Evidence for enteroviral persistence in humans

Abstract:

We have sought evidence of enteroviral persistence in humans. Eight individuals with chronic fatigue syndrome (CFS) were positive for enteroviral sequences, detected by PCR in two serum samples taken at least 5 months apart. The nucleotide sequence of the 5′ non-translated region (bases 174-423) was determined for each amplicon.

Four individuals had virtually identical nucleotide sequences ( > 97%) in both samples. The sequence pairs also each had a unique shared pattern indicating that the virus had persisted. In one individual (HO), it was clear that there had been infection with two different enteroviruses.

In the remaining three individuals, the lack of unique shared features suggested that re-infection had occurred, rather than persistence. With the exception of HO, the sequences fell into a subgroup that is related to the Coxsackie B-like viruses.

 

Source: Galbraith DN, Nairn C, Clements GB. Evidence for enteroviral persistence in humans. J Gen Virol. 1997 Feb;78 ( Pt 2):307-12. http://www.ncbi.nlm.nih.gov/pubmed/9018051

 

Comparison of coxsackie B neutralisation and enteroviral PCR in chronic fatigue patients

Abstract:

Coxsackie B enteroviruses have been implicated repeatedly as agents associated with chronic fatigue syndrome (CFS). The objective of this study was to compare the serological evidence for the presence of Coxsackie B virus neutralising antibody, with the polymerase chain reaction (PCR) detecting a portion of the 5′ nontranslated region (NTR) of the enterovirus genome.

Serum samples from 100 chronic fatigue patients and from 100 healthy comparison patients were used in this study. In the CFS study group, 42% patients were positive for enteroviral sequences by PCR, compared to only 9% of the comparison group. Using the neutralisation assay, 34% of study patients were positive, compared to 41% of comparison patients.

In the study group, 66/100 patient results correlated, i.e., they were either positive/positive or negative/negative for both tests. Of those that did not correlate, the majority were PCR-positive/Coxsackie B antibody-negative (21/34).

In the comparison group, 58/100 patient results correlated. Of those that did not, the majority were PCR-negative/Coxsackie B antibody-positive (37/42).

The Coxsackie B antibody neutralisation assay was not able to differentiate the CFS study group from the healthy comparison group, and thus the clinical relevance of this assay may be questioned. The PCR assay did differentiate the two groups with significantly more CFS patients having evidence of enterovirus than the comparison group.

Source: Nairn C, Galbraith DN, Clements GB. Comparison of coxsackie B neutralisation and enteroviral PCR in chronic fatigue patients. J Med Virol. 1995 Aug;46(4):310-3. http://www.ncbi.nlm.nih.gov/pubmed/7595406

 

Immune responsiveness in chronic fatigue syndrome

Abstract:

We have endeavoured to find immunological indications of chronic virus infection in patients with chronic fatigue syndrome (myalgic encephalomyelitis) and to investigate immune responsiveness to viruses in such patients in comparison with normal subjects and patients with muscular dystrophy.

Levels of circulating IgM immune complexes were elevated (above the 95% normal control range) in 10 (17%) of 58 patients with chronic fatigue syndrome, which was not significantly different from the normal controls or from dystrophy controls (by Mann Whitney U test). Levels of IgG complexes were only increased in 10% of patients. Lymphocyte proliferation in response to concanavalin A (Con A), assessed by increase in 3H-thymidine incorporation, did not differ between 14 patients and 18 normal subjects.

The proliferative response to Coxsackie B virus antigen did not differ between chronic fatigue patients and normal subjects when expressed either as an increase in counts or as a stimulation index. Adjustment of the counts in relation to the proliferation response to Con A, as an indication of the overall proliferative response of the cell preparation, did not reveal any hidden difference. IgM antibodies to Coxsackie B viruses were not found in any of 20 patients and in 1 of 20 dystrophy controls.

Significant levels of neutralizing antibodies to Coxsackie B viruses 1-5 were found in 6 out of 19 (32%) patients compared with 4 out of 17 (24%) dystrophy controls, which does not differ from currently expected normal incidence. Antibody titres to other respiratory viruses were also not notably different between the patient and control groups.

In conclusion we can find no evidence for a definable viral aetiology for the chronic fatigue syndrome, neither in terms of a persistent infection nor an altered ability to respond to virus.

