A new systematic review showed that patients with multiple sclerosis (MS) have shorter telomeres (TLs) in blood cells when compared to control individuals without the disease.
“The evidence of an association of relatively short TLs and MS is convincing despite the fact that only few studies (n=7) with small sample sizes (n ≤138 patients for studies comparing against controls) and heterogeneous study populations (eg, with regard to age, sex and ancestry) have been published so far,” explained the study authors.
In addition, Bühring et al found an association between TL shortening and greater disability, diminished brain volume, higher relapse rate, and a quicker conversion from relapsing to progressive MS.
Most of the studies used peripheral blood samples to measure MS patients’ TLs. In fact, out of the 7 studies included in this review, only a single study used bone marrow cells. Though peripheral blood is a safe and convenient biological source, it comprises several cell types. These include different types of immune cells that exhibit varying TL shortening rates. Hence, Bühring et al underlined the existence of confounding effects in the analysis of TL.
TLs are specific nucleoprotein structures that localize at both ends of each chromosome. The primary role of these structures is to protect the chromosomes from damage. TL shortening occurs with aging due to the end-replication problem. In addition, a number of processes accelerate TL shortening (eg, oxidative stress, chronic inflammation, and persistent viral infections). As result, cellular senescence or apoptosis can occur.
Shorter TLs have been associated with a number of diseases. The findings in this systematic review also suggest a potential role for TLs as a biomarker of immunosenescence in MS.
Bühring J, Hecker M, Fitzner B, Zettl UK. Systematic review of studies on telomere length in patients with multiple sclerosis. 2021;12(5):1272. Aging Dis. doi:10.14336/AD.2021.0106