BMC Seminar Thursday 26th November at 12:00 in room 124 Læknagarður
Title: Platelet concentrates storage and pathogen inactivation methods.
Speaker: Níels Árni Árnason, a PhD student at the Blood Bank Center, Landspítali University Hospital.
Abstract: Platelets are small, discoid shaped cells of 1-2 μm in diameter, lacking a nucleus but with an otherwise well-defined and highly compartmentalised interior. Although without a nucleus platelets harbour RNA, mRNA, ribosome’s and all the necessary components for de novo protein synthesis. Post transcriptional control of protein synthesis in platelets is partly controlled by small 18-24 nucleotide none coding RNA molecules named micro RNA (miRNA). Platelets originate ultimately from hematopoietic stem cell differentiation followed by megakaryocyte fragmentation. Circulating in blood for up to 10 days at a concentration of roughly 150-350 x 109/L, platelets are key blood elements and renowned for their central role in haemostasis. Modern healthcare is greatly dependent on the banking and transfusion of blood products in the form of plasma, red blood cell and platelet concentrates. Unfortunately, platelets have a limited storage time due to a reduction in functionality that occurs during storage commonly referred to as platelet storage lesion (PSL). PSL can be induced by multiple factors.
Alongside bacterial contamination, PSL is one of two biggest factors that limit platelet storage time, to 5-7 days. To reduce the risk of pathogen contamination beyond the standard bacterial and viral screening many blood banks have implemented new procedures that use chemical and UVA light treatment. The effect of these new procedures on platelet function has been studied to some extend with conflicting outcomes in some cases. To further decipher the processes leading to PSL and possible effects of newly implemented pathogen inactivation (PI) treatments hour lab will use a system biology approach monitoring changes in the platelet miRnome, metabolome, proteome, morphology and degree of activation during storage.
Two platelet units are manufactured from 8 buffy coat units each with matched ABO blood type . The two units are combined into a single unit and then split again, generating two identical units stemming from 16 donors each. These units will serve as control or receive PI treatment. Both units will be sampled prior to the PI treatment (Day 1) and three times after the PI treatment (day 2, 4 and 7).
Preliminary results indicate that platelet receiving PI treatment show elevation of some activation markers more prematurely compared to the control. When comparing the miRNA profile, more miRNA where statistically different early in the storage period for PI treated platelets compared to control platelets. These results indicate that PI treatment effects the time rate of PSL in stored platelets.