Abstract: Disclosed herein are methods of diagnosing a disease or condition associated with abnormal platelet activation in a subject. Also disclosed herein are methods for assessing the propensity of donor platelets to release an uptaken fluorescent false neurotransmitter (FFN).

Abstract: The present disclosure provides methods of determining the presence of the risk of developing complement activation by protein/heparin binding complexes in a subject, methods of determining the presence of complement activation by protein/heparin binding complexes in a subject, and methods of treating diseases including heparin-induced thrombocytopenia (HIT) in a subject by administering a compound capable of blocking the classical pathway of complement activation.

Abstract: A method for diagnosing a predisposition for developing HIT is provided.

Abstract: The invention includes compositions, kits and methods comprising a monoclonal antibody which shares key functional properties with the polyclonal antibodies which participate in the pathogenesis of heparin induced thrombocytopenia/thrombosis (HIT/HITT) in a mammal. The monoclonal antibody of the invention preferentially binds with a PF4/heparin complex relative to the binding of the antibody with PF4 or heparin alone. The monoclonal antibody of the invention also binds specifically with PF4 in a complex with other glycosaminoglycans besides heparin, and also activates platelets. The monoclonal antibody of the invention is useful in methods for diagnosing and treating HIT/HITT in a mammal. A humanized version of the monoclonal antibody of the invention is also included, along with a process for humanizing the monoclonal antibody of the invention.