Category: Etiology

Diverse etiologies for chronic fatigue syndrome

Comment on: Markers of viral infection in monozygotic twins discordant for chronic fatigue syndrome. [Clin Infect Dis. 2002]

 

SIR—Koelle et al.  recently studied 22 pairs of identical twins discordant for chronic fatigue syndrome and concluded that there was no major contribution for viral infections in the perpetuation of chronic fatigue syndrome (CFS). The authors should be commended for their methodology and the use of well-matched control subjects. However, the study raised several issues.

First, similar to previous studies, the approach of Koelle et al.  was to look for statistical differences among the well-matched pairs with respect to the presence of viral antibodies and, more specifically, the presence of DNA of the viruses studied. Although these viruses were no more prevalent among the patients with CFS than among their healthy twins, one cannot conclude that these viruses are not the cause of CFS in a small subset of patients. CFS has been described in a small number of patients who had had well-documented acute Epstein-Barr virus (EBV), cytomegalovirus (CMV), and parvovirus B19 infections, and many of the patients responded to specific antiviral therapy. Of the first 200 patients with CFS who we evaluated for viral etiologies , only ∼10% had etiologies that were attributed to the viruses studied by Koelle et al. Chlamydia pneumoniae infection, an uncommon, although treatable, cause of CFS, was also dismissed in a previous, smaller study .

You can read the rest of this comment here: http://cid.oxfordjournals.org/content/36/5/671.long

 

Source: Chia JK, Chia A. Diverse etiologies for chronic fatigue syndrome. Clin Infect Dis. 2003 Mar 1;36(5):671-2; author reply 672-3. http://cid.oxfordjournals.org/content/36/5/671.long (Full article)

 

Chronic fatigue syndrome in patients with macrophagic myofasciitis

Macrophagic myofasciitis (MMF), a condition first reported in France in 1998, is defined by the presence of a stereotyped and immunologically active lesion at deltoid muscle biopsy . It was recently demonstrated that this lesion is an indicator of long-term persistence of the immunologic adjuvant aluminum hydroxide within the cytoplasm of macrophages at the site of previous intramuscular (IM) injection. MMF is typically detected in patients with diffuse arthromyalgias that have appeared subsequent to aluminum hydroxide administration in the absence of a clearly defined anatomic substratum. Patients also report unexplained chronic fatigue. These manifestations are reminiscent of the so-called chronic fatigue syndrome (CFS), a poorly understood condition manifesting as disabling fatigue, musculoskeletal pain, sleep disturbance, impaired concentration, and headaches. The present study was conducted to determine the proportion of MMF patients fulfilling international criteria for CFS.

You can read the rest of this article here: http://onlinelibrary.wiley.com/doi/10.1002/art.10740/full

 

Source: Authier FJ, Sauvat S, Champey J, Drogou I, Coquet M, Gherardi RK. Chronic fatigue syndrome in patients with macrophagic myofasciitis. Arthritis Rheum. 2003 Feb;48(2):569-70. http://onlinelibrary.wiley.com/doi/10.1002/art.10740/full (Full article)

 

Unconscious amygdalar fear conditioning in a subset of chronic fatigue syndrome patients

Abstract:

Here, a novel hypothesis for chronic fatigue syndrome (CFS) is proposed. CFS may be a neurophysiological disorder focussing on the amygdala. During a ‘traumatic’ neurological event often involving acute psychological stress combined with a viral infection or other chemical or physiological stressor, a conditioned network or ‘cell assembly’ may be created in the amygdala. The unconscious amygdala may become conditioned to be chronically sensitised to negative symptoms arising from the body. Negative signals from the viscera or physiological, chemical and dietary stressors, become conditioned stimuli and the conditioned response is a chronic sympathetic outpouring from the amygdala via various brain pathways including the hypothalamus.

This cell assembly then produces the CFS vicious circle, where an unconscious negative reaction to symptoms causes immune reactivation/dysfunction, chronic sympathetic stimulation, leading to sympathetic dysfunction, mental and physical exhaustion, and a host of other distressing symptoms and secondary complications. And these are exactly the symptoms that the amygdala and associated limbic structures are trained to monitor and respond to, perpetuating a vicious circle. Recovery from CFS may involve projections from the medial prefrontal cortex to the amygdala, to control the amygdala’s expressions. I shall firstly discuss predisposing, precipitating, and perpetuating factors involved in the possible etiology of chronic fatigue syndrome (CFS), followed by the patient’s experience of the illness. Finally, I shall look at a suggested explanation for the symptoms of CFS.

Copyright 2002 Elsevier Science Ltd.

