Reconstitution of Epstein-Barr Virus-Specific T Lymphocytes at the Early Stage of Allogeneic Stem Cell Transplantation

Backgroud:

Epstein-Barr virus (EBV) infection/reactivation is an common complication following allogeneic stem cell transplantation (allo-HSCT) which usually occure at the early stage after transplantation. EBV-specific cytotoxic T lymphocytes (EBV-CTLs) are considered to provide protection from EBV infection/reactivation and associated diseases in recipients of allo-HSCT. Herein, we evaluated the levels of EBV-CTLs early after transplantion and investigated the associaton between the reconstitution of EBV-CTLs and EBV infection/reactivation after allo-HSCT.

Methods:

Thirty patients undergoing allo-HSCT between November 2013 to September 2014 were enrolled in this study. Of these patients, 16 received HLA-matched donor and 14 received HLA-mismatched transplantation. Antithymocyteglobulin was given in 20 patients. EBV-CTLs were tested using Enzyme-linked immunospot assay (ELISPOT) presenting 9 peptides derived from 3 EBV proteins in +30, +90 and +180 days after transplantation.

Results:

EBV-CTLs, although low levels, were detected in 90% (27/30) patients in +30 days after HSCT. In most patients, EBV-CTLs levels in +90 days was significantly higher than +30 days and returned to normal levels within +180 days after HSCT. Thirteen patients developed EBV infection/reactivation within the median time of 48 (range, 23-110) after transplantation. EBV-CTLs levels had no significant difference among the patients with or without infection/reactivation in +30 days while the patients with EBV infection/reactivation had higher EBV-CTLs levels than those without in +90d after HSCT.

Conclusion:

Reconstitution of EBV-CTLs seems rapid in both HLA-matched and -mismatched donor transplantation. The association between EBV infection/reactivation and EBV-CTLs levels at monthly intervels after HSCT should be studied further.