Mini Symposium: Multisystem Autoimmune Disease Flashcards
Name some connective tissue diseases?
- Systemic Lupus Erythematosus
- Systemic sclerosis
- Sjogren’s syndrome
- Auto-immune myositis
- Mixed connective tissue disease
Name some systemic vasculitides?
- Giant cell arteritis
- Granulomatosis with polyangiitis (Wegeners)
- Microscopic polyangiitis
- Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
What is the approach to diagnosing a patient with multisystem inflammatory disease?
•Cardinal clinical features: history & examination •Bedside investigations •Immunology •Imaging •Tissue diagnosis Exclusion of differential diagnoses
What are some mimics of multi system inflammatory disease?
- Malignancy - lymphoma
- Infections - endocarditis, hepatitis B and C, TB, HIV
- Drugs - cocaine, Minocyline, Propylthiouracil
Rarer:
•Cardiac myxoma
•Cholesterol emboli
•Scurvey
Who gets SLE?
- Female:Male 9:1
- Onset - 15-50 years
- Afro-Caribbean>Asian>Caucasian
What are the genetic factors that cause SLE?
- High concordance in monozygotic twins
- Sibling risk for developing SLE is 30-fold higher than in the general population
- Polygenic mode of inheritance
What are the environmental factors that cause SLE?
- UV light
- Drugs
- Infections
What other factors may cause SLE?
Hormonal
Describe the pathogenesis if SLE
- Immune response against endogenous nuclear antigens (break in immunological tolerance)
- Immune complex formation
- Complement activation
- Tissue injury
What is the classification criteria for lupus?
4 of the following:
1) Malar rash (butterfly rash)
2) Discoid rash (raised, scarring, permanent marks, alopecia)
3) Photosensitivity
4) Oral ulcers
5) Arthritis (2 joints at least)
6) Serositis (pleurisy or pericarditis)
7) Renal (significant proteinuria or cellular casts in urine)
8) Neurological (unexplained seizures or psychosis)
9) Haematological (low WCC, platelets, lymphocytes, haemolytic anaemia)
10) Immunological (anti ds-DNA, Sm, cardiolipin, lupus anticoagulant, low complement)
11) ANA (anti-nuclear antibody)
How is kidney involvement classed in SLE?
•Lupus nephritis important cause of morbidity and mortality •Renal involvement can be single organ involvement I - minimal mesanginal II - mesanginal proliferative III - focal IV - diffuse V - membranous VI - advanced sclerosing
When to consider a diagnosis of SLE?
- Usually seen in women of childbearing age with
- Constitutional symptoms of fever, weight loss, malaise, and severe fatigue
- Skin rash and/or stomatitis (mouth and lips)
- Arthritis
- Pleuritic chest pain
- Renal disease
- Cytopenia
What are the autoantibodies seen in SLE?
- ANA
- Anti-ds DNA
- Anti-Sm (Smith)
- Anti-Ro
- Antiphospholipid antibodies
What percentage of SLE cases have a positive ANA?
95%
What makes ANA testing less useful in diagnosing SLE?
- Not specific for SLE
- Seen in many inflammatory, infectious, and neoplastic diseases
- Seen in 5% to 15% of healthy population
What percentage of SLE cases are positive for anti-ds (double-stranded) DNA?
- 60%
* Highly specific for SLE
What is anti-ds DNA closely associated with?
Nephritis
What percentage of SLE cases are positive for anti-sm (Smith)?
- 10-30%
* Highly specific for SLE
What is the clinical significance of being positive for anti-Ro autoantibody?
- Risk of foetal congenital heart block
- Neonatal lupus
- Foetal cardiac monitoring from 16weeks onwards
What is the clinical significance of being positive for antiphospholipid antibodies?
- Arterial/venous thrombosis
* Miscarriages
What types of antiphospholipid antibodies are relevant to SLE?
- Anti-cardiolipin
* Lupus anticoagulant
What is systemic sclerosis also known as?
Scleroderma (fibrosis of skin and internal organs)
How can scleroderma be classified?
•Localised scleroderma
•Systemic sclerosis (SSc):
-Limited cutaneous systemic sclerosis (CREST)
-Diffuse cutaneous systemic sclerosis
What is localised scleroderma limited to?
Fibrotic involvement of the skin and subcutaneous tissue - should be reassured no risk of systemic involvement
How are limited cutaneous systemic sclerosis (CREST)
and diffuse cutaneous systemic sclerosis defined?
- Limited - skin involvement distal to knees and elbows (slow progression)
- Diffuse - skin thickening proximal to knees and elbows and trunkal involvement (fast progression with organ involvement - usually lungs)