 

Source: Gupta A. Unconscious amygdalar fear conditioning in a subset of chronic fatigue syndrome patients. Med Hypotheses. 2002 Dec;59(6):727-35. http://www.ncbi.nlm.nih.gov/pubmed/12445517

A status report on chronic fatigue syndrome

Abstract:

Medical history has shown that clinical disease entities or syndromes are composed of many subgroups–each with its own cause and pathogenesis. Although we cannot be sure, we expect the same outcome for chronic fatigue syndrome (CFS), a medically unexplained condition characterized by disabling fatigue accompanied by infectious, rheumatological, and neuropsychiatric symptoms. Although the ailment clearly can occur after severe infection, no convincing data exist to support an infectious (or immunologic) process in disease maintenance. Instead, data point to several possible pathophysiological processes: a covert encephalopathy, impaired physiological capability to respond to physical and mental stressors, and psychological factors related to concerns about effort exacerbating symptoms. Each of these is under intense investigation. In addition, some data do exist to indicate that environmental agents also can elicit a state of chronic fatigue. We expect data to accumulate to support the belief that CFS has multiple causes.

 

Source: Natelson BH, Lange G. A status report on chronic fatigue syndrome. Environ Health Perspect. 2002 Aug;110 Suppl 4:673-7. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1241224/ (Full article)

 

IgM serum antibodies to human cytomegalovirus nonstructural gene products p52 and CM2(UL44 and UL57) are uniquely present in a subset of patients with chronic fatigue syndrome

Abstract:

Human cytomegalovirus (HCMV) IgM serum antibodies to two nonstructural gene products UL44 and UL57 (p52 and CM2) were assayed in patients with the diagnosis of the chronic fatigue syndrome (CFS) according to criteria established by the US Centers for Disease Control and Prevention. A subset of 16 CFS patients demonstrated HCMV IgG, but no HCMV IgM serum antibodies to conformational structural HCMV antigens (designated, V). By convention, these findings are interpreted to indicate only a remote HCMV infection.

However, HCMV IgM p52 and CM2 antibodies were uniquely present in these 16 CFS patients. Other CFS patients with similar HCMV (V) IgG antibodies (18 patients), non-fatigued HCMV (V) IgG-positive control patients (18 patients), random HCMV (V) IgG-positive control patients from a clinical laboratory (26 patients), and non-fatigued HCMV (V) IgG-negative control patients (15 patients) did not have HCMV, IgM p52 or CM2 serum antibodies (p < 0.05). Control HCMV (V) IgG-positive patients had no serum IgM HCMV (V) antibodies to conventional structural HCMV (V) antigen. Thus, 77 various control patients did not contain IgM p52 or CM2 serum antibodies. The presence of IgM p52 and/or CM2 HCMV serum antibodies in this subset of CSF-specific patients may detect incomplete HCMV multiplication in which a part of the HCMV protein-coding content of the HCMV genome is processed, but remains unassembled.

These findings suggest that the presence of HCMV IgM p52 and CM2 serum antibodies may be a specific diagnostic test for the diagnosis of a subset of CFS patients. Further, these data suggest an etiologic relationship for HCMV infection in this group of CFS patients

 

Source: Lerner AM, Beqaj SH, Deeter RG, Fitzgerald JT. IgM serum antibodies to human cytomegalovirus nonstructural gene products p52 and CM2(UL44 and UL57) are uniquely present in a subset of patients with chronic fatigue syndrome. In Vivo. 2002 May-Jun;16(3):153-9. http://www.ncbi.nlm.nih.gov/pubmed/12182109

 

Elevated nitric oxide/peroxynitrite mechanism for the common etiology of multiple chemical sensitivity,chronic fatigue syndrome, and posttraumatic stress disorder

Abstract:

Various types of evidence implicate nitric oxide and an oxidant, possibly peroxynitrite, in MCS and chemical intolerance (CI). The positive feedback loops proposed earlier for CFS may explain the chronic nature of MCS (CI) as well as several of its other reported properties. These observations raise the possibility that this proposed elevated nitric oxide/peroxynitrite mechanism may be the mechanism of a new disease paradigm, answering the question raised by Miller earlier: “Are we on the threshold of a new theory of disease?”

