systemic lupus erythmatosous Flashcards
define SLE
SLE is an inflammatory autoimmune connective tissue disorde
pathophysiology of SLE (full)
- B and T cells that react against self-antigens are usually destroyed in the bone marrow
- In SLE, these cells survive due to a defect in central or peripheral tolerance.
- Increased defective clearance of apoptotic cells, combined with the production of autoantibodies leads to the formation of immune complexes.
- These immune complexes are deposited in tissues and trigger a complement cascade, leading to further inflammation.
- The persistent inflammation of organs can lead to damage (e.g. glomerulonephritis).
pathophysiology of SLE (shortened)
aNA and antiDsDNA antibodies attack soft tissue causing chronic inflammation and damage
what type of hypersensitivity is SLE
HYPERSENSISITIVTY TYPE 3 - antigen antibody complex deposition
who is at high risk of SLE
- Asian, African, Caribbean, and Hispanic patients
- middle-aged adults
- women
risk factors for SLE
- female
- drugs
- genetics (HLAB8/DR2/DR3)
signs and symptoms of SLE
- Fatigue
- Weight loss
- Arthralgia (joint pain)
- Non-erosive arthritis
- Myalgia (muscle pain)
- Fever
- Lymphadenopathy
- Splenomegaly
- Shortness of breath
- Pleuritic chest pain
- Mouth ulcers
- Hair loss
- Raynaud’s phenomenon
- Oedema (due to nephritis)
- Malar/butterfly rash (across the nose and cheeks and worsened/triggered by sunlight)
what investigations do you do for SLE
- bloods
- urine dipstick/urinalysis
- serology
- renal biopsy
what do bloods for SLE show
- anaemia (normocytic)
- raised ESR, normal CRP
- decreased C3 &C4
what does urinalysis of SLE show
- proteinuria (in lupus nephritis)
- haematuria
what does serology for SLE show
- ANA Ab’s (85% of patients)
- Anti dsDNA Ab’s (50% of patients)
which antibodies are more useful for SLE diagnosis
anti-dsDNA are highly specific so if present, high indication of SLE
how to look for specific antibodies
An extractable nuclear antigen looks for specific antibodies to distinguish between specific tissue disorders
what is antiphospholipid syndrome
Antiphospholipid antibodies/syndrome can occur secondary to SLE in 40% of patients.
how to establish a diagnosis for SLE
Patients are diagnosed using the European League Against Rheumatism or American College of Rheumatology criteria.
