IgM serum antibodies to Epstein-Barr virus are uniquely present in a subset of patients with the chronic fatigue syndrome

Abstract:

BACKGROUND: A unique subset of patients with chronic fatigue syndrome (CFS) and IgM serum antibodies to cytomegalovirus (HCMV) non-structural gene products p52 and CM2 (UL 44 and UL 57) has been described.

PATIENTS AND METHODS: Fifty-eight CFS patients and 68 non-CFS matched controls were studied. Serum antibodies to EBV viral capsid antigen (VCA) IgM and EBV Early Antigen, diffuse (EA, D) as well HVCMV(V), IgM and IgG; VP (sucrose, density purified V); p52 and CM2 IgM serum antibodies were assayed.

RESULTS: Mean age of CFS patients was 44 years (75% women). Control patients were 9 years older (73% women). Serum EBV VCA IgM positive antibody titers were identified in 33 CFS patients (Group A subset EBV VCA IgM 62.3+/-8.3, neg. <20), but were not present in other CFS patients, (Group B subset EBV VCA IgM 6.8+/-0.7) controls (p<0.0001). EBV VCA IgM titers remained positive in CFS patients from Group A for 24-42 months.

CONCLUSION: Serum antibody to EBV VCA IgM may be a specific diagnostic test for a second subset of CFS patients.

 

Source: Lerner AM, Beqaj SH, Deeter RG, Fitzgerald JT. IgM serum antibodies to Epstein-Barr virus are uniquely present in a subset of patients with the chronic fatigue syndrome.  In Vivo. 2004 Mar-Apr;18(2):101-6. http://iv.iiarjournals.org/content/18/2/101.long (Full article)

 

Levels of DHEA and DHEAS and responses to CRH stimulation and hydrocortisone treatment in chronic fatigue syndrome

Abstract:

BACKGROUND: An association between chronic fatigue syndrome (CFS) and abnormalities of the hypothalamo-pituitary-adrenal axis has been described, and other adrenal steroid abnormalities have been suggested. Dehydroepiandrostenedione (DHEA) and its sulphate (DHEA-S), apart from being a precursor of sex steroids, have other functions associated with memory, depression and sleep. It has been suggested that CFS may be associated with a state of relative DHEA(-S) deficiency. Therefore we investigated basal levels of DHEA(-S), the cortisol/DHEA molar ratio and the responsiveness of DHEA to stimulation by corticotrophin-releasing hormone (CRH). Recent studies have also suggested that low dose hydrocortisone may be effective at reducing fatigue in CFS. We therefore also assessed these parameters prior to and following treatment with low dose oral hydrocortisone.

METHODS: Basal levels of serum DHEA, DHEAS and cortisol were measured in 16 patients with CFS without depression and in 16 controls matched for age, gender, weight, body mass index and menstrual history. CRH tests (1 g/kg i.v.) were carried out on all subjects and DHEA measured at 0, +30 and +90 min. In the patient group, CRH tests were repeated on two further occasions following treatment with hydrocortisone (5 or 10 mg, p.o.) or placebo for 1 month each in a double-blind cross over study protocol.

RESULTS: Basal levels of DHEA were higher in the patient, compared to the control, group (14.1+/-2.2 vs. 9.0+/-0.90 ng/ml, P=0.04), while levels of DHEAS in patients (288.7+/-35.4 microg/dl) were not different from controls (293.7+/-53.8, P=NS). Higher DHEA levels were correlated with higher disability scores. Basal cortisol levels were higher in patients, and consequently the cortisol/DHEA molar ratio did not differ between patients and controls. Levels of DHEA (8.9+/-0.97 ng/ml, P=0.015) and DHEAS (233.4+/-41.6 microg/dl, P=0.03) were lower in patients following treatment with hydrocortisone. There was a rise in DHEA responsiveness to CRH in the patients after treatment but this did not attain significance (AUCc: 2.5+/-1.7 ng/ml h pre-treatment vs. 6.4+/-1.2 ng/ml h post-hydrocortisone, P=0.053). However, those patients who responded fully to hydrocortisone in terms of reduced fatigue scores did show a significantly increased DHEA responsiveness to CRH (AUCc: -1.4+/-2.5 ng/ml h at baseline, 5.0+/-1.2 ng/ml h after active treatment, P=0.029).

CONCLUSIONS: DHEA levels are raised in CFS and correlate with the degree of self-reported disability. Hydrocortisone therapy leads to a reduction in these levels towards normal, and an increased DHEA response to CRH, most marked in those who show a clinical response to this therapy.

