Category: Pathogenesis

Chronic fatigue syndrome beginning suddenly occurs seasonally over the year

Abstract:

The fact that many patients with chronic fatigue syndrome (CFS) have an infectious like sudden onset to their illness has led to the hypothesis that CFS is a medical illness. If CFS were, on the other hand, a psychiatric disorder related to symptom amplification, one would expect illness onset to occur randomly over the calendar year.

This study tested that hypothesis with 69 CFS patients whose illness was on the more severe side of the illness spectrum; all patients reported sudden illness onset with the full syndrome of sore throat, fatigue/malaise, and diffuse achiness developing over no longer than a 2-day period. Date of illness onset was distinctly nonrandom. It peaked from November through January and was at its lowest from April through May. These data support the hypothesis that an infectious illness can trigger the onset of CFS.

 

Source: Zhang QW, Natelson BH, Ottenweller JE, Servatius RJ, Nelson JJ, De Luca J, Tiersky L, Lange G. Chronic fatigue syndrome beginning suddenly occurs seasonally over the year. Chronobiol Int. 2000 Jan;17(1):95-9. http://www.ncbi.nlm.nih.gov/pubmed/10672437

 

Incidence, risk and prognosis of acute and chronic fatigue syndromes and psychiatric disorders after glandular fever

Abstract:

BACKGROUND: The role of viruses in the aetiology of both chronic fatigue syndrome (CFS) and depressive illness is uncertain.

METHOD: A prospective cohort study of 250 primary care patients, presenting with glandular fever or an ordinary upper respiratory tract infection (URTI).

RESULTS: The incidence of an acute fatigue syndrome was 47% at onset, after glandular fever, compared with 20% with an ordinary URTI (relative risk 2.3, 95% CI 1.3-4.1). The acute fatigue syndrome lasted a median (interquartile range) of eight weeks (4-16) after glandular fever, but only three weeks (2-4) after an URTI. The prevalence of CFS was 9-22% six months after glandular fever, compared with 0-6% following an ordinary URTI, with relative risks of 2.7-5.1. The most conservative measure of the incidence of CFS was 9% after glandular fever, compared with no cases after an URTI. A conservative estimate is that glandular fever accounts for 3113 (95% CI 1698-4528) new cases of CFS per annum in England and Wales. New episodes of major depressive disorder were triggered by infection, especially the Epstein-Barr virus, but lasted a median of only three weeks. No psychiatric disorder was significantly more prevalent six months after onset than before.

CONCLUSIONS: Glandular fever is a significant risk factor for both acute and chronic fatigue syndromes. Transient new major depressive disorders occur close to onset, but are not related to any particular infection if they last more than a month.

 

Source: White PD, Thomas JM, Amess J, Crawford DH, Grover SA, Kangro HO, Clare AW. Incidence, risk and prognosis of acute and chronic fatigue syndromes and psychiatric disorders after glandular fever. Br J Psychiatry. 1998 Dec;173:475-81. http://www.ncbi.nlm.nih.gov/pubmed/9926075

 

Increased production of interleukin-6 by adherent and non-adherent mononuclear cells during ‘natural fatigue’ but not following ‘experimental fatigue’ in patients with chronic fatigue syndrome

Abstract:

In an investigator-blinded study, adherent (monocytes) and non-adherent cells (lymphocytes) from patients with chronic fatigue syndrome (CFS) were examined on two separate occasions (when feeling ‘fatigued’ and when feeling ‘rested’) for in vitro spontaneous, phytohemagglutinin- (PHA, for lymphocytes), and lipopolysaccharide- (LPS, for monocytes) induced production of IL-6 by ELISA assay.

A group of CFS patients and controls were also subjected to exercise-induced fatigue (‘experimental fatigue’) and IL-6 production was compared, in a double-blinded manner, prior to and following induction of fatigue.

A significant increase in spontaneous, PHA- and LPS-induced IL-6 secretion by both lymphocytes and monocytes was observed in CFS patients during ‘natural fatigue’ as compared to during state. However, no such changes in IL-6 production were observed during ‘experimental fatigue’.

These data suggest a role of IL-6 in natural symptomatology and perhaps in the pathogenesis of CFS. In addition, the data demonstrate that laboratory-induced fatigue (experimental fatigue) may not be a good model to study immunological changes in CFS; immunological parameters should be studied in a longitudinal manner during the natural course of the disease.

