Rheumatoid Arthritis

Question 1

Presentation RA:

Answer 1

• stiffness worse in morning
• gradually gets worse and larger joints involved
• develops over few months
• positive squeeze test
• late: swan neck and boutonnières deformities
• rare: systemic

Question 2

Prognostic factors RA: (poor) 8

Answer 2

• rheumatoid factor positive
• poor functional status at presentation
• HLA DR4
• early erosions on x-ray
• extra articular features e.g. nodules
• insidious onset
• anti-CCP Ab
• female

Question 3

Rheumatoid factor:

Answer 3

• circulating Ab (usually IgM) which reacts with Fc portion of own IgG
• detect with Rose-Waaler test (sheep red agglutination) or Latex agglutination test (less specific)
• increased titre - severe progressive

Question 4

What is rheumatoid factor also associated with?

Answer 4

• Felty’s
• Sjogren’s
• infective endocarditis
• SLE
• systemic sclerosis
• general pop
• rarely TB, HBV, EBV, leprosy

Question 5

Anti-ccp Ab:

Answer 5

• up to 10 years before RA development
• early detection for anti-TNF therapy
• similar sensitivity but increased specificity to rheumatoid factor
• if rheumatoid factor negative, test anti-ccp

Question 6

Complications of RA:

Answer 6

• respiratory: pulmonary fibrosis, pleural effusion, pulmonary nodules, bronchiolitis obliterates, methotrexate pneumonitis, pleurisy
• ocular: keratoconjuncitvitis sicca, episcleritis, scleritis, corneal ulceration, keratitis, storied induced cataracts, chloroquine retinopathy
• osteoporosis
• ischaemic heart disease
• increased risk of infections
• depression
• less common: Felty’s syndrome, amyloidosis
• atlantoaxial subluxation - SCC

Question 7

What is Felty’s syndrome?

Answer 7

RA + splenomegaly + decreased WCC

Question 8

Management of RA:

Answer 8

Initial:

• DMARD mono therapy with/without short course prednisolone
• methotrexate (risk of myelosuppression and liver cirrhosis, pneumonitis)
• sulfasalazine, leflunomide, hydroxychloroquine
• monitor with CRP and disease activity e.g. DAS28
• flares: corticosteroids
• TNF inhibitors: if inadequate response to at least 2 DMARDs including methotrexate
• Rituximab
• Abatacept

Question 9

TNF inhibitors used in RA:

Answer 9

• etanercept - recombination human protein, decoy receptor for TNF alpha, subcutaneous (risk of demyelination and reactivation of TB)
• infliximab - monoclonal Ab, binds to TNF alpha, IV (risk of TB activation)
• adalimumab - monoclonal Ab, subcutaneous (reactivation of TB)

Question 10

Rituximab:

Answer 10

• anti-CD20 monoclonal Ab - B cell depletion
• 2, 1g IV infusions 2 weeks apart
• infusion reactions

Question 11

Abatacept:

Answer 11

• modulates T lymphocyte activation
• reduced proliferation + cytokine production
• infusion (reactions common)
• not recommended

Question 12

X-ray changes in RA:

Answer 12

Early:
-loss of joint space
-juxta articular osteoporosis
-soft tissue swelling 
Later:
-periarticular erosions
-subluxation