Physical Examination of Potential Deceased Organ and Tissue Donors: An Overview of the European Landscape.

Physical examination (PE) of donors is essential to identify potential risks to the safety and efficacy of donated organs and tissues and is mandatory in the EU. However, no detailed guidance is available as to how PE should be performed. Health authorities (HA) and health professionals (HP) in member states of the European Committee on Organ Transplantation of the Council of Europe (CD-P-TO) and observer countries completed surveys relating to the regulatory requirements for PE and the professional practice of PE in their countries for organ and tissue donors. The HA survey addressed regulatory aspects, and the HP survey addressed professional practices, training, and respondents' opinions on the value of PE. These surveys revealed significant inter-country variation in the regulatory approach to PE and the performance of PE by professionals. Most respondents opined that PE was important and yielded valuable information in identifying contraindications to donation. There is no consensus at a regulatory or professional level as to how PE should be performed on organ and tissue donors. There is a requirement for agreed best practice guidelines in this area.

How donor selection criteria can be evaluated with limited scientific evidence: lessons learned from the TRANSPOSE project.

BACKGROUND AND OBJECTIVE: Donor selection criteria (DSC) are a vital link in the chain of supply of Substances of Human Origin (SoHO) but are also subject to controversy and differences of opinion. Traditionally, DSC have been based on application of the precautionary principle. MATERIALS AND METHODS: From 2017 to 2020, TRANSPOSE (TRANSfusion and transplantation PrOtection and SElection of donors), a European research project, aimed to identify discrepancies between current DSC by proposing a standardized risk assessment method for all SoHO (solid organs excluded) and all levels of evidence. RESULTS: The current DSC were assessed using a modified risk assessment method based on the Alliance of Blood Operators' Risk-based decision-making framework for blood safety. It was found that with limited or diverging scientific evidence, it was difficult to reach consensus and an international standardized method for decision-making was lacking. Furthermore, participants found it hard to disregard their local guidelines when providing expert opinion, which resulted in substantial influence on the consensus-based decision-making process. CONCLUSIONS: While the field of donation-safety research is expanding rapidly, there is an urgent need to formalize the decision-making process regarding DSC. This includes the need for standardized methods to increase transparency in the international decision-making process and to ensure that this is performed consistently. Our framework provides an easy-to-implement approach for standardizing risk assessments, especially in the context of limited scientific evidence.

Critical pathway for deceased tissue donation: a novel adaptative European systematic approach.

A 'Critical pathway for deceased tissue donation' was developed by the European Committee on Organ Transplantation of the Council of Europe (CD-P-TO) with the aim of providing a common systematic approach to the deceased tissue donation process. Definitions of tissue donors according to the donation stage have been developed so that they can be adapted to different local scenarios. This critical pathway can be used retrospectively to evaluate the potential of tissue donation, assess performance in the tissue donation process and identify areas for improvement. It sets the basis to build indicators to compare organizations, regions and countries. The critical pathway can also be used prospectively to promote good practices in tissue donation programmes aimed at covering the tissue transplantation needs of patients.

Re-assessing the risk of undetected HBV, HCV and HIV in deceased tissue and living surgical bone donors in England.

Testing of living surgical bone and deceased tissue donors by NHS Blood and Transplant (NHSBT) has included individual donation (ID) nucleic acid testing (NAT) for HBV, HCV and HIV since 2008. Here, the well-established window period methodology was used to estimate residual risk (RR). Prevalence of viral markers was calculated among both tissue donor populations. Incidence was derived by adjusting incidence among new blood donors by the prevalence ratio for tissue and new blood donors. Residual risk (RR) was calculated as the product of incidence and duration of WP for single donor HBV NAT at 0.058 years (21 days), HCV NAT at 0.008 years (3 days) and HIV NAT at 0.014 (5 days). Between 2013 and 2017, 7886 living surgical bone donors were tested, 16 were positive for markers of HBV, HCV and HIV. HCV had the highest prevalence at 114/100,000 donors. Incidence and RR was highest for HBV at 3.55/100,000-person years and 0.32/100,000 donors (95% CI 0.11/100,000-1.42/100,000). Among 9751 deceased tissue donors tested, 22 were positive for viral markers. HBV had highest prevalence at 174/100,000 donors, and the highest incidence and RR at 8.12/100,000 person years and 0.74/100,000 donors (95% CI 0.08/100,000-2.99/100,000). Using ID NAT, RR of not detecting a HBV, HCV and HIV WP donation among tissue donors is less than 1/100,000 donors. These estimates provide a good starting point for discussing potential risks of viral transmission through tissue transplant with patients.

