In a new study, researchers showed that serum levels of different biomarkers showed no differences between female fibromyalgia (FM) patients and healthy women. Disease severity and depression also showed no correlation with biomarkers’ levels. The study, “Evaluation of cytokines, oxidative stress markers and brain-derived neurotrophic factor in patients with fibromyalgia – A controlled cross-sectional study,” was published in the journal Cytokine.
The team determined how the levels of cytokines (interleukin (IL)-6, IL-8, IL-10 and TNF-a), oxidative stress markers and brain-derived neurotrophic factor (BDNF) in patients with fibromyalgia related to depression and severity of disease.
The team performed a prospective, controlled, cross-sectional study with 69 fibromyalgia patients and 61 healthy women. All study participants were women. Patients in the FM group fulfilled both the American College of Rheumatology 1990 and 2010 criteria for diagnosis of fibromyalgia.
In both groups, researchers measured serum concentrations of IL-6, IL-8, IL-10, TNF-alpha, thiobarbituric acid reactive substances (TBARS), protein carbonyl, and BDNF. Additionally, fibromyalgia patients were evaluated using the Fibromyalgia Impact Questionnaire (FIQ), the Beck Depression Inventory (BDI), and the Hamilton Depression Rating Scale (HDRS).
Patients’ quality of life was significantly impaired by disease severity. And, a large percentage of fibromyalgia patients showed signs of depression at some level (82.6 percent and 87.0 percent as assessed by BDI and HDRS, respectively).
However, most biomarkers tested (IL-6, IL-8, TNF-a, TBARS and protein carbonyl) and BDNF showed no differences between groups, FM and controls, with the exception being IL-10, with higher levels of serum IL-10 in fibromyalgia patients when compared to healthy women.
Researchers hypothesized that IL-10 increase, a cytokine with anti-allodynic and anti-hyperalgesic properties, may occur as a compensatory mechanism through suppression of inflammatory cytokines, such as TNF-alpha, IL-6, and IL-1.
These results suggest there are no differences in the levels of serum biomarkers between fibromyalgia patients and controls, with the exception of IL-10, an anti-inflammatory cytokine whose values were higher in fibromyalgia patients. In addition, the levels of the different biomarkers showed no correlation with parameters of disease and depression severity.