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Viral connections

me by hotel pool.jpgIs MS linked to a retrovirus? Ian Cook shares some very interesting research

One of the perks of being a freelance journalist is that people ‘tip you off’ about interesting new developments in multiple sclerosis (MS) research. These tip offs are often stories ignored by the mainstream medical press.

One tip-off that came to me recently was a phone call from another MSer telling me about an academic paper titled ‘HIV infection and multiple sclerosis: a case with unexpected ‘no evidence of disease activity’ status’. The paper was published in March in the Journal of International Medical Research.

The paper outlines the case of a patient diagnosed with MS who saw his condition substantially improve following subsequent HIV infection and treatment. The patient achieved No Evidence of Disease Activity (NEDA) without any MS disease-modifying drugs and continues to have no disease activity more than ten years after being first diagnosed. The authors speculate that antiretroviral therapy, which the man is still taking for his HIV, may be responsible for his MS ‘disappearing’, with the HIV medication perhaps treating his MS as well.

Human endogenous retrovirus

Of course, MS is not a retroviral infection like HIV so what is going on? One theory is that this patient’s MS, and all MS, is caused by something called a HERV or human endogenous (inherited) retrovirus. HERVs share similarities to retroviral illnesses like HIV and thus respond to HIV drugs as is shown in the above study.

retrovirus.jpgNot a lot is known about HERVs but basically, they are remnants of retroviral infections which infected our ancestors and which entered our DNA, being inherited by subsequent generations. In everyone’s DNA there are hundreds of HERVs. Amazingly HERVs make up around 8 per cent of the human genome and several disorders are thought to be associated with the re-activation of HERVs. The ‘MS-HERV’ theory hypothesises that under certain circumstances, like infection with another virus (Epstein Barr virus  for example), HERVs can spring back to life causing illnesses like MS. HIV drugs, being anti-viral, help keep these HERVs ‘under control’ in the same way that they keep HIV under control. This is what is assumed was happening in the 2021 case study.

Interestingly the 2021 case study is not the first one where a patient taking anti-retroviral drugs for HIV saw a disappearance of MS. A case report was published in 2011 in the European Journal of Neurology saying the same thing. It was titled ‘Could antiretroviral drugs be effective in multiple sclerosis?’ and outlined the case of an Australian man with HIV and MS who also experienced a marked improvement in his after taking anti-retroviral HIV drugs. The 2011 Australian case study led to two important developments in exploring the theory that a HERV could be involved in MS.

First, a 2015 survey of people with HIV found that far fewer of them had MS than would be expected. The thinking was that the HIV drugs used by patients who had both HIV and MS were also treating the patients’ MS like in the two case studies already mentioned.

Secondly, in 2019, an anti-retroviral HIV drug raltegravir (Isentress) was tried out on a small group of MSers. Sadly, raltegravir did not lead to any improvement in the MSers’ condition. It was later suggested that ratelgravir was the wrong HIV drug to use on its own. This idea makes sense because HIV patients like the above two take a ‘cocktail’ of drugs, sometimes ten or more, and choosing the right anti-retroviral drug or drugs would obviously be crucial to success.

As far as I am aware there is no current project to try out other HIV drugs on MS. But I emailed the March paper to Prof. Julian Gold, who led the raltegravir trial and published the 2011 case study. I asked him for his view. He said he would send the 2021 paper to his colleague, Professor Gavin Giovannoni from London University and that he was personally still ‘very committed’ to the concept of viral or HERV involvement in MS although he acknowledged that research in this area is ‘very sporadic.’

Hope for the future

Sporadic, of course does not mean non-existent and there is some work going on right now exploring the idea that HERVs and MS are connected. A bio-tech company based in Switzerland called Geneuro is currently pursuing the HERV theory for treating MS but using a drug it has been developed specially rather than using an existing HIV drug like Gold did in his 2019 trial.

Geneuro recently announced that enrolment of MS patients had been completed for a 48-week Phase 2 study of temelimab, a drug it has developed to treat the ‘MS-HERV’. Results are due to be reported in the first three months of 2022. This is certainly something to look out for next year.

In the meantime I shall look out for further stories similar to ones published in the European Journal of Neurology and the Journal of International Medical Research. There is a steady stream of these stories, and it’s a shame that so few MS researchers give them the attention their investigation so richly deserves.

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