Stricter vigilance and fewer transfusions are the way
forward
Until recently it seemed that the United Kingdom's blood services could
maintain continuous improvement in blood safety bythe progressive
introduction of extra screening tests and newprocedures. These
would, it was hoped, minimise the risk of bloodborneinfection
without the ongoing supply of volunteer donors' bloodbeing
compromised. Today that hope seems vain unless some decisiveactions
are taken. Not only does allogeneic blood continue tocarry general
microbial and immunological risks that can neverbe entirely
eliminated, but also there is no way at present todeal with the
possibility that a proportion of blood donors inthe United Kingdom
may turn out to transmit variant Creutzfeldt-Jakobdisease. No
current test can identify that risk. Even if sucha test were to be
devised, the time needed to evaluate its specificity,sensitivity,
and acceptability would mean that many months, possiblyseveral
years, would separate its discovery from its routine application;and
once applied it might put great strains on blood procurementin
UnitedKingdom.
The risk of Creutzfeldt-Jakob disease, discussed widely in medical journals
and in the lay press,1 remains notional, andso far no evidence exists that either the classical or the variantform of the disease can be transmitted by transfusion. Nevertheless,experiments with the bovine spongiform encephalopathy agent in
sheep and mice show that in variant Creutzfeldt-Jakob disease,at
least, involvement of the lymphoreticular system might occur
relatively early.2 The potential risk from
allogeneic transfusionis therefore undeniable. This creates a
dilemma for our bloodservices, heightened by the recent judgment by
Mr Justice Burtonthat defined blood as a "product" under the
Consumer ProtectionAct 1988. He found that, avoidable or not, "if
the existence ofthe defect (in that particular case infection with
non A non Bhepatitis viruses) was known or should have been known in
thelight of accessible information, then the producer (the NationalBlood Service] continued to produce at his own risk."3
Allogeneicblood transfusion is an everyday lifesaving procedure for
whichthere is mostly no alternative. Thus the only possible responseto that judgment must be that the necessity for each transfusionis now carefully weighed up beforehand by senior clinical staff
and the search for alternatives to allogeneic transfusion
intensified.
When transfusion is resorted to, what steps can be taken to limit the risk?
Blood from the United Kingdom is already leucodepleted,largely
removing the lymphocytes that are one possible sourceof infectivity
for variant Creutzfeldt-Jakob disease, and plasmafor fractionation
is sourced from the United States (which isfree of bovine spongiform
encephalopathy). Further expedientsare, however, available that
would limit exposure to allogeneicblood. Half of all red cell
concentrates are used in support ofplanned surgery, and this
reliance could be reduced by correctionof preoperative anaemia,
autologous transfusion (particularlythrough cell salvage at
operation), use of pharmacological agentsto reduce bleeding,
anaesthetic techniques to minimise blood loss,and acceptance of a
lower postoperative haemoglobin where appropriate. 45
Other ploys could be considered. The number of donors to whom a recipient is
exposed might be reduced in various waysfewerunits given, individual donors assigned to recipients, and largervolumes collected from some donors. The incorporation of very
many units into a transfusionwhether,
for example, as plateletconcentrates or fresh frozen plasmashould,
as far as is feasible,be avoided. For infants and pregnant women
especially, considerationcould be given to sourcing blood components
from outside the UnitedKingdom. In fact, last week the Department of
Health decided totreat babies and young children with imported blood
only. As afurther precaution, should previously transfused people
not beallowed to donate blood? This would greatly reduce supply at atime when donor recruitment and retention are becoming more difficult.A better first step would be to contain risk and conserve suppliesby observing the general rule that the aim of allogeneic transfusionis to save life and prevent deterioration, not simply to hasten
recovery.
To put these changes into effect in the United Kingdom will require a
cultural shift among clinicians, managers, and policymakers. No
longer should clinicians prefer the convenience andimmediate
benefits of allogeneic transfusion over more troublesomebut safer
alternatives. Managers and policy makers, too, shouldbe forced to
take account of the costs of possible long term harmand delayed
liability and not be deterred from investing in alternative
procedures to allogeneic transfusion. It also needs to be decidedwho
will take responsibility for driving the changes that arenecessary
to minimise exposure to allogeneic blood. Clinical endusers,
although they are becoming more aware of the risk, mostlydo not
regard safety of blood as their responsibility. The recipients
themselves are not empowered to demand change (although they should
be informed of the risks as well as the benefits of transfusionand
ought to have a louder voice than they do). The blood services,
though they are anxious to address the problem, would be put inan
invidious position if expected not only to be cost efficient
providers but also to ration the supply and police the use ofblood.
At two recent symposiums, the United Kingdom's chief medical officers have
sought to educate senior health service managersand clinicians in
better transfusion practice and the alternativesto allogeneic
transfusion. Without reinforcement of their message,however,
sustained change seems unlikely. By contrast, the Frenchgovernment
has, since a highly politicised blood scandal in themid-1980s,
implemented a policy of national haemovigilance thathas brought
about a substantial reduction in the previously highrate of
allogeneic blood use. A similar haemovigilance is in placein the
Irish Republic after a costly failure to oversee national
arrangements for the preparation and supply of anti-Dimmunoglobulin.
A haemovigilance programme is overdue in United Kingdom, with mandatory local
participation, new funds to pay for training,innovation, and audit,
removal of incentives to supply and useblood, and an independent
body to administer the programme. Althoughit may turn out to be more
expensive to use blood sparingly inthe short run, lower consumption
of allogeneic blood will bothminimise the danger from variant
Creutzfeldt-Jakob disease andalleviate the growing problem of
recruiting loyal volunteer donors.If the threat of variant
Creutzfeldt-Jakob disease transmittedby transfusion materialises it
will be hard to defend the casualpractices in the use of blood that
linger from an era when itwas believed that British blood was by
definition safe. The remedyis not to wait for the unscheduled
arrival of yet another screeningtest, but to bring allogeneic blood
use under firm controlnow.
Philip P Mortimer, director.
Sexually Transmitted and Bloodborne Virus Laboratory, Central Public Health
Laboratory, London NW9 5HT
Brown P, Cervenáková L, Diringer H. Review Article: Blood
infectivity and the prospects for a diagnostic screening test in
Creutzfeldt-Jakob disease. J Lab Clin Med 2001; 137: 5-13[Medline].
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