Chlamydia pneumonia infection and risk of multiple sclerosis: A meta-analysis

Gut microbiota in multiple sclerosis and animal models

Multiple sclerosis (MS) is a chronic central nervous system (CNS) neurodegenerative and neuroinflammatory disease marked by a host immune reaction that targets and destroys the neuronal myelin sheath. MS and correlating animal disease models show comorbidities, including intestinal barrier disruption and alterations of the commensal microbiome. It is accepted that diet plays a crucial role in shaping the microbiota composition and overall gastrointestinal (GI) tract health, suggesting an interplay between nutrition and neuroinflammation via the gut-brain axis. Unfortunately, poor host health and diet lead to microbiota modifications that could lead to significant responses in the host, including inflammation and neurobehavioral changes. Beneficial microbial metabolites are essential for host homeostasis and inflammation control. This review will highlight the importance of the gut microbiota in the context of host inflammatory responses in MS and MS animal models. Additionally, microbial community restoration and how it affects MS and GI barrier integrity will be discussed.

Atherosclerosis associated with Chlamydia pneumoniae: Dissecting the etiology

Chlamydia pneumoniae related infections and atherosclerosis are both common entities. Today, the literature presents an enormous amount of data regarding the role of C. pneumoniae in the development and sustainment of atherosclerosis and allowing us to comprehend the molecular mechanisms behind better. The implications of C. pneumoniae in atherogenesis include altered platelet function, hypercoagulability, macrophage dysfunction, vascular smooth muscle proliferation, and increased neutrophilic migration. Therefore, it would not be wrong to implicate that, C. pneumoniae plays important roles in almost every stage of atherogenesis. Furthermore, various serological markers suggestive of active or past C. pneumoniae infection are known to be associated with multiple clinical presentations, such as abdominal aortic aneurysms, subclinical atherosclerosis in the young individuals, aggravated atherosclerosis in heterozygous familial hypercholesterolemia. This review, as a result, aims to provide detailed insights into the pathophysiological mechanisms of atherogenesis associated with C. pneumoniae and its clinical implications.

How to and should we target EBV in MS?

INTRODUCTION

The etiology of multiple sclerosis (MS) remains unknown. Pathogenesis likely relies on a complex interaction between multiple environmental, genetic, and behavioral risk factors. However, a growing body of literature supports the role of a preceding Epstein-Barr virus (EBV) infection in the majority of cases.

AREAS COVERED

In this narrative review, we summarize the latest findings regarding the potential role of EBV as a predisposing event inducing new onset of MS. EBV interactions with the genetic background and other infectious agents such as human endogenous retrovirus are explored. Additional data regarding the role of EBV regarding the rate of mid- and long-term disease progression is also discussed. Lastly, the effect of currently approved disease-modifying therapies (DMT) for MS treatment on the EBV-based molecular mechanisms and the development of new EBV-specific therapies are further reviewed.

EXPERT OPINION

Recent strong epidemiological findings support that EBV may be the primary inducing event in certain individuals that shortly thereafter develop MS. More studies are needed in order to better understand the significant variability in susceptibility based on environmental factors such as EBV exposure. Future investigations should focus on determining the specific EBV-related risk antigen(s) and phenotyping people with likely EBV-induced MS. Targeting EBV via several different avenues, including development of an EBV vaccine, may become the mainstay of MS treatment in the future.