Possible role for early-life immune insult including developmental immunotoxicity in chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME)

Abstract:

Chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME) in some countries, is a debilitating disease with a constellation of multi-system dysfunctions primarily involving the neurological, endocrine and immune systems. While substantial information is available concerning the complex dysfunction-associated symptoms of CFS, environmental origins of the disease have yet to be determined.

Part of the dilemma in identifying the cause(s) has been the focus on biomarkers (hormones, neurotransmitters, cytokines, infectious agents) that are contemporary with later-life CFS episodes. Yet, recent investigations on the origins of environmental diseases of the neurological, endocrine, reproductive, respiratory and immune systems suggest that early life toxicologic and other insults are pivotal in producing later-life onset of symptoms. As with autism and childhood asthma, CFS can also occur in children where the causes are certainly early-life events.

Immune dysfunction is recognized as part of the CFS phenotype but has received comparatively less attention than aberrant neurological or endocrine function. However, recent research results suggest that early life immune insults (ELII) including developmental immunotoxicity (DIT), which is induced by xenobiotics, may offer an important clue to the origin(s) of CFS.

The developing immune system is a sensitive and novel target for environmental insult (xenobiotic, infectious agents, stress) with major ramifications for postnatal health risks. Additionally, many prenatal and early postnatal neurological lesions associated with postnatal neurobehavioral diseases are now recognized as linked to prenatal immune insult and inflammatory dysregulation. This review considers the potential role of ELII including DIT as an early-life component of later-life CFS.

 

Source: Dietert RR, Dietert JM. Possible role for early-life immune insult including developmental immunotoxicity in chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME). Toxicology. 2008 May 2;247(1):61-72. doi: 10.1016/j.tox.2008.01.022. Epub 2008 Feb 8. https://www.ncbi.nlm.nih.gov/pubmed/18336982

 

Intracellular immune dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome: state of the art and therapeutic implications

Abstract:

BACKGROUND: Evidence in support of intracellular immune dysfunctions in people with myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) is accumulating, but few studies have addressed intracellular immunity as a potential therapeutic target.

OBJECTIVE: To provide an overview of our present understanding of intracellular immunity in ME/CFS, to relate the intracellular immune dysfunctions to other aspects of the illness like decreased natural killer cell function, the presence of infections and poor exercise performance, and to point to potential therapeutic targets.

METHODS: An in-depth review of the scientific literature of intracellular immunity in people with ME/CFS was performed.

RESULTS/CONCLUSION: From the scientific literature it is concluded that proteolytic cleavage of the native RNase L enzyme is characteristic of the dysregulation of intracellular immunity in people with ME/CFS, but the origin of the dysregulation is speculative. There is increasing evidence for immune cell apoptosis and upregulation of various aspects of the 2′-5′ oligoadenylate (2-5A) synthetase/RNase L pathway in ME/CFS. This review provides the theoretical rationale for conducting studies examining the effectiveness of direct or indirect drug targeting of the 2-5A synthetase/RNase L pathway in ME/CFS patients.

 

Source: Nijs J, Frémont M. Intracellular immune dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome: state of the art and therapeutic implications. Expert Opin Ther Targets. 2008 Mar;12(3):281-9. doi: 10.1517/14728222.12.3.281.https://www.ncbi.nlm.nih.gov/pubmed/18269338

 

Double-blind, randomized study of the effects of influenza vaccination on the specific antibody response and clinical course of patients with chronic fatigue syndrome

Abstract:

OBJECTIVE: To determine whether influenza immunization is associated with early side effects, a deleterious impact on the illness course and depressed antibody response in patients with chronic fatigue syndrome (CFS).

DESIGN: Prospective, randomized, double-blind, placebo controlled trial. CFS patients and healthy volunteers filled out a questionnaire on immunization side effects and had hemagglutination-inhibiting (HI) antibody titres measured pre- and three weeks after immunization. CFS patients completed symptom and function questionnaires before and during the six-week, postimmunization period.

SETTING: Ambulatory care.

POPULATION STUDIED: Convenience sample of 40 CFS patients fulfilling the Centers for Disease Control and Prevention criteria and 21 demographically matched healthy volunteers.

INTERVENTIONS: CFS patients were randomly selected to receive commercially available whole virus influenza vaccine (n=19) or an injection of saline placebo (n=21). Healthy volunteers received vaccine only.