Comment in: Immune responsiveness in chronic fatigue syndrome. [Postgrad Med J. 1992]

 

Source: Milton JD, Clements GB, Edwards RH. Immune responsiveness in chronic fatigue syndrome. Postgrad Med J. 1991 Jun;67(788):532-7. http://www.ncbi.nlm.nih.gov/pubmed/1656416

Note: You can read the full article herehttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2398884/

 

Enteroviral RNA sequences detected by polymerase chain reaction in muscle of patients with postviral fatigue syndrome

Abstract:

OBJECTIVE: To determine the presence of enteroviral sequences in muscle of patients with the postviral fatigue syndrome.

DESIGN: Detection of sequences with the polymerase chain reaction in a well defined group of patients with the syndrome and controls over the same period.

SETTING: Institute of Neurological Sciences, Glasgow.

SUBJECTS: 60 consecutive patients admitted to the institute with the postviral fatigue syndrome who had undergone extensive investigation to exclude other conditions. 41 controls from the same catchment area without evidence of fatigue, all undergoing routine surgery.

MAIN OUTCOME MEASURES: Routine investigations, serological screen for antibodies to a range of viruses, and presence of enteroviral RNA sequences in muscle biopsy specimens.

RESULTS: 15 (25%) patients and 10 (24.4%) controls had important serological findings. 12 patients had neutralising antibody titres of greater than or equal to 256 to coxsackieviruses B1-5 (six positive for enteroviral RNA sequences, six negative); three were positive for Epstein-Barr virus specific IgM (two positive, one negative). Six controls had similar neutralising antibody titres to coxsackieviruses (all negative); one was positive for Epstein-Barr virus specific IgM (negative); and three had titres of complement fixing antibody greater than or equal to 256 to cytomegalovirus (all negative). Overall, significantly more patients than controls had enteroviral RNA sequences in muscle (32/60, 53% v 6/41, 15%; odds ratio 6.7, 95% confidence interval 2.4 to 18.2). This was not correlated with duration of disease, patient and age, or to raised titres of antibodies to coxsackieviruses B1-5.

CONCLUSIONS: Persistent enteroviral infection of muscle may occur in some patients with postviral fatigue syndrome and may have an aetiological role.

Comment in: Postviral fatigue syndrome. [BMJ. 1991]

 

Source: Gow JW, Behan WM, Clements GB, Woodall C, Riding M, Behan PO. Enteroviral RNA sequences detected by polymerase chain reaction in muscle of patients with postviral fatigue syndrome. BMJ. 1991 Mar 23;302(6778):692-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1669122/ (Full article)

 

Coxsackie B virus and postviral fatigue syndrome

Comment onAntibody to Coxsackie B virus in diagnosing postviral fatigue syndrome. [BMJ. 1991]

 

SIR,-Dr N A Miller and colleagues highlight the difficulty of associating a virus (coxsackie B virus) with a disease (postviral fatigue syndrome) when the virus in question is common in the general population.’ In a recent serological survey of the family members of children with insulin dependent diabetes mellitus we also found a high prevalence of IgM antibody specific to enterovirus: 14% of children with recently diagnosed insulin dependent diabetes mellitus, 8% of unaffected siblings, and 18% of parents had the antibody at the time of entry into the study. Serum samples were collected between 1985 and 1987. These seroprevalence figures are higher than those reported among control populations in earlier studies in the United Kingdom-5 5% in children during 19822 and 3-5% in adults during 1979-80.3 Because the assay used in these studies was the same as that used by Dr Miller and colleagues this indicates that enterovirus was endemic during 1985-7, which covers the period of the study of Dr Miller and colleagues.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1675464/pdf/bmj00117-0062c.pdf

 

Source: Muir P, Nicholson F, Banatvala JE, Bingley PJ. Coxsackie B virus and postviral fatigue syndrome. BMJ. 1991 Mar 16;302(6777):658-9. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1675464/

 

Chronic fatigue syndrome

SIR,

Dr Anthony David and colleagues (1) cite our paper (2) as one that makes inflated claims about the chtionic fatigue syndrome.

