Category: Viruses

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

 

The nosology of sub-acute and chronic fatigue syndromes that follow infectious mononucleosis

Abstract:

BACKGROUND: A previous principal components analysis of symptoms occurring after infectious mononucleosis suggested that a discrete fatigue syndrome occurs, which is independent of psychiatric disorder. This work has not been replicated and no latent class analysis of subjects has been published.

METHOD: We prospectively examined a cohort of 150 American primary care patients 2 and 6 months after the onset of corroborated infectious mononucleosis. A subset of 50 subjects was studied 4 years after onset. We performed principal components analyses of both psychological and somatic symptoms and latent class analyses of subjects.

RESULTS: Principal components analyses consistently delineated two fatigue factors at 2 and 6 months and one fatigue factor at 4 years. These factors were separate from a mixed anxiety and depressive factor. A four-class solution for the latent class analyses consisted of most subjects with few symptoms, a few with many symptoms, a group with predominantly mood symptoms and some subjects with fatigue symptoms.

CONCLUSIONS: The symptoms of the principal factors with fatigue were similar to those previously described. Both the factors and classes were independent of an equally delineated mood factor and class. These results support the existence of two discrete chronic fatigue syndromes after infectious mononucleosis, one of which is still demonstrable 4 years after onset.

 

Source: White PD, Thomas JM, Sullivan PF, Buchwald D. The nosology of sub-acute and chronic fatigue syndromes that follow infectious mononucleosis. Psychol Med. 2004 Apr;34(3):499-507. http://www.ncbi.nlm.nih.gov/pubmed/15259835

 

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)

 

Enterovirus related metabolic myopathy: a postviral fatigue syndrome

Abstract:

OBJECTIVE: To detect and characterise enterovirus RNA in skeletal muscle from patients with chronic fatigue syndrome (CFS) and to compare efficiency of muscle energy metabolism in enterovirus positive and negative CFS patients.

METHODS: Quadriceps muscle biopsy samples from 48 patients with CFS were processed to detect enterovirus RNA by two stage, reverse transcription, nested polymerase chain reaction (RT-NPCR), using enterovirus group specific primer sets. Direct nucleotide sequencing of PCR products was used to characterise the enterovirus. Controls were 29 subjects with normal muscles. On the day of biopsy, each CFS patient undertook a subanaerobic threshold exercise test (SATET). Venous plasma lactate was measured immediately before and after exercise, and 30 minutes after testing. An abnormal lactate response to exercise (SATET+) was defined as an exercise test in which plasma lactate exceeded the upper 99% confidence limits for normal sedentary controls at two or more time points.

RESULTS: Muscle biopsy samples from 20.8% of the CFS patients were positive for enterovirus sequences by RT-NPCR, while all the 29 control samples were negative; 58.3% of the CFS patients had a SATET+ response. Nine of the 10 enterovirus positive cases were among the 28 SATET+ patients (32.1%), compared with only one (5%) of the 20 SATET- patients. PCR products were most closely related to coxsackie B virus.

CONCLUSIONS: There is an association between abnormal lactate response to exercise, reflecting impaired muscle energy metabolism, and the presence of enterovirus sequences in muscle in a proportion of CFS patients.

Comment in: Enteroviruses in chronic fatigue syndrome: “now you see them, now you don’t”. [J Neurol Neurosurg Psychiatry. 2003]

 

Source: Lane RJ, Soteriou BA, Zhang H, Archard LC. Enterovirus related metabolic myopathy: a postviral fatigue syndrome. J Neurol Neurosurg Psychiatry. 2003 Oct;74(10):1382-6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1757378/ (Full article)