Improved assessment of donor liver steatosis using Banff consensus recommendations and deep learning algorithms.

BACKGROUND & AIMS: The Banff Liver Working Group recently published consensus recommendations for steatosis assessment in donor liver biopsy, but few studies reported their use and no automated deep-learning algorithms based on the proposed criteria have been developed so far. We evaluated Banff recommendations on a large monocentric series of donor liver needle biopsies by comparing pathologists' scores with those generated by convolutional neural networks (CNNs) we specifically developed for automated steatosis assessment. METHODS: We retrospectively retrieved 292 allograft liver needle biopsies collected between January 2016 and January 2020 and performed steatosis assessment using a former intra-institution method (pre-Banff method) and the newly introduced Banff recommendations. Scores provided by pathologists and CNN models were then compared, and the degree of agreement was measured with the intraclass correlation coefficient (ICC). RESULTS: Regarding the pre-Banff method, poor agreement was observed between the pathologist and CNN models for small droplet macrovesicular steatosis (ICC: 0.38), large droplet macrovesicular steatosis (ICC: 0.08), and the final combined score (ICC: 0.16) evaluation, but none of these reached statistically significance. Interestingly, significantly improved agreement was observed using the Banff approach: ICC was 0.93 for the low-power score (p <0.001), 0.89 for the high-power score (p <0.001), and 0.93 for the final score (p <0.001). Comparing the pre-Banff method with the Banff approach on the same biopsy, pathologist and CNN model assessment showed a mean (±SD) percentage of discrepancy of 26.89 (±22.16) and 1.20 (±5.58), respectively. CONCLUSIONS: Our findings support the use of Banff recommendations in daily practice and highlight the need for a granular analysis of their effect on liver transplantation outcomes. IMPACT AND IMPLICATIONS: We developed and validated the first automated deep-learning algorithms for standardized steatosis assessment based on the Banff Liver Working Group consensus recommendations. Our algorithm provides an unbiased automated evaluation of steatosis, which will lay the groundwork for granular analysis of steatosis's short- and long-term effects on organ viability, enabling the identification of clinically relevant steatosis cut-offs for donor organ acceptance. Implementing our algorithm in daily clinical practice will allow for a more efficient and safe allocation of donor organs, improving the post-transplant outcomes of patients.

The American Association of Tissue Banks tissue donor screening for Mycobacterium tuberculosis-Recommended criteria and literature review.

After two multistate outbreaks of allograft tissue-transmitted tuberculosis (TB) due to viable bone, evidence-based donor screening criteria were developed to decrease the risk of transmission to recipients. Exclusionary criteria, commentary, and references supporting the criteria are provided, based on literature search and expert opinion. Both exposure and reactivation risk factors were considered, either for absolute exclusion or for exclusion in combination with multiple risk factors. A criteria subset was devised for tissues containing viable cells. Risk factors for consideration included exposure (e.g., geographic birth and residence, travel, homelessness, incarceration, healthcare, and workplace) and reactivation (e.g., kidney disease, liver disease, history of transplantation, immunosuppressive medications, and age). Additional donor considerations include the possibility of sepsis and chronic illness. Donor screening criteria represent minimal criteria for exclusion and do not completely exclude all possible donor TB risks. Additional measures to reduce transmission risk, such as donor and product testing, are discussed but not included in the recommendations. Careful donor evaluation is critical to tissue safety.

A risk-based approach for cell line development, manufacturing and characterization of genetically engineered, induced pluripotent stem cell-derived allogeneic cell therapies.

Advances in cellular reprogramming and gene-editing approaches have opened up the potential for a new class of ex vivo cell therapies based on genetically engineered, induced pluripotent stem cell (iPSC)-derived allogeneic cells. While these new therapies share some similarities with their primary cell-derived autologous and allogeneic cell therapy predecessors, key differences exist in the processes used for generating genetically engineered, iPSC-derived allogeneic therapies. Specifically, in iPSC-derived allogeneic therapies, donor selection and gene-editing are performed once over the lifetime of the product as opposed to as part of the manufacturing of each product batch. The introduction of a well-characterized, fully modified, clonally derived master cell bank reduces risks that have been inherent to primary-cell derived autologous and allogeneic therapies. Current regulatory guidance, which was largely developed based on the learnings gained from earlier generation therapies, leaves open questions around considerations for donor eligibility, starting materials and critical components, cell banking and genetic stability. Here, a risk-based approach is proposed to address these considerations, while regulatory guidance continues to evolve.

