Cytomegalovirus viremia in solid organ transplantation: does the initial viral load correlate with risk factors and outcomes?

Consistent data for using CMV quantitative PCR (QnPCR) on initial presentation to predict outcomes after solid organ transplantation (SOT) are lacking. Recipients with measurable CMV QnPCR and either CMV-V (asymptomatic viremia) or CMV-D (symptomatic CMV infection) were analyzed over 24 months. Risk factors and outcomes were evaluated in relation to initial QnPCR by regression analysis and time-to-event curves. Twenty-eight recipients were identified: five CMV-V, 23 CMV-D. Patients with CMV-D had a higher median initial QnPCR (230 000 copies/mL) compared with CMV-V (2500 copies/mL; p 10 000 copies/mL compared with 83% of the CMV-D (p = 0.004). The initial QnPCR was higher (250 000 copies/mL) in patients who did not clear CMV PCR than those who cleared (8000 copies/mL) after 14 d of treatment (p = 0.03). Risk factors and indirect CMV effects were not associated with initial QnPCR. Our results highlight the importance of the initial CMV QnPCR in relation to the development of symptomatic CMV and a slower response to therapy. Alternatively, late asymptomatic viremia and recurrent CMV are associated with lower PCR levels and a low likelihood to progress and result in clinical disease.