Our weekly roundup of research abstracts that have not already appeared on the MEA website.
Semin Neurol. 2011 Jul;31(3):325-37. doi: http://dx.doi.org/10.1055/s-0031-1287654. Epub 2011 Sep 30.
Role of infection and neurologic dysfunction in chronic fatigue syndrome.
Komaroff AL, Cho TA.
Division of General Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. Komaroff@hms.harvard.edu
Chronic fatiguing illnesses following well-documented infections and acute “infectious-like” illnesses of uncertain cause have been reported for many decades. Chronic fatigue syndrome (CFS) was first formally defined in 1988.
There is considerable evidence that CFS is associated with abnormalities of the central and autonomic nervous systems. There also is evidence linking several infectious agents with CFS, although no agent has been proven to be a cause of the illness.
Most of the infectious agents that have been linked to CFS are able to produce a persistent, often life-long, infection and thus are a constant incitement to the immune system. Most also have been shown to be neuropathogens. The evidence is consistent with the hypothesis that CFS, in some cases, can be triggered and perpetuated by several chronic infections that directly or indirectly affect the nervous system, and that symptoms are a reflection of the immune response to the infection.
Cancer Epidemiol Biomarkers Prev. 2011 Oct;20(10):2232-6. Epub 2011 Aug 22.
The retrovirus XMRV is not directly involved in the pathogenesis of common types of lymphoid malignancy.
Waugh EM, Jarrett RF, Shield L, Montgomery D, Dean RT, Mitchell A, Greaves MF, Gallagher A.
LRF Virus Centre, MRC and University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
BACKGROUND: A novel retrovirus, xenotropic murine leukemia virus-related virus (XMRV), has been detected in prostate cancer samples and in peripheral blood mononuclear cells (PBMC) from patients with chronic fatigue syndrome. In addition, the virus has been identified in PBMCs from healthy controls.
These data suggest that XMRV is circulating in the human population. XMRV is closely related to murine leukemia viruses, which cause lymphoid malignancies in mice. The aim of this study was to determine whether XMRV is directly associated with common forms of human lymphoma or leukemia.
METHODS: DNA samples from 368 patients with lymphoid malignancies and 139 patients with benign lymphadenopathy or other malignant disease were screened for XMRV, using three specific and sensitive quantitative PCR assays.
RESULTS: XMRV was not detected in any sample using any of the three assays.
CONCLUSIONS: The data suggest that this virus is not directly involved in the pathogenesis of common types of lymphoid malignancy and that XMRV is not a prevalent blood borne infection, at least in the United Kingdom.
IMPACT: There is no evidence that XMRV is associated with lymphoid malignancies, and further studies should resolve inconsistencies in results of studies examining XMRV prevalence.
J Psychosom Res. 2011 Sep;71(3):129-35. Epub 2011 May 18.
Deviations in daily physical activity patterns in patients with the chronic fatigue syndrome: a case control study.
Evering RM, Tönis TM, Vollenbroek-Hutten MM.
Roessingh Research and Development, Post Box 310, 7500 AH Enschede, The Netherlands. email@example.com
OBJECTIVES: Deviations in daily physical activity patterns may play an important role in the development and maintenance of fatigue in the chronic fatigue syndrome (CFS). The aim of this study is to gain insight into the objective daily physical activity pattern of patients with CFS in comparison with healthy controls. The secondary objective is studying the awareness in performing physical activities.
METHODS: The objective daily physical activity pattern was measured with a tri-axial accelerometer in 35 patients with CFS and in 35 age- and gender-matched healthy controls. The objective daily physical activity level and distribution of physical activities at low, medium and high intensity levels during the day were measured. Moreover, variability in performing physical activities within and between subjects was computed. Subjective ratings of self-reported daily physical activity levels were assessed at a visual analog scale.
RESULTS: CFS patients were significantly less physically active in the afternoon and evening, and spent fewer activities at high intensity levels and more at low intensity levels. Moreover, CFS patients showed more variability in their own physical activity pattern during the afternoon. The heterogeneity in the physical activity pattern between subjects within the CFS and control group did not differ. Finally, CFS patients were more aware about their daily physical activity level than healthy controls.
CONCLUSION: CFS patients showed deviations in the objectively measured daily physical activity pattern. Future research should elucidate the relation between impaired balances in daily physical activity patterns and fatigue severity in CFS.
J Psychosom Res. 2011 Sep;71(3):124-8. Epub 2011 Apr 3.
Measuring disability in patients with chronic fatigue syndrome: reliability and validity of the Work and Social Adjustment Scale.
