Evaluation of cytomegalovirus "Blips" in high-risk kidney/kidney-pancreas transplant recipients.

Background: Cytomegalovirus (CMV) is a significant cause of morbidity and mortality after solid organ transplantation. While guidelines suggest using highly sensitive QNAT assays for CMV detection, there is no defined viral load to guide initiation of preemptive therapy. This study evaluates the progression to quantifiable CMV (DNAemia) following a CMV "blip" in high-risk (D+/R) kidney/kidney-pancreas (KP) transplant recipients.

Methods: This is a single center, retrospective study. A CMV "blip" was defined as the first positive QNAT assay below the level of quantification (<1.37 × 10 IU/ml or <200 viral copies). Subsequent CMV QNAT assays were followed to assess the progression from blip to CMV DNAemia for 1 year following transplant.

Results: A total of 134 patients were included in the study. Fifty-three (39.6%) patients had their first positive CMV QNAT value below the level of quantification, a "CMV blip." Of these 53 patients, 69.8% (n = 37) progressed to DNAemia while 30.2% (n = 16) did not. The median time from transplant to the first CMV blip was 68 (46-97) days and most patients with viral blips (71.1%) were on prophylaxis. No differences in patient characteristics were found among those who progressed from blip to DNAemia and those who only had a blip.

Conclusions: In CMV high-risk kidney/KP transplant recipients, CMV blips progressed to CMV DNAemia in the majority of cases. This progression typically occurred 2-3 weeks following the initial blip. CMV blips are common early posttransplant despite prophylaxis and likely represent an early marker of CMV infection.