Algorithms for the Testing of Tissue Donors for Human Immunodeficiency Virus, Hepatitis B Virus, and Hepatitis C Virus.

BACKGROUND: Although transmission of pathogenic viruses through human tissue grafts is rare, it is still one of the most serious dreaded risks of transplantation. Therefore, in addition to the detailed medical and social history, a comprehensive serologic and molecular screening of the tissue donors for relevant viral markers for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) is necessary. In the case of reactive results in particular, clear decisions regarding follow-up testing and the criteria for tissue release must be made. METHODS: Based on the clinical relevance of the specific virus markers, the sensitivity of the serological and molecular biological methods used and the application of inactivation methods, algorithms for tissue release are suggested. RESULTS: Compliance with the preanalytical requirements and assessment of a possible hemodilution are mandatory requirements before testing the blood samples. While HIV testing follows defined algorithms, the procedures for HBV and HCV diagnostics are under discussion. Screening and decisions for HBV are often not as simple, e.g., due to cases of occult HBV infection, false-positive anti-HBc results, or early window period positive HBV NAT results. In the case of HCV diagnostics, modern therapies with direct-acting antivirals, which are often associated with successful treatment of the infection, should be included in the decision. CONCLUSION: In HBV and HCV testing, a high-sensitivity virus genome test should play a central role in diagnostics, especially in the case of equivocal serology, and it should be the basis for the decision to release the tissue. The proposed test algorithms and decisions are also based on current European recommendations and standards for safety and quality assurance in tissue and cell banking.

Parvalbumin Interneurons Shape Neuronal Vulnerability in Blunt TBI.

Excessive excitation has been hypothesized to subsume a significant part of the acute damage occurring after traumatic brain injury (TBI). However, reduced neuronal excitability, loss of neuronal firing, and a disturbed excitation/inhibition balance have been detected. Parvalbumin (PV) interneurons are major regulators of perisomatic inhibition, principal neurons firing, and overall cortical excitability. However, their role in acute TBI pathogenic cascades is unclear. We exploited the chemogenetic Pharmacologically Selective Activation Module and Pharmacologically Selective Effector Module control of PV-Cre+ neurons and the Designer Receptors Exclusively Activated by Designer Drug (DREADD) control of principal neurons in a blunt model of TBI to explore the role of inhibition in shaping neuronal vulnerability to TBI. We demonstrated that inactivation of PV interneurons at the instance or soon after trauma enhances survival of principal neurons and reduces gliosis at 7 dpi whereas, activation of PV interneurons decreased neuronal survival. The protective effect of PV inactivation was suppressed by expressing the nuclear calcium buffer PV-nuclear localisation sequence in principal neurons, implying an activity-dependent neuroprotective signal. In fact, protective effects were obtained by increasing the excitability of principal neurons directly using DREADDs. Thus, we show that sustaining neuronal excitation in the early phases of TBI may reduce neuronal vulnerability by increasing activity-dependent survival, while excess activation of perisomatic inhibition is detrimental to neuronal integrity.

EuroGTP II: a tool to assess risk, safety and efficacy of substances of human origin.

A systematic methodology, able to assess risk and predict clinical safety and efficacy of Substances of Human Origin' (SoHO) has been developed. The model consists of a risk based approach taking into account factors such as novelty of the product, preparation process, clinical indication, and its technical complexity.

Ethanol Intoxication Alleviates the Inflammatory Response of Remote Organs to Experimental Traumatic Brain Injury.

