Human cytomegalovirus-specific T cell reconstitution in young patients receiving T cell-depleted, allogeneic hematopoietic stem cell transplantation.
BACKGROUND
Reconstitution of human cytomegalovirus (HCMV) T cell-specific immunity is of crucial relevance in patients receiving a hematopoietic stem cell transplant (HSCT). Scarce data on this subject are available for children receiving a T cell-depleted HSCT.


METHODS
We investigated HCMV-specific T cell recovery in 48 recipients of a T cell-depleted HSCT from a human leukocyte antigen (HLA)-disparate relative. Autologous HCMV-infected dendritic cells were used to stimulate HCMV-specific CD8+ and CD4+ T cells producing interferon-gamma (IFN).


RESULTS
The 1-year cumulative incidence of both HCMV infection and specific T cell reconstitution was 83% among the 23 HCMV-seropositive patients and 4% and 8%, respectively, among the 25 HCMV-seronegative patients (P < .01). HCMV-specific T cell reconstitution was significantly delayed in patients receiving T cell-depleted grafts, compared with patients receiving unmanipulated HSCTs (median time to reconstitution, 75 vs. 47 days, respectively; P < .01). The median time from HCMV infection to immune recovery in recipients of T cell-depleted grafts was 47 days. Detection of HCMV-specific T cells correlated with control of HCMV infection. The number of residual T cells in the graft predicted earlier T cell recovery (P = .02).


CONCLUSIONS
Latent HCMV in the recipient was the major cause of HCMV reactivation and also promoted specific T cell reconstitution in patients given a T cell-depleted HSCT from an HLA-disparate relative. Routine immunologic monitoring is valuable in identifying patients with early HCMV-specific T cell reconstitution.
Lilleri
Daniele
D
Servizio di Virologia, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Università di Pavia, Pavia, Italy.
Gerna
Giuseppe
G
Fornara
Chiara
C
Chiesa
Antonella
A
Comolli
Giuditta
G
Zecca
Marco
M
Locatelli
Franco
F
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000601:surgery*; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008212:Lymphocyte Depletion; D008297:Male; D012008:Recurrence; D013601:T-Lymphocytes / Q000276:immunology*; D014184:Transplantation, Homologous; D055815:Young Adult