A team from London, England, evaluated the use of viral load measurements as a guide to treating cytomegalovirus (CMV) infection after liver transplantation.
A total of 150 liver allograft recipients were included in the trial.
They were prospectively monitored for the presence of CMV DNA for the first 12 weeks after orthotopic liver transplantation, using the Murex hybrid capture system.
The first CMV DNA value after liver transplantation and weekly rise in CMV DNA (gradient value) were analyzed as risk factors for CMV infection.
The CMV DNA value on clinical detection of active infection (critical value) was also assessed.
It was found that 29% of the patients had detectable CMV DNA within 12 weeks of transplantation, and 13% experienced symptomatic CMV infection.
|Risk factors for CMV infection:|
- Baseline CMV DNA level
- Positive weekly increase in CMV DNA
- Critical CMV DNA level
| Transplantation |
Multiple regression analysis demonstrated that baseline CMV DNA level above 10 pg/ml and positive weekly increase in CMV DNA level were independent risk factors for clinically significant infection.
Critical CMV DNA level above 13 pg/ml was also an independent determinant.
Using Cox's multiple regression model, the researchers found that the hazard ratio was 13.9 for baseline CMV DNA above 10 pg/ml, and 13 for a weekly increase in the gradient.
Critical CMV DNA level above 13 pg/ml correlated with active infection (100% sensitivity, 98% specificity, 90% positive predictive value, and 100% negative predictive value).
Dr Suzanne Norris, of the Institute of Liver Studies, King's College Hospital, London, said on behalf of her colleagues, "Baseline and gradient CMV DNA viral load levels correlate with active CMV infection in liver allograft recipients."
"These data indicate that CMV viral load detection by hybridization methodology is useful in predicting active CMV infection and could be used in a preemptive strategy in liver allograft recipients," she concluded.