Traumatic brain injury (TBI) may cause damage to distant organs. Acute ethanol intoxication (EI) induces complex local and systemic anti-inflammatory effects and influences the early outcomes of traumatized patients. Here, we evaluated its effects on the BI-induced expression of local inflammatory mediators in the trauma-remote organs the lungs and liver. Male mice were exposed to ethanol as a single oral dose (5g·kg-1, 32%) before inducing a moderate blunt TBI. Sham groups underwent the same procedures without TBI. Ether 3 or 6h after the TBI, the lung and liver were collected. The gene expression of HMGB1, IL-6, MMP9, IL-1ß, and TNF as well as the homogenate protein levels of receptor for advanced glycation end products (RAGE), IL-6, IL-1ß, and IL-10 were analyzed. Liver samples were immunohistologically stained for HMGB1. EI decreased the gene expressions of the proinflammatory markers HMGB1, IL-6, and MMP9 in the liver upon TBI. In line with the reduced gene expression, the TBI-induced protein expression of IL-6 in liver tissue homogenates was significantly reduced by EI at 3h after TBI. While the histological HMGB1 expression was enhanced by TBI, the RAGE protein expression in the liver tissue homogenates was diminished after TBI. EI reduced the histological HMGB1 expression and enhanced the hepatic RAGE protein expression at 6h post TBI. With regard to the lungs, EI significantly reduced the gene expressions of HMGB1, IL-6, IL-1ß, and TNF upon TBI, without significantly affecting the protein expression levels of inflammatory markers (RAGE, IL-6, IL-1ß, and IL-10). At the early stage of TBI-induced inflammation, the gene expression of inflammatory mediators in both the lungs and liver is susceptible to ethanol-induced remote effects. Taken together, EI may alleviate the TBI-induced pro-inflammatory response in the trauma-distant organs, the lungs and liver, via the HMGB1-RAGE axis.

STAT6 mediates the effect of ethanol on neuroinflammatory response in TBI.

Traumatic brain injury (TBI) and ethanol intoxication (EI) frequently coincide, particularly in young subjects. However, the mechanisms of their interaction remain poorly understood. Among other pathogenic pathways, TBI induces glial activation and neuroinflammation in the hippocampus, resulting in acute and chronic hippocampal dysfunction. In this regard, we investigated the role of EI affecting these responses unfolding after TBI. We used a blunt, weight-drop approach to model TBI in mice. Male mice were pre-administered with ethanol or vehicle to simulate EI. The neuroinflammatory response in the hippocampus was assessed by monitoring the expression levels of >20 cytokines, the phosphorylation status of transcription factors and the phenotype of microglia and astrocytes. We used AS1517499, a brain-permeable STAT6 inhibitor, to elucidate the role of this pathway in the EI/TBI interaction. We showed that TBI causes the elevation of IL-33, IL-1ß, IL-38, TNF-α, IFN-α, IL-19 in the hippocampus at 3 h time point and concomitant EI results in the dose-dependent downregulation of IL-33, IL-1ß, IL-38, TNF-α and IL-19 (but not of IFN-α) and in the selective upregulation of IL-13 and IL-12. EI is associated with the phosphorylation of STAT6 and the transcription of STAT6-controlled genes. Moreover, ethanol-induced STAT6 phosphorylation and transcriptional activation can be recapitulated in vitro by concomitant exposure of neurons to ethanol, depolarization and inflammatory stimuli (simulating the acute trauma). Acute STAT6 inhibition prevents the effects of EI on IL-33 and TNF-α, but not on IL-13 and negates acute EI beneficial effects on TBI-associated neurological impairment. Additionally, EI is associated with reduced microglial activation and astrogliosis as well as preserved synaptic density and baseline neuronal activity 7 days after TBI and all these effects are prevented by acute administration of the STAT6 inhibitor concomitant to EI. EI concomitant to TBI exerts significant immunomodulatory effects on cytokine induction and microglial activation, largely through the activation of STAT6 pathway, ultimately with beneficial outcomes.

