Plasma Cytokine Fluctuations Over Time in Healthy Controls and Patients with Fibromyalgia. Exp Biol Med (Maywood). 2008 Dec 8. [Epub ahead of print] Togo F, Natelson BH, Adler GH, Ottenweller JE, Goldenberg DL, Struzik ZR, Yamamoto Y. Department of Work Stress Control; Japan National Institute of Occupational Safety and Health. PMID: 19064941 We examined the pattern of cytokine secretion across the 24 hr day for women with widespread pain and tenderness having the diagnosis of fibromyalgia (FM) and matched healthy controls. Subjects were given time to habituate to being in a clinical research laboratory environment and then were sampled for cytokines without their being disturbed for a 24 hr period including an 8 hr sleep period. Cytokine levels were uniformly low but characterized by bursts of secretion. Bursting occurred either in singlets or in doublets with a range from 88 to 131 min between doublets. There was an element of synchronization of these bursts with most occurring at the beginning of sampling. FM patients showed a shift to increased IL-10 in the night-time compared to controls. The relation between this anti-inflammatory cytokine to the pro-inflammatory cytokines studied also differed between groups: FM patients showed a reduced ratio of IL-10 burst amplitude to that of pro-inflammatory cytokines IL-1beta, IL-8, and TNF-alpha. We interpret this to indicate a skew away from the normal balance favoring pro-inflammatory cytokines in controls toward one favoring an anti-inflammatory response in FM. These changes toward anti-inflammatory predominance in FM may explain their common complaint of disturbed sleep because these cytokines are known to disrupt sleep.