Rheumatoid Arthritis - Definition
Is a systemic autoimmune disease which is characterised primarily by joint inflammation with extra-articular manifestations of disease in some patients.
Antigens in Rheumatoid Arthritis
Not known what is always the cause, but some theories are...
- Type 2 Collagen
- Immunoglobulins (IgG)
Fibroblasts in Rheumatoid Arthritis
These can act in a positive and a negative way...
Positively, they produce hyaluronan which is an important component of the joint fluid which may help.
Negatively, when they are in an inflamed synovium they produce metalloproteinases. These metalloproteinases are responsible for degrading all the components of the extracellular matrix and causing irreversible damage.
What Causes the Joint Pain in RA?
The joint capsule has a rich supply of nerve endings.
These are located primarily in the lining of the joint.
Inflammatory mediators are released into the joint in arthritis, which stimulates the nerve endings in the capsule and lining.
TNF-alpha and RA
TNF-alpha is one of the focal cytokines in RA pathology. This is present in high amounts most of the time in RA and inhibiting it causes structural, clinical, and functional benefits to RA patients.
Demographics of Rheumatoid Arthritis
Most commonly affects individuals in their mid-40's to early 50's.
Affects women 3x more often than men.
Stages of RA
Stage 1 - antigens presented, no clinical symptoms
Stage 2 - T/B cells proliferate, cytokines are released, clinically may feel unwell or have joint pain and/or swelling
Stage 3 - synovial hypertrophy, clinically more joint pain and swelling, malaise, low energy
Stage 4 - pannus invades the joint space, enzymatic damage to cartilage
Stage 5 - bone erosion, loss of cartilage, ligamentous damage. Clinically deformity.
Systemic Complaints of RA
Very similar to B-symptoms
Fevers (sometimes night sweats)
Extra-Articular Features of RA
When do Nodules Form?
Usually in patients with...
Strongly RF positive
In some patients on methotrexate
RA and Respiratory System
Pleural disease. (Pain when breathing in)
Interstitial lung disease.
You must examine the lungs for a patient with RA.
RA and Cardiovascular System
Pericardium. (Hurts to lie down as it stretches pericardium)
Problems with heart muscles
Problems with coronary arteries
RA and Vascular Disease
Can cause problems with small vessels, and can also cause accelerated atherosclerosis.
These can lead to ulcers and gangrene or in the bowel can cause perforation. In the eye, it can cause scleritis or episcleritis.
RA and Neurological System
Peripheral nerves may be affected because of the direct pressure that may occur around the swollen joints.
Median nerve may be affected by increasing pressure at the wrist which can result in carpal tunnel syndrome.
Associated with RA.
Causes chronic dry eyes, dry mouth, and other dry organs such as the lungs, vagina etc.