56. Jahrestagung der Deutschen Gesellschaft für Transfusionsmedizin und Immunhämatologie

Vorsitz

Prof. Dr.

HEV incidence in the German blood donor population - 1 in 1000 is RNA positive

Background Transfusion transmitted HEV infections pose a risk of serious illness especially to immunocompromised recipients. In Germany, screening of blood donations for HEV-RNA is mandatory since 2020 for all non-virus-inactivated packed red cells, platelet concentrates and plasma. A detection limit of 2000 IU/ml HEV-RNA must be ensured. This is the first nationwide analysis of HEV incidence in the German blood donor population. Methods Data from the national blood donor surveillance system were used to estimate sex, age and regional stratified incidences of acute asymptomatic HEV infections and compared to data from mandatory reports according to the Infection Protection Act on symptomatic infections.Results Altogether 3507 HEV infections were reported in 2020 in 3,437,039 donors (102/100,000 donors). Male donors were 1.8 times more affected than females (127 vs. 71/100,000). HEV incidence was twice as high in donors &gt;44 yrs as in donors &lt;25 yrs (150 vs 74/100,000). Regional differences were found with highest incidence in the state of Brandenburg (169/100,000) and lowest in Baden-Wurttemberg (74/100,000). Reported symptomatic infections showed a similar pattern but incidences were 20 to 30 times lower. The overall incidence was 5.2/100,000 in the general population (18-78 yrs) and was also age dependent (44 yrs: 2.5 vs. 6.5/100,000). The difference between males (6.0/100,000) and females (4.3/100,000) was less pronounced. The regional spread of infections among donors was also observed in symptomatic infections.Conclusion In 2020 1 in 1000 donors was detected positive for HEV RNA. This is a much larger incidence than any other infection tested for. According to recent viral load analyses [1, 2] the current obligatory test sensitivity could result in further 3000-10,000 undetected infections. While it is assumed that most are not infectious due to a low viral load, the large number of undetected infections may pose a residual risk of infectious donations that should not go unnoticed. Therefore, hemovigilance data should be carefully monitored to check whether the required sensitivity should be amended. [1] Vollmer T, Diekmann J, Knabbe C, Dreier J. Hepatitis E virus blood donor NAT screening: as much as possible or as much as needed? Transfusion. 2019;59(2):612-22. [2] Cordes AK, Goudeva L, Lütgehetmann M, Wenzel JJ, Behrendt P, Wedemeyer H, et al. Risk of transfusion-transmitted hepatitis E virus infection from pool-tested platelets and plasma. J Hepatol. 2022;76(1):46-52. Offenlegung Interessenkonflikt: The authors declare that they have no conflict of interests. Invited talks abstract/summary

Blood Safety

Freier Vortrag (Reinhold-Eckstein-Investigator-Award)

Hepatitis E and blood donation: Status quo after 3 years of mandatory testing

Background The testing of blood and stem cell donations for the hepatitis E virus (HEV) was introduced as mandatory for Germany on 01.01.2020. Since then, numerous donations have been found to be HEV-positive and have not been marketed. The positive test result was associated with a traceability procedure as defined in Votum 48 of the Working Group on Blood. We report on our experience with testing in the period from 01.01.2020 to 31.12.2022.Methods Sample material from each donation was tested for the presence of HEV genome using NAT. Routine HEV nucleic acid test (NAT) donor screening of minipools ≤ 96 was performed on the fully automated cobas 8800 system using the cobas HEV test kit (Roche Diagnostics). Minipools and subpools for pool resolution are generated by MicroLab Star IVD liquid handler (Hamilton) using 100 µl aliquots EDTA-anticoagulated plasma of each donor sample. Initially reactive minipool resolution has been performed by "chessboard subpooling" testing, finally confirming putative HEV positive sample(s) by individual NAT.Results 1734 donations were identified as HEV-positive, 1613 from repeat donors and 121 from first-time donors. In the look-back procedure, the pre-donations of 25 donors were identified as HEV genome positive. All donors were clinically healthy at the time of donation.Conclusion Donors cannot be identified as possibly infected with HEV on the basis of the donor questionnaire because the infection is usually not a sexually transmitted disease. The infestation of our donor population is high compared to other pathogens tested. In contrast to the other mandatory donor tests, a significantly higher group of repeat donors is affected for HEV because, unlike other test parameters, the prevalence of the infection is always reflected in the group of multiple donors.Offenlegung Interessenkonflikt: Keine Interessenskonflikte

Freier Vortrag

Malaria testing: NAT or infectious serology or both?

Background Potential donors who have a malaria risk are currently examined by means of NAT before collecting a first donation in the DRK BSD West. According to a recommendation of the WGB, it is preferable to be tested with an infectious serological test. In 2022 we identified two potential donors who had plasmodia genome in the NAT. Only one case showed a positive result in an infection serological test for antibodies against plasmodia.Methods In accordance with GL, nucleic acid testing (NAT) by PCR is performed at our facility after a retention period of 4 years using the AltoStar Purification Kit 1.5 combined with RealStar Malaria PCR Kit 1.0 and Alto Star AM 16 system (altona Diagnostics). In addition to the validated molecular biological testing, an infectious serological examination by means of an ELISA, which is approved for donor testing in Germany, shall be introduced. Therefore, the NovaLISA malaria immunoassay and the ETI-Max 3000 analyser will be used. The results of the two methods will be compared.Results Still pending.Conclusion The results are to be discussed against the background of the WBG recommendation. The question will be raised whether PCR tests are dispensable or whether the combination of infection serological and NAT tests should be preferred.Offenlegung Interessenkonflikt: Keine Interessenskonflikte

Implementation of a UVC-based pathogen reduction treatment for apheresis platelets at a regional blood service in Germany

