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

BACKGROUND

Fatigue 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.

AIMS

We performed an exploratory analysis to determine if there is evidence of a relationship between EBV reactivation and post-stroke fatigue.

METHODS

In a chronic ischemic stroke cohort (> 5 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.

RESULTS

We 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, we observed an altered circulating anti-EBV antibody profile in participants with high fatigue, with reduced IgM against the Viral Capsid Antigen (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 anti-EBV antibodies (3.23 × 105 ± 4.44 × 104 high fatigue versus 4.60 × 105 ± 9.28 × 104 low fatigue; P = 0.288).

CONCLUSIONS

These data 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.

Structural changes in liver under conditions of experimental hemorrhagic stroke

The article describes the results of histological and morphometric studies of liver in Balb/c mice with hemorrhagic stroke. The hemorrhagic stroke was modeled in the animals by administering autoblood in volume of 0.1 ml in the right hemisphere, and within 5, 10 and 30 days an analysis of structural changes in the liver was performed. Progressive changes were established in terms of 5-10 days of the experiment. This consisted of changes in the sinusoidal capillaries and notable changes in the central veins of the liver lobuli. Herein, acute dilatation and erythrocytal stasis were most pronounced around the lumen of the central veins, while hepatocytes with signs of necrosis (severe cytoplasmic swelling, vacuolar dystrophic changes) were detected in the sinusoid capillaries. The results of the morphometry indicated an increase in the area of the nucleus and the cells caused by intracellular swelling, domination of euchromatin and decrease of total density of chromatin in nuclei. Partial regression of the diameter of sinusoidal capillaries and the area of hepatocytes were detected on the 30th day of the experiment. The changes in the sinusoidal capillaries of the liver lobules are assessed as secondary to stroke, as well as to changes in organ microcirculation, and are associated with dystrophic changes in the hepatocytes.

Nerve Regeneration in Conditions of HSV-Infection and an Antiviral Drug Influence

Herpes simplex virus type I (HSV-I) is a latent neuroinfection which can cause focal brain lesion. The role of HSV-infection in nerve regeneration has not been studied so far. The aim of the work was to study sciatic nerve regeneration in the presence of HSV-infection and the influence of an antiviral drug. BALB/c line mice were divided into five groups. Group 1 animals were infected with HSV-I. After resolution of neuroinfection manifestations the sciatic nerve of these animals was crushed. Group 2 mice were administered acyclovir following the same procedures. Groups 3-5 mice served as controls. Thirty days after the operation distal nerve stumps and m.gastrocnemius were studied morphologically and biochemically. Ultrastructural organization of the sciatic nerve in control animals remained intact. Morphometric parameters of the nerves from the experimental groups have not reach control values. However, in the group 1 diameter of nerve fibers was significantly smaller than in the group 2. Both nerve regeneration and m.gastrocnemius reinnervation were confirmed. The muscle hypotrophy was found in groups 1, 2, and 3 (the muscle fibers diameter decreased). Metabolic changes in the muscles of the infected animals (groups 1 and 2) were more pronounced than in control groups 3 and 4. The levels of TBA-active products, conjugated dienes, carbonyl and SH-groups were reduced in m.gastrocnemius of the experimental groups, however no significant difference associated with acyclovir administration was found. HSV-infection is not limited to the local neurodegenerative changes in the CNS but affects regeneration of the injured sciatic nerve. Anat Rec, 301:1734-1744, 2018. © 2018 Wiley Periodicals, Inc.

Ultrastructural changes in murine liver following HSV infection and stroke

The study of herpetic infection is a topical problem. Although the peculiarities and consequences of acute HSV-I infection in the brain are quite well-studied, little is known about the damage to other organs which are not a source of latent HSV-I infection, the liver in particular. The current study is aimed at determining the ultrastructural changes in murine liver following HSV infection and stroke. Liver samples obtained from four groups of animals were studied: 1) intact mice; 2) mice with stroke; 3) mice infected with HSV-I; 4) mice aflicted with HSV-I and subsequently simulated stroke. The study showed the reproduction of the virus in hepatic endotheliocytes, although no virions were detected in the hepatocytes. Therefore, the described changes were considered the consequences of the infectious process. Pathological changes of hepatocytes consisted of deformation and fragmentation of the nuclei, as well as accumulation of osmiophilic granules, lysosomes and lamellary bodies. Latent HSV-I infection may reactivate in liver after the stroke, potentially causing the complications of the underlying disease.