SLE

Question 1

American Rheumatism Association criteria for SLE

Answer 1

1. Malar rash - sparing the nasolabial folds
2. Discoid rash
3. Photosensitivity rash
4. Oral ulcers
5. Arthritis - non-erosive and affecting 2 or more peripheral joints
6. Serositis - pleurisy or pericarditis with audible rub, effusion or ECG changes
7. Renal disorder - persistent proteinuria >5g/day or cellular casts
8. Neurological disorder- seizures or psychosis not related to drugs or metabolic abnormalities
9. Haematological disorder - haemolytic anaemia, leukopenia, lymphopenia, thrombocytopenia
10. Immunological disorder - anti-DNA antibodies; anti-smith antibodies; positive anti-phospholipid antibodies
11. Abnormal ANA >1:160
    * 4 or more manifestations of the 11 must be present serially or simultaneously

Question 2

Summary of system’s review for SLE

Answer 2

Apthous ulcers
Serositis
Raynaud’s
Alopecia
Photosensitivity rashes
Dry eyes and mouth
Thrombosis 
Miscarriages 
Nephritis

Question 3

Drugs inducing SLE

Answer 3

Procainamide (most patients are ANA positive within 1 year; 15-20% develop SLE)
Hydralazine (most patients are ANA positive within 1 year; 5-10% develop SLE)
Isoniazid*
Methyldopa*
Penicillamine*
Chlorpromazine*
Anticonvulsants, particularly phenytoin*
*Rarely cause overt SLE, but ANA is commonly positive

Question 4

Antibodies associated with SLE

Answer 4

Anti-single stranded DNA
Anti-dsDNA - high titres are specific
Anti-Sm - specific for SLE

Question 5

Features of mixed connective tissue disease

Answer 5

1. Overlapping features of SLE, polymyositis and systemic sclerosis
2. Height titre of anti-U1-RNP antibodies
3. Pericardial effusion
4. Raynaud’s, swollen hands, fatigue, arthritis
5. Pulmonary Arterial HTN (main cause of death)
6. Treat symptoms with steroids, anti malarials, NSAIDs, immunosuppression (cyclophosphamide for PAH)

Question 6

Bloods in SLE

Answer 6

Anaemia - normochromic normocytic related to the chronic inflammatory process
ESR elevated but CRP normal
Leukopenia (especially lymphopenia)
Lupus anticoagulant & anticardiolipin antibodies
Thrombocytopenia