The invention generally relates to methods of measuring cleaved von Willebrand factor (VWF) fragments. More specifically, the invention relates to methods of measuring the ability of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) to cleave VWF in vivo. The invention also relates to methods of using various animal models which demonstrate ADAMTS13 activity similar to that of a human. The invention further relates to methods of measuring the cleavage products of rVWF in mammals, particularly in humans and in human plasma.

In a first aspect, there is provided an isolated polypeptide substrate for a disintegrin-like and metallopeptidase with thrombospondin type-1 motif, 13 (ADAMTS13) that is from 45 to 70 amino acids in length and has an amino acid sequence that is substantially similar to part of the von Willebrand factor A2 domain sequence set forth in SEQ ID NO: 2, with one or more of the following modifications: (i) the amino acid corresponding to position 1599 of SEQ ID NO: 2 is mutated from Q to K; (ii) the amino acid corresponding to position 1610 of SEQ ID NO: 2 is mutated from N to C; and (iii) the amino acids corresponding to Q1624 to R1641 of SEQ ID NO: 2 are deleted. In another aspect, there is provided an ADAMTS13 polypeptide substrate that is from 50 to 75 amino acids in length and has an amino acid sequence that is substantially similar to part of the von Willebrand factor A2 domain sequence set forth in SEQ ID NO: 2, with one or more of the following modifications: (i) the amino acid corresponding to position 1599 of SEQ ID NO: 2 is mutated from Q to K; (ii) the amino acid corresponding to position 1610 of SEQ ID NO: 2 is mutated from N to C; (iii) the amino acid corresponding to position 1629 of SEQ ID NO: 2 is mutated from G to E; and (iv) the amino acids corresponding to G1631 to R1641 of SEQ ID NO: 2 are deleted.

The present disclosure provides methods and compositions for diagnosing and treating subject having a bleeding disorder. The disclosed methods comprise contacting a sample, e.g., a blood or plasma sample obtained from the patient, with an activation mixture comprising an activated coagulation factor and a phospholipid mixture, wherein the activation mixture is dried onto a solid substrate. Also provided is a global hemostasis test based on the integration of clotting time (Ct) and pharmacokinetics data. The methods and compositions presented can be applied to point-of-care diagnostic systems.

Composition comprising recombinant Gplb? receptor protein

Various aspects of the invention relate to recombinant polypeptides that specifically bind human von Willebrand Factor. Such recombinant polypeptides typically include a modified extracellular domain of platelet glycoprotein Ib? that typically comprises at least one mutation selected from G233T, D235V, and K237V, and such recombinant polypeptides optionally include an oligomerization domain.

The present invention relates to polypeptides comprising at least one single domain antibody directed against vWF, vWF A1 domain, A1 domain of activated vWF, vWF A3 domain, gpIb and/or collagen, homologs of said polypeptides, and/or functional portions of said polypeptides, for the treatment for conditions which require a modulation of platelet-mediated aggregation and which overcomes the problems of the prior art. A further aspect of the invention is methods of production of said polypeptides, methods to coat devices with such polypeptides used in medical procedures (e.g. PCTA, stenting), methods and kits for screening for agents that modulate platelet-mediated aggregation and kits for the diagnosis of diseases related to platelet-mediated aggregation.

Disclosed herein are methods for determining the presence of a coagulation inhibitor in a patient. A patient curve associated with the patient sample and having a patient slope (Ps) and a a standard curve associated with a control sample and having a control slope (Cs) are generated, and the Ps and the Cs are compared to obtain a Ps/Cs parallelism ratio. A Ps/Cs parallelism ratio of less than a predetermined ratio is indicative of presence of a coagulation inhibitor in the patient sample.

The present invention relates to endothelial cell biomarkers and diagnostic and prognostic methods for vascular diseases, including cardiovascular and cerebrovascular diseases. The invention also provides compositions for detecting endothelial cell biomarkers (e.g., endothelial cell-derived exosome biomarkers) as well as compositions and methods useful for treating vascular diseases (e.g., atherosclerotic cerebrovascular disease).

Described herein are methods and kits for selective and sensitive activity measurement of human coagulation factor VIII (FVIII).

The present invention relates to a method for prophylactic treatment of spontaneous bleeding in a subject with severe von Willebrand Disease comprising administering a therapeutic amount of recombinant von Willebrand Factor (rVWF) to the subject.

The present disclosure provides methods and compositions for diagnosing and treating subject having a bleeding disorder. The disclosed methods comprise contacting a sample, e.g., a blood or plasma sample obtained from the patient, with an activation mixture comprising an activated coagulation factor and a phospholipid mixture, wherein the activation mixture is dried onto a solid substrate. Also provided is a global hemostasis test based on the integration of clotting time (Ct) and pharmacokinetics data. The methods and compositions presented can be applied to point-of-care diagnostic systems.