The significance of cytomegalovirus viremia at day 100 or more following allogeneic hematopoietic stem cell transplantation.

We conducted a single-center retrospective review of patients who had received allogeneic hematopoietic stem cell transplantation (HSCT) between January 2003 and December 2007, to assess the incidence and risk factors for late CMV infection and evaluate its effects on outcomes. Twenty of 49 HSCT recipients (41%) developed CMV infection at day ≥ 100 after transplant. Univariable analysis showed that having a matched unrelated donor, having early CMV infection, having a diagnosis of lymphoma, and receipt of antithymocyte globulin were risks for developing late CMV. On multivariable analysis, the occurrence of CMV prior to day 100 and lymphoma conferred a significant risk for late CMV infection. Of the 20 patients with late CMV infection, two patients manifested CMV disease (10%). Despite the relatively low incidence of CMV disease, patients with late CMV infection had a 4.8-fold increased risk of death compared to patients without late CMV. Identifying patients at increased risk for developing late CMV infection may be important for prompting more intensive monitoring of infection late after HSCT, particularly because this manifestation of CMV is associated with poorer outcomes.