Category: Viruses

Chronic fatigue syndrome and herpesvirus reactivation

Abstract:

Human herpesvirus 6(HHV-6) and human herpesvirus 7(HHV-7) establish life-long latency, reactivate frequently, and are shed in saliva. To identify the factor(s) of their reactivation, we have studied the association with the reactivation and fatigue. Reactivation was examined for viral DNA by real-time PCR method. As a result, healthy adults shed the reactivated HHV-6 in the saliva during work -induced fatigue, and the copy number of HHV-6 DNA was reduced after holidays. However, no significant HHV-6 DNA increase was observed in chronic fatigue syndrome (CFS) patients. In contrast, increase of HHV-7 reactivation was observed both in the case of work-induced fatigue and CFS. These findings suggest that the amount of HHV-6 and HHV-7 reactivation can be an objective biomarker for fatigue.

 

Source: Kondo K. Chronic fatigue syndrome and herpesvirus reactivation. Nihon Rinsho. 2007 Jun;65(6):1043-8. [Article in Japanese] https://www.ncbi.nlm.nih.gov/pubmed/17561695

 

Gene expression correlates of postinfective fatigue syndrome after infectious mononucleosis

Abstract:

BACKGROUND: Infectious mononucleosis (IM) commonly triggers a protracted postinfective fatigue syndrome (PIFS) of unknown pathogenesis.

METHODS: Seven subjects with PIFS with 6 or more months of disabling symptoms and 8 matched control subjects who had recovered promptly from documented IM were studied. The expression of 30,000 genes was examined in the peripheral blood by microarray analysis in 65 longitudinally collected samples. Gene expression patterns associated with PIFS were sought by correlation with symptom factor scores.

RESULTS: Differential expression of 733 genes was identified when samples collected early during the illness and at the late (recovered) time point were compared. Of these genes, 234 were found to be significantly correlated with the reported severity of the fatigue symptom factor, and 180 were found to be correlated with the musculoskeletal pain symptom factor. Validation by analysis of the longitudinal expression pattern revealed 35 genes for which changes in expression were consistent with the illness course. These genes included several that are involved in signal transduction pathways, metal ion binding, and ion channel activity.

CONCLUSIONS: Gene expression correlates of the cardinal symptoms of PIFS after IM have been identified. Further studies of these gene products may help to elucidate the pathogenesis of PIFS.

Comment in: What causes prolonged fatigue after infectious mononucleosis: and does it tell us anything about chronic fatigue syndrome? [J Infect Dis. 2007]

 

Source: Cameron B, Galbraith S, Zhang Y, Davenport T, Vollmer-Conna U, Wakefield D, Hickie I, Dunsmuir W, Whistler T, Vernon S, Reeves WC, Lloyd AR; Dubbo Infection Outcomes Study. Gene expression correlates of postinfective fatigue syndrome after infectious mononucleosis. J Infect Dis. 2007 Jul 1;196(1):56-66. Epub 2007 May 24. http://jid.oxfordjournals.org/content/196/1/56.long (Full article)

 

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

 

Is human herpesvirus-6 a trigger for chronic fatigue syndrome?

Abstract:

Chronic fatigue syndrome (CFS) is an illness currently defined entirely by a combination of non-specific symptoms. Despite this subjective definition, CFS is associated with objective underlying biological abnormalities, particularly involving the nervous system and immune system.

Most studies have found that active infection with human herpesvirus-6 (HHV-6)–a neurotropic, gliotropic and immunotropic virus–is present more often in patients with CFS than in healthy control and disease comparison subjects, yet it is not found in all patients at the time of testing. Moreover, HHV-6 has been associated with many of the neurological and immunological findings in patients with CFS.

Finally, CFS, multiple sclerosis and seizure disorders share some clinical and laboratory features and, like CFS, the latter two disorders also are being associated increasingly with active HHV-6 infection. Therefore, it is plausible that active infection with HHV-6 may trigger and perpetuate CFS in a subset of patients.

 

Source: Komaroff AL. Is human herpesvirus-6 a trigger for chronic fatigue syndrome? J Clin Virol. 2006 Dec;37 Suppl 1:S39-46. https://www.ncbi.nlm.nih.gov/pubmed/17276367

 

Pathogenesis of parvovirus B19 infection: host gene variability, and possible means and effects of virus persistence

Abstract:

Since conducting follow-up studies of patients with acute symptomatic parvovirus B19 infection which showed that a significant proportion of patients develop prolonged arthritis and chronic fatigue syndrome (CFS), we have become interested in the mechanisms of this phenomenon. We showed that these cases have high levels of pro-inflammatory cytokines in their circulation and that this correlates with the symptoms. However, the underlying mechanisms were not apparent, and we have used various approaches to begin studying this phenomenon.