We first reported retrospectively an association between antibodies to coxsackie virus B and a group of symptoms similar to those previously described as myalgic encephalomyelitis. (3) We were faced with an ever increasing clinical problem of which we had little understanding, and the prospective investigation of coxsackie virus B antibody titres in these patients seemed a reasonable step forward. No widely accepted definition of the chronic fatigue syndrome existed in 1983, and we did not attempt to define it. We approached the problem from the opposite direction in that we had a definable test and we tried to show what happened to the results of this test in a group of ill patients.

Since 1983 much research into this syndrome has been carried out. It has taken a long time for a consensus to be agreed defining the syndrome. We believe that today’s definition that the syndrome cannot be diagnosed before six months has elapsed is acceptable. In our study 72% of our patients were still unwell six months into the illness.

The comparison made by Dr David and colleagues of their paper with ours is invalid. They questioned 611 general practice attenders whereas we reported on a group of 140 patients presenting over six months with what we believe to be the same illness.

In retrospect we think that what we observed was the slow spread of an infective agent through our town in 1983 and through neighbouring towns in our district in 1984 and 1985. The clinical syndrome coincided with a rise in the prevalence of coxsackie virus B antibodies in the general population from 10-12% in 1973-84 (we found 25% in 1983) to 55% in 1985-6. (4) Since then our clinical impression has been one of a return to normal; we see occasional new cases but not as many as in 1983.

The prevalence of this condition seems to depend on the activity of an infective agent of some kind, be it viral or otherwise, in the area of study at the time, and further research is made difficult by the wide fluctuations of prevalence that will be found from place to place and from time to time.

~B D CALDER

~P J WARNOCK Helensburgh G84 8BW

1 David A, Pelosi A, McDonald E, et al. Tired, weak, or in need of rest: fatigue among general practice attenders. BMJ 1990;301:1199-202. (24 November.)

2 Calder BD, Warnock PJ, McCartney RA, Bell EJ. Coxsackie B viruses and post-viral syndrome J R Coll Gen Pract 1987;37: 11-4.

3 Calder BD, Warnock PJ. Coxsackie B infections in Scottish general practice. J R Coll Gen Pract 1984;34:15-9.

4 Miller NA, Carmichael HA, Calder BD, et al. Antibody to coxsackie B virus in diagnosing postviral fatigue syndrome. BMJ (in press).

 

Source: B D Calder and P J Warnock. Chronic fatigue syndrome. BMJ. 1991 Jan 19; 302(6769): 181. PMCID: PMC1668832 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1668832/

 

Antibody to Coxsackie B virus in diagnosing postviral fatigue syndrome

Abstract:

OBJECTIVE: To study the association between coxsackie B virus infection and the postviral fatigue syndrome and to assess the immunological abnormalities associated with the syndrome.

DESIGN: Case-control study of patients with the postviral fatigue syndrome referred by local general practitioners over one year.

SETTING: General practitioner referrals in Dunbartonshire, Scotland.

PATIENTS: 254 Patients referred with the postviral fatigue syndrome (exhaustion, myalgia, and other symptoms referable to postviral fatigue syndrome of fairly recent onset–that is, several months) and age and sex matched controls obtained from same general practitioner; 11 patients were rejected because of wrong diagnoses, resolution of symptoms, and refusal to participate, leaving 243 patients and matched controls.

MAIN OUTCOME MEASURES: Detailed questionnaire (patients and controls) and clinical examination (patients) and blind analysis of blood sample at entry and after six months for determination of coxsackie B virus IgM and IgG antibodies and other variables (including lymphocyte protein synthesis, lymphocyte subsets, and immune complexes).

RESULTS: Percentage positive rates for coxsackie B virus IgM at entry were 24.4% for patients and 22.6% for controls and for coxsackie B virus IgG 56.2% and 55.3% respectively; there were no significant differences between different categories of patients according to clinical likelihood of the syndrome nor any predictive value in a fourfold rise or fall in the coxsackie B virus IgG titre in patients between entry and review at six months. The rates of positive antibody test results in patients and controls showed a strong seasonal variation. Of the numerous immunological tests performed, only a few detected significant abnormalities; in particular the mean value for immune complex concentration was much higher in 35 patients and 35 controls compared with the normal range and mean value for total IgM was also raised in 227 patients and 35 controls compared with the normal range.

CONCLUSIONS: Serological tests available for detecting coxsackie B virus antibodies do not help diagnose the postviral fatigue syndrome. Percentage positive rates of the antibodies in patients simply reflect the background in the population as probably do the raised concentrations of total IgM and immune complexes.

