Surveillance over cytomegalovirus (CMV) reactivation following hematopoietic stem cell transplantation: a single-center experience

Cytomegalovirus (CMV) infection is widespread and usually asymptomatic in immunocompetent individuals. However, during immune suppression, especially after hematopoietic stem cell transplantation (HSCT), viral reactivation may result in symptomatic infection and end-organ disease. Because there is high incidence of CMV seropositivity in Bulgaria, CMV infection/reactivation is an expected common complication in HSCT recipients which requires frequent monitoring. CMV reactivation monitoring via qRT PCR has a significant role in terms of the moment of initiating pre-emptive therapy in these high-risk patients in order to avoid the development of CMV disease and better clinical management. The aim of this study was to determine and analyze the incidence of CMV reactivation in HSCT recipients in a new transplant center in Bulgaria. The incidence of early CMV reactivation after HSCT in our center is very high (76.7%) most likely related to the high-risk donor/recipient (D/R) profile of our recipients. The mean period from HSCT to the first positive PCR result was quite short, 21.5 days on average. The highest-risk group donor-/recipient+ (D-/R+) experienced the longest and the highest levels of viremia, as well as the highest number of reactivations. The nature of the D/R status most significantly affected the degree of viral load. Our data demonstrate the essential role of monitoring of CMV with reliable and sensitive laboratory methods, such as qRT-PCR to avoid development of CMV disease in high-risk patients.