Accumulation of STIM1 is associated with the degenerative muscle fibre phenotype in ALS and other neurogenic atrophies.

AIM: Upon denervation, skeletal muscle fibres initiate complex changes in gene expression. Many of these genes are involved in muscle fibre remodelling and atrophy. Amyotrophic lateral sclerosis (ALS) leads to progressive neurodegeneration and neurogenic muscular atrophy (NMA). Disturbed calcium homeostasis and misfolded protein aggregation both in motor neurones and muscle fibres are key elements of ALS pathogenesis that are mutually interdependent. Therefore, we hypothesized that the calcium sensor STIM1 might be abnormally modified and involved in muscle fibre degeneration in ALS and other types of NMA. METHODS: We examined ALS and NMA patient biopsy and autopsy tissue and tissue from G93A SOD1 mice by immunohistochemistry and immunoblotting. RESULTS: In normal human and mouse muscle STIM1 was found to be differentially expressed in muscle fibres of different types and to concentrate at neuromuscular junctions, compatible with its known role in calcium sensing. Denervated muscle fibres of sALS and NMA cases and SOD1 mice showed diffusely increased STIM1 immunoreactivity along with ubiquitinated material. In addition, distinct focal accumulations of STIM1 were observed in target structures within denervated fibres of sALS and other NMA as well as SOD1 mouse muscles. Large STIM1-immunoreactive structures were found in ALS-8 patient muscle harbouring the P56S mutation in the ER protein VAPB. CONCLUSION: These findings suggest that STIM1 is involved in several ways in the reaction of muscle fibres to denervation, probably reflecting alterations in calcium homeostasis in denervated muscle fibres.

Regulation of Thyroid Hormone Gatekeepers by Thyrotropin in Tanycytes.

Background: Tanycytes are specialized glial cells within the mediobasal hypothalamus that have multiple functions, including hormone sensing and regulation of hypophysiotropic hormone secretion. There are ongoing discussions about the role of tanycytes in regulating the supply of hypothalamic thyroid hormones (THs) through the expression of TH transporters (Slc16a2, Slco1c1) and deiodinases (Dio2, Dio3). In this study, we investigated the potential feedback effect of thyrotropin (TSH) on the transcription of these gatekeeper genes on tanycytes. Methods: We analyzed the changes in the expression of TH-gatekeeper genes, in TSH-stimulated primary tanycytes, using quantitative polymerase chain reaction (qPCR). We also used RNAScope® in brain slices to further reveal the local distribution of the transcripts. In addition, we blocked intracellular pathways and used small-interfering RNA (siRNA) to elucidate differences in the regulation of the gatekeeper genes. Results: TSH elevated messenger RNA (mRNA) levels of Slco1c1, Dio2, and Dio3 in tanycytes, while Slc16a2 was mostly unaffected. Blockade and knockdown of the TSH receptor (TSHR) and antagonization of cAMP response element-binding protein (CREB) clearly abolished the increased expression induced by TSH, indicating PKA-dependent regulation through the TSHR. The TSH-dependent expression of Dio3 and Slco1c1 was also regulated by protein kinase C (PKC), and in case of Dio3, also by extracellular signal-regulated kinase (ERK) activity. Importantly, these gene regulations were specifically found in different subpopulations of tanycytes. Conclusions: This study demonstrates that TSH induces transcriptional regulation of TH-gatekeeper genes in tanycytes through the Tshr/Gαq/PKC pathway, in parallel to the Tshr/Gαs/PKA/CREB pathway. These differential actions of TSH on tanycytic subpopulations appear to be important for coordinating the supply of TH to the hypothalamus and aid its functions.

Partial Resistance to Thyroid Hormone-Induced Tachycardia and Cardiac Hypertrophy in Mice Lacking Thyroid Hormone Receptor ß.

