The Role of Viruses in ME/CFS, XMRV and the MRC PACE Trial – Margaret Williams – 21st November 2009
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The role of viruses in ME/CFS: what, if any, will be the effect of the discovery linking XMRV to ME/CFS on the MRC PACE Trial?
by Margaret Williams
21 November 2009
For decades it has been known and shown that viruses play a role in ME/CFS; some illustrations from the literature are provided below (all of which are relevant and significant).
In relation to “CFS”, the most-studied viruses have been the Epstein-Barr Virus (EBV) and the Human Herpes Virus-6 (HHV-6). In relation to “pure” ME, the most studied viruses (and for which there is extensive evidence) have been the enteroviruses, usually Coxsackie B (CBV). Some illustrations from the literature of the role that viruses play in ME/CFS are provided at the end of this paper; all are significant.
There is increasing awareness that the dysregulated immune system that is a hall-mark of ME/CFS allows multiple latent viruses and microbial agents to become reactivated (Co-Cure NOT:12th November 2009).
Moreover, recent research has shown that even viruses which were hitherto believed not to persist after an acute infectious episode are capable of long-term viral persistence.
Nora Chapman et al from the Enterovirus Research Laboratory, Department of Pathology and Microbiology, University of Nebraska Medical Centre, have shown that human enteroviruses Coxsackie B can naturally delete sequence from the 5’ end of the RNA genome and that this deletional mechanism results in long-term viral persistence, which has substantially altered the previously held view
(http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440640/?tool=pubmed ). In a specially commissioned piece for the charity Invest in ME, the researchers say: “This previously unknown and unsuspected aspect of enterovirus replication provides an explanation for reports of enteroviral RNA detected in diseased tissue in the apparent absence of virus particles” (Journal of IiME 2009:3:1).
Dr John Chia, an infectious diseases specialist from Torrance, California, who specialises in ME/CFS, is on record: “I believe that the main reason (ME)CFS patients are symptomatic is due to continuing inflammatory response toward viruses living within the cells, enteroviruses in most of the cases I see. We have clearly documented certain enterovirus infections triggering autoimmune responses in some patients…Can you imagine how we would feel if there are viruses surviving in our muscles, brains, hearts and gastrointestinal tracts triggering ongoing immune responses?”
The CFIDS Chronicle (Research Update, Summer 1993) explained viruses and retroviruses as follows:
“A virus is a microscopic organism that lives within the cells of another living organism. Viruses cause disease at the most basic level, by damaging the cells of living things. By themselves, viruses are lifeless particles incapable of reproduction, but once they enter the cell of another living thing they become active organisms that can multiply hundreds of times.
“Viruses are comprised of two parts – a core of either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) and a protective envelope of protein. RNA viruses are smaller than DNA viruses and sometimes contain a special enzyme called reverse transcriptase which allows them to convert RNA to DNA. These specialised viruses are known as retroviruses and have a unique ability to merge with the host’s own genetic material.
“Retroviruses have the unique ability to replicate themselves by (i) making a double-stranded DNA copy called a ‘pro-virus’ once they enter living cells. Pro-viruses integrate themselves into the human chromosome and become part of the host’s genetic code (ii) alter the host’s immune response by evading detection as a ‘hidden invader’ (iii) remain hidden and latent, spliced within the host’s DNA, for long periods of time. Retroviruses are known to be potent stimulators of cytokines”.
On 8th October 2009 the premier journal Science published a paper online showing a direct link between a retrovirus and ME/CFS (Detection of infectious retrovirus XMRV, in blood cells of patients with chronic fatigue syndrome. Lombardi VC, Ruscetti FW, Peterson DL, Silverman RH, Mikovits JA et al) which caused global reverberations.
However, this was not the first time that a retrovirus had been associated with ME/CFS.
