Rheumatoid arthritis - causes, symptoms, diagnosis, treatment, pathology

Summary

This video provides an in-depth explanation of rheumatoid arthritis, a chronic autoimmune disorder that primarily affects the joints. It covers the disease's mechanism, where the immune system mistakenly attacks joint tissues, leading to inflammation, cartilage damage, and bone erosion. The script explores genetic and environmental triggers, the role of immune cells, and how antibodies contribute to joint destruction. It also highlights common symptoms, joint deformities, extra-articular complications, and diagnostic methods. Finally, it outlines treatment options, including disease-modifying drugs, biologics, and anti-inflammatory medications for managing flares.

Takeaways

• 🦠 Rheumatoid arthritis is a chronic, autoimmune inflammatory disorder that mainly affects joints but can also involve other organs like the skin, lungs, and heart.
• 🦴 Healthy joints are protected by articular cartilage and synovial fluid, which help bones glide smoothly and reduce friction.
• 🧬 Rheumatoid arthritis is triggered by a genetic predisposition and environmental factors, leading to an autoimmune response that attacks the body's own tissues.
• 🧪 The immune response involves proteins like citrullinated vimentin and collagen, causing the immune system to target these as foreign antigens.
• 🔬 Activated immune cells produce cytokines that cause inflammation in the joints, leading to the formation of a pannus that damages cartilage and bone.
• 🧫 Antibodies like rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) form immune complexes that contribute to joint inflammation.
• 💉 The condition also causes extra-articular symptoms such as fever, muscle weakness, rheumatoid nodules, and increased risk of heart disease and lung problems.
• 🖐️ Rheumatoid arthritis typically affects multiple joints symmetrically, particularly the small joints in the hands and feet, leading to deformities over time.
• ⚕️ Diagnosis is based on blood tests for antibodies (RF and CCP) and imaging that shows joint damage and bone erosion.
• 💊 Treatment includes disease-modifying antirheumatic drugs (DMARDs) like methotrexate and biologics, along with anti-inflammatory medications for acute flares.

Q & A

What is rheumatoid arthritis?

Rheumatoid arthritis is a chronic, inflammatory autoimmune disorder that primarily affects the joints but can also involve other organs such as the skin and lungs.

How does rheumatoid arthritis affect a healthy joint?

In a healthy joint, two bones are covered with articular cartilage, which acts as a cushion for smooth movement. Rheumatoid arthritis causes inflammation of the synovial membrane, leading to joint damage, cartilage breakdown, and bone erosion.

What is the role of the synovial membrane in joints?

The synovial membrane lines the joint capsule, produces synovial fluid to lubricate the joint, and helps remove debris from the joint space.

What triggers rheumatoid arthritis?

Rheumatoid arthritis is typically triggered by a combination of genetic susceptibility, such as the presence of HLA-DR1 and HLA-DR4 genes, and environmental factors like smoking or bacterial infections, which can cause modifications to proteins in the body.

What is citrullination and how is it related to rheumatoid arthritis?

Citrullination is a process where the amino acid arginine is converted into citrulline in certain proteins. In rheumatoid arthritis, this modification confuses immune cells, leading to an autoimmune response against these proteins.

How does the immune system contribute to joint damage in rheumatoid arthritis?

Immune cells like T-helper cells and antibodies enter the joint, releasing cytokines that recruit inflammatory cells. This leads to the formation of a pannus, which is a thickened synovial membrane that damages cartilage and bone over time.

What is the role of rheumatoid factor (RF) and anti-CCP antibodies in rheumatoid arthritis?

Rheumatoid factor (RF) is an IgM antibody that targets altered IgG antibodies, and anti-CCP antibodies target citrullinated proteins. Both antibodies form immune complexes in the joint, contributing to inflammation and joint damage.

What are some common deformities seen in rheumatoid arthritis?

Common deformities include ulnar deviation of the fingers, boutonniere deformity, and swan neck deformity, which affect the metacarpophalangeal and interphalangeal joints.

How is rheumatoid arthritis diagnosed?

Rheumatoid arthritis is diagnosed using blood tests that detect rheumatoid factor and anti-citrullinated peptide antibodies. Imaging studies like X-rays show joint damage, soft tissue swelling, and bone erosions.

What treatments are available for rheumatoid arthritis?

Long-term treatment includes disease-modifying antirheumatic drugs (DMARDs) like methotrexate, biologics such as abatacept and adalimumab, and medications that block inflammatory cytokines. Acute flares are treated with NSAIDs and short-term glucocorticoids.