MAIN RESULTS: As a group, immunized CFS patients had lower geometric mean HI antibody rises than healthy volunteers (P<0.001). However, there was no difference in the rates of fourfold titre rises, and immunization did achieve a probably protective titre (1:32 or greater) in most CFS patients. No difference could be detected between immunized and placebo CFS patients in immunization side effects, although CFS patients as a group reported four times as many side effects as healthy volunteers. Further, in the six weeks following immunization, placebo and immunized CFS patients did not demonstrate any differences in terms of functioning, symptom severity and sleep disturbance.

CONCLUSIONS: In patients with CFS, influenza immunization is safe, not associated with any excess early reactions, and stimulates an immunizing response comparable with that of healthy volunteers.

 

Source: Sleigh KM, Danforth DG, Hall RT, Fleming JA, Stiver HG. Double-blind, randomized study of the effects of influenza vaccination on the specific antibody response and clinical course of patients with chronic fatigue syndrome. Can J Infect Dis. 2000 Sep;11(5):267-73. https://www.ncbi.nlm.nih.gov/pubmed/18159300

 

Increased serum IgM antibodies directed against phosphatidyl inositol (Pi) in chronic fatigue syndrome(CFS) and major depression: evidence that an IgM-mediated immune response against Pi is one factor underpinning the comorbidity between both CFS and depression

Abstract:

Major depression and chronic fatigue syndrome (CFS) are accompanied by signs of oxidative and nitrosative stress (O&NS) and an inflammatory response. Phosphatidyl inositol (Pi) is thought to play a role in depression. The aim of the present study is to examine whether depression and CFS are characterized by an IgM-mediated immune response directed against Pi. Toward this end, this study examines the serum IgM antibodies directed against Pi in 14 patients with major depression, 14 patients with CFS, 14 subjects with partial CFS, and in 11 normal controls.

We found that the prevalence and mean value for the serum IgM levels directed against Pi were significantly greater in patients with major depression and CFS than in normal controls and patients with partial CFS. There were significant and positive correlations between serum IgM levels directed against Pi and two symptoms of the FibroFatigue Scale, i.e. fatigue and depression.

The results show that an IgM-related immune response directed against Pi may occur in both depression and CFS and may play a role in the pathophysiology of the key symptom of CFS and major depression. It is suggested that the above disorders in Pi result from increased O&NS in both depression and CFS. Autoanti-Pi antibodies may have biological effects, for example, by changing inositol 1,4,5-triphosphate (IP3), phosphatidylinositol-4,5-bisphosphate (PIP2), diacylglycerol and phosphatidylinositol-3,4,5-triphosphate (PIP3) production, thus interfering with intracellular signalling processes. Future research in major depression and CFS should focus on the functional consequences of the immune responses directed against Pi.

 

Source: Maes M, Mihaylova I, Leunis JC. Increased serum IgM antibodies directed against phosphatidyl inositol (Pi) in chronic fatigue syndrome(CFS) and major depression: evidence that an IgM-mediated immune response against Pi is one factor underpinning the comorbidity between both CFS and depression. Neuro Endocrinol Lett. 2007 Dec;28(6):861-7. https://www.ncbi.nlm.nih.gov/pubmed/18063934

 

IFN-gamma mediated pathways in patients with fatigue and chronic active Epstein Barr virus-infection

Abstract:

BACKGROUND: Chronic active Epstein Barr virus (EBV)-infection is characterized by mononucleosis like symptoms including fatigue, lymphadenopathy and/or hepatosplenomegaly and serologic evidence for ongoing EBV replication. Interferon-gamma (IFN-gamma) triggers several antiviral mechanisms in target cells including the induction of indoleamine-2,3-dioxygenase (IDO), which degrades the essential amino acid tryptophan to kynurenine. Because tryptophan is a precursor of the neurotransmitter 5-hydroxytryptamine (serotonin), tryptophan depletion by IDO can cause mood disturbances in patients with chronic immune activation.

METHODS: This study investigated the tryptophan metabolism in 20 patients with chronic active EBV-infection, who were followed up for 4 to 8 months and in 10 healthy age-matched controls. The clinical suspicion of chronic active EBV infection was verified by the presence of circulating antibodies against EBV early antigen (EA) and virus capsid antigen (VCA).

RESULTS: Patients with detectable EBV-DNA had higher serum neopterin (p<0.01) and lower tryptophan concentrations (p=0.01) than EBV-DNA negative patients. Serum concentrations of neopterin, indicating Th-1 mediated immune activation via IFN-gamma, were positively correlated to enhanced tryptophan degradation (rs=0.650, p<0.001) in patients, but not in healthy individuals. Patients suffering from more severe symptoms (as assessed by questionnaires) tended to have aggravated tryptophan degradation.

