can chemotherapy be used to treat polymyositis?!
Question: Can chemotherapy be used to treat polymyositis?
It seems like you are worried because chemotherapy is supposed to be anti-cancer treatment. You don't have to worry. Chemo pills are used to treat polymyositis when more common treatments such as corticosteroids don't work.
To understand the reason why chemo may work on polymyositis is because of the nature of polymyositis and the mechanism the chemo works.
Polymyositis is inflammation of connective tissues in the body. The reason why there is an inflammation is because your body's very own antibodies (these normally defend your body against bacteria or viruses) start attacking your own body tissue. Obviously, this is not normal. Since we do not know why the antibody start attacking your own body (this is called auto-immune response) the only treatment available is to suppress your immune system.
What chemo does is it hinders cell division. Cancer cells are fast dividing. Slowing cell division in cancer case would be benenficial. The catch is that chemo kills all cells that are fast dividing, not just cancer cells.
Your antibody is created in the bone marrow, fast dividing cells. I said that chemo kills all fast dividing cells. So it kills bone marrow too.
Of course, it only partially kills the bone marrow. Since the bone marrow is production site of antibody, killing parts of bone marrow will slow down production of antibody, suppressing the immune system.
Therefore, using chemotherapy for polymyositis is a reasonable treatment. However, due to its toxic nature, I wouldn't use it unless other safer drugs (such as corticosteroids) do not work. It looks like your father is one such case. I'm so sorry for that.
Yes chemotherapy drugs are sometimes used to treat polymyositis, such as cyclophosphamide which works as an immunosuppressive agent. See these links: