Background: The platelet functionality of cold-stored platelets remains a subject of debate. Our aim was to investigate the effect of temperature on the hemostatic properties of stored platelets. Methods: Ten split pooled platelets stored at cold and at room temperature were evaluated in vitro on storage days 1, 5, 10, and 15 for metabolic, physiological, and vesiculation parameters, as well as their hemostatic profile using rotational thromboelastometry (ROTEM^®). Results: The integrity profile was better preserved in the cold-stored platelets, as lower lactate dehydrogenase levels were documented (e.g., day 10: 261 ± 46 vs. 572 ± 220 U/L, 4 vs. 22 °C, p = 0.004). A time-dependent decrease in hemostatic capacity was evident regardless of the temperature, but the cold-stored units were linked to shorter clot initiation times and increased elasticity, strength, and firmness parameters, especially during extended storage (e.g., maximum clot firmness, INTEM day 15: 81 ± 2 vs. 19 ± 4 mm, 4 vs. 22 °C, p = 0.0008). Additionally, the aggregation of cold-stored platelets was superior after the addition of any agonist tested. Regarding vesiculation parameters, the extracellular vesicles of the units at 4 °C were characterized by a larger size from day 10 onwards, when they also presented higher procoagulant activity (e.g., phospholipid-dependent clotting time of day 15: 21.4 ± 2.3 vs. 25.0 ± 3.0 s, 4 vs. 22 °C, p = 0.016). Conclusion: Our results indicate that cold-stored platelets perform better than those stored at room temperature, demonstrating superior clot formation and stability. This suggests that cold storage may more effectively preserve platelet function, potentially offering advantages for transfusion therapy and the extension of shelf-life. However, the clinical relevance of these findings requires further investigation.

Special populations, particularly pregnant women, are uniquely susceptible to infectious diseases due to alterations in their immunological, respiratory, and cardiovascular systems during gestation. Influenza infections during the perinatal period have been associated with more severe maternal and perinatal outcomes, underscoring the critical importance of vaccination data for pregnant women. According to the World Health Organization (WHO), all pregnant women and those of childbearing age should receive the inactivated influenza vaccine, irrespective of their pregnancy stage. This study aimed to elucidate factors influencing neonatal antibody presence following maternal influenza vaccination. Conducted through convenience sampling in Athens, Greece, this study involved 78 pregnant women who received flu vaccinations. The participants completed questionnaires covering demographics, obstetric history, attitudes toward influenza vaccination, and knowledge about the influenza virus and pregnancy vaccination. Blood samples were collected from 83 neonates to assess IgG antibody presence. Five of the surveyed women had twin pregnancies. The statistical analysis employed IBM SPSS-Statistics version 26.0. This study revealed the presence of positive influenza A and B antibodies in neonates following maternal immunization. Furthermore, it identified factors such as the gestational week and timing of vaccination during pregnancy that influenced the transfer of antibodies from mother to fetus. These findings offer valuable insights for healthcare professionals to provide informed recommendations on influenza vaccination during pregnancy and empower expectant mothers to make informed decisions about the benefits of immunization.