Human antibody specific for activated state of platelet integrin receptor GPIIb/IIIa

1. An antibody of human origin, wherein said antibody inhibits platelet aggregation and has a greater binding affinity to the activated state of platelet integrin receptor GPIIb/IIIa than to the inactive conformation of the platelet integrin receptor GPIIb/IIIa, wherein the antibody is a single chain antibody or Fab fragment, and wherein the antibody comprises heavy chain variable and light chain variable domains, wherein said antibody comprises

(i) a heavy chain variable domain comprising CDR1 and CDR2 of the heavy chain variable domain encoded by nucleic acids comprising nucleotides 9 to 399 of SEQ ID NO:3 and CDR3 having the sequence as set forth in SEQ ID NO:163 and a light chain variable domain comprising CDR1 and CDR2 of the light chain variable domain encoded by nucleic acids comprising nucleotides 432 to 810 of SEQ ID NO:3 and CDR3 having the sequence as set forth in SEQ ID NO:170 or SEQ ID NO:171; or

(ii) a light chain variable domain encoded by nucleic acids comprising nucleotides 432 to 810 of SEQ ID NO:3, wherein the CDR3 encoded by SEQ ID NO:3 is replaced by a CDR3 having the sequence as set forth in SEQ ID NO:170 or SEQ ID NO:171; or

(iii) a heavy chain variable domain encoded by nucleic acids comprising nucleotides 9 to 399 of SEQ ID NO:3, wherein the CDR3 encoded by SEQ ID NO:3 is replaced by a CDR3 having the sequence as set forth in SEQ ID NO:163.

2. The antibody according to claim 1 , wherein the heavy chain variable domain comprises the sequence as set forth in SEQ ID NO:172.

3. The antibody according to claim 1 , wherein the light chain variable domain comprises the sequences as set forth in SEQ ID NO:173.

4. The antibody according to claim 1 , wherein the variable domains of the heavy and light chains are of a single chain antibody or a Fab fragment.