Purpose: To evaluate bacterial presence and evidence of inflammatory metabolic activity in blood of patients with Fibromyalgia Syndrome (FMS).
Patients and methods: A human clinical pilot study involved eight FMS patients and four healthy controls. Whole blood and purified erythrocytes were cultured and examined by darkfield fluorescence microscopy and flow cytometry. DNA was subjected to amplification using polymerase chain reactions. Bioactivity of bacterial metabolites was tested on peripheral blood mononuclear cells (PBMC), cultured in the presence of metabolite fractions from FMS and healthy control erythrocyte cultures. CD69 and CD25 expression was evaluated by flow cytometry, and levels of inflammatory cytokines tested by Luminex array.
Results: Blood cultures from fibromyalgia patients revealed growth of bacteria under culture conditions involving RPMI-1640 medium, increased levels of glucose and iron, and reduced oxygen. The ex vivo expansion of bacteria through culture, combined with 16S rDNA PCR analysis of DNA isolated from whole blood and erythrocyte cultures, identified bacterial sequences derived from the Aquabacterium genus. The design of Aquabacterium-specific primers resulted in detection of Aquabacterium DNA in blood from some healthy control subjects as well, suggesting a low level of bacteria in a more quiescent state. PBMC cultured in the presence of supernatants from FMS erythrocyte cultures showed increased levels of CD69+ CD25+ lymphocytes, and increased production of the inflammatory cytokines IL-6 (p<0.25), IL-8 (p<0.08), and TNF-alpha (p<0.01) when compared to supernatants from erythrocyte cultures from healthy individuals.
Conclusion: Bacteria from the biofilm-forming microaerophilic Gram-negative Aquabacterium genus were detected in blood from FMS patients and some healthy controls. Only bacterial cultures from FMS patients produced inflammatory metabolites, suggesting that Aquabacterium bacteria from FMS patients may express different genes than in healthy controls, potentially contributing to the chronic pain and inflammation characteristic of FMS.