Prospective long-term study on primary CMV infections in adult liver transplant (D+/R-) patients after valganciclovir prophylaxis.

Background: Cytomegalovirus (CMV) can cause severe infections in transplanted patients. To prevent CMV infection, most liver centers use prophylaxis for CMV-seronegative recipients receiving an organ from a seropositive donor (D+/R-). Valganciclovir is mostly given for 3-6 months after transplantation. However, the patients may develop primary CMV infection after the cessation of prophylaxis and late-onset CMV disease may occur.

Objective: A prospective long-term follow-up of CMV (D+/R-) adult liver transplant recipients after 3 months valganciclovir prophylaxis was investigated.

Methods: Of 154 consecutive adult liver recipients transplanted from 2006 to 2009, 20 (13%) were CMV D+/R- and received antiviral prophylaxis up to 3 months after transplantation. After excluding the recipients with incomplete prophylaxis or monitoring, 13 (D+/R-) patients with follow-up of >4 years after the 3-month period of valganciclovir prophylaxis were included in the study.The patients were monitored for CMV by real-time quantitative plasma PCR.

Results: No break-through CMV infections were recorded during the prophylaxis period. After cessation of valganciclovir prophylaxis 12/13 (90%) patients demonstrated CMV-DNAemia following a post transplantation mean interval of 165 days (range 95-320). Ten patients with high viral loads (peak viral load mean 81,510, range 1900-648950cps/ml) were successfully treated, 6 with valganciclovir, and 4 with ganciclovir. Two patients with low level CMV-DNAemia (<1000cps/ml) were asymptomatic and not treated. No intragraft infection was seen, but one patient developed gastrointestinal CMV infection verified from ileum biopsy. During long-term follow-up, 3 patients demonstrated low-level viral replication, but no symptomatic recurrences occurred. One patient died of bacterial sepsis, but no patient or graft was lost due to CMV.

Conclusions: Primary CMV infections after cessation of prophylaxis were common, but were successfully treated with valganciclovir or ganciclovir.