 

Source: Cleare AJ, O’Keane V, Miell JP. Levels of DHEA and DHEAS and responses to CRH stimulation and hydrocortisone treatment in chronic fatigue syndrome. Psychoneuroendocrinology. 2004 Jul;29(6):724-32. http://www.ncbi.nlm.nih.gov/pubmed/15110921

 

Cognitive processing in monozygotic twins discordant for chronic fatigue syndrome

Abstract:

Twenty-one pairs of monozygotic twins discordant for chronic fatigue syndrome (CFS) and 21 matched healthy control (HC) subjects were assessed with 5 untimed tests and 5 timed tests from the computer-based NeuroCognitive Assessment Battery (R. K. Mahurin, 1993). Random effects regression showed no difference between CFS and healthy twins on any of the cognitive tests. Further, the twin groups did not differ from the HC group on any content-dependent measure. In contrast, both sets of twins performed worse than the HC group on all speed-dependent tests except Finger Tapping. Self-rated fatigue and dysphoric mood were only weakly correlated with cognitive performance.

These data point toward a shared genetic trait related to information processing that is manifest in the CFS context. The findings have implications for differentiating genetic and acquired vulnerability in the symptomatic expression of the disorder. ((c) 2004 APA, all rights reserved)

 

Source: Mahurin RK, Claypoole KH, Goldberg JH, Arguelles L, Ashton S, Buchwald D. Cognitive processing in monozygotic twins discordant for chronic fatigue syndrome. Neuropsychology. 2004 Apr;18(2):232-9. http://www.ncbi.nlm.nih.gov/pubmed/15099145

 

Sleep assessment in a population-based study of chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a disabling condition that affects approximately 800,000 adult Americans. The pathophysiology remains unknown and there are no diagnostic markers or characteristic physical signs or laboratory abnormalities. Most CFS patients complain of unrefreshing sleep and many of the postulated etiologies of CFS affect sleep. Conversely, many sleep disorders present similarly to CFS. Few studies characterizing sleep in unselected CFS subjects have been published and none have been performed in cases identified from population-based studies.

METHODS: The study included 339 subjects (mean age 45.8 years, 77% female, 94.1% white) identified through telephone screen in a previously described population-based study of CFS in Wichita, Kansas. They completed questionnaires to assess fatigue and wellness and 2 self-administered sleep questionnaires. Scores for five of the six sleep factors (insomnia/hypersomnia, non-restorative sleep, excessive daytime somnolence, sleep apnea, and restlessness) in the Centre for Sleep and Chronobiology’s Sleep Assessment Questionnaire (SAQ) were dichotomized based on threshold. The Epworth Sleepiness Scale score was used as a continuous variable.

RESULTS: 81.4% of subjects had an abnormality in at least one SAQ sleep factor. Subjects with sleep factor abnormalities had significantly lower wellness scores but statistically unchanged fatigue severity scores compared to those without SAQ abnormality. CFS subjects had significantly increased risk of abnormal scores in the non-restorative (adjusted odds ratio [OR] = 28.1; 95% confidence interval [CI]= 7.4-107.0) and restlessness (OR = 16.0; 95% CI = 4.2-61.6) SAQ factors compared to non-fatigued, but not for factors of sleep apnea or excessive daytime somnolence. This is consistent with studies finding that, while fatigued, CFS subjects are not sleepy. A strong correlation (0.78) of Epworth score was found only for the excessive daytime somnolence factor.

CONCLUSIONS: SAQ factors describe sleep abnormalities associated with CFS and provide more information than the Epworth score. Validation of these promising results will require formal polysomnographic sleep studies.

 

Source: Unger ER, Nisenbaum R, Moldofsky H, Cesta A, Sammut C, Reyes M, Reeves WC. Sleep assessment in a population-based study of chronic fatigue syndrome. BMC Neurol. 2004 Apr 19;4:6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC419502/  (Full article)

 

Associations between neuroendocrine responses to the Insulin Tolerance Test and patient characteristics in chronic fatigue syndrome

Abstract:

OBJECTIVE: Subtle dysregulations of the hypothalamic-pituitary-adrenal (HPA) axis have been proposed as an underlying pathophysiological mechanism in chronic fatigue syndrome (CFS). This study attempted to assess the relationship between patient characteristics and HPA axis functioning using a neuroendocrine challenge test.

METHOD: A test battery designed to assess different dimensions of CFS was given to 18 CFS patients and 17 controls. To evaluate the integrity of the HPA axis, the Insulin Tolerance Test (ITT), a centrally acting neuroendocrine challenge test, was performed on patients and controls. ACTH, salivary free cortisol and total plasma cortisol levels were assessed as a measure of the HPA axis stress response. Correlations of patient characteristics were calculated with integrated responses for all endocrine parameters.

