Pathology Flashcards
What are the types of hypersensitivity?
Type 1- immediate, IgE mediated
Type 2-antibody mediated
Type 3 -immune compplex
Type 4 -delayed
What is a good diagnostic tool in Connetive tissue diseases
Presence of auto antibodies - some ahem stronger and more specific associations
Where are the auto-antibodies targeted in lupus
structural parts of DNA
Name a photolytic systemic auto-immune condition
SLE
What is vasculitis
Inflammation of the vessels- typically arteries but all forms of vessels can be affected
Rarely infectious organisms can cause vascular inflammation. What are examples of these?
Myocotic aneurysms with bacterial endocarditis and primary angioinvasive infections
large vessel vasculitis
Granulomatous disease
Where does Giant cell arteritis affect?
Affects arteries of the head esp superficial femoral artery
What do you do if you suspect giant cell arteritis
If suspected put patient on steroid therapy
biopsy to prove arteritis
disease is segmental with skip lesions
can be very focal- a negative biopsy doesn’t rule out this diagnosis
Risk of going blind - keep on steroids until 100% sure it isn’t
The ophthalmic artery is an ….
end artery
what does Polyasteritis Nodosa affect
Small to medium sized arterial vessels
spares lung but often involves many organ systems
What is polyasteritis nodosa
segmental transmural inflammation with necrosis
ANCA negative
It untreated then fatal
fibroid necrosis of vessel wall
Gout
Usually in joints-lower temperature
associated with the deposition of urate crystals(needle shaped)
arthritic process- subsequent inflammatory reaction to trauma and foreign material.
Renal disease- stones and direct deposition in tubules and interstitium
What is the cause of Hyperuricaemia
Making too much
-Usually idiopathic (90%), HGPRT def in Lysch Nyhan syndome, increased cell turnover (cancer, leukaemia, tumour lysis with chemo, psoriasis)
Getting rid of too little
-Thiazide diuretics reduce the excretion
-under-excretion is the most common cause of gout.
calcium pyrophosphate
Usually asymptomatic
crystals aren’t distinct histologically
fresh microscopy- weak positive birefringence