Background: Thyroid hormones regulate cardiac functions mainly through direct actions in the heart and by binding to the thyroid hormone receptor (TR) isoforms α1 and ß. While the role of the most abundantly expressed isoform, TRα1, is widely studied and well characterized, the role of TRß in regulating heart functions is still poorly understood, primarily due to the accompanying elevation of circulating thyroid hormone in TRß knockout mice (TRß-KO). However, their hyperthyroidism is ameliorated at thermoneutrality, which allows studying the role of TRß without this confounding factor. Methods: Here, we noninvasively monitored heart rate in TRß-KO mice over several days using radiotelemetry at different housing temperatures (22°C and 30°C) and upon 3,3',5-triiodothyronine (T3) administration in comparison to wild-type animals. Results: TRß-KO mice displayed normal average heart rate at both 22°C and 30°C with only minor changes in heart rate frequency distribution, which was confirmed by independent electrocardiogram recordings in freely-moving conscious mice. Parasympathetic nerve activity was, however, impaired in TRß-KO mice at 22°C, and only partly rescued at 30°C. As expected, oral treatment with pharmacological doses of T3 at 30°C led to tachycardia in wild-types, accompanied by broader heart rate frequency distribution and increased heart weight. The TRß-KO mice, in contrast, showed blunted tachycardia, as well as resistance to changes in heart rate frequency distribution and heart weight. At the molecular level, these observations were paralleled by a blunted cardiac mRNA induction of several important genes, including the pacemaker channels Hcn2 and Hcn4, as well as Kcna7. Conclusions: The phenotyping of TRß-KO mice conducted at thermoneutrality allows novel insights on the role of TRß in cardiac functions in the absence of the usual confounding hyperthyroidism. Even though TRß is expressed at lower levels than TRα1 in the heart, our findings demonstrate an important role for this isoform in the cardiac response to thyroid hormones.

P21-A141†Quantification of bioactive factors in human serum eyedrops.

PURPOSE: NHS Blood and Transplant supply serum eye drops (SED) for the treatment of severe dry eye syndrome, however, understanding of what components of SED contribute to their activity is limited. SEDs are produced from a patient's own blood or from an allogeneic donor source. The serum component is separated from the whole blood which is then diluted 50/50 with sterile saline, and contains bioactive molecules that are believed to help heal and maintain the ocular surface. The objective of this study is to quantify the amount of bioactive molecules in donor serum, and to understand how processing variables effects these factors. METHODS: Samples of SEDs from 28 male allogenic donors were taken from ultra-low temperature storage and thawed. They were then centrifuged at 13,000 rpm at 4oC to remove potential contaminants such as residual red blood cells. Duplicate test samples were analysed for epidermal growth factor (EGF) and fibroblast growth factor (FGF) using ELISA kits. Analysis was carried out using Excel. RESULTS: The age range of the donors was 17 to 79 years (mean 47.9).Mean time from venepuncture to refrigerated storage was 6 hours 12 minutes with time ranging from 2 hours 40 minutes to 9 hours 35 minutes.The concentration of EGF found in the diluted serum ranged from 0.048 to 1.90 ng/ml (mean 0.87 ng/ml), and FGF concentration ranged from 4.88 to 39.50 pg/ml (mean 12.37 pg/ml).Analysis showed that there was no correlation between either age of the donor, or sample transfer time and growth factor concentration. CONCLUSION: Our study demonstrated that with both types of growth factors measured in the SED, a wide range of concentrations were found in the donor samples. Compared to published data EGF was at higher range while FGF was lower. Further analysis of other factors present in the donor serum is being undertaken to determine if any pattern can be found.

P22-A142†Validation of an improved closed system for dispensing serum eye drops.

