Epigenetic markers as predictors of neurodegeneration in long COVID survivors

The persistence of neurological symptoms in long COVID survivors including cognitive impairment, brain fog, and fatigue raises concerns about accelerated neurodegenerative processes.Recent developments suggest that epigenetic alterations, especially changes in DNA methylation and "epigenetic clock" acceleration, could serve as early predictors of future neurodegeneration [1].Several longitudinal studies demonstrate that SARS-CoV-2 infection induces persistent epigenetic dysregulation.A 3-year cohort study using multiple epigenetic clocks showed that COVID-19 infection significantly accelerates biological aging measured by DNAmGrimAge, DNAmGrimAge2, and DNAmFitAge (p <0.05) after adjustment for confounders [1].Genome-wide methylation analysis six months post-infection revealed enhanced epigenetic drift, accelerated aging signatures, and disruption in pathways linked to metabolic, immune, and vascular health [2].Specifically in long COVID and post-acute COVID-19 symptoms (PACS) subgroups, systematic reviews found preliminary evidence that DNA methylation profiles related to immune regulation, autonomic nervous system function, and metabolic genes differ from recovered individuals [3].In mild/asymptomatic cases seven months post-infection, a household study identified reproducible differential methylation at CpG sites annotated to AFAP1L2 and PC genes implicated in cytoskeletal response and metabolic regulation suggesting a long-term molecular footprint of infection [4].Parallel findings in neurodegenerative disease research affirm the relevance of epigenetic markers.DNA methylation dysregulation is consistently linked to neurological disorders and neurodegenerative diseases.In Alzheimer's disease (AD), DNA hypomethylation in promoter regions of genes like amyloid- protein precursor (APP) and -site APP-cleaving enzyme1 (BACE1) leads to their upregulation and the accumulation of A.