Systemic Lupus Erythematosus Flashcards
What is SLE?
A multisystemic autoimmune disease
What causes SLE (pathophysiology)?
- Autoantibodies are made against a variety of autoantigens (ANA) which form immune complexes.
- Inadequate T cell suppressor activity and increased B cell activity.
- Inadequate clearance of the immune complexes causes the host to amount an immune response, causing tissue inflammation and damage.
What are some risk factors for SLE?
- Women
- Child bearing age
- Commoner in African-Caribbean’s and Asians
- 1st/2nd degree relative with SLE
What are the common clinical features of SLE?
SOAP BRAIN
S - Serositis (pleurisy, pericarditis)
O - Oral ulcers, mostly on the palate
A - Arthritis, small joints non erosive
P - Photosensitivity, malar or discoid rash
B - Blood disorders, low WCC, lymphopenia, thrombocytopenia, haemolytic anaemia
R - Renal involvement (glomerulonephritis)
A - Autoantibodies (ANA positive)
I - Immunologic tests (low complement)
N - Neurological disorder - Seizures or psychosis
What are some general, non specific symptoms of SLE?
- Malaise
- Fatigue
- Myalgia
- Fever
What are the best three blood tests for lupus?
- Anti-dsDNA antibody titres
- Complement - low C3 and C4, denotes consumption of complement and increased C3d/C4d the degradation products
- Raised ESR
Describe the immunology of SLE?
- 95% are ANA positive
- 60% are anti-dsDNA positive
- 20-30% ENA - anti-Ro, anti-La
- 40% are RhF positive
- Antiphospholipid antibodies
What other autoimmune conditions can SLE present with?
- Sjogrens
- Autoimmune thyroid disease
What is the standard work up for a suspected SLE patient other than immunological studies?
- BP
- Urinalysis - Casts or proteins
- FBC, U+E, LFT, CRP (usually normal)
- Skin or renal biopsies can be diagnostic
What does raised ESR but normal CRP make you consider?
LUPUS
What does raised ESR and raised CRP make you consider?
- Infection
- Serositis
- Arthritis
aka NOT LUPUS
What drugs can cause SLE?
Does it remit once the drug is stopped?
- Isoniazid
- Hydralazine (if over 50mg)
- Procainamide
- Phenytoin
- Anti-TNF agents
Yes
What is the general management for SLE?
- High factor sun cream
- Screen for comorbidities and medication toxicity
- Topical steroids firstline for skin flares
What is the pharmacological management for SLE?
- Hydroxychloroquine
- NSAIDs unless renal disease for joint/skin symptoms
- Azathioprine/methotrexate/mycophenolate motefil as steroid sparing agents
- Belilumab as add on if antibody positive and high disease activity
- Short course prednisolone for flares
What symptoms occur with drug induced SLE?
- Skin and lung signs prevail
- CNS and renal system rarely affected
