Risk factors of cytomegalovirus infection after pediatric liver transplantation and effectiveness of preemptive therapy

Cytomegalovirus (CMV) infection is the most common infection following pediatric liver transplantation (LT). Preemptive therapy (PET) is an approach to initiate antiviral treatment for asymptomatic early CMV viremia detected by surveillance testing. However, data on CMV infection after PET are scarce, and the optimal cut-off remains controversial. This study aimed to evaluate the incidence, risk factors, and consequences of CMV infection in pediatric LT using 2 different viral load (VL) cut-offs.We retrospectively reviewed patients aged 0-18 years who underwent LT at Ramathibodi Hospital between March 2001 and August 2020. Demographic data, CMV infection, CMV treatment, and consequences of CMV infection were collected. CMV viremia was monitored by a quantitative nucleic acid amplification test. Clinical outcomes were compared after starting antiviral therapy at a low (>400 but <2000 IU/mL) and a high VL cut-off (≥2000 IU/mL).A total of 126 patients were included. CMV infection was 71% (90/126), with an incidence rate of 5.5 per 1000 patient-day. Higher tacrolimus and prednisolone dosages were associated with CMV infection with an adjusted hazard ratio of 1.2 (95%CI 1.0-1.4, p = .02) and 2.4 (95%CI 1.9-3.4, p < .001), respectively. The consequences of CMV infection did not differ significantly for the low and high CMV VL cut-off groups.CMV infection in LT recipients is common and is associated with higher tacrolimus and corticosteroid dosage. Additionally, using the CMV VL cut-off at 2000 IU/mL to initiate antiviral therapy is practical and effective in preventing CMV disease.