Systemic Lupus Erythematous (SLE)

Intro

- Multi-systemic autoimmune disorder

- Auto-Ab vs.  auto-antigen

Aetiology

- Cause: unknown, probably triggered by viral infection

- In genetically predisposed individuals

Epidem

Prevalence ~0.2%

Young F (F:M=10:1)

20-30yo

Higher incidence in African and Asians

Revised criteria for diagnosing SLE – > 4 out of 11

Mnemonics: ‘ A RASH POINts an MD’

A	Arthritis	Non-erosive arthritis (90%) a)        > 2 joints (tenderness, swelling, effusion) b)        Jaccoud’s arthropathy d/t capsular laxity – reversible deformity
R	Renal	Renal disorder a)        Persistent proteinuria >0.5 g/d (or > 3+ on dipstick) b)        Cellular casts
A	ANA	Anti-nuclear Ab (95%)
S	Serositis	Serositis a)      Pleuritis b)      Pericarditis
H	Haematological	Haematological disorder a)      Haemolytic anaemia b)      Leukopenia               <4.0X109/L on > 2 occasions c)       Lymphopenia           <1.5X109/L on > 2 occasions d)      Platelet                       <100—X109/L
P	Photo	Photosensitivity
O	Oral	Painless oral ulcer
I	Immune	Immunological disorder a)      Anti-dsDNA – exclusive to SLE (60%) b)      Anti-Sm, Anti-Rho, Anti- RNP (ribonucleoprotein) c)       Anti-phospholipid Ab
N	Neuro	CNS disorder a)      Seizures b)      Psychosis
M	Malar	Malar rash (butterfly rash) (33%) a)      Fixed erythema over malar eminence b)      Spare nasolabial fold
D	Discoid	Discoid rash a)      Erythematous raised patches b)      Sites: scalp, forehead, cheek, ear, chest c)       3 stages rash                                         i.      Erythema                                       ii.      Pigmented hyperkeratotic oedematous papules                                     iii.      Atrophic depressed lesion

Other signs and symptoms (Not in criteria)

1. Low grade fever

2. Fatigue

3. Urticaria

4. Vasculitic lesions

5. Raynaud's phenomenon

6. Sjogren's syndrome

7. Myopathy

I(X)

1.       FBC – haemolytic anaemia, leukopenia, lymphopenia, thrombocytopenia

2.       ↑ ESR, CRP – normal, CRP ↑ if serositis

3.       C3, C4 ↓, but C3d, C4d ↑ (degradation product)

4.       Serology

a.       ANA +ve             95%

b.      anti-dsDNA       60%

c.       Rh F +ve             40%

*false +ve syphilis d/t anti-cardiolipin Ab

5.       Urinalysis – protein, cell casts

6.       U&E

7.       LFT

8.       Direct Coombs test-AIHA

9.       Skin / renal biopsy

Treatments

Non-pharmacological

1.       Avoid direct exposure to sunlight to prevent flares

2.       Use sunblock cream at least SPF>30

3.       Wear long sleeves

4.       Avoid sport activities in the sun

5.       Avoid OCP as it is associated with increased risk for clot formation (especially in anti-phospholipid syndrome)

6.       Advise regarding steroid therapy-compliance and side effects

Pharmacological

1.       NSAIDs

- useful for patients with mild disease and with arthralgia

2.       Chloroquine/hydrochloroquine

- in joint / skin symptoms uncontrolled by NSAIDS

- Dose      : 200-400mg/d PO

- SE           : Irreversible retinopathy

3.       Corticosteroids

-the mainstay of treatment. Particularly in moderate-severe disease

Dose: 30 mg/day for 4/52 before gradually reducing the dose

4.       Immunosuppressives

- e.g  azathioprine, cyclophosphamide: are used for severe SLE, example if there is renal or neurological manifestation

5.       High dose prednisolone PO/IV + DMARDS

- often used with IV cyclophosphamide

For severe flares of SLE

·         Haemolytic anaemia

·         Nephritis

·         Severe pericarditis

·         CNS disease

- Maintainance therapy : Azathioprine

   SE: BM supression, GI disturbance, pancreatitis

6.       Topical steroids: are used for discoid lupus