RESULTS: CFS patients had a significantly reduced area under the ACTH response curve (AUC) in the ITT. The AUC was significantly associated with the duration of CFS symptoms (r = -.592, P = .005) and the severity of fatigue symptomatology (r = -.41, P = .045). In addition, duration of CFS was correlated with the severity of fatigue symptoms (r = .38, P = .045). Similar associations were not observed for cortisol parameters.

CONCLUSION: It has been postulated that neuroendocrine dysregulations observed in CFS are of an acquired nature. The results of a strong association between the integrated ACTH response and the duration of CFS emphasizes the need to consider factors known to be risk factors for the chronicity of CFS symptoms, such as profound inactivity, deconditioning and sleep abnormalities, as possible candidates for secondary causes of neuroendocrine dysregulations in CFS.

Copyright 2004 Elsevier Inc.

 

Source: Gaab J, Engert V, Heitz V, Schad T, Schürmeyer TH, Ehlert U. Associations between neuroendocrine responses to the Insulin Tolerance Test and patient characteristics in chronic fatigue syndrome.  J Psychosom Res. 2004 Apr;56(4):419-24. http://www.ncbi.nlm.nih.gov/pubmed/15094026

 

Prevalence of chronic fatigue syndrome-like caseness in the working population: results from the Maastricht cohort study

Abstract:

AIM: To determine the prevalence of chronic fatigue syndrome (CFS)-like caseness in the working population.

METHODS: Using data from the prospective Maastricht Cohort Study on Fatigue at Work, the prevalence and incidence of CFS-like cases (employees meeting research criteria for CFS) were determined among 5499 employees who responded to the follow up assessment 3 years and 8 months after baseline.

RESULTS: Of the 5499 employees, 199 (3.6%) were identified as CFS-like cases. By deleting possible CFS-like cases at baseline, the annual incidence of CFS-like caseness was estimated to be 85 per 10 000. Twenty employees (0.36%) reported having been diagnosed with CFS by a physician.

CONCLUSIONS: The prevalence of CFS-like cases (3.6%) was considerably higher than the prevalence of CFS reported in previous studies (0.006-3%). These findings suggest that the CFS-like caseness may be underdetected in the working population and perhaps in other populations as well.

 

Source: Huibers MJ, Kant IJ, Swaen GM, Kasl SV. Prevalence of chronic fatigue syndrome-like caseness in the working population: results from the Maastricht cohort study. Occup Environ Med. 2004 May;61(5):464-6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1740780/ (Full article)

 

Chronic fatigue and indicators of long-term employment disability in psychosomatic inpatients

Abstract:

The major goal of this study was to determine indictors of long-term disability for psychosomatic inpatients with chronic fatigue syndrome. To this end, a cross-sectional study was performed with a random sample of patients (n=1000, response rate: 83.9%) at a psychosomatic inpatient clinic. 51.1% of the patients (n=429) reported intensely persistent exhaustion that had no logical relation to actual exertion. 159 (37.1%) patients in this group were disabled from working and these comprised the main target group of this study.

Significantly more patients in the target group worked part time, were disabled for a disproportionately long period of time (50.9% of all were disabled for more than 6 months in the previous year), and felt stressed because of conflicts with their superiors and/or colleagues (in each case, P<0.01). While more frequent psychological comorbidity was not found, they reported physical complaints more often. It was not the patients fit for work who felt more burdened with chronic fatigue, but rather the employment-disabled, who were actually exposed to fewer demands.

These patients had, in comparison with those fit to work, a stronger fixation on somatic complaints, inadequate perception of physical and psychic sensations, difficulties getting along with other people and in coping with a regular job (in each case, P<0.01). Prospective examination of these indicators could help detect predictor variables for long-term disability in chronic fatigue. Such predictors could contribute to timely social-medical assessment and treatment.

 

Source: Tritt K, Nickel M, Mitterlehner F, Nickel C, Forthuber P, Leiberich P, Rother W, Loew T. Chronic fatigue and indicators of long-term employment disability in psychosomatic inpatients. Wien Klin Wochenschr. 2004 Mar 31;116(5-6):182-9. http://www.ncbi.nlm.nih.gov/pubmed/15088993

 

Midodrine treatment for chronic fatigue syndrome

Abstract:

The long term results of midodrine treatment in a patient having debilitating chronic fatigue syndrome (CFS) are reported. Midodrine treatment, directed at the autonomic nervous system, resulted in correction of the dysautonomia followed by improvement of fatigue. This finding is consistent with the hypothesis that dysautonomia plays a major part in the pathophysiology of CFS and that therapies directed at the autonomic nervous system may be effective in the treatment of CFS.

