Sero-positive inflammatory arthritis (excluding RA)

Question 1

Define sero-positive inflammatory arthritis

Give three examples

Answer 1

Inflammatory arthropathies that test positive for rheumatoid factor

Includes:

• Rheumatoid arthritis
• Systemic lupus erythematosus (SLE)
• Sjorgren’s syndrome
• Bacterial and viral infections ^eg. septic arthritis

Question 2

What is Systemic lupus erythematosus (SLE)?

Answer 2

A multi-systemic autoimmune disease featuring autoantibodies against a variety of autoantigens (ANA).

Insufficient phagocytosis of these ANAs causes secretion of pathogenic autoantibodies, resulting in a tissue damage.

Question 3

Name three risk factors for SLE

Answer 3

• Female (9:1) - especially pre-menopausal
• Aged 20-40
• Afro-Caribbean and Asian ethnicity
• HLA B8, DR2, DR3 associated
• FHx in 1^o relatives
• Epstein-Barr virus

Drug-induced lupus

UV light - can trigger flares

Question 4

Name three causes of drug-induced lupus

How does drug-induced lupus differ from typical SLE?

Answer 4

• Hydralazine: HTN vasodilator
• Isoniazid
• Procainamide: Class Ia antiarrhythmic
• Penicillamine: Wilson’s disease treatment
• Anti-TNF

Drug-induced lupus is usually mild as it does not affect the kidneys or CNS. 95% positive for anti-histone antibodies

Question 5

Give five presenting features of systemic lupus erythematosus

Answer 5

High variable presentation between patients.

• Non-specific symptoms of fatigue, malaise, myalgia, fever
• Symmetrical small joint arthralgia
• Photosensitive malar/butterfly rash; Discoid rash; alopecia
• Recurrent pleurisy and pleural effusions, ILD
• Pericarditis; Libman-Sacks endocarditis
• Lupus nephritis; end-stage renal disease
• Depression, psychosis, epilepsy, migraines, cerebellar ataxia, aseptic meningitis, stroke
• Sjogren’s (15%), retinal vasculitis
• Mouth ulcers

Question 6

How is systemic lupus erythematosus diagnosed?

Answer 6

4 of 11 of the following: SOAP BRAIN MD

• Serositis: Pleurisy or pericarditis
• Oral ulcers
• Arthritis: Non-erosive, 2+ peripheral joints
• Photosensitivity
• Blood disorders: Leukopenia, lymphopenia, thrombocytopenia
• Renal (lupus nephritis): Proteinuria (>0.5g/d) or cellular casts
• ANAs (95%)
• Immune: Anti-dsDNA (70%), anti-Sm, or anti-pl antibodies
• Neurological: Seizures or psychosis
• Malar rash
• Discoid rash

Question 7

What markers are used to monitor progression of SLE?

Answer 7

• Raised Anti-dsDNA
• Reduced C3 and C4
• Raised ESR

Question 8

Request three investigations for suspected SLE

Answer 8

• FBC: Leukopenia, lymphopenia, thrombocytopenia
• Normal CRP and raised ESR
• U+Es; Urinalysis: Proteinuria and cellular casts
• ANA; Anti-dsDNA; Anti-Sm (most specific)
• Anti-phospholipid: associated with antiphospholipid syndrome

Question 9

Outline the management of SLE

Answer 9

• Avoid excessive exposure to sunlight
• Reduce increased cardiovascular risk
• Many respond well to NSAIDs, and do not need steroids or immunosuppresive agents
  
  • Maintenance: NSAIDs, hydroxychloroquine (retinal tests), azathioprine
  • Cutaneous lupus: Topical steroids
  • Severe flares: Urgent IV cyclophosphamide + high-dose prednisolone/single dose IM long-acting steroid
  • Lupus nephritis: ACEi
  • If glomerulonephritis on Bx, high-dose prednisolone + cyclophosphamide/mycophenolate

Question 10

What is anti-phospholipid syndrome?

Answer 10

• Autoimmune coagulation disorder
• Thrombosis and/or recurrent miscarriages
• Persistently positive tests for anti-phospholipid antibodies

Question 11

Describe the clinical features of anti-phospholipid syndrome

Answer 11

• Coagulation defect ^eg. DVT; stroke
• Livedo reticularis: reticular cyanotic discolouration
• Recurrent miscarriage
• Thrombocytopenia: increased APTT

Question 12

How is anti-phospholipid syndrome diagnosed?

Answer 12

Both:

• Hx of thrombosis and/or recurrent miscarriage
• One positive blood test:
  
  • Anticardiolipin test
  • Lupus anticoagulant test
  • Anti B2-glycoprotein I test

Question 13

Describe the management of anti-phospholipid syndrome

Answer 13

Treat if patient has had at least one thrombosis

• Low-dose aspirin or warfarin (Target INR 2-3)
• If pregnant, give aspirin and LMWH in early gestation
  
  • Does not prevent pre-eclampsia or poor foetal growth

Question 14

Define Sjogren’s syndrome

Answer 14

• A chronic inflammatory autoimmune disorder
• Lymphocytic infiltration and fibrosis of exocrine glands
  
  • esp. lacrimal and salivary glands

Question 15

What is primary Sjogren’s syndrome?

Answer 15

Syndrome of dry eyes

In the absence of RA or any autoimmune disease

Anti-Ro (90% in primary, 10% in secondary)

Question 16

Give two risk factors for Sjogren’s syndrome

Answer 16

• Female 9:1
• Commonest onset 40-50yrs
• Associated with lymphoma (40x increased risk)

Question 17

Give three presenting features of Sjogren’s syndrome

Answer 17

• Majority only dryness (eyes, mouth, vagina) and fatigue
• Parotid and salivary gland enlargement may be seen
• Minority have systemic symptoms such as:
  
  • Arthralgia
  • Raynaud’s phenomenon
  • Dysphagia and dry cough

Other organ-specific autoimmune disease ^eg. thyroid disease, myasthenia gravis, PBC, autoimmune pancreatitis

Question 18

How is Sjogren’s syndrome investigated?

Answer 18

• Schirmer tear test
  
  • <10mm in 5 min suggest defective tear production
• Rose Bengal staining
• Immunology:
  
  • RF positive
  • ANA (80%)
  • Anti-Ro: (60-90% in primary Sjogren’s)
  • Anti-La

Question 19

Outline the management of Sjogren’s syndrome

Answer 19

Symptomatic treatment:

• Dry eyes: artificial tears, avoid smoke filled rooms
• Dry mouth: good oral hygiene, regular drinks, sugar-free lozenges, artificial saliva
• Arthralgia: NSAIDs, hydroxychloroquine

Question 20

How does viral arthritis differ from bacterial arthritis?

Answer 20

• Arthritis in viral disease is generally a transient polyarthritis
  
  • Occuring before, during, or after many viral illnesses
• Bacterial causes of septic arthritis are a medical emergency