Читать книгу Arthritis For Dummies - Barry Fox - Страница 61

The truth is that nobody really knows what causes RA, although some believe it is linked to a defect in the immune system. Many people with RA have a particular genetic marker — HLA-DR4 — so it’s reasonable to suspect that this gene may be to blame. Yet, not everyone with this gene ends up with RA, and not everyone with RA has this gene. And scientists are certain that more than just one gene is involved: Perhaps HLA-DR4 is only one of several genes that can tip the scales in favor of developing RA. Most likely, genetic markers play a part in the development of the disease but aren’t the determining factor. Some researchers believe that RA may be triggered by a virus, or perhaps an unrecognized bacteria, that “wakes up” a dormant genetic defect and sets it in motion. As of yet, no such infectious agent has been discovered, and RA has not been found to be contagious.

Hormones or hormone deficiencies may also play a part, although their possible role is unclear. Women are more likely than men to develop RA, suggesting a possible link to estrogen. But, at present, doctors have more questions than answers about RA.