 

Source: Gupta S, Aggarwal S, Starr A. Increased production of interleukin-6 by adherent and non-adherent mononuclear cells during ‘natural fatigue’ but not following ‘experimental fatigue’ in patients with chronic fatigue syndrome. Int J Mol Med. 1999 Feb;3(2):209-13. http://www.ncbi.nlm.nih.gov/pubmed/9917531

 

Chronic fatigue syndrome in psychiatric patients: lifetime and premorbid personal history of physical health

Abstract:

OBJECTIVE: This preliminary report compares a group of chronic fatigue syndrome (CFS) patients and controls on several variables of potential significance in the etiology of CFS.

METHOD: The lifetime prevalence of reported physical disorders was compared among 46 CFS psychiatric patients, 92 relatively physically healthy psychiatric patients (C-I), and 46 psychiatric patients selected without regard to physical health (C-II). All patients were matched on age, sex, and psychiatric diagnosis and were drawn from the same psychiatric practice. The same groups were compared on a 7-point scale of lifetime physical health by three raters independently evaluating physical health narratives of the CFS patients up to the time of onset of CFS and that of the controls up to the corresponding age.

RESULTS: The CFS patients had a significantly higher reported lifetime prevalence of irritable bowel syndrome (IBS), infectious mononucleosis-like syndromes (IM), infectious mononucleosis-like syndromes two or more times (IM x 2), and herpes (other than genital or perioral herpes) than one or both control groups. The CFS group also had a higher incidence of allergic rhinitis or asthma, IBS, IM, and IM x 2 than the combined controls. On the independent ratings, the CFS patients had significantly more impaired physical health up to the time of onset of the CFS than C-I at a comparable age.

CONCLUSIONS: The findings suggest that a general health factor may be involved in the pathogenesis of some cases of CFS.

 

Source: Endicott NA. Chronic fatigue syndrome in psychiatric patients: lifetime and premorbid personal history of physical health. Psychosom Med. 1998 Nov-Dec;60(6):744-51. http://www.ncbi.nlm.nih.gov/pubmed/9847035

 

Multiplex PCR for the detection of Mycoplasma fermentans, M. hominis and M. penetrans in cell cultures and blood samples of patients with chronic fatigue syndrome

Abstract:

A multiplex polymerase chain reaction (PCR) was initially developed to detect the presence of mycoplasma genus DNA sequences in cell cultures and to differentiate between three human pathogenic mycoplasma species simultaneously. The assay in turn, proved to be a useful tool for the detection of mycoplasma infection in human DNA samples.

One set of oligonucleotide primers which are specific for a highly conserved region among all members of the genus mycoplasma along with three other primer sets which are specific for Mycoplasma fermentans, Mycoplasma hominis andMycoplasma penetrans species were used in this assay. The sensitivity of detection was determined by infecting peripheral blood mononuclear cells (PBMC) of healthy individuals with known bacterial copy numbers from each species, extracting the DNA, and subjecting 1 microgram of DNA from each sample to 40 cycles of amplification. By using agarose gel electrophoresis the detection level was determined to be 7, 7, 9 and 15 mycoplasma cells per microgram of human genomic DNA for M. genus,M. fermentans, M. hominis and M. penetrans, respectively.

The assay was applied to DNA extracted from the PBMCs of individuals suffering from chronic fatigue syndrome (CFS) (n=100) as determined by the Center for Disease Control (CDC) criteria, and compared to healthy individuals (n=100).

The percentage of M. genus infection was found to be 52% in CFS patients and only 15% in healthy individuals. Mycoplasma fermentans, M. hominis andM. penetrans were detected in 32, 9 and 6% of the CFS patients while they were detected in 8, 3 and 2% of the healthy control subjects, respectively.

This assay provides a rapid and cost efficient procedure to screen either cell cultures or clinical samples for the presence of three potentially pathogenic species of mycoplasma with a high level of sensitivity and specificity.

Copyright 1998 Academic Press.

 

Source: Choppa PC, Vojdani A, Tagle C, Andrin R, Magtoto L. Multiplex PCR for the detection of Mycoplasma fermentans, M. hominis and M. penetrans in cell cultures and blood samples of patients with chronic fatigue syndrome. Mol Cell Probes. 1998 Oct;12(5):301-8. http://www.ncbi.nlm.nih.gov/pubmed/9778455

 

Chronic fatigue syndrome: an immunological perspective

Abstract:

OBJECTIVE: The aim of this study is to review research examining an immunological basis for chronic fatigue syndrome (CFS) and to discuss how a disturbance in immunity could produce central nervous system (CNS)-mediated symptoms.

