Polymyositis – Autoimmunity & Cancer Link Theory

[TischSEB]

Hi – This article is a couple of years old, but I thought the theory of the immune system being misdirected after fighting cancer was kind of interesting. Seems in line with the thinking of an immune system trying to get at something elusive or confusing, not just acting without reason. I pulled out just a little below, see the link for the full article.

http://www.nytimes.com/2007/03/27/health/27immu.html?pagewanted=1

?The big question we have is: why are autoimmunity and cancer linked, as occurs in myositis?? she said. ?We think it?s telling us something.?
The immune system?s role is to recognize and attack foreign infectious agents like bacteria and viruses, and it is also believed to take part in tumor surveillance. But what if the immune system becomes overzealous or misfires ? or if a tumor starts producing proteins that the system recognizes as threatening and foreign, but that are also found in other normal cells?
Dr. Antony Rosen, director of the division of rheumatology at Hopkins, says myositis patients in their 40s, 50s and 60s ? the time of life when cancer rates increase ? may actually be cancer survivors.
?I believe the autoimmune rheumatic diseases that occur in people over age 40 may reflect an anticancer immune response in a large number of people,? he said. ?These people may be effective cancer survivors.?
Dr. Levine, of the vasculitis center, said the muscle cells might be like ?innocent bystanders,? accidentally harmed during the immune system?s assault on the tumor.
In a study published two years ago in The Journal of Experimental Medicine, Dr. Livia Casciola-Rosen, together with Dr. Rosen, Dr. Levine and others, reported that the antigens that produce the immune response are present in normal muscle tissue, but at low levels. They are much more prevalent in myositis patients? cells and in muscle cells that are regenerating, as after an injury.
Dr. Rosen believes a vicious cycle occurs when damaged muscle cells start to repair themselves. These cells express higher amounts of the antigens, causing the immune system to respond; the immune response causes further damage to the muscle, which in turn repairs itself, its regenerating cells expressing even more antigens, and continuing the cycle.

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