The<unk><unk>  platelet adhesion <unk>  is an ex vivo assay for live platelet function. It measures platelet<unk>  with the help of von Willebrand factor (vWF) and exogenous antibiotic<unk>  added in a graded fashion. It is similar to the<unk>  cofactor assay but has the added benefit in that it helps in the diagnosis of type 2B/pseudo von Willebrand disease (vWD) and Bernard–Soulier syndrome because it uses patient's live endogenous platelets, whereas<unk>  cofactor assay tests the function of only the vWF and not the platelets.<unk>  cofactor assay uses the patient's platelet poor plasma (with vWF but no platelets) and adds<unk>  and exogenous formalin-fixed platelets which can passively agglutinate (but not actively aggregate, as they are dead). Formalin does not allow the extrinsic platelets to secrete the vWF of their α-granules, and thus only the activity of the intrinsic vWF is tested. In an unknown fashion, the antibiotic<unk>  causes von Willebrand factor to bind the platelet receptor glycoprotein Ib (GpIb), so when<unk>  is added to normal blood, it causes agglutination of fixed platelets or initiates the initial agglutination phase of<unk>  of live platelets. The results of the<unk>  in some characteristic diseases are the following: * Type 1 vWD: hypoactive agglutination occurs (consistent with<unk>  cofactor assay results) * Type 2A vWD: hypoactive agglutination occurs (consistent with<unk>  cofactor assay results) * Type 2B vWD: hyperactive agglutination occurs (when the<unk>  cofactor assay is used, the agglutination is hypoactive) * Type 2M vWD: hypoactive agglutination occurs (consistent with<unk>  cofactor assay results) * Type 2N vWD: normal agglutination occurs (consistent with<unk>  cofactor assay results) * Type 3 vWD: no agglutination occurs (consistent with<unk>  cofactor assay results) * Pseudo-vWD: hyperactive agglutination occurs (when the<unk>  cofactor assay is used, the agglutination is hypoactive) * Bernard-Soulier syndrome: hypoactive agglutination occurs (when the<unk>  cofactor assay is used, the agglutination is normal) INTERPRETATION OF TEST RAT+ Ve= normal (gp1b & vWF present) RAT-ve=abnormal(gp1b & vWF absent)
Ristocetin-induced platelet aggregation
Platelet swirling
Thrombin generation assay
Plasmin-α2-antiplasmin complex
Procoagulant platelets
Thrombin time
Thrombin–antithrombin complex
Platelet membrane glycoprotein