CONCLUSION: Our data show that EBV viremia is associated with cell-mediated immune activation and increased tryptophan degradation, which may partly account for the symptoms found in this disorder.

 

Source: Bellmann-Weiler R, Schroecksnadel K, Holzer C, Larcher C, Fuchs D, Weiss G. IFN-gamma mediated pathways in patients with fatigue and chronic active Epstein Barr virus-infection. J Affect Disord. 2008 May;108(1-2):171-6. Epub 2007 Oct 22. https://www.ncbi.nlm.nih.gov/pubmed/17945348

 

Decreased expression of CD69 in chronic fatigue syndrome in relation to inflammatory markers: evidence for a severe disorder in the early activation of T lymphocytes and natural killer cells

Abstract:

There is some evidence that patients with chronic fatigue syndrome (CFS) suffer from immune abnormalities, such as immune activation and decreased immune cell responsivity upon polyclonal stimili. This study was designed to evaluate lymphocyte activation in CFS by using a CD69 expression assay. CD69 acts as a costimulatory molecule for T- and natural killer (NK) cell activation.

We collected whole blood from CFS patients, who met CDC criteria, and healthy volunteers. The blood samples were stimulated with mitogens during 18 h and the levels of activated T and NK cells expressing CD69 were measured on a Coulter Epics flow cytometer using a three color immunofluorescence staining protocol.

The expression of the CD69 activation marker on T cells (CD3+, CD3+CD4+, and CD3+CD8+) and on NK cells (CD45+CD56+) was significantly lower in CFS patients than in healthy subjects. These differences were significant to the extent that a significant diagnostic performance was obtained, i.e. the area under the ROC curve was around 89%. No differences either in the number of leukocytes or in the number or percentage of lymphocytes, i.e. CD3, CD4, CD8 and CD19, could be found between CFS patients and the controls.

Patients with CFS show defects in T- and NK cell activation. Since induction of CD69 surface expression is dependent on the activation of the protein kinase C (PKC) activation pathway, it is suggested that in CFS there is a disorder in the early activation of the immune system involving PKC.

 

Source: Mihaylova I, DeRuyter M, Rummens JL, Bosmans E, Maes M. Decreased expression of CD69 in chronic fatigue syndrome in relation to inflammatory markers: evidence for a severe disorder in the early activation of T lymphocytes and natural killer cells. Neuro Endocrinol Lett. 2007 Aug;28(4):477-83. https://www.ncbi.nlm.nih.gov/pubmed/17693977

 

Chronic fatigue syndrome: biochemical examination of blood

Abstract:

Though patients with chronic fatigue syndrome (CFS) have lots of complaints, abnormal findings cannot be detected by biochemical screening tests. However, some specialized blood tests have revealed neuroendocrine immune axis abnormalities, which is closely associated with each other. Recent studies indicate that CFS can be understood as a special condition based on abnormality of the psycho-neuro-endocrino-immunological system, with the distinguishing feature of CFS seeming to be the secondary brain dysfunction caused by several cytokines and/or autoantibodies. In this paper, we summarize these abnormalities found in CFS and show the neuro-molecular mechanism leading to chronic fatigue.

 

Source: Hakariya Y, Kuratsune H. Chronic fatigue syndrome: biochemical examination of blood. Nihon Rinsho. 2007 Jun;65(6):1071-6. [Article in Japanese] https://www.ncbi.nlm.nih.gov/pubmed/17561699

 

Antinuclear antibodies in patients with chronic fatigue syndrome

Abstract:

Significance of antinuclear antibodies (ANA) in the patients with chronic fatigue syndrome (CFS) was reviewed. When indirect immunofluorescence with the HEp-2 cells as the substrates was used, prevalence of the positive ANA was reportedly 15-25%. The ANA titers were low and the immunofluorescent staining patterns were heterogeneous.

One group in the USA reported that ‘nuclear envelope staining pattern’ was found in more than 50% of the patients with CFS. This results, however, have not been confirmed by any other research groups. Clinical significance of the positive ANA in the CFS patients resides in differential diagnoses of systemic lupus erythematosus and other diffuse connective tissue diseases. Recently, several ANAs specific to CFS have been described.

