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  1. Science & Research (Biologics)

Studies on Safety and Efficacy of Platelets and Other Transfused Blood Products

Principal Investigator: J.G. Vostal, MD, PhD
Office / Division / Lab: OBRR / DH / LCH

General Overview

Our laboratory studies ways to improve the safety and effectiveness of platelet and red cell transfusion products. We are trying to understand how the cells that will be transfused are affected by collection, processing, storage conditions and new materials used to make equipment for these activities. Our staff is developing new ways to measure the quality of current and future transfusion products to,understand how changes in the quality of the products could impact the health of patients.

One safety issue relevant to current transfusion products is contamination by pathogens, such as bacteria, during the collection process. The current approach to transfusion of contaminated products is to test them for the presence of pathogens. However, pathogen testing has drawbacks. Post-marketing clinical trials of a culture-based bacterial detection system found that these methods lack sensitivity and often falsely reported that there was no bacterial contaminated of platelets. European countries faced with the same problem use pathogen reduction (PR)--treatments that reduce the number of infectious microorganisms--as an alternative to testing blood products for the presence of pathogens. In the US, a Phase 3 clinical trial that investigated the safety and efficacy of platelets treated with a pathogen reduction process found an unexpectedly high rate of lung related adverse events associated with this technique. These and other clinically significant problems found by this study have raised serious questions about the safety and efficacy of platelets treated by PR.

Another safety issue concerns the age of stored red cells. Recent reports on retrospective clinical studies have noted that there may be a difference in clinical outcomes of patients transfused either with fresh or stored red cells. Prospective studies will be needed to resolve this issue, but such studies did raise concerns about the safety of stored red cells.

Our laboratory is working to find solutions to the problems associated with stored and processed platelets and red blood cells. Specifically, we are developing an animal model of acute lung injury in response to platelet products exposed to pathogen reduction methods. This project involves characterizing changes to platelets exposed to PR methods (ultraviolet light) and monitoring physiological changes associated with infusion of PR platelets into the animal model. We are also trying to identify the differences between stored and fresh red cells that could account for the unexpected clinical outcomes following transfusion. This research could lead to safer and more effective transfusion products. The training and experience it provides to our staff will make them more effective regulators of blood products.

Scientific Overview

Our laboratory studies ways to improve on the safety and efficacy of platelet and red cell transfusion products. We work to understand how these cellular transfusion products are affected by collection and processing methods, storage conditions, and new materials used to make equipment for these activities. We are working to develop new ways to evaluate current and future transfusion products that maintain and improve their safety and efficacy and to understand how their transfusion impacts the welfare of patients.

As part of this work we exposed human platelets to UV A or UV B light at doses similar to those used in current pathogen reduction methods. We characterized the exposed platelets with in vitro tests and infused them into immunodeficient animals to monitor intravascular recovery and survival. To measure in vivo distribution, we infused fluorescently labeled platelets into anaesthetized animals and monitored the platelet distribution into organs in real time and post mortem. Using cell staining and microscopy we also studied alterations in lung physiology and used confocal microscopy to localize human platelets in lung tissue. Our studies found that infused, UV-exposed platelets accumulated in the lungs but only in animals that were sensitized by an infusion of bacterial extract (LPS) to simulate sepsis. This also led to increased numbers of leukocytes and platelets in bronchoalveolar lavage fluid, which reflects acute lung injury. Platelets that were not processed with UV light did not accumulate in the lungs. These results suggest that the clinical lung-related adverse events could have been the result of UV exposed platelets accumulating in lung of patients who may have had a simultaneous bacterial infection. We are currently investigating the molecular mechanisms in platelets induced by UV light that mediate platelet accumulation in the lungs and acute lung injury.

Our work with red cells focuses on the changes that take place during their storage. As red cells age in storage they become more fragile, less flexible, and more likely to lyse. These changes could potentially pose health risks to transfused patients as has been suggested by some recent clinical studies. Hemoglobin released during red cell lysis is highly toxic to vascular cells and organs, such as the kidney. Release of hemoglobin in clinical situations could lead to acute organ damage or could increase the morbidity of the patient in the long term.

One characteristic of stored red cells is a decrease in resistance to osmotic stress, which has been correlated with loss of both cell membrane and intrinsic membrane flexibility. We found that incubating stored red cells with medium containing extra nutrients to replenish their internal energy stores improved the resilience of stored red cells to physical and osmotic stress. We compared the resistance of fresh and red cells to osmotic stress or physical stress induced by repeated passage through a pump that squeezes the cells. Cells that were rejuvenated in the high nutrient solution had significant improvement in resistance to osmotic and physical stress. Rejuvenation of stored red cells may be useful in improving clinical performance of red cell transfusions.


