Leucodepletion for transmissible spongiform encephalopathies

School of Life Sciences, Kingston University, Penrhyn Road, Kingston-upon-Thames, Surrey KT1 2EE, UK.
British journal of biomedical science (Impact Factor: 1.3). 02/2004; 61(1):48-54.
Source: PubMed


Transmissible spongiform encephalopathies (TSEs) have been recognised around the world for many years. Creutzfeldt-Jakob disease (CJD), one of the human forms of TSE, has been studied widely and thus far has not proved a great threat to human health. The emergence of two new TSEs--bovine spongiform encephalopathy (BSE) in cattle and variant Creutzfeldt-Jakob disease (vCJD) in humans in the UK--has caused great concern. BSE has had an economic impact and vCJD is a threat to human health. It has been shown that these two diseases are caused by the same prion agent and are linked. Research indicates that vCJD behaves differently to CJD and there is strong evidence to suggest that vCJD is present in lymphoid tissues and B lymphocytes, which presents a theoretical risk that it may be transmitted by transfusion of blood and blood products. To minimise/prevent this risk, the UK government has decided that plasma should be sourced from abroad and has instructed the National Blood Service to leucodeplete all blood and blood products, at a cost of 70 million pounds per annum, although it is not known if this will remove this risk.

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    • "The measure was predicated on studies suggesting that B lymphocytes were likely to be involved in the initial phases of disease and that leucocytes were an important locus of infectivity in the peripheral blood. Subsequently, it has become apparent that in animal studies leucodepletion does not reduce infectivity in plasma and is likely to reduce the prion concentration in blood by only about 40% (Prowse & Bailey, 2000; Gregori et al, 2004; St Romaine et al, 2004). Universal leucodepletion is also considered to offer a number of additional benefits, e.g. "
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    ABSTRACT: The improvement of transfusion medicine technology is an ongoing process primarily directed at increasing the safety of allogeneic blood component transfusions for recipients. Over the years, relatively little attention had been paid to the leukocytes present in the various blood components. The availability of leukocyte removal (leukoreduction) techniques for blood components is associated with a considerable improvement in various clinical outcomes. These include a reduction in the frequency and severity of febrile transfusion reactions, reduced cytomegalovirus transfusion-transmission risk, the reduced incidence of alloimmune platelet refractoriness, a possible reduction in the risk of transfusion-associated variant Creutzfeldt-Jakob disease transmission, as well as reducing the overall risk of both recipient mortality and organ dysfunction, particularly in cardiac surgery patients and possibly in other categories of patients. Internationally, 19 countries have implemented universal leukocyte reduction (ULR) as part of their blood safety policy. The main reason for not implementing ULR in those countries that have not appears to be primarily concerns over costs. Nonetheless, the available international experience supports the concept that ULR is a process that results in improved safety of allogeneic blood components.
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