 

Source: Pall ML, Satterlee JD. Elevated nitric oxide/peroxynitrite mechanism for the common etiology of multiple chemical sensitivity,chronic fatigue syndrome, and posttraumatic stress disorder.  Ann N Y Acad Sci. 2001 Mar;933:323-9. http://www.ncbi.nlm.nih.gov/pubmed/12000033

 

Chronic Fatigue Syndrome and Herpesviruses: the Fading Evidence

Abstract:

Herpesviruses, in particular Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpesvirus 6 (HHV-6), have, for the past two decades, come under considerable scrutiny as aetiological agents of chronic fatigue syndrome (CFS). However, virological findings of herpesviruses in CFS have not been consistent between different studies, and the unusual patterns of serological responses to EBV, CMV and HHV-6 have not been specific for CFS, being observed also in asymptomatic individuals. In addition, patients with symptomatology suggestive of CFS do not appear to have an increased frequency of these herpesviruses, as detected by culture or polymerase chain reaction, compared with controls, which argues against an ongoing active herpetic infection. Studies have also shown that the presumable elevation of antibody titres to EBV, CMV or HHV-6 in CFS are not observed only with these viruses, but also with other organisms such as herpes simplex virus and measles.

 

Source: Soto NE, Straus SE. Chronic Fatigue Syndrome and Herpesviruses: the Fading Evidence. Herpes. 2000 May;7(2):46-50. http://www.ncbi.nlm.nih.gov/pubmed/11867001

 

Chronic fatigue syndrome

Comment on:

Chronic fatigue syndrome. [Br J Gen Pract. 2001]

Frequency of attendance in general practice and symptoms before development of chronic fatigue syndrome: a case-control study. [Br J Gen Pract. 2001]

 

Professor Murdoch in the September BJGP 1 uses his study of Down’s syndrome,2 which demonstrated that mothers had an increased number of reported illnesses in the year before the birth, to undermine our interpretation of the findings in our chronic fatigue syndrome (CFS) study in the July BJGP. 3 He asks why anyone should believe CFS is caused by behavioural factors.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1314178/pdf/11766858.pdf

 

Source: Hamilton W. Chronic fatigue syndrome. Br J Gen Pract. 2001 Dec;51(473):1015. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1314178/pdf/11766858.pdf (Full comment)

 

Sexual abuse, physical abuse, chronic fatigue, and chronic fatigue syndrome: a community-based study

Abstract:

Using a randomly selected community-based sample, this investigation examined whether histories of childhood sexual, physical, and death threat abuse predicted adulthood outcomes of specific medical and psychiatric conditions involving chronic fatigue. This study also tested prior suggestions that most individuals with chronic fatigue syndrome report a past history of interpersonal abuse.

Multinomial logistic regression was used to examine the relationship between abuse history and chronic fatigue group outcomes while controlling for the effects of sociodemographics. Compared with healthy controls, childhood sexual abuse was significantly more likely to be associated with outcomes of idiopathic chronic fatigue, chronic fatigue explained by a psychiatric condition, and chronic fatigue explained by a medical condition. None of the abuse history types were significant predictors of chronic fatigue syndrome.

A closer examination of individuals in the chronic fatigue syndrome group revealed that significantly fewer individuals with CFS reported abuse as compared with those who did not. The implications of these findings are discussed.

 

Source: Taylor RR, Jason LA. Sexual abuse, physical abuse, chronic fatigue, and chronic fatigue syndrome: a community-based study. J Nerv Ment Dis. 2001 Oct;189(10):709-15. http://www.ncbi.nlm.nih.gov/pubmed/11708672

 

A family history study of chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is characterized by unexplained, disabling fatigue and is associated with high rates of comorbid depression. While the aetiology is unknown, findings from recent twin surveys suggest that genetic factors may be relevant to prolonged fatigue states (> 1 month). To date, however, there has been no exploration of the role of familial/genetic factors in operationally defined CFS.

The aims of the present study were: (i) to examine whether CFS is familial by comparing the rates of CFS in the first-degree relatives of CFS cases and medical control subjects; and (ii) to determine whether the high rate of comorbid depression in CFS is reflected in a greater familial loading for affective disorder.

Twenty-five CFS cases and 36 medical control subjects were assessed for fatigue symptoms based on the Centre for Disease Control (CDC) criteria for CFS, and for lifetime psychiatric symptoms using the Schedule for Schizophrenia and Affective Disorders-Lifetime Version. Informant family history was obtained regarding first-degree relatives using the CDC criteria and the Family History Research Diagnostic Criteria. In addition, informant history was supplemented by sending a questionnaire to first-degree relatives.

There were significantly higher rates of CFS in the relatives of CFS cases compared with the relatives of control subjects. The rate of depression in the CFS cases was similar to previous studies but did not appear to reflect a greater familial loading for depression when compared with control subjects. However, these analyses were complicated by higher than expected rates of depression in the control group. These findings suggest that familial factors are important in the aetiology of chronic fatigue syndrome.

 

Source: Walsh CM, Zainal NZ, Middleton SJ, Paykel ES. A family history study of chronic fatigue syndrome. Psychiatr Genet. 2001 Sep;11(3):123-8. http://www.ncbi.nlm.nih.gov/pubmed/11702053