Connective tissue disease part 1 Flashcards
what are connective tissue diseases
spontaneous over activity of the immune system with specific autoantibodies
evolve over years, sometimes leading to organ failure and death
what is SLE
A systemic autoimmune disease that can affect any part of the body
the immune systems attacks the bodies tissue leading to inflammation and tissue damage
antibody immune complexes can precipitate and cause a further immune response
who is more likely to get SLE
FEMALES (9 females:1 male)
higher prevalence in asians, afro-americans and afro-caribbeans
uncommon in African blacks
What hormonal factors increase likelihood of SLE
Those with a high exposure to oestrogen eg. early first mensuration, on the pill or HRT
What is the pathogenesis of SLE
loss of immune regulation
leads to increased defective apoptosis
dying cells release their nuclear material which act as autoantigens
B and T cells are stimulated against the auto antigens
autoantibodies are produced
how does SLE cause renal disease
immune complexes are formed in circulation between auto antigens and autoantibodies and deposited in the kidneys
this activates complement and cytokines which attract neutrophils leading to necrosis and scaring
what is the SLICC criteria
criteria for SLE, need >4
acute cutaneous lupus chronic cutaneous lupus oral or nasal ulcers non-scarring alopecia arthritis serostitis renal neurologic haemolytic anaemia leukopenia thrombocytopenia
systemic general symptoms of SLE
Fever malaise poor appetite weight loss fatigue
Skin and mucus membrane features of SLE
photosensitivity malar rash discoid lupus erythematosus subacute cutaneous lupus mouth ulcers alopecia
MSK features of SLE
non-deforming polyarthritis/polyarthalgia
deforming arthopathy
myopathy -weakness, myalgia and myositis
what is serositis
inflammation of a serous membrane
pericarditis
pleurisy
pleural effusion
pericardial effusion
renal sign of SLE
proteinuria >500mg in 24 hours
red cell casts
neurological features of SLE
Depression/psychosis migrainous headache seizures cranial or peripheral neuropathy mononeuritis multiplex
haematological features of SLE
Lymphadenopathy Leucopenia (decrease in white cells) Lymphopenia (low lymphocytes) haemolytic anaemia (decrease in red cells) thrombocytopenia (low platelets)
what are anti-phospholipid syndrome symptoms
venous and arterial thrombus recurrent miscarriage livido reticularis (mottled skin) thrombocytopenia prolonged blood clotting
what intrinsic SLE factors cause increase susceptibility to infection
low complements
impaired cell mediated immunity
defective phagocytosis
poor antibody response to antigens
extrinsic SLE factors causing increase susceptibility to infection
steroids
other immunosuppressants
nephrotic syndrome
Immunological investigations for SLE
ANA antibody (98% have)
Anti-double stranded DNA antibody (60% have, v specific)
Anti-ENA
anti-phospholipids (must be positive on two occasions 12 weeks apart)
what is the next step after diagnosis of SLE
Screen for organ involvement
why is anti-dsDNA monitored in people with SLE
positively correlated with disease activity
what relationship do C3/4 levels show with SLE activity
negative correlation
what is monitored in people with SLE
anti-dsDNA C3/C4 levels Urine examination full blood count blood biochem
general management for lupus
counselling
regular monitoring
avoid excessive sun exposure
pregnancy issues
drug treatment for SLE
NSAIDS and simple analgesia Anti-malarias-hydroxychoroquine (useful for arthritis, cutaneous manifestations and constitutional symptoms) steroids immunosupressives Biologics
negative side effects of immunosuppressants
cause bone marrow suppression
cause increased susceptibility to infection
potentially teratogenic (affects foetus)
how do you treat mild SLE
hydroxychoroquine
topical steroids
NSAIDS
how to treat moderate SLE
Oral steroids
Azathioprine
Methotrexate
how to treat severe SLE
IV steroids
cyclophosphamide
rituximab
belimumab
what ANA level is suggestive of SLE
1:160
How to screen for organ involvement in SLE
urinalysis