PURPOSE: NHS Blood and Transplant Tissue and Eye Services provide a serum eye drop (SED) service to patients suffering from severe dry eye syndrome. Currently SED are dispensed using an automatic closed filling system (TF) manufactured by Meise Medizintechnik (Germany). An improved version (ATS) has recently been introduced by Meise, based on patient feedback on the TF system. ATS vials are easier to open, with a more secure, tamper evident closure and a better quality nozzle.To evaluate the suitability of ATS vials, a validation protocol, previously developed for TF vials, was repeated. It comprised assessment of their integrity following simulated storage and transport, and the stability and sterility of SED stored in them. METHOD: Firstly, a process simulation assessment was performed using bovine serum. Vials were filled, and frozen to -80oC. They were then removed from frozen storage and checked for damage, before being put into transport containers and shipped on a round-trip journey to simulate delivery to patients. On return the vials were thawed and the integrity of each vial checked visually and by application of a standard force.Subsequently a shelf-life study was carried out using three batches of human SED. The vials were initially frozen to -80oC, then stored for set time points of 1, 3, 6 and 12 months in a standard domestic freezer set at 20oC (to mimic a home freezer). At each time point, 10 vials were thawed and examined for integrity, and the sterility and stability of the contents. Stability was assessed by measuring serum albumin concentrations and sterility by testing for presence of microbial contamination, under aerobic and anaerobic conditions. RESULTS: No vial damage or leakage was found at any time point in the ATS vials. No microbial contamination was detected, and no change in albumin levels was detected in SED throughout the storage period. CONCLUSION: This study has demonstrated that the ATS vials are suitable for provision of SED for clinical use to patients. Feedback is now being gathered from a patient focus group relating to usability of the vials.

Protection of haematopoietic progenitor cell donors: an updated overview of the European landscape.

Haematopoietic progenitor cell donation from bone marrow and mobilised peripheral blood obtained from related and unrelated donors is an established procedure. The donation process in general has proven to be safe, but in rare cases severe and even fatal events have been reported. The present study aimed at providing a description of the current situation of donor protection measures in Council of Europe member States. A specific questionnaire was developed to compile information on donation activities, graft sources, legal frameworks, donor protection measures, collection of donor outcome data, and long-term follow-up of paediatric and adult related and unrelated donors. The outcome of this survey served as a basis for elaborating the Recommendation CM/Rec(2020)6 of the Committee of Ministers to member States on establishing harmonised measures for the protection of haematopoietic progenitor cell donors.

A pilot to examine the logistical and feasibility issues in testing deceased tissue donors for vCJD using tonsil as the analyte.

Transplanted tissues have transmitted transmissible spongiform encephalopathies and in the UK there have been more cases of variant Creutzfeldt-Jakob disease (vCJD) than elsewhere in the world. A pilot study was undertaken to look at the feasibility of testing for vCJD in deceased donors using tonsillar tissue. This pilot showed that obtaining consent for removal and testing tonsil tissue was feasible. Donor eligibility for inclusion in the pilot was limited to tissue donors from the National Health Service Blood and Transplant, Tissue Services and to donors shared with the Corneal Transplant Service Eye Banks. Obtaining tonsillar tissue in the immediate post-mortem period was limited by the presence of rigor mortis. Tonsillar tissue was suitable for routine analysis for the presence of prion associated with vCJD in deceased tissue donors. Production and processing of tissue was straightforward and a low assay background was obtained from most samples. Since palatine and lingual tonsil tissue can be obtained in pairs it was possible, in the majority of cases, to set aside an intact sample for confirmatory testing if required. In one instance a sample was reactive by Western blot. However, the pattern of reactivity was not typical for that obtained from vCJD patients. Unfortunately the sample was not of sufficient quality for the confirmatory test to provide a conclusive result.

Results of the clinical donor case and quality system case workshops of the European Association of Tissue Banks annual meeting 2009.

The European Association of Tissue Banks (EATB) Donor Case Workshop and Quality System Case workshop are forums held within the program of the EATB Annual Congress. These workshops offer an opportunity to discuss and evaluate approaches taken to challenging situations, regarding donor selection and quality issues, and strengthen the professional tissue banking and regulatory networks across Europe. This report reflects some of the discussion at the congress workshops and also subsequent correspondence between the various individuals who submitted cases for discussion. The cases presented to the workshops demonstrate that the findings, their interpretation, deducted actions and preventive measures in tissue banks are not predictable. The varied responses and lack of consensus corroborate this and clearly indicate that operating procedures cannot comprehensively cover or prepare for all eventualities. For many of the issues raised there is a lack of information in the published literature. The workshops actively engage participants, representing a wide array of international expertise, in an informal, secure and enjoyable setting, which facilitates learning from peers and provides potential solutions to those submitting cases. By publishing a summary of the discussions, we hope to reach a wider audience and to stimulate individuals to undertake full literature reviews or research on some of the discussed subjects.

