Transfusion in CMV seronegative T -depleted allogeneic stem cell transplant recipients with CMV -unselected blood components results in zero CMV transmissions in the era of universal leukocyte reduction: a UK dual centre experience

Objectives
To establish rates of cytomegalovirus (CMV) transmission with use of CMV‐unselected (CMV‐U), leukocyte‐reduced blood components transfused to CMV‐seronegative patient/CMV‐seronegative donor (CMV neg/neg) allogeneic stem cell transplantation (SCT) recipients including those receiving T‐depleted grafts.

Background
CMV infection remains a major cause of morbidity following SCT. CMV‐seronegative SCT recipients are particularly at risk of transfusion transmitted CMV (TT‐CMV) and until recently they have received blood components from CMV‐seronegative donors with significant resource implications. Although leukocyte reduction of blood components is reported to minimise risk of TT‐CMV, its efficacy in high‐risk situations, such as in T‐depleted transplant recipients, is unknown.

Methods
We retrospectively analysed the incidence of TT‐CMV in CMV neg/neg allogeneic SCT recipients transfused with CMV‐U, leukocyte‐reduced blood components in two transplantation centres in the UK. Patients were monitored for CMV infection by weekly CMV polymerase chain reaction testing. Leukocyte reduction of blood components was in accordance with current UK standards.

Results
Among 76 patients, including 59 receiving in vivo T‐depletion, no episodes of CMV infection were detected. Patients were transfused with 1442 CMV‐unselected, leukocyte‐reduced components, equating to 1862 donor exposures.

Conclusions
Our findings confirm the safety of leukocyte reduction as a strategy in preventing TT‐CMV in high‐risk allogeneic SCT recipients.