Detection of Herpesvirus and Adenovirus Infections in Patients Undergoing Stem Cell Transplantation: Looking Below the Tip of the Iceberg with the Microarray Technology.

Infections with herpesvirus and adenovirus is a major cause of morbidity and mortality in patients undergoing stem cell transplantation (SCT). In those patients, the frequency of herpesvirus and adenovirus co-infections as well as their contribution to the infectious burden remain so far unclear. In this study, we have postulated that co-infections with herpesviruses and adenoviruses are frequent in the 100 days following SCT, contributing significantly to the infectious burden. To address this issue, 615 blood samples collected from patients undergoing SCT (n=35) were retrospectively tested by quantitative real-time PCR for the presence of HSV 1/2, VZV, EBV, CMV, HHV6 A/B, and adenovirus. Infections with a single virus were detected in 46.1% (283/615) of the samples, whereas co-infections with two or three viruses were detected in 9.9% (61/615) and 2.1% (13/615) of the samples, respectively. Interestingly, about 50% of the patients (17/35) displayed a co-infection with two or more viruses, with [CMV+HHV6 A/B], and [EBV + HHV6 A/B +adenovirus] being most frequently detected, respectively. Comparison of viral loads indicated that the infectious burden increases proportionally to the number of viruses detected. Moreover, a DNA-microarray allowing simultaneous detection of HSV 1/2, VZV, EBV, CMV, HHV6 A/B, and adenovirus was developed. The assay displayed a high diagnostic accuracy, being an attractive device for routine assessment of the infectious burden in immunocompromised patients after SCT.