Comparison of antigenemia assay and semiquantitative polymerase chain reaction test for monitoring active cytomegalovirus infection in allogeneic hematopoietic cell transplant recipients.

OBJECTIVES

We sought to compare the antigenemia assay and in-house semiquantitative polymerase chain reaction to monitor human cytomegalovirus infection after transplant in hematopoietic cell transplant recipients.

MATERIALS AND METHODS

A pp65 antigen test for polymorphonuclear leukocytes and a semiquantitative polymerase chain reaction for whole blood were performed for 201 samples obtained from 26 hematopoietic cell transplant recipients over a 3-month surveillance period.

RESULTS

Fourteen episodes of antigenemia positivity were detected in 7 patients in whom human cytomegalovirus DNA loads and pp65-positive cells ranged between < 102 to 2.96 x 104 copies/mL and 0-35/ 5 x 104 polymorphonuclear leukocytes, respectively. A significant correlation was detected between human cytomegalovirus DNA load and the antigenemia test. A receiver operating characteristic analysis determined 5000 copies/mL of human cytomegalovirus as the threshold value for initiation of ganciclovir therapy.

CONCLUSIONS

Based on a comparison of the pp65 antigenemia assay, quantification of human cytomegalovirus DNA in whole blood can be used to guide clinical management of hematopoietic cell transplant recipients. This approach may have important advantages including superior sensitivity and efficient monitoring of preemptive therapy, allowing inclusion of kinetic criteria in clinical guidelines. Furthermore, a high human cytomegalovirus load among patients with grade II-IV acute graft-versus-host disease may indicate a high risk of human cytomegalovirus disease among hematopoietic cell transplant patients. Human cytomegalovirus reactivation must be monitored using more-sensitive assays such as real-time polymerase chain reaction.