Category: Pathogenesis

Fluctuations in perceived energy and mood among patients with chronic fatigue syndrome

Comment in: Fluctuations in perceived energy and mood among patients with chronic fatigue syndrome. [J R Soc Med. 1992]

Comment on: Fluctuations in perceived energy and mood among patients with chronic fatigue syndrome. [J R Soc Med. 1992]

 

I find it surprising that Wood et al. (April 992 JRSM, p 195) no longer appear to consider,that the presence of a precipitating infection should be necessary for the selection of patients involved in the study of chronic fatigue syndromes. The reference they quote, which refers to guidelines laid down at Oxford in 1990, states very clearly that post-infectious patients with chronic fatigue do indeed form a distinct subgroup, and that to fulfil research criteria there, must be,’definite evidence of infection at onset or presentation’.

Having failed to make such a distinction it is not, altogether surprising that they go on to conclude that the higher levels of depression found in their study …. serve to reinforce the now widely–current, notion that such patients may be suffering from a depressive illness, of which physical fatigue is a somatic manifestation’.

You may read the rest of this comment as well as the author’s response here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1293670/pdf/jrsocmed00107-0092b.pdf

 

Source: Shepherd C. Fluctuations in perceived energy and mood among patients with chronic fatigue syndrome. J R Soc Med. 1992 Sep;85(9):588. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1293670/

 

Immunologically mediated fatigue: a murine model

Abstract:

Chronic fatigue syndrome (CFS) is an idiopathic disorder in which the chief symptoms is profound fatigue. To explore the relationship between immune stimulation and fatigue, we developed a murine model for quantifying fatigue: reduction in voluntary running and delayed initiation of grooming after swimming.

Inoculation of female BALB/c mice with Corynebacterium parvum antigen or the relatively avirulent Me49 strain of Toxoplasma gondii induced fatigue: baseline running reduced to less than 50 and 30% for 8 and 14 days, respectively, and delayed initiation of grooming after swimming in both immunologically stimulated groups.

A threefold evaluation of serum transforming growth factor-beta levels, a cytokine increased in CFS patients, was found in fatigued C. parvum- and T. gondii-inoculated mice. This murine model appears promising for investigation of the pathogenesis of immunologically mediated fatigue.

 

Source: Chao CC, DeLaHunt M, Hu S, Close K, Peterson PK. Immunologically mediated fatigue: a murine model. Clin Immunol Immunopathol. 1992 Aug;64(2):161-5. http://www.ncbi.nlm.nih.gov/pubmed/1643746

 

Serum levels of lymphokines and soluble cellular receptors in primary Epstein-Barr virus infection and in patients with chronic fatigue syndrome

Abstract:

The immunopathology in primary Epstein-Barr virus (EBV) infections and in chronic fatigue syndrome was studied by examining serum levels of interleukins (IL) and of soluble T cell receptors in serum samples.

Serum samples were from patients during and 6 months after primary EBV-induced infectious mononucleosis and from patients with chronic fatigue syndrome and serologic evidence of EBV reactivation. Markers for T lymphocyte activation (soluble IL-2 and CD8) and for monocyte activation (neopterin) were significantly elevated during acute infectious mononucleosis but not in patients with chronic fatigue syndrome.

Interferon-alpha, IL-1 beta, and IL-6 levels were not significantly increased in any patient group but inferferon-gamma levels were significantly increased during the acute phase of infectious mononucleosis. The levels of IL-1 alpha were significantly higher than in controls both in patients with infectious mononucleosis and in those with chronic fatigue syndrome. In the latter, the lack of most markers for lymphocyte activation found in patients with infectious mononucleosis makes it less likely that EBV reactivation causes symptoms.

 

Source: Linde A, Andersson B, Svenson SB, Ahrne H, Carlsson M, Forsberg P, Hugo H, Karstorp A, Lenkei R, Lindwall A, et al. Serum levels of lymphokines and soluble cellular receptors in primary Epstein-Barr virus infection and in patients with chronic fatigue syndrome. J Infect Dis. 1992 Jun;165(6):994-1000. http://www.ncbi.nlm.nih.gov/pubmed/1316417

 

Chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS), which is characterized by devastating fatigue, mild fever, lymphadenopathy, headache, myalgia, insomnia and neuropsychiatric disorders, now has drawn much attentions from many physicians, researchers and even peoples in general society world wide. The pathogenesis of CFS is still remains to be clarified and clinico-pathological difference between CFS and mood disorder is controversial. In this paper, CFS would be reviewed in detail.

