systemic lupus erythematosus Flashcards
diagnosis of SLE
at least 4/11 diagnostic criteria
skin:
1. malar rash/ butterfly rash after sun exposure
2. discoid rash - plaque like and can scar
3. general photosensitivity of the skin
mucosa:
4. ulcers of mouth and nose
serosa:
5. serositis: pleuritis around lungs or chest cavity or pericarditis, endocarditis or myocarditis
joints:
6. arthritis of two or more joints
kidneys:
7. renal disorders: abnormal urine protein, diffuse proliferative GN
brain:
8. neurological disorders causing seizures or psychosis
blood:
9. haematological disorders: anaemia, thrombocytopaenia, lauekopaenia
antibodies:
10. Antinuclear antibody: sensitive but not specific to SLE
11. other antibodies: anti-smith, anti-dsDNA, anti-phospholipid
affects of SLE on the skin
skin:
1. malar rash/ butterfly rash after sun exposure
2. discoid rash - plaque like and can scar
3. general photosensitivity of the skin
affects of SLE on the mucosa
- ulcers of mouth and nose
affects of SLE on the serosa
- serositis: pleuritis around lungs or chest cavity or pericarditis, endocarditis or myocarditis
epidemiology
women of reproductive age
highest in african descent
aetiology of SLE
genetic predisposition
hormonal factors: high oestrogen states e.g due to oral contraceptive use, postmenoupausal hormone therapy, endometriosis
environmental factors eg. cigarette smoking and silica exposure
uV light and EBV infection can trigger flares
drugs can cause drug induced lupus erythematosus
clinical features
can affect any organ
constitutional: fatigue, fever, weight loss
joints: arthritis and arthralgia, distal symmetrical polyarthritis (SLE does not lead to deformity unlike RA)
skin:
- malar rash: flat or raised erythema overr both malar eminences
- raynaud phenomenon
- photosensitivity
- discoid rash
- oral ulcers
- non scarring alopaecia
laboritory studies
antinuclear antibodies
antigen specific ANAs - request if ANAs are positive
Anti-dsDNA
- autoantibodies against double stranded DNA
- highly specific for SLE
- levels correlate with disease activity
Anti-Sm
- autoantibodies against smith antigens
- only positive in 30% but highly specific for SLE
anti phospholipid antibodies - screen all patients for anti phospholipid syndrome
lab markers of disease activity or active organ damage in SLE
decreased compliment levels
inflammatory markers: high ESR and CRP.
FBC may show leukopaenia, thrombocytopaenia, or anaemia of chronic disease
metabolic panel may show high BUN or creatinine or electrolyte abnormalities
urinalysis may show protienuria, haematuria or urinary casts
ESR
Erythrocyte sedimentation rate
Abbreviation: ESR
A test that measures the distance erythrocytes fall after one hour in a vertical tube of anticoagulated blood. Can be elevated in many conditions such as infection, inflammation, and malignancy.
antibody specificity in SLE
ANAs are highly sensitive but not specific
anti-dsDNA and anti-sm are most specific for SLE
imaging studies
x-ray joints: perform in patients with articular symptoms
x-ray or CT chest: perform in patients with pulmonary involvement
echocardiography: in patients with suspected pericardial effusion or Libman-sacks endocarditis
general principles of treatment
usually require lifelong immunosuppressants
NSAIDs can providesymptomatic relief
smoking cessation, aerobic excercise
avoidance of UV light
pharmacology
all patients: hydroxychloroquinine iss the cornerstone of therapy regardless of disease activity
consider oral glucocorticoids for mild to moderate disease
for severe disease: induction therapy with high dose IV glucocorticoids and other immunosuppressive agents
monitoring of medication induced side effects
immunisations
monitor for side effects of glucocorticoid therapy
hydroxychloroquinine: request opthalmologic screening at baseline, after 5 years, and every year thereafter
discoid lupus erythematosus
erythematous, inflammatory scaly plaques that are painful to remove
plaques heal but cause scarring alopecia, atrophy, peripheral hyperpigmnetation and central depigmentation
typically affects face, neck and head
triggered by exposure to UV light
cutaneous lupus erythematosus (CLE)
lupus that presents with predominantly cutaenous manifestations
including
- acute cutaneous lupus erythematosus
- subacute cutaneous lupus erythematosus
- discoid lupus erythematosus
management of CLE
sunblock
hydroxychloroquinine
topical glucocorticoids eg. fluocinonide
lupus nephritis
most dangerous specific manifestation due to high morbidity and mortality
common
pathophysiology of lupus nephritis
mesangial and/or subendothelial deposition of immune complexes, expansion and thickening of mesangium, capillary walls, and/or GBM
clinical features of lupus nephritis
hypertension
oedema
haematuria
laboritory studies of lupus nephritis
metabolic panel: increase in creatinine
urinalysis: proteinuria, haematuria, cellular casts (RBCs, haemoglobin, granular, tubular, or mixed)
kidney biopsy for lupus nephritis
findings: immune complex mediated GN
management of lupus nephritis
all patients should recieve standard therapy for lupus plus CKD
IV glucocorticoids
plus immunosuppressants
neuropsychiatric manifestations of sysetmic lupus erythematosus
aseptic meningitis, CVD, demylination, haedache, chorea, myelopathy, seizures, acute confusional state, cognitive impairment, mood disorder, psychosis
high risk drugs for drug induced LE
procainamide and hydralazine
complications of SLE
- infection: responsible for 25-50% of deaths in patinets with SLE
- CVD: increased risk of thrombosis, especially if anti=phospholipid syndrome is present
- increased risk of myocardial infarction and stroke due to accelerated atherosclerosis
comorbidities
Libman-sacks endocarditis
pancytopaenia
non-hodgkin lymphoma
osteonecrosis
interstitial lung disease, pulmonary hypertension
medication induced adverse effects
anti-phospholipid syndrome
A systemic autoimmune disease characterized by thrombotic (e.g., DVT, stroke) and/or obstetrical complications (e.g., recurrent early miscarriages, severe preeclampsia) in patients with persistent antiphospholipid antibodies.
