6: Rheumatoid Arthritis

Question 1

what is rheumatoid arthritis?

Answer 1

• a chronic autoimmune systemic illness characterised by a symmetrical polyarthritis and other systemic features.
• it affects commonly small joint of hands (MCPs, PIPs), wrists and feet (MTPs).

Question 2

RA epidemiology

prevalence, incidence, gender ratio, age of onset

Answer 2

• prevalence: approx 1% of population e.e. approx 4000 cases in Grampian
• incidence: approx 200 new cases in Grampian/annum
• F:M 3:1
• age of onset: peak age 40-50s but may occur at any age from 16 years

Question 3

RA aetiology

Answer 3

• genetic: HLA-DRB1 (shared epitope)
• environmental: smoking, chronic infection e.g. periodontal disease, EBV and Parvovirus B19
• hormonal: early age at menopause, low testosterone level in men

Question 4

symptoms of RA

Answer 4

• pain
• stiffness > 30mins
• immobility
• poor function
• systemic symptoms: lethargy, malaise, multi-organ involvement

Question 5

clinical signs of RA

Answer 5

• joint swelling
• tenderness
• warmth, redness
• limitation of movement

Question 6

RA investigations

Answer 6

• baseline bloods: FBC, kidney function, LFTs, CRP and ESR
• immunology: rheumatoid factor, anti CCP, ACPA.
• imaging: x-ray

Question 7

severity of RA and the efficacy of treatment are often monitored using which score?

Answer 7

disease-activity (DAS) score

Question 8

interpret the DAS-28 scores

Answer 8

• < 2.6 disease remission
• 2.6-3.2 low disease activity
• 3.2-5.1 moderate disease activity
• 5.1 or greater is high disease activity

Question 9

list the different categories of therapeutics used to treat RA

Answer 9

• NSAIDs
• disease modifying anti-rheumatic drugs (DMARD)
• biologics
• corticosteroids (oral, i-m, i-a)

Question 10

list some DMARDs used to treat RA

non-biologic

Answer 10

• methotrexate
• sulfasalazine
• hydroxychloroquine
• leflunomide

Question 11

list some biologics used to treat RA

Answer 11

• TNF-alpha inhibitors
• IL-1 inhibitors (Anakinra)
• anti B cell therapies (CD20, Rituximab)
• Anti T cell therapies (Abatacept)
• IL-6 inhibitors (tocilizumab, sarilumab)
• oral kinase inhibitors