PhD defense: Níels Árni Árnason

Pathogen inactivation in platelet concentrate storage: Effects on quality and utilization

  • 26.8.2022, 15:00 - 17:00

The PhD defense of Níels Árni Árnason will be held on Friday the 26th of August at 15:00 in room M103.

Title of thesis: Pathogen inactivation in platelet concentrate storage: Effects on quality and utilization

Candidate: Níels Árni Árnason

Date and time: 26th of August 2022 at 15:00

Room: M103

Thesis Committee:
Dr. Ólafur Eysteinn Sigurjónsson, Supervisor, Professor, Reykjavík University
Dr. Óttar Rolfsson, Co-supervisor, Professor, University of Iceland
Dr. Per Sandgren, Co-supervisor, Associated Professor, Karolinska Institutet, Huddinge, Sweden
Dr. Sisse Ostrowski, Co-supervisor, Professor at Rigshospitalet, Copenhagen, Denmark

Dr. Larry Dumont, Clinical Professor, University of Colorado School of Medicine, USA
Affiliated Investigator, Vitalant Research Institute, USA


In transfusion medicine and blood banking, product quality and safety of patients are both essential. Blood transfusion is, in many instances, a lifesaving procedure; however, is not without risk. Blood products contain biological response modifiers (BRMs) that can induce febrile and allergic reactions and there is risk of donor/patient incompatibility, resulting in hemolytic transfusion reaction. Pathogen contamination of donor origin or due to collection and processing is another risk. The implementation of efficient viral screening has made blood transfusions safer, despite not addressing the risks from emerging pathogens or from bacterial contamination. For platelet concentrates (PCs) in particular, the standard storge conditions (room temperature) present an elevated risk of bacterial contamination and transfusion transmitted bacterial infection (TTBI) compared to other blood components, which are stored at subzero or refrigerated temperatures. Though the risk of TTBI can be minimized via the use of various screening assays, TTBI resulting in sepsis still occurs, with a high mortality rate. Therefore, methods have been developed to inactivate pathogens in blood products; such methods include photo or photochemical techniques, which influence the nucleic acids of pathogens and disable transcription. These methods have proven highly efficient in reducing the pathogenic load in blood products, namely PCs and plasma. As these methods have been approved through clinical trials and then implemented in routine use, indications of negative effects on blood products have emerged, specifically effects on platelet quality have been of concern. In response to the concern about reduced platelet quality, we investigated effect of pathogen inactivation (PI) with amotosalen and ultraviolet A (UVA) on the quality of stored platelets using a pool and split strategy and whole blood collected buffy coat (BC) platelet concentrates, with the aim of adding to the existing information. Multiple reports have suggested that micro RNA (miRNA) are important post transcription regulators in platelets, and there have been indications of altered miRNA profile due to pathogen inactivation (PI) methods. Therefore, we examined PI effects on 25 pre-selected miRNAs. Minimal influence was observed, with only 1 out of the 25 showing PI treatment-related down regulation. The release of BRMs from platelets into the storage media presents a potential risk of adverse events, as well as BRMs being indicators of platelet activation during storge. Monitoring the concentration of 36 proteins, we observed both reduction and increase of BRMs related to PI treatment. Additionally, PC utilization in national blood transfusion services (at the Blood Bank of Iceland) was analyzed pre- and post-PI implementation. We observed several PI treatment-related effects on both miRNA profiles and protein concentrations in the storage media, as well as elevated expression of markers of platelets storge lesion (PSL), though these effects did not translate to increased utilization or adverse events. We also observed increased product availability and more efficient stock management due to increased storge time, without an increase in outdated stock.

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