[Clinical Study of Cytomegalovirus Infection after Allogeneic Hematopoietic Stem Cell Transplantation]

To explore the risk factors of cytomegalovirus (CMV) and refractory CMV infection (RCI) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and their influences on survival.

A total of 246 patients who received allo-HSCT from 2015 to 2020 were divided into CMV group (n=67) and non-CMV group (n=179) according to whether they had CMV infection. Patients with CMV infection were further divided into RCI group (n=18) and non-RCI group (n=49) according to whether they had RCI. The risk factors of CMV infection and RCI were analyzed, and the diagnostic significance of Logistics regression model was verified by ROC curve. The differences of overall survival (OS) and progression-free survival (PFS) between groups and the risk factors affecting OS were analyzed.

For patients with CMV infection, the median time of the first CMV infection was 48(7-183) days after allo-HSCT, and the median duration was 21 (7-158) days. Older age, EB viremia and gradeⅡ-Ⅳacute graft-versus-host disease (aGVHD) significantly increased the risk of CMV infection (P=0.032, <0.001 and 0.037, respectively). Risk factors for RCI were EB viremia and the peak value of CMV-DNA at diagnosis≥1×10⁴ copies/ml (P=0.039 and 0.006, respectively). White blood cell (WBC)≥4×10⁹/L at 14 days after transplantation was a protective factor for CMV infection and RCI (P=0.013 and 0.014, respectively). The OS rate in CMV group was significantly lower than that in non-CMV group (P=0.033), and also significantly lower in RCI group than that in non-RCI group (P=0.043). Hematopoietic reconstruction was a favorable factor for OS (P<0.001), whereas CMV-DNA≥1.0×10⁴ copies/ml within 60 days after transplantation was a risk factor for OS (P=0.005).

The late recovery of WBC and the combination of EB viremia after transplantation are common risk factors for CMV infection and RCI. CMV-DNA load of 1×10⁴ copies/ml is an important threshold, higher than which is associated with higher RCI and lower OS risk.