Compositions and methods useful for the diagnosis and treatment of heparin induced thrombocytopenia/thrombosis

An isolated human antibody capable of binding specifically with a PF4/heparin complex, wherein said antibody preferentially binds with said PF4/heparin complex relative to the binding of said antibody with either PF4 or heparin alone.

An Fab antibody capable of binding specifically with a PF4/heparin complex, wherein said antibody preferentially binds with said PF4/heparin complex relative to the binding of said antibody with either PF4 or heparin alone.

A single chain scFv antibody comprising a single chain of protein comprising an Fv fragment, wherein said antibody is capable of binding specifically with a PF4/heparin complex, wherein said antibody preferentially binds with said PF4/heparin complex relative to the binding of said antibody with either PF4 or heparin alone.

A humanized version of the monoclonal antibody produced by hybridoma KKO (ATCC Accession Number PTA-6133).

An antigen-binding fragment of the monoclonal antibody produced by hybridoma KKO (ATCC Accession Number PTA-6133), wherein said fragment is capable of binding specifically with a PF4/heparin complex, wherein said antibody preferentially binds with said PF4/heparin complex relative to the binding of said antibody with either PF4 or heparin alone.

A humanized version of an antigen-binding fragment of the monoclonal antibody produced by hybridoma KKO (ATCC Accession Number PTA-6133), wherein said fragment is capable of binding specifically with a PF4/heparin complex, wherein said antibody preferentially binds with said PF4/heparin complex relative to the binding of said antibody with either PF4 or heparin alone.

A method of assessing the level of a polyclonal antibody in a bodily fluid or tissue sample obtained from a mammal, wherein said polyclonal antibody binds specifically with a PF4/heparin complex and preferentially binds with said PF4/heparin complex relative to the binding of said polyclonal antibody with either PF4 or heparin alone, said method comprising:

• (a) assessing the level of said polyclonal antibody in said bodily fluid or tissue sample obtained from said mammal;
• (b) comparing the level of said polyclonal antibody in said sample with the level of a monoclonal antibody or antigen-binding fragment thereof which is specific for said PF4/heparin complex in a reference standard which comprises said monoclonal antibody or antigen-binding fragment thereof, wherein said monoclonal antibody or antigen-binding fragment thereof preferentially binds with said PF4/heparin complex relative to the binding of said monoclonal antibody or antigen-binding fragment thereof with either PF4 or heparin alone;
• (c) determining from (a) or (b) the level of said polyclonal in said sample, whereby the level of said polyclonal antibody in said sample is assessed.

A kit for diagnosing HIT/HITT in a mammal, said kit comprising (a) a positive control solution comprising a monoclonal antibody or antigen-binding fragment thereof which binds specifically with a PF4/heparin complex, wherein said monoclonal antibody or antigen-binding fragment thereof preferentially binds with said PF4/heparin complex relative to the binding of said monoclonal antibody or antigen-binding fragment thereof with either PF4 or heparin alone;

• and
• (b) an instructional material describing the use of said positive control solution for diagnosing HIT/HITT in a mammal.