SLE

Question 1

epidemiology of SLE

Answer 1

affect F>M (10:1)
affect reproductive age (13 - 40; more on 18-40)
african american and asian >
more common in family where one member already has the disease
most are sporadic cases

Question 2

pathogenesis of SLE

Answer 2

autoantibodies + self antigens form immune complexes -> deposite/ forms in peripheral tissues -> initiating inflammatory reaction -> activates complements, recruit inflammatory cells

Question 3

Etiology of SLE

Answer 3

genetic

• commonly associated with HLA-B8/DR2
• 10x in first degree relatives

estrogen
- pre-pubertal/post-menopausal women have similar incidence to men
more in female
associated with OCPs/ HRT
men with SLE have increase concentration of estrogenic metabolites
(androgen treatment may help)

Ultraviolet B radiation

infection - HBV, HTLV-1
extreme stress

Drugs (remit when drug stoppes, symptoms limited to skin and lung, no renal/ CNS)
- phenytoin (anti-convulsants), hydralazine (anti-HTN), procainamide (anti-arrhythmics), isoniazid (INH), biologics,
-

Question 4

what is the dx criteria of SLE

Answer 4

4,7,11 rule (more then 4 out of 11 criteria; 7 clinical + 4 lab)

= 4 criteria (>/= 1 clincila and 1 immunological) or biopsy proven lupus nephritis with +ve ANA/ anti-DsDNA Ab

Question 5

what are the clinical dx criteria of SLE

Answer 5

acute cutaneous lesion

• *photosensitivity (skin rash as an unusal reaction to sunlight)
• *malar rash (fixed erythema, flat/raised, over malar eminence, spare nasolabial fold (vs. seborrheic dermatitis: involve nasolabial fold + scalp), no scaring
• maculopapular lupus rash
• txoic epidermal necrolysis variant of SLE
• bullous lupus

chronic cutaneous lesion
- discoid lesion: erythematous raised patched with adherent keratotic scalig & follicular plugging, may scar due to invasion of basement membrane (localised is above neck, generalised is above and below neck)
- hypertrophic lupus
lupus pannicululitis: inflam of subcut adipose tissue
- mucosal lupus

non scaring alopeica

oral/nasopharyngeal ulcers: painless
arthritis - non erosive >/= 1 peripheral jts
serositis: pleural effusion, pericardial efusion

neuro:

• sezure, psychosis*
• mononeuritis multiplex, myelitis, peripiheral/ cranial neuropathy, acute confusion state (in absence of other cuase: primary vasculitis, infeciton, DM, toxic/metabolic, uremia, drugs)

Question 6

what are the lab crtieria of SLE

Answer 6

renal
- proteinuria: 24 hour protein > 500 mg
- urine protein creatitine ratio = 500 mg /24 hour
red blood cell casts

hemolytic anaemia,
leukopenia, (

Question 7

What is SLE

Answer 7

chronic multisystem autoimmune inflammatory disease characterized by relapse and remission + production of autoantibodies of unknown etiology