METHOD: Data relevant to the hypothesis that abnormal cytokine release plays a role in the pathogenesis of CFS are reviewed as well as recent evidence relating to potential mechanisms by which immune products may enter the brain and produce a disturbance in CNS processes.

RESULTS: Examinations of cytokine levels in patients with CFS have produced inconclusive results. Recent evidence suggests that abnormal release of cytokines within the CNS may cause neural dysfunction by a variety of complex mechanisms.

CONCLUSION: Neuropsychiatric symptoms in patients with CFS may be more closely related to disordered cytokine production by glial cells within the CNS than to circulating cytokines. This possibility is discussed in the context of unresolved issues in the pathogenesis of CFS.

 

Source: Vollmer-Conna U, Lloyd A, Hickie I, Wakefield D. Chronic fatigue syndrome: an immunological perspective. Aust N Z J Psychiatry. 1998 Aug;32(4):523-7. http://www.ncbi.nlm.nih.gov/pubmed/9711366

 

Elevated apoptotic cell population in patients with chronic fatigue syndrome: the pivotal role of protein kinase RNA

Abstract:

OBJECTIVES: A prominent feature of chronic fatigue syndrome (CFS) is a disordered immune system. Recent evidence indicates that induction of apoptosis might be mediated in a dysregulated immune system by the upregulation of growth inhibitory cytokines. Therefore, the purpose of this study was to evaluate the apoptotic cell population, interferon-alpha (IFN-alpha) and the IFN-induced protein kinase RNA (PKR) gene transcripts in peripheral blood lymphocytes (PBL) of CFS individuals, as compared to healthy controls.

SUBJECTS AND METHODS: PBL were isolated from CFS (n = 29) and healthy control individuals (n = 15) and subjected to quantitative analysis of apoptotic cell population and cell cycle progression by flow cytometry. Quantitative competitive polymerase chain reaction (Q/C PCR) and Western blot analysis were used to assess the levels of PKR mRNA and protein in control and CFS individuals. In addition, circulating IFN-alpha was measured by ELISA assay.

RESULTS: Increased apoptotic cell population was observed in CFS individuals, as compared to healthy controls (26.6 +/- 12.9% and 9.9 +/- 4.2%, respectively). The increased apoptotic subpopulation in CFS individuals was accompanied by an abnormal cell arrest in the S phase and the G2/M boundary of the cell cycle as compared to the control group (8.6 +/- 1.2 to 22.8 +/- 2.4 and 3.6 +/- 0.82 to 24.3 +/- 3.4, respectively). In addition, CFS individuals exhibited enhanced PKR mRNA and protein levels (mean basal level 3538 +/- 1050 and 2.7 +/- 0.26, respectively) as compared to healthy controls (mean basal level 562 +/- 162 and 0.89 +/- 0.18, respectively). In 50% of the CFS samples (n = 29) treated with 2-aminopurine (2-AP) (a potent inhibitor of PKR) the apoptotic population was reduced by more then 50%.

CONCLUSIONS: PKR-mediated apoptosis in CFS individuals may contribute to the pathogenesis and the fatigue symptomatology associated with CFS.

Comment in: Cortisol deficiency may account for elevated apoptotic cell population in patients with chronic fatigue syndrome. [J Intern Med. 1999]

 

Source: Vojdani A, Ghoneum M, Choppa PC, Magtoto L, Lapp CW. Elevated apoptotic cell population in patients with chronic fatigue syndrome: the pivotal role of protein kinase RNA. J Intern Med. 1997 Dec;242(6):465-78. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.1997.tb00019.x/epdf (Full article)

 

Elevation of bioactive transforming growth factor-beta in serum from patients with chronic fatigue syndrome

Abstract:

The level of bioactive transforming growth factor-beta (TGF-beta) was measured in serum from patients with chronic fatigue syndrome (CFS), healthy control subjects, and patients with major depression, systemic lupus erythematosis (SLE), and multiple sclerosis (MS) of both the relapsing/remitting (R/R) and the chronic progressive (CP) types.

