[Cytomegalovirus infection after haploidentical stem cell transplantation may reduce relapse risk in leukemia]

To analyze the relationship between cytomegalovirus (CMV) reactivation and leukemia relapse after haploidentical hematopoietic stem cell transplantation (haplo-HSCT).

A total of 61 patients diagnosed as hematological malignancies undergoing haplo-HSCT were analyzed retrospectively in our center.

In the cohort, 36 patients had CMV reactivation after haplo-HSCT. The 100-day cumulative incidence of CMV reactivation was 59%. Compared with that in patients without CMV reactivation after transplantation, the incidence of leukemia relapse was lower in patients with CMV reactivation (16.9% vs 40.0%, P=0.034). The correlation of CMV reactivation and decreased relapse rate was only found in patients with acute myeloid leukemia (P=0.019). In multivariate analysis, relapsed disease status before transplant was a significant negative predictor of overall survival (OS) and relapse after transplant (RR was 2.866 and 3.331 respectively). CMV reactivation after transplant had a protective effect on disease relapse (RR=0.300, P=0.047).

The rate of CMV reactivation after haplo-HSCT is high. CMV reactivation may reduce risk of relapse in patients diagnosed as acute myeloid leukemia undergoing haplo-HSCT. However, CMV reactivation is one of the important predictors of non-relapse death after transplant, active anti-viral treatment is still needed.