Timori NH and Badlou BA
Introduction: We previously described that metabolic resting preserves old and cold platelets (PLTs) concentrates (PCs). In Badlou et al. 2006 we have established that P-selectin involved as an intermediate in binding, and the combination of PS exposure with (-out) changes in GPIb in phagocytosis of PCs. Using a standard threshold over the interaction between donors PLTs and patient’s phagocytes might increase success of transfusion, and decrease side effects, pretransfusion.
The aim of this study is to introduce a novel method, which could be used as an in-vitro prediction model system to envisage PCs fate, posttransfusion.
Materials and Methods: Human PCs were stored for different periods to obtain a wide range of surface expressed P-selectin and-PS exposure. The quantitative change in GPIb was deduced from decreased binding of an anti GPIb- antibody measured by FACS flowcytometry. Correlations established in RT stored-PCs were compared with PCs stored at 0°C, and metabolic suppressed stored at 4°C (MSP4).
Results: Qualitative and quantitative analysis revealed that ‘good PCs’ which had low P-selectin and PS exposure, and high GPIb expression were not removed by phagopcytes. Comparison studies between C22, C0 and MSP4 showed that at a given amount of PS exposure and GPIb expression, phagocytes immediately removed ‘bad PCs’. Threshold- dependent removal might be caused by ageing-dependent lesions. At high GPIb expression was phagocytosis almost 0%, when GPIb expression decreased below certain degree phagocytosis increased, remarkably.
Discussions: Our results signify that these chosen three markers combination measurements are reliable markers for phagocytic (ir-) responsiveness. In the near future, when these thresholds established as standard thresholds then any (Para-)medic can predict on the basis of relatively simple analysis, whether delivered PCs from the blood banks are immunogenic or not. In conclusion, our introduced in-vitro model system could be used as the quality control of any randomly selected and prepared PCs, pretransfusion.