Rheumatoid Arthritis(RA) is classified as a inflammatory disease. Inflammatory disease results from the body’s reaction to a localized injurious agent.
(Mace J.D & Kowalczyk N.,2004)
ETIOLOGY (CAUSES)
The etiology of Rheumatoid arthritis is remain unknown.
Genetic (inherited) factors:
- Maybe genetically inherited.
- Infections or factors in the environment might trigger the immune system to attack the body's own tissues, resulting in inflammation in various organs of the body such as the lungs or eyes.
- Regardless of the exact trigger, the result is an immune system that is geared up to promote inflammation in the joints and occasionally other tissues of the body.
- Immune cells, called lymphocytes, are activated and chemical messengers (cytokines, such as tumor necrosis factor/TNF and interleukin-1/IL-1) are expressed in the inflamed areas.
- A viral or bacterial infection appears likely, but the exact agent is not yet known.
- This does not mean that rheumatoid arthritis is contagious (a person cannot catch it from someone else).
- Some scientists also think that a variety of hormonal factors may be involved.
- Women are more likely to develop rheumatoid arthritis than men, pregnancy may improve the disease, and the disease may flare after a pregnancy.
- Breastfeeding may also aggravate the disease.
- Recently, scientists have reported that smoking tobacco increases the risk of developing rheumatoid arthritis.
Can occur at any age, but usually begins in people between the ages of 20 and 45. This condition is more common in older people, but children also can develop juvenile rheumatoid arthritis.
Women are more likely to have RA than men. They also have a higher risk of developing the more severe form of disease. Different sources estimate that two to four times as many women have rheumatoid arthritis as men.
Pathogenesis (sequence of event) :
- Joint damage in rheumatoid arthritis begins with the proliferation of synovial macrophages and fibroblasts after a triggering incident, possibly autoimmune or infectious.
- Lymphocytes infiltrate perivascular regions, and endothelial cells proliferate. Neovascularization then occurs.
- Blood vessels in the affected joint become occluded with small clots or inflammatory cells.
- Over time, inflamed synovial tissue begins to grow irregularly, forming invasive pannus tissue. Pannus invades and destroys cartilage and bone.
- Multiple cytokines, interleukins, proteinases, and growth factors are released, causing further joint destruction and the development of systemic complications.
Manifestation (observe changes)
- The symptoms of rheumatoid arthritis come and go, depending on the degree of tissue inflammation.
- When body tissues are inflamed, the disease is active. When tissue inflammation subsides, the disease is inactive (in remission).
- Remissions can occur spontaneously or with treatment, and can last weeks, months, or years.
- During remissions, symptoms of the disease disappear, and patients generally feel well.
- When the disease becomes active again (relapse), symptoms return.
- The return of disease activity and symptoms is called a flare.
- The course of rheumatoid arthritis varies from patient to patient, and periods of flares and remissions are typical.
Sign:
- Swelling-Fluid enters into the joint and it becomes puffy; this also contributes to stiffness.
- Redness during disease flares-The joints may be somewhat warmer and more pink or red than the neighboring skin.
Symptom:
- Fatigue-Periods of fatigue which gets worse during a flare-up.
- Lack of appetite.
- low-grade fever.
- Pain-Inflammation inside a joint makes it sensitive and tender. Prolonged inflammation causes damage that also contributes to pain.
- Stiffness-Stiffness of the affected joint with period of activity or exacerbations and remissions of the disease process. Muscle and joint stiffness are usually most notable in the morning and after periods of inactivity.
- Sjogren's syndrome-Inflammation of the glands of the eyes and mouth can cause dryness of these areas.
- Pleuritis-Rheumatoid inflammation of the lung lining can causes chest pain with deep breathing or coughing. The lung tissue itself can also become inflamed, and sometimes nodules of inflammation (rheumatoid nodules) develop within the lungs.