 

Source: Matsuda J. Chronic fatigue syndrome. Nihon Rinsho. 1992 Apr;50(4):887-91. [Article in Japanese] http://www.ncbi.nlm.nih.gov/pubmed/1619775

 

Psychiatric perspectives: an overview

Abstract:

This chapter reviews the evidence concerning the importance of psychological and social factors in the aetiology and pathogenesis of chronic fatigue syndrome. The diagnosis is often offered to doctors by patients; and we consider attribution, stigma, collusion between doctor and patient, and abnormal illness behaviour in this context. We then give a brief description of a model for common mental disorders, and show how chronic fatigue syndrome relates to this model. It emerges that there are special vulnerability factors in these patients’ personalities before the viral illness, but the disorder is seen as being released by the viral illness. By the time the disorder becomes established the original causal nexus is seen as no longer so important, and the disorder can be seen as a form of abnormal illness behaviour maintained by special factors. The implications for treatment are then considered.

 

Source: Woods TO, Goldberg DP. Psychiatric perspectives: an overview. r Med Bull. 1991 Oct;47(4):908-18. http://www.ncbi.nlm.nih.gov/pubmed/1794090

 

Myalgic encephalomyelitis

Comment on: Myalgic encephalomyelitis. [J R Soc Med. 1991]

 

The exchange of views between Drs Wessely and Wilson in the correspondence columns of the March issue of the Journal (March 1991 JRSM, p 182) highlights the divergence of opinion concerning the nature of myalgic encephalomyelitis (ME).

Recognition of ME as a significant health problem in New Zealand dates from an outbreak of ‘Tapanui ‘flu’ in a small country town in 1983. As it seemed possible that the wide range of symptoms could be indicative of impaired capillary blood flow, we studied the filtrability of blood samples from members of ME support groups. We found that subjects who were acutely unwell had prolonged blood filtration times which returned towards normal in the chronic state.

More recently it has been shown that ME symptoms are associated with increased percentages of nondiscocytic erythrocytes and the percentage of such cells showed an inverse correlation with wellbeing. The significance of altered red cell shape in the pathogenesis of ME has been discussed and it has been found that an injection of vitamin B12 improved wellbeing within 24 h. The loss of symptoms was associated with reduced percentages of nondiscocytes in about 50% of subjects. Those who failed to perceive a beneficial response from the B12 showed no change in red cell shape. Further studies at varying degrees of completion confirm and extend the published observations.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1295578/pdf/jrsocmed00119-0075a.pdf

 

Source: Simpson LO. Myalgic encephalomyelitis. J R Soc Med. 1991 Oct;84(10):633. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1295578/

 

Amplification and identification of enteroviral sequences in the postviral fatigue syndrome

Abstract:

Evidence from several sources has long suggested that enteroviruses might play a role in the postviral fatigue syndrome (PVFS).

We used the most sensitive molecular virological method available at present, the polymerase chain reaction (PCR) amplification technique, to look for enteroviral copies in peripheral blood leucocytes and muscle from a well-defined group of patients. We demonstrated that our PCR method amplified a sequence common to a wide range of enteroviral serotypes. A highly significant number of the muscle biopsies (53%: P = less than 0.001) from the patients were positive for enteroviral sequences. With regard to the leucocyte samples, 16% in both patient and control were positive.

The PCR results on the peripheral blood leucocytes were in keeping with serological findings, in showing that the level of exposure to enteroviruses seemed to be the same in patients and controls: it was therefore of the greatest interest that patients were 6.7 times more likely to have enteroviral genome in their muscle.

We conclude that persistent enteroviral infection plays a role in the pathogenesis of PVFS, also providing preliminary evidence that severe mitochondrial injury is one of the mechanisms involved.

