Analysis and applications of cell-free plasma DNA in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Despite the significant advancement in the diagnostic and imaging modalities, there is no established biomarker of the disease. In this review, we discuss the utility of cell-free plasma DNA (cfpDNA) as a potential medium for biomarker development. CfpDNA (cfpDNA) is a metabolic derivative of the global turnover of cells, and it is present in human plasma as 0.5-5.0 kilobase (kb) polynucleotide chains with preserved methylation sites. Alterations of concentration and methylation patterns of cfpDNA can indicate presence of pathological or disease processes. Implicitly, CNS inflammation and cell injury in MS are potential mechanisms of generating unique and disease-specific patterns. We are also discussing the changes in cfpDNA in patients with multiple sclerosis, and their biological and clinical significance. In summary, research on cfpDNA may have practical applications in MS, particularly in biomarker development, and can provide a new perspective of the disease pathogenesis.