- Pericarditis-Inflammation of the tissue (pericardium) surrounding the heart which can cause a chest pain that typically changes in intensity when lying down or leaning forward.
- Anemia and Felty's syndrome-The rheumatoid disease can reduce the number of red blood cells (anemia) and white blood cells. Decreased white cells can be associated with an enlarged spleen (referred to as Felty's syndrome) and can increase the risk of infections.
- Rheumatoid nodules-Firm lumps under the skin which can occur around the elbows and fingers where there is frequent pressure. Even though these nodules usually do not cause symptoms, occasionally they can become infected.
- Vasculitis-Inflammation of the blood disease. Vasculitis is rare, serious complication, and usually with long-standing rheumatoid disease. Vasculitis can impair blood supply to tissues and lead to tissue death. This is most often initially visible as tiny black areas around the nail beds or as leg ulcers.
DIAGNOSTIC TEST AND PROCEDURES
Diagnosis of RA in adults is based on the American College of Radiology (ACR)’s 1987 revised classification criteria (refer to table 1).
If an individual meet four of the seven criteria listed, a positive diagnosis of RA is indicated.
(Wilke S.W.,2008)
Table 1: Criteria for the Classification of Rheumatoid Arthritis
If an individual meet four of the seven criteria listed, a positive diagnosis of RA is indicated.
(Wilke S.W.,2008)
Table 1: Criteria for the Classification of Rheumatoid Arthritis
(Wilke S.W.,2008)
Significant Lab test
Blood test:
Rheumatoid factor
- Abnormal blood antibodies can be found in patients with rheumatoid arthritis. A blood antibody called "rheumatoid factor" can be found in 80% of patients.
- Citrulline antibody (also referred to as anti-citrulline antibody, anti-cyclic citrullinated peptide antibody, and anti-CCP) is present in most patients with rheumatoid arthritis.
- It is useful in the diagnosis of rheumatoid arthritis when evaluating patients with unexplained joint inflammation.
- A test for citrulline antibodies is most helpful in looking for the cause of previously undiagnosed inflammatory arthritis when the traditional blood test for rheumatoid arthritis, rheumatoid factor, is not present.
- Citrulline antibodies have been felt to represent the earlier stages of rheumatoid arthritis in this setting.
- Another antibody called "the antinuclear antibody" (ANA) is also frequently found in patients with rheumatoid arthritis.
- ANAs are found in patients whose immune system may be predisposed to cause inflammation against their own body tissues.
- Test which measures the concentration in blood serum.
- Used to measure the degree of inflammation present in the body.
- In cases of inflammatory rheumatic diseases, such as rheumatoid arthritis, doctors can utilize the CRP test to assess the effectiveness of a specific arthritis treatment and monitor periods of disease flare up.
Imaging procedure
Imaging consideration:
Special Positioning : AP Oblique Bilateral Projection of Hand.
- This position is performed commonly to evaluate for early evidence of RA at the second through fifth proximal phalanges and MCP joints.
- Both hands are generally taken with comparison of both hands.
Exposure Factor (Decrease)
Rheumatoid Athritis causes the affected body tissue to decrease in thickness, effective atomic number, and density. There will be less attenuation of the x-ray beam.As more photon are able to pass through the body tissue, more will be available to reach the image receptor. This disease is easier to penetrate and are called destructive condition. They require decreasing the exposure to achieve he proper image receptor exposure.
(Carlton R.R.& Adler A. M.,2006)
MRI
MRI is useful in detecting RA before radiographic changes can be detected. MRI is not only more sensitive in detecting erosions, but in addition is capable of identifying bone marrow edema and synovial hypertrophy.
Both these findings predict the development of erosive disease.
Ultrasonography
Ultrasonography is used infrequently in establishing a diagnosis of RA, and is more sensitive in the detection of synovial and tendon inflammation than clinical examination alone. Ultrasonography may also be useful in guided joint aspiration and injection.
(Wilke S.W.,2008)
