Preemptive ganciclovir for CMV viremia in liver transplantation

Use of Viral Load as a Surrogate Marker in Clinical Studies of Cytomegalovirus in Solid Organ Transplantation: A Systematic Review and Meta-analysis

Symptomatic cytomegalovirus (CMV) disease has been the standard endpoint for clinical trials in organ transplant recipients. Viral load may be a more relevant endpoint due to low frequency of disease. We performed a meta-analysis and systematic review of the literature. We found several lines of evidence to support the validity of viral load as an appropriate surrogate end-point, including the following: (1) viral loads in CMV disease are significantly greater than in asymptomatic viremia (odds ratio, 9.3 95% confidence interval, 4.6-19.3); (2) kinetics of viral replication are strongly associated with progression to disease; (3) pooled incidence of CMV viremia and disease is significantly lower during prophylaxis compared with the full patient follow-up period (viremia incidence: 3.2% vs 34.3%; P < .001) (disease incidence: 1.1% vs 13.0%; P < .001); (4) treatment of viremia prevented disease; and (5) viral load decline correlated with symptom resolution. Based on the analysis, we conclude that CMV load is an appropriate surrogate endpoint for CMV trials in organ transplant recipients.

Universal prophylaxis or preemptive strategy for cytomegalovirus disease after liver transplantation: a systematic review and meta-analysis

We systematically reviewed and meta-analyze the efficacy of universal prophylaxis (UP) and preemptive (PE) strategies (using ganciclovir or valganciclovir) in preventing cytomegalovirus (CMV) disease (CMD) among liver transplant recipients (LTRs). We performed an electronic search of MEDLINE, EMBASE and the Cochrane Database till December 2013. Studies that assessed UP or PE for preventing CMD in LTRs were included. The risk of bias was assessed using the Newcastle-Ottawa scale. The primary outcome was CMD, secondary outcomes being acute cellular rejection (ACR), graft loss (GL) and mortality. Due to the heterogeneity of comparative studies, an indirect comparison was performed. Pooled incidence rates with 95% confidence interval (CI) are calculated for each outcome using a random-effects model. Thirty-two studies involving 2456 LTRs were included. The majority of the studies were of low risk of bias. Irrespective of donor/recipient CMV sero-status, CMD was 10% with UP (95% CI: 6-14; I(2)  = 87%; 16 studies, n = 1581) and 7% with PE (95% CI: 3-10; I(2)  = 84%; 16 studies, n = 875) (mean difference 2.6; 95% CI: -3.25 to 8.45, p = 0.34). Likewise, ACR and mortality were similar with the two strategies. However, GL was significantly lower in the UP group, regardless of donor/recipient sero-status. In indirect comparison, the incidence of CMD, ACR and mortality in LTRs were similar with two strategies. Trials comparing the two strategies directly are needed.