Background: Adenovirus infection is a potentially serious complication of allogeneic hematopoietic stem cell transplantation (HSCT) and has been reported to occur more frequently following T-cell-depleted reduced-intensity HSCT. However, the true incidence and clinical significance as well as the relationship of disease to viremic titer remain unclear due to wide variation in study populations and methodology.

Methods: We performed weekly surveillance blood testing by quantitative polymerase chain reaction on all adult recipients of alemtuzumab-based reduced-intensity HSCT at our institution between January 2008 and January 2011. We collated this with clinical data on treatment and outcomes of adenovirus infection.

Results: Of 116 HSCT patients analyzed, 14 (12.1%) had adenoviremia with a titer >200 copies/mL. Median time to first detectable titer was 28 days post-HSCT (range, 10-347), and median time to maximum titer was 49 days (range, 16-368). Underlying disease diagnosis (lymphoid > myeloid) and recipient cytomegalovirus (CMV) serostatus (positive > negative) were significantly correlated with adenoviremia. Only 5 patients (with high peak titers of 99 000-2 500 000 copies/mL) received cidofovir; 1 died from complications relating to adenovirus and concurrent CMV infection.

Conclusions: We detected adenoviremia at quantifiable levels in only 12.1% of HSCT patients. Attributable mortality was low (0.9% of the entire cohort, 7% of those with adenoviremia) because even infections associated with high viral titers responded to reduction in immunosuppression and treatment with cidofovir in the majority. The clinical significance of adenoviral infection in patients receiving alemtuzumab-based HSCT appears to be less than that previously reported, and only rarely does infection lead to significant morbidity and mortality.