Pathogenic tracks in fatigue syndromes

Abstract:

This review analyses the recent literature devoted to two related fatigue syndromes: chronic fatigue syndrome (CFS) and acute onset postviral fatigue syndrome (PVFS). The articles are grouped into five pathogenic tracks: infectious agents, immune system, skeletic muscle, hypothalamo-pituitary-adrenal (HPA) axis and psychiatric factors.

Although a particular infectious agent is unlikely to be responsible for all CFS cases, evidence is shown that host-parasite relationships are modified in a large proportion of patients with chronic fatigue. Antibody titres against infectious agents are often elevated and replication of several viruses could be increased.

Chronic activation of the immune system is also observed and could be due to the reactivation of persistent or latent infectious agents such as herpes viruses (i.e. HHV-6) or enteroviruses. It could also be favorised by an impaired negative feedback of the HPA axis on the immune system.

A model is proposed where the abnormalities of the HPA axis are primary events and are mainly responsible for a chronic activation of the immune system which in turn induces an increased replication of several viruses under the control of cellular transcription factors. These replicating viruses together with cytokines such as TNF-alpha would secondarily induce functional disorders of muscle and several aspects of asthenia itself.

 

Source: Moutschen M, Triffaux JM, Demonty J, Legros JJ, Lefèbvre PJ. Pathogenic tracks in fatigue syndromes. Acta Clin Belg. 1994;49(6):274-89. http://www.ncbi.nlm.nih.gov/pubmed/7871934

 

Chronic fatigue syndrome: immune dysfunction, role of pathogens and toxic agents and neurological and cardial changes

Abstract:

375 patients with chronic fatigue syndrome (CFS) were examined using a standardized questionnaire and subsequent interview on 11 risk factors and 45 symptoms. Additionally immunologic, serologic, toxicologic, neuroradiologic, neurophysiologic and cardiologic investigations were performed.

Immunologic tests showed cellular immunodeficiences particularly in functional regard (pathological lymphocyte stimulation in 50% of the patients, disorders of granulocyte function in 44%). Furthermore variable deviations were found in the lymphocyte subpopulations (CD3, CD4, CD8, CD19, DR, Leu 11 + 19).

In the humoral part tendencies to low IgG-3- and IgG-1-subclass-levels occurred (59% respectively 11% of the patients) also as decreases in complement system (CH50, C3, C4, C1-esterase-inhibitor). In the group of activation markers and cytokines 42% of the investigated patients had circulating immune complexes (CIC), 47% increases of tumor-necrosis-factor (TNF-a) and 21% increases of soluble interleukin-2-receptor (IL-2-R).

The increased occurrence of autoantibodies in the CFS-patients (specially antinuclear anti-bodies [ANA], microsomal thyroid antibodies) suggest, that CFS is associated with or the beginning of manifest autoimmune disease.

Under the pathogens 78% of the patients had a striking serological constellation of Epstein-Barr-Virus (EBV-EA positive, low EBNA-titers), in the HHV-6-Virus 47% showed increased antibody-titers. Tests on further herpes viruses and on Borreliae, Chlamydiae, Candida and Amoebae were positive in 8 to 36% of the examined patients. Furthermore there were found variable deficits of vitamins and trace elements also as hormonal disturbances.

In 26% of the patients there were hints of pollutants (e.g. wood preservatives), in 32 patients blood-levels of pentachlorphenol (PCP) and gamma-hexachlorcyclohexan (γ-HCH, lindan) were measured, which showed vanable increases.

178 (83%) of 225 investigated patients showed disturbances of perfusion in cerebral SPECT imaging, 65 (29%) of 218 patients cerebral punctuate signal changes in cranial magnetic resonance imaging (MRI).

Neurophysiologic measurements (motor evoked potentials, MEP) showed in about 50% of 112 patients prolonged central motor conduction times. 62 patients were additionally investigated by myocardial SPECT-imaging, which was abnormal under exercise in 73%. Our data confirm the concept, that CFS must be considered as a complex psycho-neuro-immunological disorder.

 

Source: Hilgers A, Frank J. Chronic fatigue syndrome: immune dysfunction, role of pathogens and toxic agents and neurological and cardial changes. Wien Med Wochenschr. 1994;144(16):399-406.[Article in German] http://www.scopus.com/record/display.uri?eid=2-s2.0-0027940724&origin=inward&txGid=0

and http://www.ncbi.nlm.nih.gov/pubmed/7856214