BLOOD BANK IMMUNODIAGNOSTICS FOR PLATELET PROTEINS

DURING THE NEXT YEAR, OVER 4 MILLION UNITS OF PLATELETS WILL BE TRANSFUSED IN THE UNITED STATES FOR A VARIETY OF MEDICAL REASONS. IN SPITE OF THE REMARKABLE BODY OF KNOWLEDGE ABOUT PLATELET PHYSIOLOGY AND BIOCHEMISTRY, EFFICACY OF THIS BLOOD PRODUCT IN CORRECTING BLEEDING PROBLEMS IS USUALLY MEASURED ACCORDING TO THE PLATELET COUNT AND THE BLEEDING TIME, BOTH OF WHICH CAN BE DETERMINED ONLY AFTER THE PLATELETS HAVE BEEN TRANSFUSED. POOR IN VIVO EFFICACY AND SURVIVAL CORRELATE WITH THE EXTENT TO WHICH THE PLATELETS HAVE BEEN ACTIVATED PRIOR TO TRANSFUSION. WITHIN THE PAST FEW YEARS, A NUMBER OF NOVEL PLATELET PROTEINS HAVE BEEN DESCRIBED, WHICH ARE FOUND ONLY ON THE SURFACE OF ACTIVATED PLATELETS. ONE SUCH PROTEIN, THE PADGEM OR GMP-140 PROTEIN, IS FOUND IN THE ALPHA GRANULES BUT IS EXPRESSED ON THE SURFACE OF THE PLATELET AFTER THIS CELL HAS BEEN ACTIVATED TO EXPRESS ITS BIOCHEMICAL POTENTIAL IN HEMOSTASIS. CBR LABORATORIES, INC. PROPOSES TO DEVELOP A RAPID IMMUNODIAGNOSTIC TEST FOR PLATELET ACTIVATION THAT WILL MEASURE PADGEM/GMP-140 ON THE SURFACE OF PLATELETS DURING THE TIME THESE CELLS ARE STORED PRIOR TOTRANSFUSION. IN THIS PHASE I STUDY, CBR LABORATORIES, INC. WILL DETERMINEWHETHER THE KINETICS OF APPEARANCE OF THIS PROTEIN ON THE PLATELET SURFACE DURING STORAGE CORRELATES WITH THE PRESENCE OF KNOWN BIOCHEMICAL MARKERS OF PLATELET ACTIVATION AND THE IN VIVO SURVIVAL OF THIS CELL. IF CORRELATION IS FOUND BETWEEN THESE TWO FACTORS, IN PHASE II, CBR LABORATORIES, INC. WILL FORMAT A SUITABLE IMMUNOASSAY FOR PADGEM/GMP-140 ON PLATELET SURFACES FOR USE IN THE BLOOD BANK AND UNDER-TAKE FULL CLINICAL TRIALS IN HUMANS.