  1. J Med Virol 2021 Aug;93(8):5134-40
    Viral reduction of human blood by UVA photosensitized vitamin K5.
    He Y, Xu F, Ibrahim Z, Feyissa Q, Reed JL, Vostal JG
  2. PLoS One 2021 May 11;16(5):e0250120
    P38 mitogen activated protein kinase inhibitor improves platelet in vitro parameters and in vivo survival in a SCID mouse model of transfusion for platelets stored at cold or temperature cycled conditions for 14 days.
    Skripchenko A, Gelderman MP, Vostal JG
  3. Transfusion 2021 Feb;61(2):594-602
    Synergistic bactericidal effects of pairs of photosensitizer molecules activated by ultraviolet A light against bacteria in plasma.
    Feyissa Q, Xu F, Ibrahim Z, Li Y, Xu KL, Guo Z, Ahmad J, Vostal JG
  4. Transfusion 2020 Oct;60(10):2379-88
    Validation of a SCID mouse model for transfusion by concurrent comparison of circulation kinetics of human platelets, stored under various temperature conditions, between human volunteers and mice.
    Gelderman MP, Cheng C, Xu F, Skripchenko A, Ryan J, Li Y, Whitley P, Wagner SJ, Vostal JG
  5. Photodiagnosis Photodyn Ther 2020 Jun;30:101713
    Inactivation of bacteria in plasma by photosensitizers benzophenone and vitamins K3, B1 and B6 with UV A light irradiation.
    Xu F, Feyissa Q, Ibrahim Z, Li Y, Xu KL, Guo Z, Ahmad J, Vostal JG
  6. Front Med 2019 Dec 17;6:300
    Macrophage depletion mitigates platelet aggregate formation in splenic marginal zone and alleviates LPS-associated thrombocytopenia in rats.
    Li Y, Ryan J, Xu F, Vostal JG
  7. FEMS Microbiol Lett 2018 Feb 1;365(4):fny005
    Vitamin K5 is an efficient photosensitizer for ultraviolet A light inactivation of bacteria.
    Xu F, Li Y, Ahmad J, Wang Y, Scott D, Vostal JG
  8. Transfusion 2018 Jan;58(1):25-33
    Temperature cycling during platelet cold storage improves in vivo recovery and survival in healthy volunteers.
    Vostal JG, Gelderman MP, Skripchenko A, Xu F, Li Y, Ryan J, Cheng C, Whitley P, Wellington M, Sawyer S, Hanley S, Wagner SJ
  9. Transfusion 2018 Jan;58(1):255-66
    Proceedings of the Food and Drug Administration's public workshop on new red blood cell product regulatory science 2016.
    Vostal JG, Buehler PW, Gelderman MP, Alayash AI, Doctor A, Zimring JC, Glynn SA, Hess JR, Klein H, Acker JP, Spinella PC, D'Alessandro A, Palsson B, Raife TJ, Busch MP, McMahon TJ, Intaglietta M, Swartz HM, Dubick MA, Cardin S, Patel RP, Natanson C, Weisel JW, Muszynski JA, Norris PJ, Ness PM
  10. PLoS One 2016 Dec 13;11(12):e0166657
    Evaluation of stem cell-derived red blood cells as a transfusion product using a novel animal model.
    Shah S, Gelderman MP, Lewis MA, Farrel J, Wood F, Strader MB, Alayash AI, Vostal JG
  11. Transfusion 2016 Jan;56(1):24-32
    Automated cold temperature cycling improves in vitro platelet properties and in vivo recovery in a mouse model compared to continuous cold storage.
    Skripchenko A, Gelderman MP, Awatefe H, Turgeon A, Thompson-Montgomery D, Cheng C, Vostal JG, Wagner SJ
  12. Transfusion 2015 Nov;55(11):2590-6
    Expression of the cellular prion protein affects posttransfusion recovery and survival of red blood cells in mice.
    Glier H, Simak J, Panigaj M, Gelderman MP, Vostal JG, Holada K
  13. Haematologica 2015 May;100(5):611-22
    Reversal of hemochromatosis by apo-transferrin in non-transfused and transfused Hbbth3/+ (heterozygous b1/ b2 globin gene deletion) mice.
    Gelderman MP, Baek JH, Yalamanoglu A, Puglia M, Vallelian F, Burla B, Vostal J, Schaer DJ, Buehler PW
  14. J Proteome Res 2015 Feb 6;14(2):1089-100
    Integrative proteome and transcriptome analysis of extramedullary erythropoiesis and its reversal by transferrin treatment in a mouse model of beta-thalassemia.
    Vallelian F, Gelderman MP, Schaer CA, Puglia M, Opitz L, Baek JH, Vostal J, Buehler P, Schaer DJ


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