Vwf Flashcards
What does vwf:cba detect?
ability of vwf to bind to collagen
measures preferentially the High Molecular Weight [HMW] multimers of VWF
Method CBA
Elisa- wells coated w Human collagen type III
Plasma added
Washed
HRP added to deft ab present by binding causing colour change
Amy colour proportional,to amt vwf bound to collagen
Dx of type 2n requires?
Pedigree analysis
Genetics
FVIII binding assa
Measure both fviii and vwf activity
How do,you ensure vwf assays remain précis
Use of controls w known vwf concentration to gen curves
Other DDx for mucosal bleeding
Acquired VWD, platelet-type VWD, platelet function defects, vascular malformations such as hereditary hemorrhagic telangiectasias connective tissue disorders
Which r on plts does vwf bind to
to platelet glycoprotein Iba
Pt related rf for inhibitor development
Race Fhx FVIII mutation MHC class Polymorphism of immune response genes- il 10, TNF, CTLA4
How does fviii work
Travels bound to Vwf and when act by fvii will activate fix
How is FVIII cleared
By fv and fix
Short half life
Riusk factor for F5 inhibitors
by exposure to bovine protein (i.e. bovine thrombin preparations)
Antibodies are generated as an immune response to bovine factor V which then cross-reacts with
recent surgery,
drug exposure (e.g. aminoglycosides, B-lactam antibiotics),
infections,
blood transfusions,
autoimmune disorders,
malignancy
pregnancy