Cella M, Sharpe M, Chalder T.
Institute of Psychiatry, King's College London, UK. firstname.lastname@example.org
BACKGROUND: Disability is a defining feature of chronic conditions, and it is an increasingly used measure of therapy effectiveness. The Work and Social Adjustment Scale (WSAS) is a simple and clear measure of disability. Although the scale is widely used, no study has yet investigated its psychometric properties in patients with chronic fatigue syndrome (CFS).
METHODS: Data from two samples of patients were used, one from a multicenter randomized controlled clinical trial of treatments for CFS (n=639) and the other from a clinic that specializes in CFS (n=384). All patients completed the WSAS as well as other measures.
RESULTS: Internal consistency and the Spearman-Brown split-half coefficient values indicated that the scale is reliable.
CFS patients who had comorbid diagnoses of depression, anxiety or fibromyalgia had higher WSAS scores. High levels of disability were associated with high number of physical symptoms, severe fatigue, depression, anxiety, poor sleep quality and poor physical fitness, with correlation coefficients ranging between 0.41 and 0.11.
Lower scores on the WSAS were modestly associated with better physical functioning as well as higher levels of physical capacity as assessed by a walking test. Sensitivity to change was evaluated in a subgroup of patients who had undergone a course of cognitive behavioral therapy. Disability significantly decreased after therapy and remained stable at follow-ups.
CONCLUSION: The WSAS is a reliable and valid assessment tool for disability in patients with CFS.
Indian J Biochem Biophys. 2011 Apr;48(2):82-7.
Abnormality of circadian rhythm of serum melatonin and other biochemical parameters in fibromyalgia syndrome.
Mahdi AA, Fatima G, Das SK, Verma NS.
Department of Biochemistry, C.S.M. Medical University U.P, Lucknow, 226 003, India. email@example.com
Fibromyalgia syndrome (FMS) is a complex chronic condition causing widespread pain and variety of other symptoms. It produces pain in the soft tissues located around joints throughout the body. FMS has unknown etiology and its pathophysiology is not fully understood.
However, abnormality in circadian rhythm of hormonal profiles and cytokines has been observed in this disorder. Moreover, there are reports of deficiency of serotonin, melatonin, cortisol and cytokines in FMS patients, which are fully regulated by circadian rhythm.
Melatonin, the primary hormone of the pineal gland regulates the body's circadian rhythm and normally its levels begin to rise in the mid-to-late evening, remain high for most of the night, and then decrease in the early morning. FMS patients have lower melatonin secretion during the hours of darkness than the healthy subjects. This may contribute to impaired sleep at night, fatigue during the day and changed pain perception.
Studies have shown blunting of normal diurnal cortisol rhythm, with elevated evening serum cortisol level in patients with FMS. Thus, due to perturbed level of cortisol secretion several symptoms of FMS may occur. Moreover, disturbed cytokine levels have also been reported in FMS patients. Therefore, circadian rhythm can be an important factor in the pathophysiology, diagnosis and treatment of FMS.
This article explores the circadian pattern of abnormalities in FMS patients, as this may help in better understanding the role of variation in symptoms of FMS and its possible relationship with circadian variations of melatonin, cortisol, cytokines and serotonin levels.
Brain Behav Immun. 2011 Nov;25(8):1544-7. Epub 2011 Apr 28.
Increased HDAC in association with decreased plasma cortisol in older adults with chronic fatigue syndrome.
Jason L, Sorenson M, Sebally K, Alkazemi D, Lerch A, Porter N, Kubow S
Department of Psychology, DePaul University, Chicago, IL 60614, United States.
Hypocortisolism is a frequent finding in individuals with chronic fatigue syndrome (CFS) with other research findings implying potential dysregulation of glucocorticoid signaling. Glucocorticoid signaling is under the influence of several pathways, several of which are of interest in the study of CFS.
Oxidative stress and decreased antioxidant capacity are known to disrupt the hypothalamic-pituitary-adrenal (HPA) axis (Epel et al., 2004) and the presence of histone deacetylases (HDAC) could also impact glucocorticoid signaling.
The intent of this pilot study was to investigate the relationship among oxidative stress elements, select HDAC's (2/3) and glucocorticoid receptor signaling in an elderly sample with CFS.
Findings suggest increased histone deacetylase activity, lower total antioxidant power, in the context of decreased plasma cortisol and increased plasma dehydroepiandrosterone concomitant with decreased expression of the encoding gene for the glucocorticoid receptor. These findings support the presence of HPA axis dysregulation in elderly individuals with CFS.