Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2102078 | Biology of Blood and Marrow Transplantation | 2014 | 7 Pages |
Human cytomegalovirus (CMV) reactivation frequently occurs during the early phase of immune recovery after allogeneic hematopoietic stem cell transplantation (HSCT). Whereas the recovery of virus-specific immunity in the early phase after HSCT is extensively studied, the impact of CMV on the reconstitution and composition of the T cell compartment long-term after HSCT is unknown. We analyzed T cell reconstitution 1 to 2 years after HSCT in 131 pediatric patients. One year after HSCT, patients with early CMV reactivation (n = 46) had 3-fold higher CD8+ T cell numbers (median, 1323 versus 424 cells/μL; P < .0001) compared with patients without CMV reactivation (n = 85). This effect, caused by a major expansion of CD8+ effector memory (EM) and end-stage effector (EMRA) T cells, was independent of pretransplantation donor and recipient CMV serostatus and not seen after Epstein-Barr virus or adenovirus reactivations. At 1 and 2 years after HSCT, the absolute numbers of CD8+ naive and central memory T cells, as well as CD4+ naive, CM, EM, and EMRA T cells, did not differ between patients with or without CMV reactivation. In the second year after HSCT, a significant contraction of the initially expanded CD8+ EM and EMRA T cell compartments was observed in patients with early CMV reactivation. In conclusion, CMV reactivation early after pediatric HSCT leaves a specific and dynamic imprint on the size and composition of the CD8+ T cell compartment without compromising the reconstitution of CD8+ and CD4+ naive and central memory T cells pivotal in the response to neo and recall antigens.