Ute Gravemann

A novel approach to pathogen reduction in platelet concentrates using short-wave ultraviolet light.

BACKGROUND: Transfusion of platelet concentrates (PCs) is the basic treatment for severe platelet disorders. PCs carry the risk of pathogen transmission, especially bacteria. Pathogen reduction (PR) by addition of photochemical reagents and irradiation with visible or ultraviolet (UV) light can significantly reduce this risk. We present a novel approach for PR in PCs employing UVC light alone.

BLOOD COMPONENTS: A novel approach to pathogen reduction in platelet concentrates using short‐wave ultraviolet light

BACKGROUND: Transfusion of platelet concentrates (PCs) is the basic treatment for severe platelet disorders. PCs carry the risk of pathogen transmission, especially bacteria. Pathogen reduction (PR) by addition of photochemical reagents and irradiation with visible or ultraviolet (UV) light can significantly reduce this risk. We present a novel approach for PR in PCs employing UVC light alone.

Sterilization of platelet concentrates at production scale by irradiation with short-wave ultraviolet light

BACKGROUND: Bacterial contamination of platelet concentrates (PCs) is recognized as a serious threat to transfusion safety. We developed a simple method for sterilization of PCs with short‐wave ultraviolet light (UVC). The effects of treatment on the sterility of contaminated PCs and in vitro platelet (PLT) variables were evaluated.

Elimination and multiplication of bacteria during preparation and storage of buffy coat-derived platelet concentrates.

BACKGROUND:  The prevalence of bacterial contamination of random‐donor platelet concentrates (PCs) is considerably lower than that of blood donations. Which key steps of the preparation procedure contribute to the elimination of bacteria was investigated.

West Nile virus in plasma is highly sensitive to methylene blue–light treatment

BACKGROUND:  The epidemic of West Nile virus (WNV) in the US resulted in cases of transfusion‐transmitted WNV. Effective pathogen reduction methods could have removed this infectious agent from the blood supply We have evaluated the efficacy of photodynamic treatment of fresh frozen plasma (FFP) with methylene blue (MB), a decontamination method applied in several European countries.

Two pathogen reduction technologies—methylene blue plus light and shortwave ultraviolet light—effectively inactivate hepatitis C virus in blood products

BACKGROUND: Contamination of blood products with hepatitis C virus (HCV) can cause infections resulting in acute and chronic liver diseases. Pathogen reduction methods such as photodynamic treatment with methylene blue (MB) plus visible light as well as irradiation with shortwave ultraviolet (UVC) light were developed to inactivate viruses and other pathogens in plasma and platelet concentrates (PCs), respectively. So far, their inactivation capacities for HCV have only been tested in inactivation studies using model viruses for HCV. Recently, a HCV infection system for the propagation of infectious HCV in cell culture was developed.

Inactivation of dengue, chikungunya, and Ross River viruses in platelet concentrates after treatment with ultraviolet C light

Arboviruses, including dengue (DENV 1‐4), chikungunya (CHIKV), and Ross River (RRV), are emerging viruses that are a risk for transfusion safety globally. An approach for managing this risk is pathogen inactivation, such as the THERAFLEX UV‐Platelets system. We investigated the ability of this system to inactivate the above mentioned arboviruses.

Inactivation of pathogens in single units of therapeutic fresh plasma by irradiation with ultraviolet light.

BACKGROUND: Ultraviolet (UV) light, especially UVC, is germicidal but its ability to penetrate layers of protein containing solutions is poor. This hampers its use to inactivate pathogens in therapeutic fresh plasma (FP).

Thrombin Generation Capacity of Methylene Blue-Treated Plasma Prepared by the Theraflex MB Plasma System

Background: Methylene blue (MB) / light treatment is a well-known procedure for the inactivation of pathogens in fresh frozen plasma (FFP). Aim of the current study was to investigate the thrombin generation (TG) characteristics and quality of MB plasma prepared by the Theraflex MB Plasma System. Methods: Single donor plasma units (n = 18) were MB/light-treated, with sampling before and after processing. Preparation included leukocyte depletion, addition of MB pill prior to illumination, and depletion of MB and photoproducts by filtration. Different plasma parameters and TG were measured. TG additionally was determined in solvent/detergent plasma (n = 8). Results: MB/light treatment significantly affected factors V, VIII and XI, which were decreased by 9–18%. While the antigen level was not affected, fibrinogen according to Clauss was decreased by 7%, correlating with a 12% prolongation of TT and RT. The total amount of free thrombin generated, given as ‘area under the curve’ (AUC), was comparable for untreated (93 ± 18% of normal plasma) and MB/light-treated plasma (95 ± 20%). Also peak thrombin concentration was not significantly affected by treatment (94 ± 11% (untreated) vs. 96 ± 12% (treated)). The ‘time to peak’ value (TTP) was 105% of normal plasma for untreated FFP and 89% for MB-treated plasma. Conclusion: For plasma treated with the Theraflex MB Plasma System no profound influence of MB/ light treatment on the characteristics of thrombin generation was detected. In concordance with data from the literature, coagulation factors V, VIII and XI were decreased due to MB/ light treatment. Decrease was less than 20%.

Assessment of cross-species transmission of hepatitis C virus-related non-primate hepacivirus in a population of humans at high risk of exposure.

The recent discovery of hepatitis C virus (HCV)-related viruses in different animal species has raised new speculations regarding the origin of HCV and the possibility of a zoonotic source responsible for the endemic HCV transmission. As a consequence, these new findings prompt questions regarding the potential for cross-species transmissions of hepaciviruses. The closest relatives to HCV discovered to date are the non-primate hepaciviruses (NPHVs), which have been described to infect horses. To evaluate the risk of a potential zoonotic transmission, we analysed NPHV RNA and antibodies in humans with occupational exposure to horses in comparison with a low-risk group. Both groups were negative for NPHV RNA, even though low seroreactivities against various NPHV antigens could be detected irrespective of the group. In conclusion, we did not observe evidence of NPHV transmission between horses and humans.