Insights into the diversity of blood donation practice across Asia: How blood collection agencies adapt donor criteria and processes to their population.

BACKGROUND AND OBJECTIVES: Securing an adequate blood supply relies on accurate knowledge of blood donors and donation practices. As published evidence on Asian populations is sparse, this study aims to gather up-to-date information on blood donors and donation practices in Asia to assist planning and strategy development. MATERIALS AND METHODS: Ten blood collection agencies (BCAs) provided 12 months' data on donors who met eligibility criteria or were deferred, as well as details of their donation practices. Body mass index and blood volumes were calculated and analysed. RESULTS: Data on 9,599,613 donations and 154,834 deferrals from six national and four regional BCAs revealed varied donation eligibility and collection practices. Seven used haemoglobin (Hb) criteria below the World Health Organization anaemia threshold. Seven accepted donors weighing <50 kg. Data collection on the weight and height of donors and on deferrals was inconsistent, often not routine. Deferred donors appear to weigh less, with corresponding lower estimated blood volume. CONCLUSION: The diversity in eligibility criteria and donation practices reflects each BCA's strategy for balancing donor health with securing an adequate blood supply. Use of lower Hb criteria substantiate their appropriateness in Asia and indicate the need to define Hb reference intervals relevant to each population. We encourage routine gathering of donor weight and height data to enable blood volume estimation and local optimization of donation volumes. Blood volume estimation formulae specific for the Asian phenotype is needed. Information from this study would be useful for tailoring donation criteria of Asian donors around the world.

Removal of UK-donor deferral for variant Creutzfeldt-Jakob disease: A large donation gain in Australia.

BACKGROUND AND OBJECTIVES: Until 25 July 2022, people who spent more than 6 months in the United Kingdom during the variant Creutzfeldt-Jakob disease (vCJD) risk period 1980-1996 (UK donors) were deferred from blood donation in Australia. Regulatory approval to remove the deferral was underpinned by published mathematical modelling predicting negligible vCJD transmission risk increase with a gain of 58,000 donations. MATERIALS AND METHODS: The donor questionnaire retained the UK deferral screening question until a version update effective 12 February 2023, which enabled identification of the newly eligible cohort of UK donors. Their donations were tracked for a 6-month period (25 July 2022-24 January 2023) and compared with baseline Lifeblood donation metrics and predicted gains. RESULTS: A total of 38,462 UK donors attended to donate 78,762 times in the 6 months. Of these, 32,358 donors (females = 19,456, males = 12,902) successfully donated 67,914 times representing 8.4% of total collections. CONCLUSION: Cessation of the UK deferral resulted in donation gains exceeding modelled predictions because of a higher than predicted number of donors who donated at a higher rate. Had these newly eligible donors not donated, overall donation numbers would have been 88% of target rather than the 96% achieved.

Blood donor eligibility criteria for medical conditions: A BEST collaborative study.

BACKGROUND AND OBJECTIVES: Donor eligibility questions and criteria for medical conditions vary between blood centres, suggesting that they are based more on local regulations or experience, rather than on published data, which are limited. As the donor population ages, medical conditions become more common. We assessed donor health assessment criteria at blood centre members of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative. Our aim was to compare eligibility criteria and determine their underlying basis. MATERIALS AND METHODS: A REDCap survey was sent to blood centre participants, based on medical conditions of greatest interest suggested by the Donor Studies Team of the BEST Collaborative. Participants were asked about current donor health assessment questions, deferral criteria and the basis for their deferral policy (donor risk, recipient risk or both) for 20 medical conditions. RESULTS: Complete responses were received from 26 blood donor centres (24 separate responses) representing a combination of hospital-based centres, large regional centres and community/national blood centres in 14 different countries. Most centres specifically ask about heart and lung conditions, whereas fewer than half inquire about kidney, gastrointestinal or neurological conditions. North American blood centres tended to be less restrictive, while regulatory restrictions are more prevalent in Europe. Most participants felt that the criteria were based on regulatory requirements or experience, rather than on published data. CONCLUSION: There is considerable variability in criteria by region. Ideally, criteria would be more evidence-based rather than based on regulatory requirements or experience. Deferral criteria must balance donor and recipient safety and maintain an adequate blood supply.

Report of the clinical donor case workshop of the European Association of Tissue Banks annual meeting 2014.

