Clinical significance of human cytomegalovirus viruria and the effect of antiviral therapy in hematopoietic stem cell transplant recipients

Background Cytomegalovirus (CMV) causes life-threatening infections in immunocompromised host. The clinical significance of asymptomatic CMV viruria in patients receiving hematopoietic stem cell transplantation (HSCT) remains unclear. This study aims to clarify whether antiviral therapy is associated with a favorable clinical outcome. Methods HSCT recipients whose urine was culture-positive for CMV were retrospectively reviewed and followed. Viruria episodes were divided according to whether or not antiviral therapy was used. Mortality and the estimated glomerular filtration rate (eGFR) in 2 years following CMV viruria were compared between patients with and without antiviral therapy. Results Sixty-two episodes of culture-proven asymptomatic CMV viruria were identified in 28 HSCT recipients. Antiviral therapy was used in 35 (56.5%) and spared in 27 (43.5%) viruric episodes. Compared with the baselines, there were no significant difference in the decrements of eGFR between the two groups at the end the 1st year (4.78 vs 5.02 mL/min/1.73 m2, p = 0.968) and the 2nd year (1.13 vs 7.66 mL/min/1.73 m2, p = 0.276). Antiviral therapy for asymptomatic CMV viruria was also not associated with a favorable survival (p = 0.288). On the other hand, presence of CMV viremia correlated with a poorer survival (2-year mortality rate 60% vs 13.33%, p < 0.001). Conclusion Antiviral therapy for asymptomatic CMV viruria is not associated with a clear clinical benefit in HSCT recipients. Further studies may be needed to identify if specific patient populations may benefit from antiviral therapy in CMV viruria.