Both MS and RA are considered to be autoimmune diseases. This means that for some reason, the body’s own immune system attacks parts of itself. In RA, the immune system begins to attack the joints. In MS, it attacks the brain and spinal cord. Why this happens in some people is not entirely clear. Certain autoimmune diseases and the tendency to get autoimmune diseases does seem to run in families.
It is thought that different things can trigger MS and RA. These triggers may be hormonal, genetic, or environmental. Exposure to certain viruses is thought to be a trigger. Epstein-Barr virus (EBV) has suspected links to both RA and MS.
There are also other connections. Some studies suggest that MS patients may be more likely to get RA and other autoimmune diseases. And a treatment for RA called anti-TNF therapy can cause a condition very similar to MS.
I hope this helps. As you can see, we all still have a lot to learn about MS, RA and all the other autoimmune diseases.
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