Evidence of aberrant anti-Epstein-Barr virus antibody response, though no viral reactivation, in people with post-stroke fatigue

Abstract

AbstractBACKGROUNDFatigue is a common complication of stroke that has a significant impact on quality of life. The biological mechanisms that underly post-stroke fatigue are currently unclear, however, reactivation of latent viruses and their impact on systemic immune function have been increasingly reported in other conditions where fatigue is a predominant symptom. Epstein-Barr virus (EBV) in particular has been associated with fatigue, including in long-COVID and myalgic encephalomyelitis/chronic fatigue syndrome, but has not yet been explored within the context of stroke.AIMSWe performed an exploratory analysis to determine if there is evidence of a relationship between EBV reactivation and post-stroke fatigue.METHODSIn a chronic ischemic stroke cohort (>6 months post-stroke), we assayed circulating EBV by qPCR and measured the titres of anti-EBV antibodies by ELISA in patients with high fatigue (FACIT-F <40) and low fatigue (FACIT-F >41). Statistical analysis between two-groups were performed by t-test when normally distributed according to the Shapiro-Wilk test, by Mann-Whitney test when the data was not normally distributed, and by Fisher’s exact test for categorical data.RESULTSWe observed a similar incidence of viral reactivation between people with low versus high levels of post-stroke fatigue (5 of 22 participants (24%) versus 6 of 22 participants (27%)). Although the amount of circulating EBV was similar between the groups, we observed an altered antibody response against EBV antigens in participants with high fatigue, with reduced IgM against the Viral Capsid Antigen (VCA; 2.244 ± 0.926 vs 3.334 ± 2.68; P = 0.031). Total IgM levels were not different between groups indicating this effect was specific to EBV (3.23 × 105± 4.44 × 104high fatigue versus 4.60 × 105± 9.28 × 104low fatigue; P= 0.288).CONCLUSIONSThese findings indicate that EBV is not more prone to reactivation during chronic stroke recovery in those with post-stroke fatigue. However, the dysregulated antibody response to EBV may be suggestive of viral reactivation at an earlier stage after stroke and warrants further investigation.