammation [5] Bilginer et al. showed that JIA patients with active disease have low early morning serum cortisol levels as well as low adrenocorticotropic hormone (ACTH) levels that correlate with high IL-6 levels as seen in active disease [6].