The serological screening of deceased tissue donors within the English Blood Service for infectious agents - a review of current outcomes and a more effective strategy for the future

Abstract

Background and Objectives The overall effectiveness of the NHSBT screening programme for infectious agents in deceased tissue donors is examined and evaluated in terms of current outcomes and how to improve upon these outcomes. Materials and MethodsThe screening results and any subsequent confirmatory results from a total of 1659 samples from NHSBT deceased donors referred to NTMRL for screening for infectious agents were included in the analysis.Results Overall 1566 ⁄ 1659 (94AE4%) of the samples were screen negative. A total of 93 were repeat reactive on screening for one or more of the mandatory markers screened for, of which only 12 (13%) were subsequently confirmed to be positive on confirmatory testing. The majority of the repeat reactive samples were demonstrating non-specific reactivity with the screening assays in use.Conclusion Overall, the NHSBT screening programme for infectious agents in deceased tissue donors is very effective with a relatively low overall loss of donors because of non-specific reactivity. However, unnecessary loss of tissue products is not acceptable, and although this programme compares favourably with the outcomes of other such programmes, the confirmatory results obtained demonstrate both the need and the potential for improving the outcomes. This is particularly important as one donor may donate more than one product, and can be achieved very easily with a change to the screening algorithm followed, using the confirmatory data obtained to support and validate this change.Contents Summary Critical analysis of the NHSBT screening programme for infectious agents in deceased tissue donors and a strategy involving the design and use of a different screening algorithm to improve these outcomes.

Qualification of serological infectious disease assays for the screening of samples from deceased tissue donors

“…In the past a major problem with the testing of samples from deceased donors was considered to be specificity, with reports of higher than expected levels of 'positive' screening results (Padley et al 2005;Heim et al 1999;Cahane et al 2000;Challine et al 2006;Thomas et al 2007;Pepose et al 1993). However, the data generated in this laboratory over the last few years indicate that specificity is not in itself a major problem (Kitchen and Gillan 2009), rather our view is that it is the sensitivity of the assays when used to screen these samples that is important. The level of non-specific reactivity can generally be minimised with the use of appropriate screening algorithms and well validated assays (Kitchen and Gillan 2009).…”

“…However, the data generated in this laboratory over the last few years indicate that specificity is not in itself a major problem (Kitchen and Gillan 2009), rather our view is that it is the sensitivity of the assays when used to screen these samples that is important. The level of non-specific reactivity can generally be minimised with the use of appropriate screening algorithms and well validated assays (Kitchen and Gillan 2009). However, our concern is that, as the majority of serological screening assays currently available and in use for screening post-mortem samples have not been validated with post-mortem samples, there is the potential for the loss of sensitivity (false-negative) due to inhibition of specific reactivity because of the nature of the samples.…”

Detection of human immunodeficiency virus, hepatitis C virus, and hepatitis B virus in postmortem blood specimens using infectious disease assays licensed for cadaveric donor screening

“…The results of this study provide information to increase the confidence in the spiking method of evaluating assay sensitivity that is currently recommended by the FDA, other authorities, and as described by Kitchen et al in evaluating assays for NHS Blood and Transplant in the UK and by Baleriola et al in Australia. Spiking studies are used for confirming assay performance in post‐asystole specimens because it is extremely challenging to obtain specimens from infected individuals who die with a known communicable disease.…”

Postmortem Mikrobiyolojik Analizler Güncel Yaklaşım

“…Postmortem alınmış serolojik örneklerin en önemli problemi özgüllüğünün tartışmalı olmasıdır. Tarama amacıyla yapılan postmortem serolojik incelemeler için kullanılacak testlerde kitlerin duyarlılığının yüksek olmasına özellikle dikkat edilmesi önerilmektedir (61).…”

“…FDA dan onay alan kit üreticileri postmortem kan örneklerine uygulanan antijen, antikor tespit kitlerinin doğru sonuçları gösterdiğine dair yapılmış çalışmaların çok fazla olmadığını söylemektedirler Postmortem kan numunelerinden antijen, antikor tespitinde spesifik o l m a y a n p o z i t i fl i k d ü z e y l e r i u y g u n t a r a m a algoritmalarının kullanımı ile en aza indirilebilmektedir. Antijen ya da antikor tespitinde tek bir tarama testi kullanılıyorsa doğrulaması mutlaka yapılmalıdır (55,57,(60)(61)(62)(63)(64).…”