 

Source: Gow JW, Behan WM. Amplification and identification of enteroviral sequences in the postviral fatigue syndrome. Br Med Bull. 1991 Oct;47(4):872-85. http://www.ncbi.nlm.nih.gov/pubmed/1665380

 

Clinical and pathogenetic observations on children with chronic mononucleosis

Abstract:

Epstein-Barr virus is seldom the causative agent of a prolonged atypical illness, known as chronic mononucleosis syndrome, characterized by a persistent pattern of clinical manifestations and by a defective immune response to specific viral antigens. This paper refers about 6 children for whom clinical and serological findings suggest the chronic Epstein-Barr virus infection. The authors believe that this chronic state might be explained by the unusual antibody pattern to EBV virus, with the persistent presence of anti-EA and the absence of anti-EBNA titers, expression of a reduced EBV-specific cytotoxic T cell activity.

 

Source: Cataldo F, Ammatuna P, Bellia L, Sammartano F, Violante M, Albeggiani A. Clinical and pathogenetic observations on children with chronic mononucleosis. Pediatr Med Chir. 1991 Sep-Oct;13(5):489-94. [Article in Italian] http://www.ncbi.nlm.nih.gov/pubmed/1664943

 

Altered cytokine release in peripheral blood mononuclear cell cultures from patients with the chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is an idiopathic illness associated with a variety of immunologic abnormalities. To investigate potential pathogenetic mechanisms, we evaluated serum levels and peripheral blood mononuclear cell (PBMC) production of selected cytokines and immunoglobulins.

Serum bioactive transforming growth factor beta (TGF-beta) levels were higher (P less than 0.01) in patients with CFS (290 +/- 46 pg/mL) than in control subjects (104 +/- 18 pg/mL), but levels of other cytokines tested were not different. Lipopolysaccharide-stimulated release of interleukin 1 beta (IL-1 beta), IL-6, and tumor necrosis factor-alpha was increased (P less than 0.05) in PBMC cultures from patients with CFS versus control subjects; enhanced (P less than 0.01) IL-6 release to phytohemagglutinin was also observed.

In contrast, TGF-beta release in response to lipopolysaccharide was depressed (P less than 0.01) in PBMC cultures derived from patients with CFS. No differences in IL-2 and IL-4 or immunoglobulin production were observed.

The enhanced release of inflammatory cytokines by stimulated PBMC from patients with CFS suggests that these cells are primed for an increased response to immune stimuli. These data also suggest an association between abnormal regulation of TGF-beta production in vivo and in vitro with the immunologic consequence of CFS.

 

Source: Chao CC1, Janoff EN, Hu SX, Thomas K, Gallagher M, Tsang M, Peterson PK. Altered cytokine release in peripheral blood mononuclear cell cultures from patients with the chronic fatigue syndrome. Cytokine. 1991 Jul;3(4):292-8. http://www.ncbi.nlm.nih.gov/pubmed/1873478

 

Muscle performance, voluntary activation, twitch properties and perceived effort in normal subjects and patients with the chronic fatigue syndrome

Abstract:

The decrease in maximal force-generating capacity, the degree of central activation of the muscle, and the subjective perception of effort were measured during prolonged submaximal isometric exercise in 12 male patients suffering from the ‘chronic fatigue syndrome’ and 13 naive, healthy male subjects.

Maximal voluntary isometric torque generated by the elbow flexors was measured before, and at 5 min intervals during an endurance sequence of 45 min of repetitive isometric contractions (6 s duration, 4 s rest interval) producing 30% of the initial maximal voluntary torque. Electrical stimuli were also delivered to the elbow flexors to measure the contractile force in the intervals between voluntary contractions. The degree of central motor activation during maximal voluntary contractions was assessed using a sensitive method of twitch interpolation.

In addition, the perceived effort required to achieve the target submaximal contractions was recorded using a standardized self-report scale. A high degree of central activation was achieved in maximal contractions during the endurance sequence both in the patients (mean of maximal force 93.6%; SD 7.8%), and in the control subjects (mean 90.9%; SD 9.5%).

The relative torque produced by either voluntary or electrically stimulated contractions was not significantly different between patients and control subjects throughout the test. There was no significant difference in the perceived exertion between the patients and control subjects.

These findings support the concept that neither poor motivation, nor muscle contractile failure is important in the pathogenesis of ‘fatigue’ in patients with the chronic fatigue syndrome.

 

Source: Lloyd AR, Gandevia SC, Hales JP. Muscle performance, voluntary activation, twitch properties and perceived effort in normal subjects and patients with the chronic fatigue syndrome. Brain. 1991 Feb;114 ( Pt 1A):85-98. http://www.ncbi.nlm.nih.gov/pubmed/1998892