Different Kinetics in Anti-Cytomegalovirus Immunity Reconstitution Evaluated by Lymphocyte Proliferation and IFN-γ Production in Allogeneic and Autologous Bone Marrow Transplantation

Abstract

Allogeneic bone marrow transplantation (ALLOBMT) is associated with an increased risk of cytomegalovirus (CMV) morbidity compared to autologous BMT (AUTOBMT). To investigate this, we evaluated AUTOBMT and ALLOBMT patients regarding anti-CMV immune reconstitution at 1 and 4 months after BMT and on the day after first CMV antigenemia detection. Intermittent ganciclovir preemptive therapy was prompted by antigenemia of ≧2 cells. One month after transplant, AUTOBMT recipients already displayed larger CD8+ T cell numbers than ALLOBMT recipients, but comparably small CD4+ T cell numbers. Most AUTOBMT patients had positive CMV antigen (CMV-Ag)-induced lymphoproliferation (86%) and IFN-γ secretion (86%), whereas this was infrequently seen in ALLOBMT patients (20 and 10%, respectively). This early AUTOBMT immune reconstitution was associated with a lower frequency of CMV reactivation up to +4 months in AUTOBMT (21%) than ALLOBMT patients (91%). At +4 months, most ALLOBMT recipients had also recovered CMV-Ag immune responses. At first antigenemia detection, all 3 AUTOBMT recipients already displayed anti-CMV immune functions and 2 cleared the infection without therapy, whereas of the 10 ALLOBMT recipients only 1 had positive lymphoproliferation. In the latter group, none had IFN-γ secretion or cleared the infection without therapy. Thus, differences in anti-CMV immune reconstitution may help to explain the contrasting rates of CMV morbidity between ALLOBMT and AUTOBMT patients.