DNA polymorphisms were looked for and several were shown to be more common in these subjects compared with controls; these occur within genes of both the immune response [human leucocyte antigen (HLA)-DRB1, HLA-B, transforming growth factor (TGF)-beta1] and those involved in several other cellular functions (predominantly the cytoskeleton and cell adhesion). Interestingly, one particular single-nucleotide polymorphism (SNP) which is associated with symptomatic B19 infection occurs in the Ku80 gene which has recently been shown to be a B19 co-receptor. B19 persistence is probably the key to this phenomenon, and some new data are presented on short regions of sequence homology (17-26 bp) between human, mouse and rat parvoviruses and their respective hosts which occur in many host genes. This homology may provide a foothold for virus persistence and may also play a role in the genesis of disease through gene disruption.

Finally, we used microarrays and TaqMan real-time polymerase chain reaction in 108 normal persons to study human gene expression in persons who are B19-seropositive versus B19-seronegative (age- and sex-matched) to examine the hypothesis that gene regulation may be altered in subjects harbouring the B19 virus DNA. Six genes were found to be differentially expressed with roles in the cytoskeleton (SKIP, MACF1, SPAG7, FLOT1), integrin signalling (FLOT1, RASSF5), HLA class III (c6orf48), and tumour suppression (RASSF5). These results have implications not only for B19 but also for other persistent viruses as well and confirmation is required.

In conclusion, these disparate findings contribute to our understanding of the pathogenesis of B19 disease. We are using these studies as a starting point to study the phenomenon of chronic immune activation following B19 infection.

 

Source: Kerr JR. Pathogenesis of parvovirus B19 infection: host gene variability, and possible means and effects of virus persistence. J Vet Med B Infect Dis Vet Public Health. 2005 Sep-Oct;52(7-8):335-9. http://www.ncbi.nlm.nih.gov/pubmed/16316396

 

The role of enterovirus in chronic fatigue syndrome

Abstract:

Two and a half decades after coining of the term chronic fatigue syndrome (CFS), the diagnosis of this illness is still symptom based and the aetiology remains elusive. Enteroviruses are well known causes of acute respiratory and gastrointestinal infections, with tropism for the central nervous system, muscles, and heart.

Initial reports of chronic enteroviral infections causing debilitating symptoms in patients with CFS were met with skeptism, and had been largely forgotten for the past decade. Observations from in vitro experiments and from animal models clearly established a state of chronic persistence through the formation of double stranded RNA, similar to findings reported in muscle biopsies of patients with CFS.

Recent evidence not only confirmed the earlier studies, but also clarified the pathogenic role of viral RNA through antiviral treatment. This review summarises the available experimental and clinical evidence that supports the role of enterovirus in chronic fatigue syndrome.

 

Source: Chia JK. The role of enterovirus in chronic fatigue syndrome. J Clin Pathol. 2005 Nov;58(11):1126-32. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1770761/ (Full article)

 

Stress-associated changes in the steady-state expression of latent Epstein-Barr virus: implications for chronic fatigue syndrome and cancer

Abstract:

Antibodies to several Epstein-Barr virus (EBV)-encoded enzymes are observed in patients with different EBV-associated diseases. The reason for these antibody patterns and the role these proteins might play in the pathophysiology of disease, separate from their role in virus replication, is unknown.

In this series of studies, we found that purified EBV deoxyuridine triphosphate nucleotidohydrolase (dUTPase) can inhibit the replication of human peripheral blood mononuclear cells in vitro and upregulate the production of TNF-alpha, IL-1beta, IL-6, IL-8, and IL-10. It also enhanced the ability of natural killer cells to lyse target cells. The EBV dUTPase also significantly inhibited the replication of mitogen-stimulated lymphocytes and the synthesis of IFN-gamma by cells isolated from lymph nodes and spleens obtained from mice inoculated with the protein.

It also produced sickness behaviors known to be induced by some of the cytokines that were studied in the in vitro experiments. These symptoms include an increase in body temperature, a decrease in body mass and in physical activity.

The data provide a new perspective on how an early nonstructural EBV-encoded protein can cause immune dysregulation and produce clinical symptoms observed in patients with chronic fatigue syndrome (CFS) separate from its role in virus replication and may serve as a new approach to help identify one of the etiological agents for CFS. The data also provide additional insight into the pathophysiology of EBV infection, inflammation, and cancer.

 

Source: Glaser R, Padgett DA, Litsky ML, Baiocchi RA, Yang EV, Chen M, Yeh PE, Klimas NG, Marshall GD, Whiteside T, Herberman R, Kiecolt-Glaser J, Williams MV. Stress-associated changes in the steady-state expression of latent Epstein-Barr virus: implications for chronic fatigue syndrome and cancer. Brain Behav Immun. 2005 Mar;19(2):91-103. http://www.ncbi.nlm.nih.gov/pubmed/15664781

 

Neuropsychiatric sequelae of Nipah virus encephalitis

Abstract:

The authors followed nine patients with Nipah virus encephalitis over the course of 24 months. Eight of the nine developed psychiatric features assigned to the encephalitis. Three patients developed major depressive disorder immediately after recovering from the encephalitis, and two developed depression approximately 1 year after the outbreak. Two patients developed personality changes, and two suffered chronic fatigue syndrome.

