Rheumatoid arthritis

Question 1

what is the definition of rheumatoid arthritis?

Answer 1

Rheumatoid arthritis (RA) is a chronic inflammatory condition affecting around 1% of the population, making it the most common inflammatory arthritis seen by physicians. It primarily symmetrically affects the small joints of the hands and feet and, if not treated aggressively, can be a major cause of work loss, decreased quality of life, need for joint replacement surgery, and mortality

Question 2

what is the epidemiology of rheumatoid arthritis?

Answer 2

1% of population
More common in females
peak between 30 and 50 yrs
increased prevalence in smokers

Question 3

what is the aetiology of rheumatoid arthritis?

Answer 3

The aetiology of RA is unknown
Genetics:
The presence of a major histocompatibility complex class II allele human leukocyte antigen (HLA), DRw4, is more common in patients with RA. These HLA alleles code for a shared amino acid sequence that has been named the shared epitope, which may be involved in the pathogenesis of RA. Certain genetic variants of PTPN22 and other genes have been identified as a risk factor for RA.
Infection:
An infection as a triggering factor for RA in genetically susceptible individuals has been proposed, but no specific infectious agent has been identified. Triggers:
- T cells - interferon, IL-2 & -4 
- Macrophages - IL-1 & -8 & TNF-alpha 
- Mast cells - histamine & TNF-alpha 
- Fibroblasts - IL-6

Question 4

what are the risk factors of RA?

Answer 4

Family history
Smoking
Middle age onwards

Question 5

what is the pathophysiology of RA?

Answer 5

Inflamed synovium is central to pathogenesis. The synovium shows increased angiogenesis, cellular hyperplasia, influx of inflammatory cells, changes in the expression of cell surface adhesion molecules, and many cytokines. The synovial lining becomes hyperplastic, with infiltration of the sublining with mononuclear cells including T cells, B cells, macrophages, and plasma cells. This formation of locally invasive synovial tissue is characteristic and it is involved in causing the erosions seen in RA.

Question 6

what are the key presentations of RA?

Answer 6

Symmetrical small joints in hand and feet (No spinal involvement) - MCP and PIP, MTP of feet, wrists elbows, shoulders, knees, ankles
Aged 50-55
Female
Joint pain and swelling
slowly progressive

Question 7

what are the signs of RA?

Answer 7

Aged 50-55
Female
hand deformities:
ulnar deviation, swan neck, Z thumb, boutonniere deformity

Question 8

what are the symptoms of RA?

Answer 8

Joint pain and swelling
Joints are warm and tender
Morning stiffness more than 30 mins
Worse in cold

Question 9

what are the first line and gold standard investigations for RA?

Answer 9

FBC - normocytic normochromic anaemia
CRP - raised
RF - raised (sometimes falsely positive)
Anti CCP - raised (70% are pos)
Radiographs - erosions
Ultrasonography - synovitis of wrist and finger

Question 10

what other investigations are there for RA?

Answer 10

X Rays - only if a long history, changes over time, soft tissue swelling, periarticular osteopenia, joint space narrowing, bone erosion

Question 11

what are the differential diagnoses for RA?

Answer 11

Psoriatic arthritis, infectious arthritis, gout

Question 12

how is RA managed?

Answer 12

Stop smoking advice
Reduce weight
Suppress inflammation to prevent damage - given quick
Methotrexate
Sulphasalazine
Leflunomide
Hydroxychloroquine
Pain management - NSAIDs, Paracetamol, opioids
Corticosteroids - can cause osteoarthritis
Biological therapy - TNF alpha blockers (infliximab, etenercept, adalimumab), B cell inhibitors (rutiximab), IL blockers (tocilizumab), T cell activation blockers (abatacept)

Question 13

how is RA monitored?

Answer 13

Careful monitoring of disease activity and adverse effects related to multiple medication use is essential.
Laboratory monitoring
Hepatitis B and C status, purified protein derivative (PPD), full blood count (FBC), and liver function tests (LFTs) need to be checked before starting disease-modifying antirheumatic drugs (DMARDs). Laboratory monitoring for FBC and LFT abnormalities is done every 4 to 8 weeks at the start of treatment. When the patient is on a stable dose, they should be checked every 3 to 4 months

Question 14

what are the complications of RA?

Answer 14

Work disability, increased joint replacement surgery, CAD

Question 15

what is the prognosis of RA?

Answer 15

Bad if big joints involved early on 
Disability increases over time due to joint inflammation 
Premature mortality (CV stress increased)