Infectious Complications After Umbilical Cord Blood Transplantation for Hematological Malignancy

Linder, Kathleen A; McDonald, Philip J; Kauffman, Carol A; Revankar, Sanjay G; Chandrasekar, Pranatharthi H; Miceli, Marisa H

In our cohort, HHV-6 was the second most frequent pathogen observed, consistent with prior reports [6, 13] . Most often, HHV-6 presented as viremia without end-organ disease and occurred early after UCBT. The clinical significance of asymptomatic HHV-6 viremia remains controversial; however, HHV-6 reactivation has been independently associated with graft failure after UCBT [25] . We did not find a significant relationship between HHV-6 and graft failure in our patients. With the onset of viremia, patients were treated with foscarnet, and this may have blocked the development of end-organ disease due to HHV-6. Human herpesvirus 6 was responsible for the death of 1 patient, who developed limbic encephalitis more than 100 days after UCBT; this patient had been previously treated with foscarnet for 2 episodes of HHV-6 viremia, 1 of which was accompanied by pneumonitis. Receipt of an UCBT has been described previously as a risk factor for the development of limbic encephalitis; this condition is associated with high plasma HHV-6 viral loads, which were observed in this patient [26] .