Reactivation of Cytomegalovirus Following Reduced-Intensity Cord Blood Transplantation for Adult Patients.

Backgrounds: Cytomegalovirus (CMV) infection is a major complication after allogeneic hematopoietic stem-cell transplantation. We and other groups recently reported the feasibility of cord blood transplantation using reduced-intensity regimens (RI-CBT) for adult patients with advanced hematologic diseases. We have little information on the clinical features of CMV reactivation after RI-CBT.

Patients/methods: We reviewed medical records of 142 patients who received RI-CBT at Toranomon Hospital between January 2002 and March 2005. Median age of the patients was 55 years (range 17–79). Underlying diseases were chemorefractory hematologic diseases (n=136) and severe aplastic anemia (n=6). Conditioning regimens comprised fludarabine 125 mg/m², melphalan 80 mg/m² and total body irradiation (TBI) (4–8 Gy). Graft-versus-host disease (GVHD) prophylaxis was cyclosporine (n=86) or tacrolimus (n=56). Median number of total nucleated cells and CD34+ cells was 2.7×10⁶ cells/kg (0.39–4.8), and 0.73×10⁵ cells/kg (0.03–5.7) respectively. HLA disparity was 6/6 (n=3), 5/6 (n=21), 4/6 (n=116), and 3/6 (n=2). All the patients were monitored CMV-antigenemia weekly and received pre-emptive ganciclovir or foscarnet.

Results: CMV antigenemia tested positive in 77 patients on a median of day 36 (range, 4–87) after RI-CBT. Median of maximal CMV antigenemia was 22 per 50,000 leukocytes (range, 1–1806). CMV diseases developed in 18 patients on a median of day 40 (range 15–99); enterocolitis (n=18), and adrenalitis (n=1). CMV-antigenemia remained negative in two patients, when CMV disease was diagnosed. CMV disease was successfully treated using ganciclovir or foscarnet in 17 patients, and the other patient died of septic shock. Multivariate analysis revealed grade II–IV acute GVHD as a risk factor (odds, 95% CI).

Discussion: CMV reactivation and diseases develop early after RI-CBT. Optimal strategy for preventing CMV disease should be established in RICBT.