Patients with CFS had significantly higher levels of bioactive TGF-beta levels compared to the healthy control major depression, SLE, R/R MS, and CP MS groups (P < 0.01). Additionally, no significant differences were found between the healthy control subjects and any of the disease comparison groups.

The current finding that TGF-beta is significantly elevated among patients with CFS supports the findings of two previous studies examining smaller numbers of CFS patients.

In conclusion, TGF-beta levels were significantly higher in CFS patients compared to patients with various diseases known to be associated with immunologic abnormalities and/or pathologic fatigue. These findings raise interesting questions about the possible role of TGF-beta in the pathogenesis of CFS.

 

Source: Bennett AL, Chao CC, Hu S, Buchwald D, Fagioli LR, Schur PH, Peterson PK, Komaroff AL. Elevation of bioactive transforming growth factor-beta in serum from patients with chronic fatigue syndrome. J Clin Immunol. 1997 Mar;17(2):160-6. http://www.ncbi.nlm.nih.gov/pubmed/9083892

 

Cytokine production by adherent and non-adherent mononuclear cells in chronic fatigue syndrome

Abstract:

It has been suggested that cytokines play a role in certain clinical manifestations of chronic fatigue syndrome (CFS). In this study adherent (monocytes) and non-adherent (lymphocytes) mononuclear cells were stimulated in the presence or absence of phytohemagglutinin (PHA) or lipopolysaccharide (LPS), respectively, and supernatants were assayed for IL-6, TNF-alpha, and IL-10 by ELISA. IL-6 was also measured at the mRNA level by polymerase chain reaction.

The levels of spontaneously (unstimulated) produced TNF-alpha by non-adherent lymphocytes and spontaneously produced IL-6 by both adherent monocytes and non-adherent lymphocytes were significantly increased as compared to simultaneously studied matched controls. The abnormality of IL-6 was also observed at mRNA level.

In contrast, spontaneously produced IL-10 by both adherent and non-adherent cells and by PHA-activated non-adherent cells were decreased. This preliminary study suggests that an aberrant production of cytokines in CFS may play a role in the pathogenesis and in some of the clinical manifestations of CFS.

 

Source: Gupta S, Aggarwal S, See D, Starr A. Cytokine production by adherent and non-adherent mononuclear cells in chronic fatigue syndrome. J Psychiatr Res. 1997 Jan-Feb;31(1):149-56. http://www.ncbi.nlm.nih.gov/pubmed/9201656

 

Susceptibility to immunologically mediated fatigue in C57BL/6 versus Balb/c mice

Abstract:

Proinflammatory cytokines such as interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha have been proposed to play a role in the pathogenesis of fatigue. In the present study we compared the susceptibility of two mouse strains to immunologically induced fatigue.

Daily running of two strains of mice, Balb/c and C57BL/ 6, was assessed after a single injection of Corynebacterium parvum antigen (2 mg/mouse). Spontaneous running activity of each animal was compared to mean running distance prior to injection. To evaluate the involvement of cytokines in fatigue development, C57BL/6 mice were treated with antibodies to specific cytokines at the time of challenge with C. parvum antigen. Also, cytokine mRNA expression was analyzed in the brains of mice at different time periods after immunologic challenge.

A significant difference in running activity between the two mice strains was observed after C. parvum antigen inoculation: C57BL/6 mice showing a greater (P < 0.05) reduction in running activity (relative to preinjection levels) and slower recovery to baseline than Balb/c mice. Injection of antibodies specific to either IL-1beta or TNF-alpha did not alter immunologically induced fatigue, suggesting a lack of involvement of these cytokines produced outside of the central nervous system (CNS).

However, increased TNF-alpha and IL-1beta mRNA expression was found in the brains of C57BL/6 compared to that seen in Balb/c mice at 6, 10, and 15 days after C. parvum antigen injection. The elevated CNS cytokine mRNA expression corresponded to development of fatigue. These findings are consistent with the hypothesis that expression of proinflammatory cytokines within the CNS plays a role in the pathogenesis of immunologically mediated fatigue.

 

Source: Sheng WS, Hu S, Lamkin A, Peterson PK, Chao CC. Susceptibility to immunologically mediated fatigue in C57BL/6 versus Balb/c mice. Clin Immunol Immunopathol. 1996 Nov;81(2):161-7. http://www.ncbi.nlm.nih.gov/pubmed/8906747