 

Source: Miller NA, Carmichael HA, Calder BD, Behan PO, Bell EJ, McCartney RA, Hall FC. Antibody to Coxsackie B virus in diagnosing postviral fatigue syndrome. BMJ. 1991 Jan 19;302(6769):140-3. http://www.ncbi.nlm.nih.gov/pubmed/1847316

 

Serologic and immunologic responses in chronic fatigue syndrome with emphasis on the Epstein-Barr virus

Abstract:

Although patients with chronic fatigue syndrome (CFS) can be diagnosed by clinical criteria, the lack of specific laboratory criteria delays or prevents the diagnosis and contributes to the quasi-disease status of the syndrome.

A resurgence of interest in the syndrome has followed reports suggesting that CFS may be associated with chronic active infection due to the Epstein-Barr virus. Analysis of reports to date shows that the mean titers of antibodies to viral capsid antigen and to early antigen are greater for patients with CFS than for healthy individuals; this is particularly evident in cases for which serial samples were tested.

However, these differences do not prove the cause of CFS. Cell-mediated immune responses in patients with CFS vary from study to study, and the number and function of natural killer cells in those patients are the most variable factors. Rates of isolation of virus from saliva do not differ, but in one comparison study with a large number of subjects, more lymphocytes that contained virus were isolated from patients than from controls.

Other viruses, such as the Coxsackie B virus, have been implicated as causes of CFS in studies from Great Britain. The use of a working definition of CFS and standardized tests to address abnormalities revealed by laboratory tests among homogeneous populations should allow determination of useful tests for the diagnosis of CFS and studies of its mechanisms.

 

Source:  Jones JF. Serologic and immunologic responses in chronic fatigue syndrome with emphasis on the Epstein-Barr virus. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S26-31. http://www.ncbi.nlm.nih.gov/pubmed/1850541

 

Chronic fatigue syndrome

Abstract:

Reports on conditions of chronic fatigue associated with other somatopsychic symptoms after acute viral infections have led to the hypothesis of a “chronic fatigue syndrome” (CFS). Historical disease descriptions, like e.g. “myalgic encephalomyelitits”, were updated by means of modern virological diagnostic techniques and data analysis.

Several viral agents like enteroviruses, Epstein-Barr virus, Human-Herpesvirus 6 and other herpesviruses have been implicated for possible underlying infections. A preliminary disease definition by the Center for Disease Control (CDC) seeks to provide a rational basis for further etiological studies. In fact, there is growing consensus that the syndrome comprises various separate disease entities and causative agents.

Today we can tentatively differentiate a “chronic mononucleosis” after infection with Epstein-Barr virus, an etiologically undetermined “postviral fatigue syndrome” and a fatigue syndrome of the myalgic type after Coxsackie-B virus infection. Furthermore, a valid diagnosis of CFS must be based on the exclusion of defined other diseases and the awareness of dealing with a hypothetical concept. As a result, current knowledge does not yet allow specific therapeutic recommendations.

 

Source: Ewig S, Dengler HJ. Chronic fatigue syndrome. Klin Wochenschr. 1990 Aug 17;68(16):789-96. [Article in German] http://www.ncbi.nlm.nih.gov/pubmed/2170741

 

Myalgic encephalomyelitis–a persistent enteroviral infection?

Abstract:

Myalgic encephalomyelitis is a common disability but frequently misinterpreted. Amongst 6,000 patients referred for general microbiological diagnosis between 1975 and 1987, 420 cases were recognized.

Coxsackie B neutralization tests, in 205 of these, demonstrated significant titres in 103/205 (50%), while of 124 additionally investigated for enteroviral IgM, 38/124 (31%) were positive. This illness is distinguished from a variety of other post-viral states by an unique clinical and epidemiological pattern characteristic of enteroviral infection.

Prompt recognition and advice to avoid over-exertion is mandatory. Routine diagnosis, specific therapy and prevention, await further technical advances.

 

Source:  Dowsett EG, Ramsay AM, McCartney RA, Bell EJ. Myalgic encephalomyelitis–a persistent enteroviral infection? Postgrad Med J. 1990 Jul;66(777):526-30. http://www.ncbi.nlm.nih.gov/pubmed/2170962

Note: You can read the full article herehttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2429637/