A Japanese single-hospital observational trial with a retrospective case-control analysis of varicella zoster virus reactivation after autologous peripheral blood stem cell transplantation

BackgroundVaricella zoster virus (VZV) reactivation following hematopoietic stem cell transplantation (SCT) is common. To help reduce its incidence and to identify predictive factors for VZV reactivation after autologous SCT (auto-SCT), we conducted a retrospective analysis in patients with hematologic malignancy at our hospital. MethodsWe conducted a single-hospital observational trial with a retrospective case-control analysis of post-auto-SCT VZV reactivation in patients with malignant lymphoma (ML) and multiple myeloma (MM) between January 2001 and December 2010, in the Department of Hematology at our hospital. First, we analyzed the cumulative incidence of VZV reactivation during the post-SCT period. Second, we conducted a case-control analysis to identify the risk factors for VZV reactivation within 1year after SCT. Univariate analyses were performed using Fisher's exact test for categorical variables. A multivariable model and logistic regression were used to assess the risk factors for VZV reactivation. ResultsWe included 97 patients in this study. The median duration of follow-up was 1027days. Forty-two patients experienced VZV reactivation after SCT, while 29 (69.0%) experienced reactivation within 1year after SCT. The cumulative incidence was 30.7% at 1year and 51.2% for the total observation period. Multivariate analysis showed that engraftment after day 10 was an independent risk factor for VZV reactivation (P=0.03). ConclusionsOur study showed a high incidence of VZV reactivation in the first year after auto-SCT in ML and MM patients. Patients with delayed engraftment are at high risk for VZV reactivation and should be considered for prolonged VZV prophylaxis.