Early recovery of CMV immunity after HLA-haploidentical hematopoietic stem cell transplantation as a surrogate biomarker for a reduced risk of severe infections overall

A major hurdle to the field of allogeneic hematopoietic stem cell transplantation (HSCT) is the lack of validated biomarkers of protective immunity against opportunistic infections, including CMV reactivation syndromes. This issue is particularly relevant to alternative-donor settings, for example, HLA-haploidentical HSCT (haplo-HSCT) and cord blood transplantation, where aggressive GvHD prophylaxis results in a profound and long-lasting state of immune incompetence. Despite the introduction of routine post-transplant viral monitoring and preemptive antiviral therapy, CMV reactivation syndromes remain a major cause of transplant related mortality. Accordingly, serological evidence of prior CMV infection is still one of the main negative prognostic factors in HSCT. Different studies have demonstrated that a faster recovery of CMV-specific T-cell responses associates with a reduced CMV reactivation incidence in HSCT from HLA-identical sibling and matched unrelated donors. Given its clinical and biological peculiarities, it is currently unknown whether these observations are directly translatable to the haplo-HSCT setting. In this study, while aiming to follow the recovery of CMV-specific T-cell responses after haplo-HSCT, we unexpectedly found that protective levels of CMV immunity were associated with a reduced incidence of severe infections overall.

NA