On the topic
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex multisystemic disease with a prevalence estimated between 0.2 and 0.3%. This is a disease with numerous research challenges including the lack of a disease biomarker. In theory, the discovery of a biomarker could improve accuracy of disease diagnosis and the understanding of the underlying pathological mechanisms. It could also help discerning differences between subgroups of patients, including those whose disease appeared to have been triggered by an infection.
The paper describes a genetic association study comparing two groups of ME/CFS patients according to their disease trigger (infection versus non-infection) with healthy controls. Five candidate single nucleotide polymorphisms (SNPs) were genotyped in peripheral blood mononuclear cells. These SNPs were located in genes previously associated with autoimmune diseases (PTPN22, CTLA4, TNF, and IRF5).
The analysis showed an association between the allelic and genotypic distributions of the PTPN22 and CTLA4 SNPs and the infection-triggered ME/CFS group. When comparing infection-triggered patients with patients without such trigger there was evidence for decreased B-cell frequency in the former group and higher CrP levels in the later.
In summary, the study suggested a genetic predisposition associated with autoimmunity in patients whose disease was triggered by infection.
Tables 2 and 3
There is a discrepancy in the allelic information about rs2476601 (highlighted in red).