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All the blood in our hospital is leucoreduced, and we have classified this as "CMV safe". But is this actually the case? Is leucoreduced blood the equivalent of CMV negative blood? For the following patients would you just give leucoreduced blood, or leucoreduced blood that is also CMV negative?

Intra-Uterine Transfusion

Exchange transfusion for a baby

Top-up transfusion for a premature baby

Top-up transfusion for a full term baby

 

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Leukodepleted blood is most certainly not the same as CMV Negative blood, and, even then, as far as many Blood Services are concerned, the blood would have to be tested by, and found negative by NAT, rather than by serological testing.  The whole is complicated by the fact that the foetus/baby may also be exposed to CMV from the mother, even when the mother is thought to be negative, as she may have a latent infection that can become active at any time.

I would also add that another category should be added to your list, and that is people who are about to have or have had a SCT/BMT and their donors.

Edited by Malcolm Needs
My own idiocy!

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Thanks Malcolm,

So you are saying that blood should be leucoreduced and CMV negative for the categories that I stated?  What if the blood donation center that supplies my blood does not do CMV testing? All I can do then is give the leucoreduced blood.

On a similar topic, we had a newborn baby receiving a number of leucodepleted RBC top-up transfusions since birth. At 35 days old the baby had a CMV quantitative screen done and was CMV negative. At 65 days old the baby was tested again and the CMV screen was positive.  Is the reason for this purely down to one of the transfused units? Or could other factors be involved eg infection passed on by another healthcare worker, or by the family, or by environmental causes?

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There remains controversy about this, but we have been using leukoreduction as our only method of CMV risk reduction for close to 30 years, with no reported cases of CMV transmission.  We have a 70 bed newborn intensive care unit, do about 180 stem cell transplants (about 40% allogeneic), and do the occasional intrauterine exchange transfusion.  CMV serotesting is never necessary for donor blood in my opinion.  The existing literature isn't entirely definitive but studies have not shown that combining leukoreduction and CMV serotesting has much, if any clinical benefit.  Both observational series and randomized trials demonstrate that CMV transmission after leukoreduction is not any more common than after CMV serotesting.  Indeed, most CMV transmissions are likely due to seronegative donors who have recently acquired virus, but are still seronegative, or at least that's one theory.  Bottom line, if you are 100% leukoreduced there is no need for CMV serotesting.

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Most CMV infections are acquired through environmental exposure, including breastfeeding from and close contact with a CMV infected mother.  The likely source of the infection in question was exposure to family members, not transfusion.  That's why close to 80% of adults in some populations are CMV seropositive.  The virus is ubiquitous and highly infectious, but rarely causes any serious clinical effects except in utero and in severely immunocompromised patients.  

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1 hour ago, Neil Blumberg said:

There remains controversy about this, but we have been using leukoreduction as our only method of CMV risk reduction for close to 30 years, with no reported cases of CMV transmission.  We have a 70 bed newborn intensive care unit, do about 180 stem cell transplants (about 40% allogeneic), and do the occasional intrauterine exchange transfusion.  CMV serotesting is never necessary for donor blood in my opinion.  The existing literature isn't entirely definitive but studies have not shown that combining leukoreduction and CMV serotesting has much, if any clinical benefit.  Both observational series and randomized trials demonstrate that CMV transmission after leukoreduction is not any more common than after CMV serotesting.  Indeed, most CMV transmissions are likely due to seronegative donors who have recently acquired virus, but are still seronegative, or at least that's one theory.  Bottom line, if you are 100% leukoreduced there is no need for CMV serotesting.

I totally agree, but, in the UK we are "governed" by the recommendations of the The Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO), and they say that we have to actually use CMV- tested blood and blood components for certain patients (including pregnant women), in addition to them being leukodepleted.

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We are also trying, again, to move our Medical Staff to CMV Safe.  How do you educate your Physician/ providers to CMV safe. We have providers ordering CMV Safe when it is no longer needed. Partly because  we have to have a acknowledgement by the Provider to switch, but they are worried to switch if they don't know the entire patient history. We  are now considering educating the Providers and Physicians and then allowing the Blood Bank to reflex to CMV Safe unless a specific order for CMV negative is placed.

How did you make the conversion? Any Provider education resource you are willing to share? Less than 4 mos of age and the amternal indications are the only we have clearly demarcated.I have found several education pieces in the UK and Canada but not the US?

Thank you in advance.

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This is something that only works when there is expert physician to physician communication. Your medical director needs to undertake this project. There are substantial data from randomized trials and observational cohort studies that leukoreduction abrogates CMV seroconversion.  These are the studies we used twenty plus years ago to convince our practitioners that leukoreduction was not only good enough, but almost certainly superior in overall clinical outcomes to CMV seronegative non-leukoreduced transfusions.  Of course no patient should be receiving non-leukoreduced transfusions at this late date, but in the USA not all transfusion medicine physicians are convinced of this, in my opinion,  strongly justified clinical practice.

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We use CMV seronegative blood for stem cell transplant patients who are CMV neg  their donor is CMV negative.  Other than that we use CMV safe.  We are a pediatric facility with heart, liver, renal,  stem cell, transplants.  The services that use the most blood here are CV, Heme/Onc, and neonates.

We used to insist on CMV negative components, but we found that doing so delayed transfusions while we were trying to find seronegative unis.

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Thank you Baby Banker and Neil for your recent input.  So as we are using leucoreduced blood, does that mean that a blood unit would never be implicated in causing CMV infection in a recipient? Or there is. and always will be, a very small risk a leucoreduced unit can cause a CMV infection?

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We've been using leukoreduced RBCs and PLTs in lieu of CMV seronegative for over 20 years for all pediatric (including neonate and micropremie) transfusions.  I work at a 350 bed children's hospital with a large NICU, 3 satellite NICUs, an active ECMO and heart surgery program, and we care for many children who receive bone marrow or organ transplants.  We converted to this back when studies showed that leukoreduced products were found to be basically equivalent to CMV seronegative products for rate of CMV transmission.  We use leukoreduced for all transfusions (including exchange transfusions) regardless of patient age or size.  We have never had a case of CMV transmission through transfusion.  Over 80% of our blood donors are CMV positive in our area.

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There is no such thing as never in science and medicine.  But while leukoreduced transfusions may on rare occasions be associated with a CMV seroconversion, the same is true of CMV seronegative, since it is possible to have a donor who is viremic but not yet seropositive.  There are those who believe CMV is almost never transmitted by transfusion, but that these seroconversions are by the usual route of individual to individual environmental transmission.  I am close to that point of view.  We have not used CMV seronegative, as pointed out above, for the last 20 years plus.  We have a 70 bed+ neonatal intensive care unit, do about 80-100 allogeneic transplants of stem cells, heart transplants, etc.  CMV seronegative is totally unnecessary and provides little or no benefit to patients.  Leukoreduction is much more important overall and provides enough CMV safety on its own, in my view, to beat a dead horse here :).

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