Method of Simultaneous Detection of Heparin-Induced Immunoglobulins Types G, A and M

Abstract

The invention provides a method for detecting heparin-induced antibodies comprising a) binding a PF4-heparin antigen to a solid surface; b) incubating the bound PF4-heparin with a sample comprising heparin-induced antibodies to be detected; c) contacting the sample with at least two labeled secondary antibodies, wherein the secondary antibodies bind to heparin-induced antibodies present in the sample; d) detecting the presence of the labeled secondary antibodies using flow cytometry or a suitable method, wherein the heparin-induced antibodies bound to the secondary antibodies are identified. In one embodiment, the at least two secondary antibodies are anti-human antibodies which specifically bind to heparin-induced antibodies and are selected from the group consisting of Ig, IgG, IgA, and IgM.

We claim: 
     
         1 . A kit for determining the presence or absence of heparin-induced thrombocytopenia (HIT) antibodies, comprising:
 (a) a solid support prepared by adding PF4 to heparin bound securely to the solid surface, thus creating epitopes specific to HIT antibodies; and   (b) at least two labeled immunoglobulin antibodies specific for different isotypes and labeled with different labels.   
     
     
         2 . The kit of  claim 1  additionally comprising instructions for use. 
     
     
         3 . The kit of  claim 1  wherein the labeled immunoglobulin antibodies are anti-human antibodies. 
     
     
         4 . The kit of  claim 1  wherein the label is a fluorophore. 
     
     
         5 . The kit of  claim 3  wherein the labeled immunoglobulin antibodies comprise fluorophore labeled antibodies selected from the group consisting of anti-Ig, anti-IgG, anti-IgA, and anti-IgM. 
     
     
         6 . A method of detecting heparin-induced thrombocytopenia (HIT) antibodies in a patient comprising:
 a) obtaining a sample from a patient suspected of having HIT;   b) obtaining a solid surface to which a PF4/heparin complex has been bound;   c) contacting the patient sample to the bound PF4/heparin complex, wherein HIT antibodies within the patient sample bind to the complex;   d) contacting the bound HIT antibodies with at least a first and a second labeled secondary antibody, wherein the secondary antibody binds to the HIT antibodies bound to the complex and wherein the first antibody and the second antibody are specific for different isotypes selected from the group consisting of anti-Ig, anti-IgG, anti-IgA, and anti-IgM; and   e) detecting the presence of HIT antibody isotypes based on the presence or absence of the label.   
     
     
         7 . The method of  claim 6  wherein the at least two secondary antibodies are anti-human antibodies selected from the group consisting of anti-Ig, anti-IgG, anti-IgA, and anti-IgM. 
     
     
         8 . The method of  claim 6  wherein the solid surface is a bead. 
     
     
         9 . The method of  claim 6  wherein the label is a fluorophore. 
     
     
         10 . The method of  claim 6  wherein the PF4/heparin complex is prepared using a covalent chemical reaction to bind the heparin molecules to the solid surface.