Читать книгу Arthritis For Dummies - Barry Fox - Страница 59

For reasons that aren’t completely understood, in rheumatoid arthritis the white blood cells of the immune system attack the joint lining (synovial membrane) as if it were a foreign object. And pain, swelling, loss of movement, and joint destruction are the unhappy results. After the immune system goes to work on the joint lining, here’s what happens:

1 The assaulted membrane becomes inflamed and painful, the entire joint capsule swells, and the synovial cells start to grow and divide in an abnormal way.

2 Almost as if they’re launching a counterattack, these abnormal cells invade the surrounding tissue — mostly the bone and cartilage.

3 The joint space begins to narrow, and the joint’s supporting structures become weak. At the same time, the cells that trigger inflammation release enzymes that start eating away at the bone and cartilage, causing joint erosion and scarring.

4 Reeling under this many-sided attack, the joint itself deteriorates, eventually becoming misshapen and misaligned.

See Figures 3-1 and 3-2 for comparison of a healthy joint to one with RA.

© John Wiley & Sons, Inc.

FIGURE 3-1: In the healthy joint, the synovial membrane is thin and free from inflammation; the cartilage is smooth, thick, and even. The joint space is well defined, and the joint capsule assumes a normal shape.

© John Wiley & Sons, Inc.

FIGURE 3-2: In the joint affected by RA, the synovial membrane is inflamed and swollen, with infected cells invading both bone and cartilage. The cartilage is thin, the joint space narrowed, and the joint capsule swollen.

Rheumatoid arthritis insidiously makes its way through the body and (in more severe cases) can eventually spread to all of the joints. But the joints are not its only targets. RA is a systemic disease capable of attacking various parts of the body, not just the joints. It can cause inflammation of the eyes, skin, heart, blood vessels, and lungs, generally wreaking havoc on the body as a whole.

If the tear and salivary glands partially “dry up,” Sjögren’s can develop in association with RA. See Chapter 4 for more on this “drying disease.”

Some people have RA for just a short time — a few months or a couple of years — and then it disappears forever. Others suffer through painful periods (flares) that come and go, although they can feel quite well in between episodes. Those with severe forms of RA, however, may be in pain a good deal of the time, experience symptoms for many years, and suffer serious joint damage.