Background Until now, pathogen reduction treatment for platelet concentrates (PCs) is not mandatory in Germany. Nevertheless, the Bavarian Red Cross Blood Service started to implement the THERAFLEX UV-Platelets System (Macopharma) as effective and preventive measure to increase blood safety. The UVC-based system for PCs was validated as required for manufacturing license and marketing authorization approval.Methods Six double apheresis PCs were collected and split into 12 single units. Six PCs were treated with the THERAFLEX UV-Platelets System, while the other six corresponding PCs were left untreated and served as control. Pathogen reduction of PCs using the THERAFLEX UV-Platelets System was performed under routine-like conditions. PCs were stored under agitation at 22 +/- 2 °C and samples were collected on day 2, day 6 and day 9. Platelet in vitro quality parameters were tested according to the local standard operation procedures. Manufacturing steps of the THERAFLEX UV-Platelets procedure were validated, and UVC treatment was monitored in the platelet units using a mitochondrial DNA multiplex real-time polymerase chain reaction inhibition assay.Results Platelet content per unit was between 3,12 x 1011 and 3,75 x 1011 (mean 3,43 x 1011) in UVC-treated PCs and between 3,25 x 1011 and 3,91 x 1011 (mean 3,56 x 1011) in control units. Pathogen-reduced and untreated PCs showed similar result in swirling and hypotonic shock reaction until day 9 and were tested negative for anaerobic and aerobic bacterial growth. During time of storage glucose concentration decreased and lactate concentration increased in all units. Glucose consumption was higher in UVC-treated units than in untreated units; however, glucose was still present on day 9. The mitochondrial polymerase chain reaction analysis correctly discriminated between UVC-treated and untreated PCs.Conclusion UVC treatment of apheresis PCs is a fast and easy procedure and was successfully integrated into the local manufacturing processes. All UVC-treated PCs fulfilled the specifications of the THERAFLEX UV-Platelets technology and met the requirements of the German guidelines for pathogen-reduced PCs.Offenlegung Interessenkonflikt: Macopharma supports the work with project grants for the development of UVC-based PI technology of platelets. Research Foundation of the German Red Cross Blood Services supports the work with project grants for the development of UVC-based PI technology of platelets.

Virus inactivation of plasma by methylene blue/light treatment using a DEHP-free bag system

Background DEHP is a widely used plasticizer in blood bags. Due to its endocrine disrupting properties European regulators decided to ban its use in medical devices. Although, the final sunset date is not yet clear, DEHP-free blood bags will be essential in Europe within the next years. Inactivation capacity of model viruses varying in structure and biophysical characteristics by Methylene blue (MB)/light treatment of plasma using THERAFLEX MB-plasma system (DEHP-free, Macopharma) was investigated.Methods Leuko-depleted plasma was prepared from whole blood using standard blood banking technology (containing DEHP). Plasma units were spiked with virus suspension (10% v/v; Suid Herpes Virus (SHV-1), Bovine Viral Diarrhea Virus (BVDV), Feline Calici Virus (FCV), Vesicular Stomatitis Virus (VSV)). MB/light treatment was done according to manufacturer&quot;s instructions (Macotronic B2 illumination device) with the DEHP-free THERAFLEX MB-Plasma system PROSDV1. Samples were taken after spiking and after illumination with different light doses (30, 60, 90 J/cm2: n=3 and 120 (standard) J/cm2: n=6) The virus titer were determined as tissue culture infective dose (TCID50) by endpoint titration Large volume plating was done to improve the detection limit.Results Log10 reduction factors of ≥ 5.89 and ≥ 5.50 log steps were achieved for BVDV at a light dose of 120 J/cm2 in the respective experiments with and without intermediate sampling. Log10 reduction factors of ≥ 4.29 and ≥ 4.17 log steps were achieved for FCV, ≥ 4.96 and ≥ 4.92 log steps for SHV-1 and ≥ 5.35 and 4.77 log steps for VSV with and without intermediate sampling.Conclusion All of the viruses tested in this study were inactivated with reduction factors ≥ 4 log steps at the final illumination dose of 120 J/cm2 using the DEHP-free bag disposable PROSDV1 and the illumination device Macotronic B2. Reduction factors are comparable to data achieved in the past for the DEHP-containing THERAFLEX MB-Plasma system.Offenlegung Interessenkonflikt: Study was sponsored by Macopharma Productions (CS).

Virus inactivation by UV-C irradiation of two plasma proteins, trimodulin (IgM concentrate) and fibrinogen

Background To ensure high safety margins with respect to adventitious viruses for therapeutic proteins purified from human plasma, different physico-chemical technologies are available to inactivate/remove viruses during manufacturing. Choices are limited for inactivation/removal of non-enveloped viruses which are typically more robust and smaller. Furthermore, when proteins are very large and also sensitive towards harsh treatments, no universally applicable inactivation/removal technology for non-enveloped viruses may be available.Methods Protein solutions were treated with Ultraviolet C (UV-C) irradiation at 254 nm with low-pressure mercury lamps. Inactivation of viruses was measured by cell-based infectivity assays (i.e. virus titration)Results We show effective inactivation of Hepatitis A virus (HAV) and porcine parvovirus (PPV), a model for human parvovirus B19 (B19V), after irradiation with 200 J/m². Inactivation of lipid-enveloped viruses at this dose showed mixed results . At 100 J/m², inactivation was still effective for PPV.Conclusion UV-C irradiation is a valuable virus inactivation tool for proteins from human blood or plasma when other methods cannot be employed for various reasons.Offenlegung Interessenkonflikt: Beide Autoren sind Angestellte von Biotest AG, ein kommerzieller Produzent von Arzneimitteln aus humanem Plasma.

Blood Safety

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