Efficacy of valganciclovir prophylaxis in kidney transplant recipients following low-dose rituximab induction therapy: a multicenter retrospective study.

Background: Rituximab (RIT) induction therapy is widely used for desensitization against ABO-incompatible living-donor kidney transplants (KT). However, the efficacy of valganciclovir (VGCV) prophylaxis against cytomegalovirus (CMV) disease and infection in KT recipients (KTRs) following RIT induction remains unclear.

Methods: The current multicenter retrospective study included 213 KTRs who received low-dose RIT induction between 1998 and 2021, across 6 facilities included in the Michinoku Renal Transplant Network (MRTN). VGCV dosage varied from 450 mg/day (twice weekly) to 900 mg/day (daily), with treatment durations of 3-12 months. The primary and secondary endpoints were the incidence of CMV disease and infection, respectively.

Results: The incidence of CMV disease was significantly higher in the VGCV group (23.5%; 16 patients) than in the non-VGCV group (5.5%; 8 patients) (p < 0.01). The incidence of CMV infection was 54.5% (79 patients) in the non-VGCV group and 48.5% (33 patients) in the VGCV group, with no significant difference (p = 0.42). In the subgroup of CMV-seronegative KTRs receiving allografts from CMV-seropositive donors (CMV IgG (D + /R-)), 18 out of 24 KTRs received VGCV prophylaxis, of whom 10 (55.6%) developed CMV disease. Within this subgroup, only 4 KTRs received VGCV with the standard protocol (900 mg daily for 6 months), and none developed CMV disease.

Conclusion: Insufficient VGCV prophylaxis does not reduce the incidence of CMV disease in KTRs following low-dose RIT induction. Despite concerns about leukopenia due to RIT and VGCV, in KTRs with CMV IgG (D + /R-) serostatus, VGCV prophylaxis with a standard protocol may be advisable.