Diagnosing Rheumatoid Arthritis
Rheumatoid arthritis is an autoimmune disease, resulting in chronic inflammation of the joints due to destruction of the synovial membranes. It currently affects 2.1 million Americans, 75% of which are women between the ages of 30 and 60. Without aggressive treatment, rheumatoid arthritis can be a debilitating condition as the immune system gradually destroys major joints like the knees.
At a Glance
Rheumatoid arthritis is the result of an over-zealous immune system. Although we wouldn't survive long without it (consider the outlook for those with AIDS), the immune system is a powerful network capable of massive destruction when it becomes misdirected.
The immune system is composed mostly of specialized cells and proteins. The cells are responsible for recognizing foreign particles/organisms as well as directing the goings-on of immunity, while proteins are produced by cells and directed to certain locations based upon need. During development of the immune system (from birth to early adulthood), these specialized cells are taught to recognize self vs. non-self. In the case of rheumatoid arthritis, these specialized cells have become confused and attack the synovial membranes of joints as if they were foreign. These powerful cells cause chronic inflammation within the joints as membranes, ligaments, tendons, and even bones gradually become destroyed. This inflammation and joint destruction causes extreme pain and greatly limits joint function, often leading to a loss of mobility.
What Starts Rheumatoid Arthritis in the First Place?
No one knows exactly what causes rheumatoid arthritis to develop. The many hypotheses include such things as hormones (as it occurs much more in women), previous infection, and genetics. Smoking has also been linked to development of the disease, most likely due to the fact that smoking limits one's ability to fight off infection.
How Do I Know if I Have Rheumatoid Arthritis?
Because of the complexity of rheumatoid arthritis as well as its similarity to other autoimmune diseases, it can be difficult to diagnose and often involves many tests for a firm diagnosis.
A rheumatologist (or arthritis specialist) will most likely want to know which joints you have pain in. Most with the condition present pain in smaller joints, such as those in the hands, wrists, feet, and knees. Often joint pain will be symmetric and occurs in both hands and both knees. Stiffness of joints is usually worst in the morning with rheumatoid arthritis and can be lessened with movement.
Rheumatoid Factor: Approximately 80% of people with rheumatoid arthritis also have a protein in their blood called rheumatoid factor. Its concentration usually correlates with the severity of the disease.
C-Reactive Protein (CRP): CRP concentrations increase with increasing inflammation, and can often be used as an indicator of disease activity. Its levels are often used to track disease progression and level of response to treatment.
Erythrocyte Sedimentation Rate (ESR): The ESR test is used to determine the volume of red blood cells (erythrocytes) in comparison to other blood components, such as plasma (fluid) and platelets. Erythrocytes settle faster when most fluid is present, indicating inflammation.
Imaging methods such as X-rays and MRIs can be used to visualize joints and the membranes surrounding them, allowing doctors to assess how much damage a joint has suffered or how much inflammation is present. Because rheumatoid arthritis can progress slowly, often going into remission where no symptoms are present, it can take years to diagnose. Obvious swelling and subsequent deterioration of joints is often necessary to confidently diagnose the condition. Although this extended diagnosis can be frustrating, it is necessary to prevent the immobilizing progression of the disease and hopefully soothe inflamed joints.