WURZBERG, Germany—New research showing that patients with chronic  widespread pain have significantly lower levels of the anti-inflammatory cytokines Interleukin (IL)-4  and IL-10 may help doctors develop a cytokine expression profile that can aid in the diagnosis of fibromyalgia. The new findings appear in to the August issue of Arthritis & Rheumatism. ¹

To date there is no diagnostic test for fibromyalgia. "If one combines the cytokines we measured and possibly others to be studied in the future, one might arrive at cytokine profiles with higher specificity, [and] these might then even be used as biomarkers for fibromyalgia, but more research is needed before such a goal can be reached," lead researcher Nurcan Üçeyler, MD, of Julius-Maximilians University in Wurzburg, Germany, told CIAOMed.

Researchers Examined FM, Other Chronic Pain

In the new study, researchers analyzed cytokines in 40 patients with chronic widespread pain (26 of whom had fibromyalgia), 40 controls, and an additional group of 15 patients. The 40 pain patients had received intravenous immunoglobulin (IVIG) for pain that was not responsive to standard therapy, while the additional 15 patients did not receive IVIG. Researchers analyzed expression of messenger RNA (mRNA) for IL-2, IL-4, IL-8, IL-10, tumor necrosis factor  (TNF- ), and transforming growth factor  1 (TGF 1) in peripheral blood. Patients rated their pain, fatigue, mood, cognitive function, and sleep quality on an ascending scale of 1 to 10.

Patients in the pain group did not differ in the expression of IL-2, IL-8, and TNF-α, but they did have significantly lower levels of the of the Th2 cytokines IL-4 and IL-10, compared with the healthy controls. The 15 patients in the additional group showed similar findings, although the difference in IL-10 between this group and the controls was not statistically significant, the study showed. The new study only looked at six key cytokines and it does not exclude the possibility that other cytokines may play a role in chronic widespread pain.
 
Treatment implications?

"We assume that the altered cytokine balance in the patients contributes to their pain," Dr. Üçeyler said. "Therefore, the logical step would be to normalize the cytokine balance and thus to take away at least one factor [that] maintains pain and hyperalgesia."

In animal models, gene transfer of IL-4 and IL-10 works well in reducing pain, he explained. "However, in humans, other strategies for restoring the cytokine balance should be looked at. Many drugs change cytokine levels as a ‘side effect' and these effects of the drugs could be systematically explored."

Dr. Üçeyler expects to conduct further investigations of disease-specific cytokine patterns and to examine the underlying mechanisms of such cytokine changes, particularly the role of anti-inflammatory cytokines.

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Reference

1. ÃœÃ§eyler N, Valenza R, Stock M, et al. Reduced levels of anti-inflammatory cytokines in patients with chronic widespread pain. Arthritis Rheum. 2006;54:2656-2664.