Cytomegalovirus Reactivation in Hematopoietic Stem cell Transplantation managed by Preemptive Treatment with lower dose Valganciclovir

Objective: The aim of this study was to investigate risk factors for cytomegalovirus (CMV) infection, effect of viral reactivation on hematopoietic stem cell transplantation (HSCT) and efficacy of preemptive treatment using a lower dose valganciclovir for the first time. Material and Method: The data of 447 patients who underwent HSCT for malignant and non-malignant hematological disorders at a single center from September 2009 to December 2016 were retrospectively evaluated in this study. DNA levels of CMV were routinely tested two days per week for the first 24 months following HSCT, and in case of clinical suspicion after 24 months using the Quantitative Real-Time quantitative polymerase chain reaction (RT-PCR). Results: Ninety (54.2%) allogeneic transplant patients, and forty one (14.6%) autologous transplant patients had CMV reactivation. There was a statistically significant increase in CMV reactivation in the non-myeloablative (NMA) allogeneic transplant group compared to the myeloablative (MA) group at a value of 150-1000 copies/mL CMV-PCR (p= 0.002). Acute/chronic Graft Versus Host Disease (GVHD) were observed in 30 of allogeneic HSCT patients. 29 of these patients (96.6%) had CMV antigenemia. There was a significant association between the development of acute/ chronic GVHD, and CMV viremia (p= 0.001). The patients without CMV antigenemia had a higher incidence of mortality at first 100-day, and 365-day in allogeneic transplant group (p= 0.022, p= 0.024, respectively). The 5-year overall survival (OS) rate was 61% in the viremia group, and 62% in the non-viremia group. There was no statistically significant difference between the two groups in terms of 5-year OS (p= 0.551). In patients receiving a lower dose of 900 mg/day valganciclovir treatment due to viremia, CMV disease did not develop and no adverse effect that required the drug to be discontinued was observed. Conclusion: The results conducted that development of GVHD was associated with CMV viremia. Early and late mortality rate were higher in the patients without CMV antigenemia. However; CMV reactivation had no impact on patients’ survival post allogeneic and autologous HSCT. Also, this was the first study that conducted preemptive treatment approach in the CMV viremia using a lower dose valganciclovir is safe and effective in HSCT.