Risk Factors and Mortality Associated with CMV Reactivation Post Autologous Stem Cell Transplantation.

Cytomegalovirus (CMV) is one of the most common viral pathogens post-allogeneic stem cell transplantation (SCT). However, CMV reactivation and disease are relatively uncommon events after autologous stem cell transplantation (ASCT), with a reported incidence of 2–9%. There are few studies describing risk factors for development of CMV reactivation post-ASCT.

To describe the incidence and risk factors for CMV reactivation post-ASCT in our institution and its impact on survival.

The charts of patients who underwent ASCT at our institution from January 2005 until July 2009 were manually reviewed. CMV reactivation was detected by antigenemia assay and/or real-time PCR. Variables associated with CMV in a univariate analysis with a p<0.15 were included into a multivariable logistic regression model to determine risk factors for developing CMV reactivation. Overall survival (OS) was defined from time of ASCT until death from any cause and was estimated by Kaplan-Meier method. Logrank test was used to compare unadjusted OS between patients with and without CMV reactivation.

A total of 115 ASCTs were performed at our institution during that time frame (bone marrow=8; peripheral blood stem cells=107). CMV reactivation was investigated in 50 patients (43.5%) who presented with persistent fever and 14 (12.3%) were found to be positive for CMV by either antigenemia and/or real-time PCR. Diagnosis included multiple myeloma (N=7) non-Hodgkin's lymphoma (N=6) and multiple sclerosis (N=1). Median time to CMV reactivation was 18 days (range 12–41). Seventy-two patients had information on absolute lymphocyte count at day 15. Patients with an ALC < 0.5×10⁹/L at day 15 had a higher incidence of CMV reactivation (28.5% vs. 8%, p=0.02). Variables entered in the logistic regression multivariate analysis were age, sex, years between diagnosis and ASCT and ASCT in the last 12 months. Only age (odds ratio [OR]=1.06; p=0.05) and ASCT in the last year (OR=3.7; p=0.03) were significantly associated with CMV reactivation in the multivariate analysis. When analyzing only the 72 patients that had information on day 15 ALC, the multivariate analysis revealed ASCT in the last 12 months (OR=1.56, p=0.05) and day 15 ALC < 0.5×10⁹/L (OR=4.71, p=0.03) as being associated with CMV reactivation. Patients who had CMV reactivation had a significantly inferior OS (2-years 61% vs. 23.4%, p=0.03).

We detected a relatively high incidence of CMV infection post-ASCT and this was associated with a higher mortality. Patients who develop CMV infection post-ASCT may represent a subset that has a higher degree of immunesuppression, as manifested by a lower ALC at day 15 post ASCT. We believe that patients should be monitored post-ASCT for the presence of CMV reactivation, particularly if they present with persistent lymphopenia.

No relevant conflicts of interest to declare.