The European Association of Tissue Banks (EATB) donor case workshop is a forum held within the program of the EATB annual congress. The workshop offers an opportunity to discuss and evaluate possible approaches taken to challenging situations regarding donor selection. Donor case workshops actively engage participants with diverging background and experience in an informal, secure and enjoyable setting. The resulting discussion with peers promotes consensus development in deciding tissue donor acceptability, especially when donor health issues are not conclusively addressed in standards and regulations. Finally the workshop serves to strengthen the professional tissue banking networks across Europe and beyond. This report reflects some of the discussion at the workshop during the annual congress in Lund, Sweden, in 2014. The cases presented demonstrate that the implications of various donor illnesses, physical findings and behaviours on the safety of tissue transplantation, may be interpreted in a different way by medical directors and other professionals of different tissue facilities. This will also result in diverging preventive measures and decisions taken by the tissue facilities. Some of the donor cases illustrate varied responses from participants and demonstrate that operating procedures, regulations and standards cannot comprehensively cover all tissue donor illnesses, medical histories and circumstances surrounding the cause of death. For many of the issues raised, there is a lack of published scientific evidence. In those cases, tissue bank medical director judgement is critical to guarantee transplantation safety. This judgement should be based on a proper and documented risk assessment case by case. Conditions or parameters taken into account for risk assessment are amongst others, the type of tissue, the type of processing, the characteristics of the final product, and the availability of an adequate sterilisation methodology. By publishing these difficult donor suitability cases, and the resulting discussions, we provide information for future similar cases and we identify needs for future literature review and scientific research. In this way the donor case workshops play a role in optimizing the quality and security of tissue donation.

Medication Deferrals in Blood Donors.

Medication use is extremely common in blood donors. Blood centers use various methods to obtain a history of medication use, all of which have strengths and weaknesses. Some data are available to develop policies for medications that impact product quality, transmissible disease testing, and infectious risks. Many blood centers defer donors for use of a small number of highly teratogenic medications, as a precautionary measure. Others also defer for possible harms related to the pharmacologic effects of medications. However, a single exposure to a blood component containing medication, with immediate dilution in the recipient's blood stream, is a very different situation from ongoing use of medication in a patient, with steady state concentrations achieved over time. It is therefore highly unlikely that these effects are relevant for recipient safety.

Horiba Micros ES 60 Blood Cell Analyzer in Blood Donor Eligibility: A Validation Study.

Background: Eligibility criteria for blood donation require hemoglobin levels of ≥12.5 g/dL for women and ≥13.5 g/dL for men, and a platelet count of ≥180 × 109/L. Screening methods before donation should ensure high accuracy, precision, and ease in operation. We assessed the performance, precision, and repeatability of the Horiba Micros ES 60 (Horiba) compared to the Beckman Coulter DXH 800. Methods: Performance was compared by testing samples for each of the 11 devices across 6 sites in the Transfusion Service of Friuli Venezia Giulia Region, Italy. We measured precision by calculating the coefficient of variation (CV), concordance with ρ-Pearson's correlation coefficient, and accuracy with F-tests. The intra-assay agreement was examined in the 11 devices, and repeatability was performed by using CV and the Kruskal−Wallis test. Results: The precision of Horiba was acceptable. Overall, ρ-Pearson's coefficients indicated a strong correlation and positive relationship between all variables. The Bland−Altman plots showed that most of the differences lay within the limits of agreement. All CV were below the reference threshold for all the parameters. Finally, the Kruskal−Wallis test reported non-significant statistical differences for all parameters, except platelet count (p < 0.000). Conclusions: Horiba is adequate for routine pre-donation screening. The intra-assay agreement further demonstrates the accuracy of the device.

Organ Care System Heart™ in donors requiring high-risk excision of suspected neoplastic lesions.

Although Heart Transplant is still the gold standard treatment for end-stage heart failure patients, the limitation of this procedure is the discrepancy between the amount of waiting list patients and donors. Organ Care Systems, preventing the detrimental effects of cold ischemia, potentially increase donor pool. Herein we report three cases where high-risk excisions were required to clarify the nature of suspected lesions in donors. We decided to retrieve the organs and to place them in the devices before performing the excision. Our experience confirm the possibility to utilise this device as a time buffer in these peculiar scenarios.

Regulatory considerations for pluripotent stem cell therapies.

The development of pluripotent stem cell (PSC) therapies is rapidly advancing, and a number of PSC-derived cell products are currently being tested in clinical trials. The biological complexity of these therapies results in specific challenges in complying with regulatory guidelines. This includes the choice of starting material, reproducible and consistent manufacturing, and preclinical safety and efficacy assessment of the PSC-derived product. This review discusses current US cell therapy regulations and strategies for compliance with these regulations when developing PSC-derived products.