Peripheral T-cell expansion and low infection rate after reduced-intensity conditioning and allogeneic blood stem cell transplantation.
Fiche publication
Date publication
mai 2005
Auteurs
Membres identifiés du Cancéropôle Est :
Pr DECONINCK Eric, Dr FERRAND Christophe, Dr LAROSA Fabrice
Tous les auteurs :
Larosa F, Marmier C, Robinet E, Ferrand C, Saas P, Deconinck E, Bulabois CE, Rohrlich PS, Ledu K, Helias P, Tiberghien P, Cahn JY
Lien Pubmed
Résumé
Peripheral blood stem cell transplantation after reduced-intensity conditioning (RIC-PBSCT) regimen is an alternative to conventional regimens with less immediate toxicity. Since immune recovery is of crucial importance for the control of infections, we retrospectively studied the recovery of T-, B- and NK cell subsets in 20 consecutive patients undergoing RIC-PBSCT. We also studied the thymic output using T-cell receptor excision circle assay. Engraftment was rapid and few infectious complications were seen: three early (before 2.5 months) cases of asymptomatic cytomegalovirus reactivation, two late Gram-negative bacterial infections and no fungal infection. While CD4+ T-cell reconstitution was slow, CD8+ T-cell counts were close to normal values at 4 months. Median CD19+ B-cell counts reached normal values at 11 months. Rapid CD56+ NK cell reconstitution was noticed as early as 1.5 months. Low T-cell receptor excision circle numbers and preponderance of memory-type subsets among T cells further suggested that CD8+ T-cell reconstitution resulted predominantly from peripheral expansion and that thymic-dependent reconstitution was severely impaired. In conclusion, large peripheral T-cell expansion may compensate for late thymic-dependent lymphopoiesis, and may, with other factors such as NK and B-cell reconstitution and careful antiinfectious prophylaxis, help limit the incidence of severe infections after RIC-PBSCT.
Référence
Bone Marrow Transplant. 2005 May;35(9):859-68.