Abstract
Chronic Fatigue Syndrome / Myalgic Encephalomyelitis (CFS / MS) is an incapacitating chronic disease that dramatically compromise the life quality. The CFS/ME pathogenesis is multifactorial, and it is believed that immunological, metabolic and environmental factors play a role. It is well documented an increased activity of Human endogenous retroviruses (HERVs) from different families in autoimmune and neurological diseases, making these elements good candidates for biomarkers or even triggers for such diseases. Here the expression of Endogenous retroviruses K and W (HERV–K and HERV–W) was determined in blood from moderately and severely affected ME/CFS patients. HERV-K was overexpressed only in moderately affected individuals and HERV-W showed no difference. This is the first report about HERV-K differential expression in moderate ME/CFS.
Footnotes
Methods were updated for clarify the patients classification: Participants with ME/CFS were defined as moderate or severely affected based on their mobility: those described as severely affected were house-bound or bed-bound, while those described as having mild/moderate ME/CFS were ambulatory [11]. Discussion item was updated to include a new relevant reference: Recently, it was suggested that differential methylation patterns of promoters in ME/CFS would impact on the expression of nearby transposable elements, including HERVs [19]. The following reference was added 19. Almenar-Perez E, Ovejero T, Sanchez-Fito T, Espejo JA, Nathanson L, Oltra E. Epigenetic Components of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Uncover Potential Transposable Element Activation. Clin Ther. 2019;41(4):675-698.
