Rheumatoid arthritis
How an autoimmune response turns the thin lining of synovial joints into an invasive, inflamed tissue that erodes cartilage and bone, why it affects small joints symmetrically, and why it is a disease of the whole body.
By the end, you can
- Describe the normal synovium and its role in a synovial joint.
- Explain how genetic risk, smoking and citrullinated proteins lead to autoantibodies such as anti-CCP.
- Explain how synovitis and pannus erode cartilage and bone.
- Relate prolonged morning stiffness, symmetrical small-joint swelling and deformities to the mechanism.
- Describe the main effects of rheumatoid arthritis outside the joints.
- Recognise pannus and rheumatoid nodules, apply the ACR/EULAR criteria and the antibody tests, and explain how each main treatment acts on the mechanism.
What it is
Rheumatoid arthritis is a chronic autoimmune disease in which the synovium of many joints becomes inflamed and hypertrophied, typically in a symmetrical pattern affecting the small joints of the hands and feet. Untreated, the inflamed synovium erodes cartilage and bone. It also causes inflammation and damage beyond the joints.
2 types to tell apart
- Seropositive
- Rheumatoid factor and/or anti-CCP antibodies present; tends to be more erosive.
- Seronegative
- Neither antibody detected; the diagnosis rests on the clinical pattern and imaging.
Normal function
The synovial lining
Synovial joints are enclosed by a capsule lined with synovium, a delicate layer only one to three cells thick over loose connective tissue with blood vessels. Its cells make synovial fluid, which lubricates and nourishes the articular cartilage, and remove debris from the joint.
In the hand, synovial joints include the wrist (within the ), the knuckles between the and the (metacarpophalangeal joints), and the joints between the phalanges. Tendons running over them also have synovial sheaths.
Normally the synovium contains few immune cells, and immune tolerance prevents responses against the body’s own proteins.
Underlying change · Step 1 of 4
Autoimmunity begins years before the joints
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 2 of 4
Synovitis and pannus
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 3 of 4
Joint destruction and deformity
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 4 of 4
A disease of the whole body
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Symptoms and signs
Symptoms, signs and findings
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Exam detail
Exam detail
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Treatment
How treatment works
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Recap
Recap
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Self-check
Check your understanding
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .