Method of detection of platelet-activating antibodies that cause heparin-induced thrombocytopenia/thrombosis

A method of detecting platelet-activating pathogenic HIT antibodies as opposed to non-activating non-pathogenic HIT antibodies in a patient, the method comprising the steps of:

• a) obtaining a patient sample selected from the group consisting of whole blood, plasma, and serum from a patient suspected of heparin-induced thrombocytopenia (HIT);
• b) incubating platelet factor 4 (PF4) with a sample of isolated normal platelets in the absence of heparin to yield a sample of PF4-treated platelets;
• c) contacting the patient sample with the PF4-treated platelets, wherein a combined sample is created;
• and
• d) measuring the amount of antibodies bound to platelets in the combined sample,
• wherein an increase in the amount of antibodies bound to platelets in the combined sample, relative to the amount of antibodies bound to platelets when a normal whole blood, plasma, or serum sample is substituted for the patient sample in step (c), is indicative of the patient having platelet-activating pathogenic HIT antibodies.

A method of detecting platelet-activating pathogenic HIT antibodies as opposed to non-activating non-pathogenic HIT antibodies in a patient, the method comprising the steps of:

• a) obtaining a patient sample selected from the group consisting of whole blood, plasma, and serum from a patient suspected of having heparin-induced thrombocytopenia (HIT);
• b) incubating platelet factor 4 (PF4) with a sample of isolated normal platelets and the patient sample;
• and
• c) measuring activation of the PF4-treated platelets,
• wherein increased levels of platelet activation measured in step (c) relative to activation measured when a normal whole blood, plasma, or serum sample is substituted for the patient sample is indicative that the patient has platelet-activating pathogenic HIT antibodies.

A method of detecting platelet-activating serotonin release assay positive (SRA(+)) HIT antibodies as opposed to SRA(−) HIT antibodies in a patient who has received heparin, the method comprising the steps of:

• a) obtaining a patient sample selected from the group consisting of whole blood, plasma, and serum from a patient who has received heparin and is suspected of having heparin-induced thrombocytopenia (HIT);
• b) incubating platelet factor 4 (PF4) with a sample of isolated normal platelets to yield a sample of PF4-treated platelets;
• c) contacting the patient sample with the PF4-treated platelets, wherein a combined sample is created;
• and
• d) measuring activation of the PF4-treated platelets in the combined sample,
• wherein an increase in platelet activation in the combined sample, relative to platelet activation obtained when a normal whole blood, plasma, or serum sample is substituted for the patient sample in step (c), is indicative of the patient having platelet-activating SRA(+) HIT antibodies.