 

Source: Naschitz J, Dreyfuss D, Yeshurun D, Rosner I. Midodrine treatment for chronic fatigue syndrome. Postgrad Med J. 2004 Apr;80(942):230-2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1742969/pdf/v080p00230.pdf (Full article)

 

Chronic fatigue syndrome: intracellular immune deregulations as a possible etiology for abnormal exercise response

Abstract:

The exacerbation of symptoms after exercise differentiates Chronic fatigue syndrome (CFS) from several other fatigue-associated disorders. Research data point to an abnormal response to exercise in patients with CFS compared to healthy sedentary controls, and to an increasing amount of evidence pointing to severe intracellular immune deregulations in CFS patients. This manuscript explores the hypothetical interactions between these two separately reported observations.

First, it is explained that the deregulation of the 2-5A synthetase/RNase L pathway may be related to a channelopathy, capable of initiating both intracellular hypomagnesaemia in skeletal muscles and transient hypoglycemia. This might explain muscle weakness and the reduction of maximal oxygen uptake, as typically seen in CFS patients.

Second, the activation of the protein kinase R enzyme, a characteristic feature in at least subsets of CFS patients, might account for the observed excessive nitric oxide (NO) production in patients with CFS. Elevated NO is known to induce vasodilation, which may limit CFS patients to increase blood flow during exercise, and may even cause and enhanced postexercise hypotension.

Finally, it is explored how several types of infections, frequently identified in CFS patients, fit into these hypothetical pathophysiological interactions.

 

Source: Nijs J, De Meirleir K, Meeus M, McGregor NR, Englebienne P. Chronic fatigue syndrome: intracellular immune deregulations as a possible etiology for abnormal exercise response. Med Hypotheses. 2004;62(5):759-65. http://www.ncbi.nlm.nih.gov/pubmed/15082102

 

Is chronic fatigue syndrome an autoimmune disorder of endogenous neuropeptides, exogenous infection and molecular mimicry?

Abstract:

Chronic fatigue syndrome is a disorder characterised by prolonged fatigue and debility and is mostly associated with post-infection sequelae although ongoing infection is unproven. Immunological aberration is likely and this may prove to be associated with an expanding group of vasoactive neuropeptides in the context of molecular mimicry and inappropriate immunological memory.

Vasoactive neuropeptides including vasoactive intestinal peptide (VIP) and pituitary adenylate activating polypeptide (PACAP) belong to the secretin/glucagon superfamily and act as hormones, neurotransmitters, immune modulators and neurotrophes. They are readily catalysed to smaller peptide fragments by antibody hydrolysis. They and their binding sites are immunogenic and are known to be associated with a range of autoimmune conditions. Vasoactive neuropeptides are widely distributed in the body particularly in the central, autonomic and peripheral nervous systems and have been identified in the gut, adrenal gland, reproductive organs, vasculature, blood cells and other tissues. They have a vital role in maintaining vascular flow in organs, and in thermoregulation, memory and concentration. They are co-transmitters for acetylcholine, nitric oxide, endogenous opioids and insulin, are potent immune regulators with primarily anti-inflammatory activity, and have a significant role in protection of the nervous system to toxic assault, promotion of neural development and the maintenance of homeostasis.

This paper describes a biologically plausible mechanism for the development of CFS based on loss of immunological tolerance to the vasoactive neuropeptides following infection, significant physical exercise or de novo. It is proposed that release of these substances is accompanied by a loss of tolerance either to them or their receptor binding sites in CFS. Such an occurrence would have predictably serious consequences resulting from compromised function of the key roles these substances perform. All documented symptoms of CFS are explained by vasoactive neuropeptide compromise, namely fatigue and nervous system dysfunction through impaired acetylcholine activity, myalgia through nitric oxide and endogenous opioid dysfunction, chemical sensitivity through peroxynitrite and adenosine dysfunction, and immunological disturbance through changes in immune modulation. Perverse immunological memory established against these substances or their receptors may be the reason for the protracted nature of this condition.

The novel status of these substances together with their extremely small concentrations in blood and tissues means that clinical research into them is still in its infancy. A biologically plausible theory of CFS causation associated with vasoactive neuropeptide dysfunction would promote a coherent and systematic approach to research into this and other possibly associated disabling conditions.

 

Source: Staines DR. Is chronic fatigue syndrome an autoimmune disorder of endogenous neuropeptides, exogenous infection and molecular mimicry? Med Hypotheses. 2004;62(5):646-52. http://www.ncbi.nlm.nih.gov/pubmed/15082083