The journal Transfusion has published a series of articles discussing the prevalence of CMV and strategies to reduce transfusion-transmitted infections. Among immunocompromised patients, CMV infection can cause significant morbidity and mortality. A Japanese study found CMV seroprevalence among blood donors to be greater than 75%.
CMV seronegative or leukoreduced blood is typically used to reduce transfusion associated CMV.
Here is Dr. John Roback, who wrote an editorial accompanying these articles:
“Both methods significantly and dramatically reduce the risks of CMV transmission. But there’s still this debate, is one better than the other or are there even more efficient and effective methods to prevent CMV transmission.”
Using serology to remove seropositive donors may miss new CMV infections in its window period. A recent study suggested that using leukoreduced blood from long-term seropositive donors may be an effective alternative.
Dr. Holger Hennig, who co-authored the study, noted:
“Our recent study shows that prevalences of window period donations among seronegative donors and CMV reactivations among long-term seropositive donors, as well as the CMV DNA-concentrations in whole blood and plasma from these donors are comparable.”
Dr. Hennig suggests that while donations from newly infected individuals may pose a risk of transmission, blood products from both seronegative donors and long-term seropositive donors could be used safely.
Again, here is Dr. Roback:
“What their group proposed was something novel, that is they suggested that if you screened for CMV by serology and once a donor was seropositive; if you waited at least a year after that and then you start using their blood following leukoreduction you might actually not only increase the supply of available CMV safeblood for these at risk recipients but you could also save money and potentially have even safer blood.”
Leukoreduction alone may not be fool-proof. While leukocytes harbouring CMV would be removed, plasma may still contain CMV.
Here is Dr. Roback:
“If you look at that one minor chink in the armour that is the idea that a remotely infected donor could have transiently reactivation of CMV and then have a blip of free CMV in the plasma, you could detect that individual by CMV NAT, by plasma NAT and therefore eliminate that tiny risk.”
We’ll be back on October 30th with another edition of Transfusion News. Thanks for joining us.
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