Inactivation of pathogens in platelet concentrates by using a two-step procedure
Related Experiment Video
Updated: Sep 27, 2026
Preparation and Pathogen Inactivation of Double Dose Buffy Coat Platelet Products using the INTERCEPT Blood System
Published on: December 7, 2012
1Blood Center of the German Red Cross Chapters of NSTOB, Institute Springe, Germany. hmohr@bsd-nstob.de
Background And Objectives:
Platelet concentrates are contaminated with residual leucocytes and may also be infected with viruses and bacteria. We investigated whether these pathogens can be inactivated by a two-step procedure comprising photodynamic treatment in the presence of the phenothiazine dye, thionine, followed by irradiation with ultraviolet light (UV-B, wavelength range 290-330 nm).
Materials And Methods:
Platelet concentrates were prepared from buffy coats. The concentrates were spiked with different viruses, bacteria and leucocytes, then illuminated with yellow light in the presence of thionine at dye concentrations between 1 and 5 microm and with UV-B at doses up to 2.4 J/cm2. The infectivity of samples and the viability of leucocytes were assayed before and after treatment. The influence of treatment on in vitro platelet function was also examined.
Results:
The inactivation of free viruses in platelet concentrates by photodynamic treatment with thionine/light was significantly enhanced when it was followed by irradiation with UV-B. The inactivation of leucocytes and of bacteria by UV-B was improved when it was preceded by thionine/light. Sterile platelet concentrates were prepared from buffy coats infected with Staphylococcus epidermidis. Platelet function and the storage stability of platelet concentrates were only moderately influenced by the two decontamination steps.
Conclusions:
Photodynamic treatment in the presence of the phenothiazine dye, thionine, followed by low-dose UVB, has the potential to inactivate viruses, leucocytes and bacteria, which might contaminate platelet concentrates. Both treatments complement each other.
Insights
Photodynamic treatment with thionine and UV-B light effectively inactivates viruses, bacteria, and leucocytes in platelet concentrates. This two-step procedure enhances pathogen elimination while minimally impacting platelet function.
Area of Science:
- Blood product safety
- Transfusion medicine
- Pathogen inactivation
Background:
- Platelet concentrates can harbor residual leucocytes, viruses, and bacteria.
- Contamination poses a risk to transfusion recipients.
Purpose of the Study:
- To evaluate a two-step pathogen inactivation method for platelet concentrates.
- To assess the efficacy of photodynamic treatment with thionine followed by UV-B irradiation.
Main Methods:
- Platelet concentrates were prepared and spiked with viruses, bacteria, and leucocytes.
- Treatment involved photodynamic therapy with thionine and yellow light, followed by UV-B irradiation.
- Pathogen infectivity, leucocyte viability, and platelet function were analyzed.
Main Results:
- The combination of thionine/light and UV-B significantly enhanced virus inactivation.
- UV-B efficacy against leucocytes and bacteria improved when preceded by thionine/light treatment.
- Sterile platelet concentrates were achieved, with only moderate effects on platelet function and storage.
Conclusions:
- Photodynamic treatment with thionine, followed by UV-B, is a promising method for inactivating contaminants in platelet concentrates.
- The two treatment modalities demonstrate complementary pathogen inactivation effects.
- This approach offers potential for safer platelet transfusion products.
