Distinct plasma immune signatures in ME/CFS are present early in the course of illness

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is an unexplained incapacitating illness that may affect up to 4 million people in the United States alone. There are no validated laboratory tests for diagnosis or management despite global efforts to find biomarkers of disease. We considered the possibility that inability to identify such biomarkers reflected variations in diagnostic criteria and laboratory methods as well as the timing of sample collection during the course of the illness. Accordingly, we leveraged two large, multicenter cohort studies of ME/CFS to assess the relationship of immune signatures with diagnosis, illness duration, and other clinical variables. Controls were frequency-matched on key variables known to affect immune status, including season of sampling and geographic site, in addition to age and sex. We report here distinct alterations in plasma immune signatures early in the course of ME/CFS relative to healthy controls that are not present in subjects with longer duration of illness . Analyses based on disease duration revealed that early ME/CFS cases had a prominent activation of both pro- and anti-inflammatory cytokines as well as dissociation of intercytokine regulatory networks. We found a stronger correlation of cytokine alterations with illness duration than with measures of illness severity, suggesting that the immunopathology of ME/CFS is not static. These findings have critical implications for discovery of interventional strategies and early diagnosis of ME/CFS.

High-throughput 16S rRNA gene sequencing reveals alterations of intestinal microbiota in myalgic encephalomyelitis/chronic fatigue syndrome patients

43 Patients and 36 controls from Belgium and Norway were included in the study. Gut flora composition differed between people from different geographical origins. Significant alterations of gut microbiota composition were observed in patients.

This is relevant because 70% of all immune cells are located in the gastro-intestinal tract. Increased intestinal permeability may explain the systemic inflammatory situation in CFS.
Excess d-lactic acid production could contribute to mitochondrial dysfunction, but also to neurocognitive impairments in patients, since d-lactic acidosis is known to affect CNS function.

The predominance of women among patients, the fact that disease symptoms change upon e.g. puberty, pregnancy and menopause, has long suggested an involvement of hormones in ME/CFS. ER β, the preferred receptor of equol, is down-regulated in patients.
Disruption of estrogen signaling is consistent with some dysfunctions observed in ME/CFS. It could be related, for instance, with immune dysregulation since isoflavones, and more specifically equol, induce expression of antioxidant enzymes, and exert an anti-inflammatory action. Another potentially relevant aspect of phytoestrogens and their metabolites is their capacity to regulate vitamin D receptor activity, and vitamin D synthesis. The vitamin D system is critical for maintenance of gut mucosal immunity.Vitamin D has also been shown to modulate some processes that are critical for prevention of mucosal inflammation. One of the things not known yet is if the altered gut microbiota are cause or result of CFS.