Immune Medidated Disease Flashcards
Platelet formation is mediated through ________ which is produced in the liver and kidney
Thrombopoietin
What is the hallmark clinical sign of immune mediated thrombocytopenia ?
Surface bleeding — petechiae, ecchymosis, and epistaxis
Platelet count is below _______ when petechiae and ecchymosis are present
30, 000/mcl
Normal is 200 000 to 500 000
T/F: VonWillebrands disease rarely causes petechiae, but does cause bleeding post-surgery or trauma
True
You have a prolonged mucosal bleeding time but your platelets, PT, and aPTT are all normal..
What would you suspect as you dx?
VonWillebrands dz
How do you diagnose vonWillebrands dz?
ELISA plasma
DNA testin
Treatment for vonWillebrands dz?
Desmpressin — improve hemostatic fxn
Blood components - fresh whole blood, FFP, cryoprecipitate
Primary ITP is caused by?
Antibodies bind to platelet —> destruction
Antibodies are targeted against GpIIb/IIIa fibrinogen receptor
Reduction in T regulatory cells
T/F: most cases of ITP is secondary
True
Causes of secondary ITP?
Drug - sulfonamide, cephalosporin, carprofen
Infectious
Neoplasia
Inflmmatory dz
Toxins
You do a CBC on your suspected immune mediated thrombocytopenia case, platelet count is <150,000. How can you determine this is a real thrombocytopenia?
Blood smear to rule out clumping of platelets
Treatment of ITP?
Immunosuppression
- remove cause
- glucocorticoids
- vincristine and hIVIG —> induce platelet release from megakaryocytes and shorten severe thrombocytopenia
How does Human IV IgG treat ITP?
Block macrophage from phagocytosis platelets
—> no difference between use of vincristine and this
But this agent is very expensive
What additional therapy for ITP can you use if glucocorticoid therapy fails?
Azathioprine
What is the best first line treatment for ITP if glucocorticoids are contraindicated?
Mycophenolate mofetil
You have ITP with a severe anemia, in addition to drug therapy, what can you do to stabilize the patient?
Platelet transfusion
Fresh whole blood —> best source of platelet in practice
Fresh platelet rich plasma
Lyophilized platets
What is the prognosis for ITP?
Good
93-97% survivial rate
What is the prognosis for dogs suffering form Evans syndrome/
Poor - IMHA + ITP
76% death rate within 30 dy\ays
What is a polyarthropathy?
Neutrophilic inflammation of multiple joints
Clincial signs of a immune-mediated polyarthritis?
Animal is reluctant to walk
Shows stiffness
Systemic illness
DDX for immune mediated poly arthritis?
Infectious - rickettsia, bacteria, Mycoplasma, fungi, andviral
Reactive
- drug
- neoplasia
- vaccination
- infectious focus (non-joint)
- inflammatory focus, enteropathy or hepatopathy
Primary immune mediated - erosive or non erosive
How can you diagnose immune mediated poly arthritis?
Multiple joints affected
Fever of unknown origin
Neutrophilic inflammation of the synovial fluid
Rule out
- tick
- single joint culture
- systemic dz/ neoplasia
- culture affected joins
- local fungal dz
What are causes of non-erosive primary ITP?
Systemic lupis erythematosus (SLE)
Breed associated
- shar pei —> hyaluronic acid os over expressed
Idiopathic
You have a non-erosive primary ITP, how can you determine if it is idiopathic or not?
Idiopathic occurs in animals 3-7yrs
Rule out SLE or other secondary causes
Liver biopsy - hetaptomegaly
Renal biopsy if evidence of proteinuria
Thoracic rads and abdominal US
Antinuclear antibody Tigre and rheumatoid factor
