HIV therapy might work on MS, too.

Neomatica explains how British and Australian researchers are figuring out why HIV patients show an unusual resistance to multiple sclerosis and its symptoms. It may be that MS is caused by a virus that is either outcompeted by HIV or else vulnerable to the same anti-retroviral medication:

AIDS patients or people with HIV receiving treatment have a 60% less likely chance of receiving a diagnosis of MS. Deeper analysis found that those on a treatment regimen the longest, for 5 years or more, had an 80% reduced chance of developing MS. The discovery is remarkable for the fact that no curative or preventative treatments for MS exist and this unexpected insight may be one of the most interesting avenues.

The researchers write

“If subsequent studies demonstrate there is a causal protective effect of HIV (and/or its treatment), and if the magnitude of it proves to be similar…this would be the largest protective effect of any factor yet observed in relation to the development of MS,”

The primary author of the study, Dr. Julian Gold of Prince of Wales Hospital in Australia, first observed casually that even though he treats patients with HIV and knows people with MS, he had never met a person with both. He searched through medical literature, and found 700,000 studies on HIV/AIDS and 300,000 studies on MS. Out of the approximately 1,000,000 studies, there was no reference to a patient who had both. Eventually, he did find one person whose symptoms of MS began to diminish when he began treatment for HIV.

MS is characterized by symptoms ranging from clumsiness to paralysis to depression. The symptoms are caused by the immune system attacking the central nervous system, specifically the tissue that insulates and protects the nerves. HIV strongly interferes with the immune system, as the virus takes up residence in latent pool inside immune cells. It does not seem implausible that it affects pathways employing or employed by MS, which would explain how the disease could suppress MS. So even though the etiology of MS remains unclear, antivirals used to treat HIV could also be repurposed to treat MS as well.

If it is indeed the antivirals that are suppressing MS, it could mean that treating MS is as simple as approving a few drugs for new uses, obviating lengthy safety trials. If it is the HIV that is conferring protection, treatment is more complicated as investigators would need to seek which aspects of HIV confer protection.

[I read it on reddit.]