About the Disease of Rheumatoid Arthritis
Rheumatoid arthritis is an inflammatory disorder which causes joints to become swollen and painful. In the process along its progression, joint deformation and dysfunction occur. It is said about 0.4~0.5 % of people, approximately 1% of those 30 years or older have rheumatoid arthritis. Although it occurs at any age, many patients develop the disease in their 30s to 50s with three times more female patients than male. Rheumatoid arthritis which occurs in those 15 years of age or younger is called juvenile rheumatoid arthritis and its symptoms and examination findings differ from that of the disease for adults.
It is well known that RA patients have problems in their immune system, the human defense system against germs, though the cause of the disease is still somewhat unclear. It is thought that an abnormality in genes, infectious microorganisms (viruses or germs), or a combination of the two have some relation to the disease. White cells such as macrophages or lymphocyte cells leak from increased capillaries to joint synovial tissue due to the abnormal activity of the immune system. Substances called cytokines (TNFα, IL-6, etc.) produced by macrophages or lymphocyte cells cause inflammatory reactions in joints. Synovial cells increase to cause pain and swelling while joint fluid increases to damage cartilage and bones.
Gradual pain and swelling occur on fingers, (base of fingers＝metacarpophalangeal joint, the second joints from finger tips＝proximal interphalangeal joint), toes, and wrist joints over the course of several months. There may also be occasional sensations of heat. These symptoms might be seen on big joints such as the elbows or knees as well. First, the pain starts on a few joints and as the disease progresses untreated, it spreads to more joints. There are multiple causes for joint swelling such as built up fluid or synoviali proliferation in joints. Occasionally as a deformation progresses, it could appear as swelling. Some stiffness is felt in joints when they first start to move and then movement gradually becomes smoother. This is called “morning stiffness” since stiffness is the strongest after getting up in the morning. Such symptoms are also seen after taking a nap or staying still for a long time, e.g., sitting down for prolonged periods of time. The disease is thought to be active if the “morning stiffness” is persistent. Sometimes it becomes chronic after experiencing continual improvement or deterioration while other times it completely disappears.
More often than not, weather controls the symptoms. On a clear warm day, discomfort becomes lighter while on a rainy day, or the day before rain, joint pain increases. Even in summer, a cold breeze from an air conditioner directly to an affected area increases joint pain. Due to joint deformation caused by damaged bone or cartilage, the mobility of joints becomes limited.
Among the symptoms, there are ulnar deviations, fingers curve towards the smallest finger, hallux valgus, toes curve towards the smallest toe, and fixed flexion, when knees and elbows can’t straighten out all the way. Also atlantoaxial subluxation, when the joints in neck that support the head shift out of alignment, pain in back of the head, and hands becoming numb or not being able to use strength.
General symptoms include fatigue, weakness, weight loss, and loss of appetite. On the outer side of the elbows, the occipital region of the head, or on the hips, subcutaneous nodules may develop. When viewing a chest x-ray, a shadow may be seen at the bottom of the lungs which could be an accumulation of fluid (pleural effusion) or pulmonary fibrosis. Dryness of mouth and eyes, or Sjögren's syndrome may also be seen.
Malignant rheumatoid arthritis is listed as a specified disease by the Ministry of Health and Welfare. It causes inflammation of a blood vessel in the heart, lungs, digestive tract, and skin. Also fever, pneumonitis, myocardial infarctions, and bowel infarctions are seen in patients with malignant rheumatoid arthritis. Public expense covers the self-pay burden for the patients.
The symptoms of rheumatoid arthritis vary among the individuals especially at the onset. Also there are many other diseases accompanied by joint pain. Therefore the standard established by American Rhuematism Association (ARA) (currently The American College of Rheumatology (ACR)) is used in diagnosing rheumatoid arthritis. The test includes seven items to diagnose; (1) morning stiffness that lasts over one hour (2) swelling of three or more different joints (3) swelling of hand joints (wrist, metacarpophalangeal joint, proximal interphalangeal joint) (4) symmetrical joint swelling (5) abnormal findings in hand x-rays (6) subcutaneous nodules (7) seropositive blood test results. If one’s condition matches four or more items, they will be diagnosed as having rheumatoid arthritis on the assumption that (1) to (4) last for six weeks or longer. Additionally there is diagnosis for early rheumatoid arthritis.
Testing for diagnosis includes rheumatic reaction of serum, sedimentation rates, CRP levels, and x-rays of hands. Eighty to ninety percent of RA patients test positive in rheumatic reaction testing (rheumatoid factor: RF) while some RA patients don’t. Also, sometimes patients with other diseases, or even those with no disease at all, test positive.
Positive rheumatoid factor doesn’t always mean that one has rheumatoid arthritis. With this test, some cases of early rheumatoid arthritis test negative. CCP antibody tests are more appropriate to detect early cases of rheumatoid arthritis as the anti CCP antibody is said to become positive earlier than RF. Periodic x-rays of joints are useful in testing for RA or the progress of it. Recently with MRI or ultrasonography subtle changes of tissues usually undetectable with x-rays can be detected. It is said that early observation of changes in some parts other than the bones is important.
Sedimentation and CRP levels are useful markers for rheumatic inflammation while MMP-3 is a marker for destruction of cartilage. When the disease progresses fast, anemia is seen, however with proper treatment, it disappears. Since medication is given over a long period of time to treat RA, careful testing for adverse effects is necessary. Testing includes urine analysis (protein or red cell), blood test (anemia, reduced white cells or platelets), serum chemistry (liver function, renal function) and periodic chest x-rays. Curative treatment for RA can’t be expected as the cause of the disease is still unknown. Therefore the purpose of the treatment has been reaching remission of the disease while improving the patient’s QOL with active use of anti-rheumatoid drug such as methotrexate or biological products. These are the goals in treating RA; (1) improve symptoms of RA (2) prevent joint destruction or deformation (3) restore the function of damaged joints (4) maintain physical function (5) maintain QOL (6) reach remission.