Utility of Platelet Endothelial Cell Adhesion Molecule 1 in the Platelet Activity Assessment in Mouse and Human Blood.

In our previous study, we introduced the platelet endothelial cell adhesion molecule 1 (PECAM-1)/thrombus ratio, which is a parameter indicating the proportion of PECAM-1 in laser-induced thrombi in mice. Because PECAM-1 is an antithrombotic molecule, the higher the PECAM-1/thrombus ratio, the less activated the platelets. In this study, we used an extracorporeal model of thrombosis (flow chamber model) to verify its usefulness in the assessment of the PECAM-1/thrombus ratio in animal and human studies. Using the lipopolysaccharide (LPS)-induced inflammation model, we also evaluated whether the PECAM-1/thrombus ratio determined in the flow chamber (without endothelium) differed from that calculated in laser-induced thrombosis (with endothelium). We observed that acetylsalicylic acid (ASA) decreased the area of the thrombus while increasing the PECAM-1/thrombus ratio in healthy mice and humans in a dose-dependent manner. In LPS-treated mice, the PECAM-1/thrombus ratio decreased as the dose of ASA increased in both thrombosis models, but the direction of change in the thrombus area was inconsistent. Our study demonstrates that the PECAM-1/thrombus ratio can more accurately describe the platelet activation status than commonly used parameters such as the thrombus area, and, hence, it can be used in both human and animal studies.

[The quality of platelet concentrates in dependence on storage time before pathogen inactivation]. / Jakosc koncentratów plytek krwi w zaleznosci od czasu ich przechowywania przed wykonaniem procedury inaktywacji patogenów.

UNLABELLED: Pathogen inactivation procedure performed just before distribution of platelet concentrates (PCs) may decrease costs caused by loss of these components due to relatively short expiry date. THE AIM OF STUDY: To evaluate the quality of PCs pathogen inactivated on the first or the fifth day of storage. MATERIAL AND METHODS: PCs preparated from buffy-coats were suspended in platelet additive solution (Intersol, Baxter Healthcare Corporation, Belgium). The photochemical pathogen inactivation was performed on the 1st or the 5th day of storage using amotosalen and UVA (Cerus, Europe BV). PCs were stored for 7 days. RESULTS: There were observed increased expression of CD62 and CD63, elevated activity of LDH and lower concentration of glucose in PCs pathogen inactivated on day 1 compare to the control group. PCs pathogen inactivated on day 5 showed decreased expression of CD62 and CD63 compare to the control group. There were no significant differences in platelet number, pH, lactate concentration, hypotonic shock response and release of platelet derived microparticles in both groups of pathogen inactivated PCs. CONCLUSIONS: Time of storage of PCs before pathogen inactivation has no significant impact on PCs quality. Pathogen inactivation procedure performed just after having received request for PCs is more cost effective than the routine pathogen inactivation in all PCs before storage.