The inventors produced substances that neutralize the activity of a bispecific antibody having an activity of functionally substituting for FVIII, and undertook the construction of methods for measuring the reactivity of FVIII that can ensure accuracy even in the presence of this bispecific antibody. As a result, the inventors discovered that in APTT-based one-stage clotting assay, FVIII activity in the plasma of a hemophilia A patient can be evaluated accurately, and also that in APTT-based Bethesda assay, FVIII inhibitor titer in the plasma of a hemophilia A patient carrying a FVIII inhibitor can be evaluated accurately.

In some embodiments, the invention provides methods for detecting the reversal an anticoagulant at a therapeutically relevant amount or higher in a patient, including subjecting a sample of a control blood component (known not to contain the anticoagulant) to a clotting assay in the presence of an ecarin reagent to obtain a control ecarin clotting measurement; subjecting a sample of a control blood component (known not to contain the anticoagulant) to a clotting assay in the presence of a Factor Xa reagent to obtain a control Factor Xa clotting measurement; subjecting a sample of a blood component from a patient suspected to contain a reversal agent to a clotting assay in the presence of the ecarin reagent to obtain a patient ecarin clotting measurement; subjecting a sample of a blood component from the patient suspected to contain the reversal agent to a clotting assay in the presence of the Factor Xa reagent to obtain a patient Factor Xa clotting measurement; and comparing the control ecarin clotting measurement to the patient ecarin clotting measurement and comparing the control Factor Xa clotting measurement to the patient Factor Xa measurement.

The present invention provides methods for detecting a complex with low affinity, under conditions in which the binding equilibrium of the complex is substantially maintained, and methods for measuring the concentration and/or amount of the complex. The invention also provides methods for evaluating the kinetics of a complex and methods for deciding on a therapeutic method that uses a pharmaceutical agent, based on the concentration and/or amount of the complex determined by the above-mentioned measurement method.

The present disclosure relates to an assay that measures the level of factor Xa inhibitors in a sample by detecting residual factor Xa activity. In particular, the assay utilizes a mutant variant of prothrombin that lacks proteolytic activity; a prothrombinase complex mixture; and a thrombin-specific inhibitor and measures the factor Xa activity.

The present invention is directed to a novel method of determining inhibitors of proteolytically active coagulation factors, referred to herein as anticoagulants, in a sample, in particular the qualitative detection of direct thrombin and factor Xa inhibitors in a sample. The method of the present invention allows a qualitative determination of the nature anticoagulants present in a sample. This can be achieved with only one coagulation-based test. The method can be used in a test kit, including a point-of-care (POC) system.

Disclosed herein are devices for measuring, at one or more time points, one or more properties or changes in properties of a fluid sample. The devices may comprise a chamber defining an internal volume of the device suitable for receiving and retaining the fluid sample; a plurality of layers, the plurality comprising at least a bottom layer below the chamber and at least a substrate layer above the chamber, wherein: the substrate layer is linked to at least one suspended beam at each end of its length; the suspended beam is located above the chamber, the suspended beam having a face capable of physical contact with the fluid sample; and the suspended beam is configured to oscillate upon application of an actuating signal to at least one electrically conductive path, which runs across the suspended beam. Related methods and uses are also disclosed.

A chemiluminescent biosensor for detecting a coagulation factor in a blood sample including: a fluorogenic substrate for the coagulation factor, where the fluorogenic substrate includes a fluorescent dye; and a quencher conjugated with the fluorogenic substrate. The biosensor rapidly and accurately detects a coagulation factor in a blood sample including whole blood or plasma, thereby useful for minimizing or eliminating any reversal effect of anticoagulants.

Provided herein are compositions and methods for quantifying polyphosphates. In particular, provided herein are solution and substrate based assays for quantifying polyphosphates in complex samples.

In some embodiments, the invention provides methods for detecting and/or classifying an anticoagulant at a therapeutically relevant amount or higher in a patient, including subjecting a sample of a control blood component (known not to contain the anticoagulant) to a clotting assay in the presence of a Factor Xa reagent to obtain a control clotting measurement; and subjecting a sample of a blood component from a patient suspected of having the anticoagulant to the clotting assay in the presence of the Factor Xa reagent to obtain a patient clotting measurement, wherein the patient clotting measurement sample greater than the control clotting measurement indicates the presence of the anticoagulant at a therapeutically relevant amount or higher in the patient. In some embodiments, the invention includes methods for classifying an anticoagulant as an anti-Factor Xa or a direct thrombin inhibitor anticoagulant using a clotting assay in the presence of an ecarin reagent.

The present invention is directed to a novel method of determining inhibitors of proteolytically active coagulation factors, referred to herein as anticoagulants, in a sample, in particular the qualitative detection of direct thrombin and factor Xa inhibitors in a sample. The method of the present invention allows a qualitative determination of the nature anticoagulants present in a sample. This can be achieved with only one coagulation-based test. The method can be used in a test kit, including a point-of-care (POC) system.