Neuropsychological testing was accomplished in eight of the nine patients. Deficits in attention, verbal, and/or visual memory were substantial in seven of the eight patients tested. Verbal memory was more impaired than visual memory in these patients. Comparison between psychiatric and cognitive impairment and total number of brain lesions showed no discernible trends.

 

Source: Ng BY, Lim CC, Yeoh A, Lee WL. Neuropsychiatric sequelae of Nipah virus encephalitis. J Neuropsychiatry Clin Neurosci. 2004 Fall;16(4):500-4. http://www.ncbi.nlm.nih.gov/pubmed/15616178

 

Prevalence of abnormal cardiac wall motion in the cardiomyopathy associated with incomplete multiplication of Epstein-barr Virus and/or cytomegalovirus in patients with chronic fatigue syndrome

Abstract:

We reported unique incomplete herpesvirus (Epstein-Barr Virus (EBV) and/or nonstructural (HCMV) cytomegalovirus) multiplication in 2 distinct subsets of CFS patients. The CFS subsets were identified by: a) presence of IgM serum antibodies to HCMV nonstructural gene products p52 and CM2 (UL44 and UL57), and/or b) IgM serum antibodies to Epstein-Barr virus viral capsid antigen (EBV, VCA IgM).

Diagnostic IgM serum antibodies were found in two independent blinded studies involving 49 CFS patients, but the same antibodies were absent in 170 control patients (p<0.05). Abnormal 24 Hr-electrocardiographic monitoring, tachycardias at rest and, in severe chronic cases, abnormal cardiac wall motion (ACWM) were seen in these same CFS patients.

We now report a prospective consecutive case control study from 1987–1999 of cardiac dynamics as measured by radionuclide ventriculography in 98 CFS patients from 1987–1999. Controls were patients with various malignancies who were evaluated in protocols requiring radionuclide ventriculography before initiation of cardiotoxic chemotherapeutic agents.

The prevalence of abnormal cardiac wall motion (ACWM) at rest in CFS patients was 10 out of 87 patients (11.5%). With stress exercise, 21 patients (24.1%) demonstrated ACWM. Cardiac biopsies in 3 of these CFS patients with ACWM showed a cardiomyopathy. Among the controls, ACWM at rest was present in 4 out of 191 patients (2%) (p=0.0018). A progressive cardiomyopathy caused by incomplete virus multiplication of EBV and/or HCMV in CFS patients is present.

 

Source: Lerner AM, Dworkin HJ, Sayyed T, Chang CH, Fitzgerald JT, Beqaj S, Deeter RG, Goldstein J, Gottipolu P, O’Neill W. Prevalence of abnormal cardiac wall motion in the cardiomyopathy associated with incomplete multiplication of Epstein-barr Virus and/or cytomegalovirus in patients with chronic fatigue syndrome. In Vivo. 2004 Jul-Aug;18(4):417-24. http://iv.iiarjournals.org/content/18/4/417.long (Full article)

 

Detection of antibody against Borna disease virus-p24 in the plasma of Chinese patients with chronic fatigue syndrome by Western-blot analysis

Abstract:

OBJECTIVE: To evaluate the prevalence of infection with Borna disease virus (BDV) in Chinese patients with chronic fatigue syndrome (CFS) and control subjects, and to discuss the etiological association between CFS and infection with BDV.

METHODS: The CDC (1994) diagnostic criteria for CFS were used for case definition. Sixty-one patients suffered from CFS were from 11 Provinces in China. To detect the antibody against BDV-p24 on the plasma samples from all cases and 73 healthy control subjects by Western-blotting analysis.

RESULTS: 7 of the sixty-one cases and 0 of the controls were sero-positive for BDV-p24 antibody, there was a statistical significant difference between the two groups (11.48% vs 0%; P less than 0.010).

CONCLUSION: Chinese patients with CFS showed sero-positive identifying BDV infection, by comparison, anti.BDV-p24 antibody prevalence in patients was significantly higher than in controls. An etiological association may exist between CFS and BDV infection.

 

Source: Li YJ, Wang DX, Zhang FM, Liu ZD, Yang AY, Ykuta K. Detection of antibody against Borna disease virus-p24 in the plasma of Chinese patients with chronic fatigue syndrome by Western-blot analysis. Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi. 2003 Dec;17(4):330-3. [Article in Chinese] http://www.ncbi.nlm.nih.gov/pubmed/15340544