Comparison of standard versus low-dose valganciclovir regimens for cytomegalovirus prophylaxis in high-risk liver transplant recipients

Purpose The purpose of this study was to compare the safety and efficacy of two valganciclovir (VGCV) institutional dosing protocols for cytomegalovirus (CMV) prophylaxis in liver transplant (LT) recipients with CMV serotype donor +/recipient- (D+/R-). Methods This was a single-center review of CMV D+/R- adult LT recipients who received VGCV 450 mg/day for 90 days (low-dose) or VGCV 900 mg/day for 180 days (standard-dose). The primary outcome was incidence of CMV disease at 1 year. Secondary outcomes included rates of CMV syndrome, end-organ disease, breakthrough infection, and resistance. Neutropenia, early discontinuation of VGCV, growth colony stimulating factors use (G-CSF), biopsy-proven rejection (BPAR), graft loss, and death at 1 year were analyzed. Results Ninety-six CMV D+/R- LT recipients were included. Although no difference in CMV disease was observed (low-dose 26% vs. standard-dose 23%, p = 0.71), 75% of CMV infections in the low-dose group presented with end-organ disease. Ganciclovir (GCV) resistance was observed only in the low-dose group (n = 2). Significantly more patients in the standard-dose group developed neutropenia (low-dose 10% vs 60% standard-dose, p < 0.001). In the standard-dose group, 29% required early discontinuation of VGCV (vs. 5% in the low-dose group, p < 0.001), and 20% were treated with G-CSF. Both cohorts had similar rates of BPAR, graft loss, and death at 1 year. Conclusions VGCV 900 mg/day for 180 days had higher rates of hematologic adverse effects resulting in frequent treatment interruptions. However, the occurrence of two cases of GCV-resistant CMV disease raises concerns about routinely using low-dose VGCV prophylaxis.