Rheumatoid Arthritis

Question 1

Explain the pathophysiology of Rheumatoid Arthritis

Answer 1

Genetic predisposition by HLA DR4 plus environmental triggers (infection or smoking) causes citrullination, a change from alanine to citrulline which causes activation of T cells and macrophages and results in a change in cytokine production. Increase in TNF alpha and IL-6 which results in pannus formation (invasive synovial tissue which is inflammatory).
Abnormal cytokines also lead to activation of osteoclasts which cause erosion and damage in the joint. Also get abnormal systemic effects

Question 2

What is the epidemiology and symptoms of RA?

Answer 2

• Commonly affects women with age of onset between 30-60 years. Disease more aggressive in African-Americans/Hispanic.
• Symptoms: Pain, early morning stiffness with joint gelling (stiffness with rest), swelling, small joints more likely to be affected in symmetrical pattern.

Question 3

What are the signs of Rheumatoid arthitis

Answer 3

• Synovitis (boggy swelling)
• Deformities: Swan neck, boutonniere, Z thumb and ulnar deviation.
• Rhumatoid nodules

Question 4

What are the differentials for Rheumatoid arthritis?

Answer 4

• Polyarticular gout,
• Psoriatic arthritis,
• Osteoarthritis,
• SLE

Question 5

Explain the investigations for Rheumatoid Arthritis

Answer 5

• Bloods (FBC, ESR/CRP and Urate)
• Immunology (rheumatoid factor and anti-citrullinated cyclic peptide antibodies (CCP ab))
• Imaging (plain radiograph, ultrasound for synovitis and MRI)

Question 6

Explain the indications of rheumatoid factors and anti-CCP antibodies

Answer 6

• Rheumatoid factor is an IgM antibody directed against Fc region of IgG. It is found in many autoimmune diseases and infections.
• Chronic inflammation leads to enzymatic process where alanine is converted to citrulline. Alteration of protein shape causes antibody formation and the anti-citrullinated cyclic peptide antibodies form

Question 7

What are the early and late changes of rheumatoid arthritis seen on X ray?

Answer 7

Early - x ray likely to be normal.
First changes - Peri-articular osteopenia and soft tissue swelling.
Late changes - Erosion, joint destruction and subluxation

Question 8

Explain the treatment of Rheumatoid Arthritis

Answer 8

• Reduce inflammation via use NSAIDs (ibuprofen or naproxen), COX-2 inhibitors (Etoricoxib) or steroids (IM or IA either Depomedrone or Kenalog)
• Offered DMARD within 3 months of symptoms onset, either: methotrexate, leflunomide, sulfasalazine or hydroxychloroquine for mild disease.

Question 9

Describe features of methotrexate?

Answer 9

Folate antagonist given once weekly. Side effects are often mucosal or GI effects but can cause pneumonitis. Requires monitoring of FBC and LFTs and contraindicated in pregnancy

Question 10

Describe features of sulfasalazine

Answer 10

• Immunomodulatory drug with several actions including activity against folate, T and B cells. Taken daily and can cause GI effects, headaches and rash. Requires monitoring of FBC, U+Es and LFTs but CAN be used in pregnancy

Question 11

Describe features of hydroxychloroquine

Answer 11

It blocks toll like receptors on plasmacytoid dendritic cells, reducing dendritic cell activation. Taken daily and can cause headaches, muscle pain and rash. Ocular monitoring for retinopathy and safe in pregnancy

Question 12

How can you monitor rhumatoid arthritis?

Answer 12

Via DAS28 scores. It looks at joint tenderness, swollenness, ESR, CRP and patient global health (how they feel they are). However doesn’t include feet/ankles

Question 13

What are the required screening, monitoring and contraindications for biologic DMARDs?

Answer 13

Screening - Screen for viral hepatitis and HIV, ensure to ask about varicella and give vaccine if not had chicken pox. Do CXR and IGRA for TB and give vaccines.
Monitor - For infections, malignancy, FBC, and LFTSs.
Contraindicated - If active infection, if active or latent TB infection, pregnancy, malignancy or IL6 inhibitors in diverticular disease

Question 14

Explain the use of OT, physio and nurses in management of patient with RA?

Answer 14

OT - Assess grip strength, splinting and work assessments.
PT - Joint protection, injections and exercises to improve range of motion.
Nurses - Disease assessment, monitoring and helpline.
Podiatry may also be involved.

Question 15

What are the genetic factors involved in rheumatoid arthritis?

Answer 15

HLA -DR1
HLA-DR4

Question 16

What are the cellular components of a pannus?

Answer 16

Synovial cells and immune cells form a pannus which is a swollen synovial membrane with granulation tissue. Overtime the pannus damages cartilage and bone.