Monitoring of oral cytomegalovirus DNA shedding for the prediction of viral DNAemia in allogeneic hematopoietic stem cell transplant recipients

Preemptive antiviral therapy based on detecting cytomegalovirus (CMV) DNAemia above a preestablished threshold is the mainstay strategy for the prevention of CMV disease in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients; nevertheless, CMV DNAemia, even at low levels, may increase mortality. We investigated whether surveillance of saliva for the presence of CMV DNA may anticipate the occurrence of CMV DNAemia. This was a prospective observational study with 53 consecutively enrolled allo-HSCT recipients. Saliva and plasma specimens were collected on a weekly basis from Day 0 to Day 100 after transplantation. CMV DNA was quantified in both specimen types using the Abbott Real-Time PCR assay (Abbott Molecular, Des Plaines, IL). CMV DNA was quantifiable in 44 (83%) patients: either in saliva (n=1) or plasma (n=12) only, or in both specimen types (n=31). CMV oral shedding preceded the occurrence of CMV DNAemia in eight patients (18.2%), while the opposite pattern was observed in 21 patients (47.7%). The CMV DNA loads quantified in saliva and plasma correlated modestly (P=0.33; P=0.013) and did not differ in magnitude (P=0.527). No transplantation factors, other than recipient CMV seropositivity, were associated with oral CMV DNA shedding; serum CMV IgG levels were comparable, regardless of the timing of the detection of CMV DNA at both sites. In summary, screening of saliva specimens for the presence of CMV DNA appear to be of limited value for anticipating the occurrence of CMV DNAemia in allo-HSCT recipients.