33†NHSBT tissue and eye services clinical support nurse team: advanced nursing practice.

NHS Blood and Transplant (NHSBT) Tissue and Eye Services (TES) save and improve the lives of thousands of patients every year.The Clinical Support Nurse Team (CSNT) within TES is an example of registered nurses working at an advanced level, making professionally autonomous decisions for which they are accountable.The concept of nurses working at this level began with a pilot study in 2012 under a robust governance system and change process within NHSBT. The development and progress of the team has also been reviewed by NHSBT Clinical Audit.The CSNT currently comprises two band 7 nurses and a band 8a manager who work together to safely assess and authorise donated tissue for transplant. There are plans to expand the team in 2022 and to ensure that the work is underpinned by a suitable academic framework that reflects the level of clinical responsibility. The CSNT work in conjunction with TES medical consultants who provide education, guidance and governance.The team is required to use complex reasoning, critical thinking, reflection and analysis to inform their assessment and clinical judgement.CSNT practice is guided by the Donor Selection Guidelines set by the Joint United Kingdom (UK) Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee (2013). These guidelines stipulate contraindications to tissue donation on which the CSNT bases clinical decisions to ensure the safety of the recipients of any donated tissue by ruling out the chances of contracting any transmissible illness or transplanting tissue of compromised quality.Although a large component of the TES CSNT workload is to authorise donor files from deceased donors there are also living donation programmes. CSNT also review the Autologous/Allogeneic Serum Eye Drop Programme (ASE/AlloSE). This involves reviewing clinical requests made by ophthalmologists for serum eye drop options.This is a brief summary of how CSNT nurses apply their expert knowledge and skills to a broad range of Clinically challenging and complex situations.

28†Validation of a closed system for dispensing serum eye drops.

INTRODUCTION: NHS Blood and Transplant Tissue and Eye Services (TES) offer a serum eyedrop (SE) service to patients suffering from severe ocular surface disease. SE are prepared from serum collected at blood donation sessions; the serum is diluted 1:1 with physiological saline. Formerly, 3ml aliquots of diluted serum were aliquoted into glass bottles in a Grade B clean room. Since this service was started, Meise Medizintechnik have developed an automatic closed filling system consisting of tubing-linked chains of squeezable vials. They can be heat-sealed closed, under sterile conditions, after the vials have been filled. MATERIALS AND METHODS: TES R&D were asked to validate the Meise system to increase the efficiency and speed of SE production. Validation of the closed system consisted of a process simulation assessment, using bovine serum and simulating each step of the filling process, freezing to -80oC, checking the integrity of each vial and packing the vials into storage containers. They were then put into transport containers and shipped on a round-trip journey to simulate delivery to patients. On return the vials were thawed and the integrity of each vial re-checked visually and by squeezing in a plasma expressor.Subsequently a shelf-life study was carried out on three batches of fully consented human allogeneic SE. The serum was dispensed into vials, frozen as above and stored for set time points 0, 1, 3, 6 and 12 months in a standard domestic freezer set at -15-20oC to mimic a patient's freezer. At each time point, 10 random samples of vials were removed, and the outer containers were tested for damage or deterioration, the vials for integrity and their contents for sterility and stability. Stability was assessed by measuring serum albumin concentrations and sterility by testing for microbial contamination. RESULTS: No structural damage or leakage was found in any of the vials, or the tubing evaluated, after thawing, at any time point. In addition, all samples tested negative for microbial contamination and serum albumin levels were always within the expected range (3 - 5 Dg/L) at each set time point. CONCLUSION: These results demonstrate that Meise closed system vials can successfully dispense SE drops and the vials can be stored frozen without affecting integrity, sterility or stability. These vials have been in use in TES for 3 years saving clean room space and greatly increasing the numbers of patients that can use the SE service.