Understanding Arthritis.- “AT NIGHT, I LOOK AT MY DEFORMED FEET AND HANDS AND I CRY.”—MIDORI, JAPAN. ARTHRITIS has plagued humans for centuries. Egyptian mummies give evidence that the disease existed centuries ago. Explorer Christopher Columbus evidently suffered from it. And millions today are afflicted. Just what is this crippling disease? The word “arthritis” is taken from Greek words meaning “inflamed joints” and is associated with a group of well over 100 rheumatic diseases and conditions. These diseases may affect not only the joints but also the muscles, bones, tendons, and ligaments that support them. Some forms of arthritis can damage your skin, internal organs, and even your eyes. Let us focus on two diseases commonly associated with arthritis—rheumatoid arthritis (RA) and osteoarthritis (OA). Joint Architecture. A joint is where two bones meet. A synovial joint is surrounded by a tough capsule that protects and supports it. (See illustration on page 4.) The joint capsule is lined with a synovial membrane. This membrane produces a slippery fluid. Within the joint capsule, the ends of the two bones are covered with a smooth elastic tissue known as cartilage. This prevents your bones from rubbing and grinding against each other. Cartilage acts as a shock absorber as well, cushioning the ends of your bones and distributing stress evenly across your bones. For example, when you walk, run, or jump, the pressure exerted on your hips and knees can be four to eight times your body weight! While most of the impact is absorbed by the surrounding muscles and tendons, the cartilage helps your bones to tolerate this load by compressing like a sponge. Rheumatoid Arthritis. In the case of rheumatoid arthritis (RA), the body’s immune system launches an all-out attack on its joints. For some unknown reason, a large volume of blood cells—including T cells, which are key players in the body’s immune system—rushes into joint cavities. This triggers a cascade of chemical events that result in the joint becoming inflamed. The synovial cells may begin to proliferate uncontrollably, forming a tumorlike mass of tissue called a pannus. The pannus, in turn, produces destructive enzymes that destroy the cartilage. Bone surfaces may now stick together, causing restricted motion—and excruciating pain. This destructive process also weakens the ligaments, the tendons, and the muscles, causing the joint to become unstable and partially dislocated, oftentimes leaving a deformed appearance. Usually RA affects joints in a symmetrical pattern, afflicting the wrists, knees, and feet. Upwards of 50 percent of individuals diagnosed with RA also develop nodules or bumps under the skin. Some develop anemia and dry, painful eyes and throat. Fatigue and flulike symptoms, including fever and aching muscles, accompany RA. RA is highly variable in effect, onset, and duration. In one person the pain and stiffness may come on slowly over a period of weeks and even years. For another, the onset may be quite sudden. For some people, RA lasts for a few months and then leaves without noticeable damage. Others may experience periods of worsening symptoms called flares, followed by periods of remission during which they feel better. And in some patients the disease continues active for many years, relentlessly disabling them. Who are at risk for RA? “It’s most common in women in their middle years,” notes Dr. Michael Schiff. However, Schiff further states that “it can affect anyone at any age including children, as well as men.” For those with relatives who have rheumatoid arthritis, the risk increases. Several studies further suggest that smoking, obesity, and a history of blood transfusion are all significant risk factors.
Posted on: Fri, 30 Aug 2013 17:55:36 +0000
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