In 1991, using polymerase chain reaction and in situ hybridisation, Dr Elaine De Freitas, a virologist at the Wistar Institute, Philadelphia (which is America’s oldest independent institution devoted to biological research) and Drs Daniel Peterson, Paul Cheney, David Bell et al found such an association (Retroviral sequences related to human T-lymphotropic virus type II in patients with chronic fatigue immune dysfunction syndrome. Proc Natl Acad Sci USA 1991:88:2922-2926). It is notable that co-author Hilary Koprowski is a distinguished virologist and Professor Laureate who was Director of the Wistar Institute from 1957-1991; he is a member of the US National Academy of Sciences and is Director of the Centre for Neurovirology at Thomas Jefferson University.
Before publication, the findings were presented on 4th September 1990 by Elaine De Freitas at the 11th International Congress of Neuropathology in Kyoto, Japan.
Ten days later, on 14th September 1990 Dr Peter White (as he then was) and other members of the Wessely School dismissed the findings: “in the vast majority of CFS cases there is a psychological component. About 75% of CFS sufferers are clinically depressed, according to Peter White, senior lecturer in the department of psychiatric medicine at St Bartholomew’s Hospital in London. White said he believes depression is often a cause, rather than a consequence, of CFS…Les Borysiewicz, a clinical virologist at Addenbrookes Hospital in Cambridge (now Chief Executive of the MRC, having succeeded Professor Colin Blakemore) (said) ‘Whatever causes CFS, it isn’t the virus itself’…Anthony Clare, psychiatrist and medical director of St Patrick’s Hospital in Dublin (now deceased), pointed out that…there have been many ‘fatigue’ diseases with shifting causes: ’Neurasthenia, food allergies, now viruses. Some people would always rather have a disease that might kill them than a syndrome they have to live with’ ” (Science 1990:249:4974:1240).
In their PNAS article that was published in April 1991, De Freitas et al noted that chronic fatigue immune dysfunction syndrome (CFIDS) “may be related or identical to myalgic encephalomyelitis” and examined adult and paediatric CFIDS patients for evidence of human retroviruses (HTLV types I and II). As the CFIDS Chronicle article noted, the Wistar team looked at the peripheral blood DNA to see if they could find messenger RNA (mRNA) encoding for a viral segment of the HTLV-II virus.
At that time, known human retroviruses were the human immunodeficiency viruses 1 and 2 (HIV-1 and HIV-2) which are known to cause AIDS, and human T-lymphotropic viruses HTLV-I which causes lymphoma and HTLV-II which causes leukaemia (Hunter-Hopkins ME-Letter, October 2009). The four segments of the HTLV-II virus are referred to as the env, gag, pol and tax.
After a two year study, De Freitas et al provided evidence for HTLV-II-like infection of blood cells from CFIDS patients (and also to a lesser extent from people closely associated with them). This evidence was further substantiated by patient reactivity to proteins with the molecular weights reported for HTLV-I and HTLV-II antigens.
In their article, De Freitas et al said: “The frequency of these antibodies in CFIDS patients compared with healthy non-contact controls suggests exposure / infection with an HTLV-like agent rare in healthy non-contact people”.
Following the Wistar findings, researchers at the US Centres for Disease Control (CDC) allegedly attempted to replicate De Freitas’ work but failed to do so; this was suggested to be because certain scientists appeared eager to discount any possibility of a retroviral association with CFIDS. De Freitas defended her work and insisted that the CDC investigators had modified her assays, with the result that her work could not be replicated by the CDC.
De Freitas was publicly discredited; her research funding was discontinued and her research abandoned; she was subjected to what appeared to be attempts to destroy her professional reputation. Commenting on the subsequent discovery of XMRV (see below), ME/CFS expert Dr Paul Cheney of The Cheney Clinic was unambiguous: “Her work was unfortunately assaulted by the CDC. Her proposal to fly to the CDC in Atlanta to physically run the assays side by side with the CDC scientists was dismissed by the CDC” (http://cheneyclinic.com/a-retrovirus-called-xmrv-is-linked-to-cfs/538 ).
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