Prognostic impact of viral reactivations in acute myeloid leukemia patients undergoing allogeneic stem cell transplantation in first complete response

Cytomegalovirus (CMV) serological status of donor and recipient as well as CMV reactivation have been associated with a lower risk of relapse in acute myeloid leukemia (AML) patients after allogeneic stem cell transplantation (alloSCT). Since immunosuppression following transplant allows resurgence of many other viruses, we retrospectively evaluated the impact of viral reactivations on relapse and survival in a cohort of 136 AML patients undergoing alloSCT in first remission from sibling (68%) or unrelated (32%) donors. Myeloablative and reduced-intensity conditioning regimen were given to 71 and 65 patients, respectively. Including CMV reactivations, at least 1 viral reactivation was recorded in 76 patients. Viral reactivations were associated with a lower risk of relapse (adjusted HR 0.14; 95% CI 0.07–0.30; P < 0.01), better disease-free survival (aHR 0.29; 95% CI 0.16–0.54; P < 0.01) but higher non relapse mortality. This translated into a better overall survival (aHR 0.44; 95%CI 0.25–0.77; P < 0.01) in patients who experienced viral reactivation. Thus, viral reactivations, including but not limited to CMV reactivation, are associated with a better outcome particularly with regard to the risk of relapse in AML patients undergoing alloSCT. New guidelines regarding the choice of donor according to the CMV serostatus are needed.