Fibromyalgia patients with elevated levels of anti–satellite glia cell immunoglobulin G antibodies present with more severe symptoms 2023 Krock et al

[Andy]

Transferring fibromyalgia patient immunoglobulin G (IgG) to mice induces pain-like behaviour, and fibromyalgia IgG binds mouse and human satellite glia cells (SGCs). These findings suggest that autoantibodies could be part of fibromyalgia pathology. However, it is unknown how frequently fibromyalgia patients have anti-SGC antibodies and how anti-SGC antibodies associate with disease severity.

Here, we quantified serum or plasma anti-SGC IgG levels in 2 fibromyalgia cohorts from Sweden and Canada using an indirect immunofluorescence murine cell culture assay. Fibromyalgia serum IgG binding to human SGCs in human dorsal root ganglia tissue sections was also assessed by immunofluorescence. In the cell culture assay, anti-SGC IgG levels were increased in both fibromyalgia cohorts compared with control group. Elevated anti-SGC IgG was associated with higher levels of self-reported pain in both cohorts, and higher fibromyalgia impact questionnaire scores and increased pressure sensitivity in the Swedish cohort. Anti-SGC IgG levels were not associated with fibromyalgia duration. Swedish fibromyalgia (FM) patients were clustered into FM-severe and FM-mild groups, and the FM-severe group had elevated anti-SGC IgG compared with the FM-mild group and control group. Anti-SGC IgG levels detected in culture positively correlated with increased binding to human SGCs. Moreover, the FM-severe group had elevated IgG binding to human SGCs compared with the FM-mild and control groups.

These results demonstrate that a subset of fibromyalgia patients have elevated levels of anti-SGC antibodies, and the antibodies are associated with more severe fibromyalgia symptoms. Screening fibromyalgia patients for anti-SGC antibodies could provide a path to personalized treatment options that target autoantibodies and autoantibody production.

Open access, https://journals.lww.com/pain/Fulltext/9900/Fibromyalgia_patients_with_elevated_levels_of.274.aspx

 

[Grigor]

Interesting study building on the findings by Goebel.

 

[Aspen]

@Jonathan Edwards, hoping you can respond to this. Same issues as what you stated in the Goebel thread?

 

[voner]

here is a quote from near the end of the the paper assesing the use of pooled IgG in the previous paper:

In this study, we did not find a difference between FM IgG and HC IgG binding to neurons. We had previously reported elevated IgG binding to sensory neurons in vitro, but these experiments were done using pooled IgG preparations. When looking at the data points from single individuals in this study, many individuals have no or low levels of neuron binding IgG, but there are also individuals who have higher levels of IgG binding to neurons. It remains possible that a subset of FM patients have anti-neuron antibodies. Regardless, if autoantibodies binding SGCs are driving nociceptor hypersensitivity, then they must do so by indirectly activating SGCs or by activating neuronally expressed Fcγ receptors.

 

[Andy]

Further investigated here, Anti-satellite glia cell IgG antibodies in FM patients are related to symptom severity and to metabolite concentrations in thalamus and... 2023 Fanton