Book chapter abstract
Chronic fatigue syndrome [CFS] is a symptom complex of unknown cause which is commonly present in the population, and has been labeled as postinfectious neuromyasthenia for many decades.
A microbial etiology has been considered for this disorder from the outset of its description as a distinct clinical entity. There is strong evidence that female sex and certain personality traits predispose to this condition.
The link with infectious diseases is based on the acute onset of flu-like symptoms, subjective feelings of low grade fever, sore throat, myalgias, arthralgias, or generalized body pain. Various infectious synonyms have been applied to this disorder such as chronic brucellosis, chronic Epstein–Barr virus, and chronic Lyme disease syndromes, but no good evidence to support a causative role has been found. The current understanding of the pathogenesis is discussed and previous investigations to determine an infectious etiology, including studies on coxsackie virus and the murine retrovirus and others.
The cytokines in plasma from these CFS patients was assayed in a multiplex platform, and one of us published findings showing signatures of infection; that is, significantly high levels of many proinflammatory mediators such as IL-12, MCP-1, IL-8, IP-10, IL-6, TNF-α, and IL-1β while being low in the critical antiviral cytokine IFN-α. In expanding these results, we found that subsets of these CFS patients had increased TGF-β and others had increased IL-9.
We will discuss these and other published results that suggest that chronic stimulation of the innate immune system is a component of the development and progression of disease in many CFS patients. In chronic diseases the resulting immunodeficiency allows activation and replication of many secondary pathogens. Thus CFS patients can share complex pathogenic complications with patients with HIV AIDS and HTLV-1 associated myelopathy.
In many CFS patient populations, the presence of several concomitant infections, from Borrelia burgdorferi to reactivated exogenous and endogenous viruses, chronically dysregulating the immune system, is a major risk factor in the development of pathology. Other risk factors include alterations in microbiota regulation, mitochondrial toxicity, cognitive dysfunction and impaired methylation pathways. These factors can also increase the risk of others diseases, including cancer, in some CFS patients.
These results have important implications for the management of many people with this diagnosis. We will review in this chapter the use of anti-inflammatories, anti-virals and other therapies, as well as discussing how repurposing drugs holds promise in the treatment of patients displaying the immune abnormalities identified in these CFS patients.
Chronic Fatigue Syndrome: Searching for a Microbial Etiology, by I. W. Fong, in The Role of Microbes in Common Non-Infectious Diseases Emerging Infectious Diseases of the 21st Century Volume 1, 2014, pp 111-128, 08 Aug 2014
Within this Chapter
– Is Chronic Fatigue Syndrome a Psychosocial Disorder?
– Pathobiology of Chronic Fatigue Syndrome
– Infections and Chronic Fatigue Syndrome
– Future Direction