Increased IgA responses to .. LPS of commensal bacteria .. associated with inflammation, activation of cell-mediated immunity in CFS, 2012, Maes et al

[Hutan]

An old paper, but potentially of interest given a recent finding of increased IgA in a substantial proportion of people attending a post-Covid clinic.

Abstract
Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is accompanied by a) systemic IgA/IgM responses against the lipopolysaccharides (LPS) of commensal bacteria; b) inflammation, e.g. increased plasma interleukin-(IL)1 and tumor necrosis factor (TNF)α; and c) activation of cell-mediated immunity (CMI), as demonstrated by increased neopterin.

Methods: To study the relationships between the IgA/IgM responses to the LPS of microbiota, inflammation, CMI and the symptoms of ME/CFS we measured the IgA/IgM responses to the LPS of 6 different enterobacteria, serum IL-1, TNFα, neopterin, and elastase in 128 patients with ME/CFS and chronic fatigue (CF). Severity of symptoms was assessed by the Fibromyalgia and Chronic Fatigue Syndrome (FF) Rating Scale.

Results: Serum IL-1, TNFα, neopterin and elastase are significantly higher in patients with ME/CFS than in CF patients. There are significant and positive associations between the IgA responses to LPS and serum IL-1, TNFα, neopterin and elastase. Patients with an abnormally high IgA response show increased serum IL-1, TNFα and neopterin levels, and higher ratings on irritable bowel syndrome (IBS) than subjects with a normal IgA response. Serum IL-1, TNFα and neopterin are significantly related to fatigue, a flu-like malaise, autonomic symptoms, neurocognitive disorders, sadness and irritability.

Conclusions: The findings show that increased IgA responses to commensal bacteria in ME/CFS are associated with inflammation and CMI activation, which are associated with symptom severity. It is concluded that increased translocation of commensal bacteria may be responsible for the disease activity in some ME/CFS patients.

https://pubmed.ncbi.nlm.nih.gov/21967891/

 

[Hutan]

I can only access 'snippets', but it looks as though the authors were suggesting that there might be an exaggerated IgA response to an antigen challenge.

One hundred twenty-one patients participated in this study, i.e., 90 patients with ME/CFS and 31 patients with chronic fatigue (CF). The diagnosis “ME/CFS” was made using the diagnostic criteria of the Centres for Disease Control and Prevention (CDC) (Fukuda et al., 1994). Patients who suffered from chronic fatigue for more than 6 months but did not fulfill the CDC diagnostic criteria for ME/CFS were diagnosed as “CF”.

Patients with ME/CFS showed significantly higher values for IL-1, TNFα, neopterin and elastase than those with CF (all results of ANVOVAs with age and gender as covariates).

Our results that ME/CFS is characterized by exaggerated systemic IgA and IgM responses against LPS from commensal bacteria as compared with CF patients are in agreement with a previous report (Maes et al., 2007d). The latter authors found that the IgM/IgA responses to LPS did not differ between CF patients and normal controls. The increased serum IgA responses may indicate that there is an antigenic stimulation at the mucosal site (Ahmadi et al., 1998).

 

[Midnattsol]

There's also that small study on increased translocation of LPS in pwME following exertion.