We reported anti-68/48kD protein antibodies utilizing SDS-PAGE/ immunoblot method. These autoantibodies were found in 13% of 114 CFS patients and 0% in healthy subjects (p < 0.05). Hypersomnia and difficulty in concentration were found more frequently in the CFS patients with this specific autoantibody.

 

Source: Nishikai M. Antinuclear antibodies in patients with chronic fatigue syndrome. Nihon Rinsho. 2007 Jun;65(6):1067-70. [Article in Japanese] https://www.ncbi.nlm.nih.gov/pubmed/17561698

 

Longitudinal analysis of pro- and anti-inflammatory cytokine production in severely fatigued adolescents

Abstract:

In the adolescent population, fatigue is associated with somatic complaints, unrefreshing sleep, cognitive disturbances and symptoms of depression and anxiety. This pattern of symptoms resembles the one described in chronic fatigue syndrome (CFS). Since immunological alterations have been reported in CFS patients, we wondered whether also severely fatigued girls from a healthy population would show comparable alterations in psychological and immunological parameters. We tested this hypothesis in a longitudinal design, allowing a reliable assessment of the participants’ characteristic immune status. Groups of severely fatigued (N=67) and non-fatigued (N=61) participants were selected. Severely fatigued girls reported more depressive symptoms, anxiety, reduced sleep quality, and somatic and CFS-related symptoms than non-fatigued participants across three measurements during one year (T1: spring, T2: autumn, T3: spring). In contrast, no group differences in mitogen-induced cytokine production or T-cell proliferation in vitro or in leukocyte subset counts were observed. Although absolute cytokine production and cell counts were affected by seasonal variation, the within-subject values, relatively to the rest of the participants, were fairly stable. Data from a small group of CFS patients (N=11) showed similarities in self-reported complaints between CFS patients and fatigued participants. Interestingly, CFS patients showed a distinct immune profile when compared to the severely fatigued or non-fatigued participants, i.e. increased levels of anti-inflammatory cytokines (IL-10, decreased IFN-gamma/IL-10 ratio) and reduced levels of pro-inflammatory cytokines (IL-6, TNF-alpha) over all three time points analyzed. These results show that, although overlap in symptomatology between the general population and patients with CFS was observed, only CFS patients show a skewing of the cytokine balance towards an anti-inflammatory profile.

 

Source: ter Wolbeek M, van Doornen LJ, Kavelaars A, van de Putte EM, Schedlowski M, Heijnen CJ. Longitudinal analysis of pro- and anti-inflammatory cytokine production in severely fatigued adolescents.Brain Behav Immun. 2007 Nov;21(8):1063-74. Epub 2007 Jun 1. https://www.ncbi.nlm.nih.gov/pubmed/17544255

Activation of human herpesviruses 6 and 7 in patients with chronic fatigue syndrome

Abstract:

BACKGROUND: Human herpesvirus 6 (HHV-6) and 7 (HHV-7) have been suggested as possible triggering agents for chronic fatigue syndrome(CFS).

OBJECTIVES: To determine the possible association of HHV-6 and HHV-7 infections with CFS.

STUDY DESIGN: The prevalence of latent/persistent and active viral infections by nPCR, characteristic of HHV-6 variants using restriction endonuclease analysis and changes of lymphocyte subsets in peripheral blood by laser flow-cytometry in 17 CFS patients was examined. In addition, 12 patients with unexplained chronic fatigue and 20 blood donors (BD) were studied.

RESULTS: No difference in prevalence of latent/persistent single viral infections between the patients and BD was found but dual infection rate was significantly higher in CFS patients. Active HHV-6 and dual (HHV-6 + HHV-7) infections were detected in CFS patients only and frequency of HHV-7 reactivation was also significantly higher in these patients. HHV-6 variant B was predominant in CFS patients (12/13). The changes of immunological parameters in CFS patients with active dual infection were characterized by significant decrease of CD3+ and CD4+ T cells, significant increase of CD95+ cells and decrease of CD4+/CD8+ ratio.

CONCLUSIONS: HHV-6 and HHV-7 may be involved in the pathogenesis of CFS and reactivation of both viruses may provoke changes in the phenotype of circulating lymphocytes.

 

Source: Chapenko S, Krumina A, Kozireva S, Nora Z, Sultanova A, Viksna L, Murovska M. Activation of human herpesviruses 6 and 7 in patients with chronic fatigue syndrome. J Clin Virol. 2006 Dec;37 Suppl 1:S47-51. https://www.ncbi.nlm.nih.gov/pubmed/17276369