Clinical Significance of EBV-Associated LPD After Cord Blood Transplantation.

The number of cord blood transplantation (CBT) is rapidly increasing. In this setting, development of Epstein-Barr virus (EBV)-associated lymphoproliferative disorder (LPD) appears to be at high risk. To clarify this issue, we retrospectively analyzed EBV serology and clinical course of 57 patients who received CBT during the past 12 years.

We underwent 79 CBT until 2008. Fifty-seven patients were available for assessing EBV serology. The mean age of patients was 63 months (range, 6m-28y5m). The underlying disease was hematologic malignancy (n=27), hematologic non-malignancy (n=10), autoimmune disease (n=2), solid tumor (n=7), and EBV-associated T/NK-LPD (n=11).

Forty-six (80.7%) of the 57 recipients were EBV seropositive before CBT (sero+/). Nineteen (41.3%) of 46 EBV seropositive recipients before CBT became EBV seronegative after CBT (sero+/sero-). Five patients (8.8%) developed EBV-associated post-transplantation LPD. Three of the 5 LPD patients arose from 27 patients of sero+/sero+ group, and the time of onset of LPD was 2-6 months after CBT. Two of them died of LPD. The remaining 2 patients arose from 19 patients of sero+/sero- group, and the time of onset of LPD was 6-9 months. These 2 patients were successfully treated. None of the 11 patients (6 in sero-/sero- group and 5 in sero-/sero+ group) developed LPD.

Among EBV seropositive patients, about 60% of them remained seropositive (endogenous infection group), and 40% of them became seronegative after CBT. The latter group is likely to experience exogenous infection (secondary primary infection). In both instances, incidence of LPD seems to be quite high. Therefore regular monitoring of EBV serology and EBV-DNA load after CBT should be essentially required for all CBT patients.

No relevant conflicts of interest to declare.