Some pro-inflammatory cytokines elevated in fibromyalgia; correlation with pain intensity
This is an important publication because it clearly demonstrates that fibromyalgia is a disease of inflammation and that symptomatic relief can be achieved through the reduction of inflammation.
Higher than normal levels of pro-inflammatory cytokines in the blood indicate ongoing inflammation. When inflammation is relieved, as demonstrated by a reduction in those pro-inflammatory cytokines, symptoms improve – pain decreases.
Results of the investigation
Initial findings in fibromyalgia patients:
IL-8 levels are high
TNF levels are high
IL-6 levels are normal
IL-4 levels are normal
IL-10 levels are normal (IL-10 is an anti-inflammatory cytokine)
Once treatment begins:
TNF levels drop quickly, by 10 days, and remain low through 6 months after treatment.
IL-8 is substantially decreased by six months.
Pain reduction does not correlate with TNF levels.
Pain reduction does correlate with IL-8 levels.
The authors conclude that pro-inflammatory cytokines TNF and IL-8 are involved in FM, but that they most likely do not directly cause the pain of fibromyalgia.
Nonetheless, IL-8 may be very closely associated with pain, because the pain decreases when levels of IL-8 decrease.
IL-8 is frequently associated with inflammation. An excess of IL-8 has been demonstrated in certain cancers, inflammatory bowel disease, psoriasis and other ailments. Its excess clearly demonstrates an ongoing inflammatory condition.
Circulating cytokine levels compared to pain in patients with fibromyalgia — a prospective longitudinal study over 6 months.
Summary of the abstract
OBJECTIVE: This prospective study examined circulating cytokines in patients with fibromyalgia (FM) over 6 months rather than at only one time point, and investigated correlations between serum cytokine concentrations and pain intensity in FM patients receiving multidisciplinary pain therapy.
RESULTS: On admission, serum levels of IL-8 and TNF-alpha, but not IL-6, were elevated in patients with FM.
No significant difference in IL-4 and IL-10 was found between FM patients and controls. High IL-8 levels remained consistent during the followup, but TNF-alpha was already reduced after 10 days and until 6 months after therapy.
After 6 months’ treatment with multidisciplinary pain therapy, IL-8 and TNF-alpha levels were significantly lower than at the beginning.
IL-8 but not TNF-alpha serum levels were correlated with pain intensity in FM patients after 6 months’ multidisciplinary pain therapy.
CONCLUSION: Our results suggest that pro-inflammatory cytokines TNF-alpha and IL-8 are involved in FM, but they do not apparently provoke the pain of FM directly. Multidisciplinary pain therapy modified the cytokine profile in patients with FM during the observation period.