Distribution patterns of β- and γ-herpesviruses within Waldeyer's ring organs

The Waldeyer's ring designates a functional unit of lymphoid tissue within the pharynx including the adenoids and tonsils. To gain insight into distribution patterns of (beta- and gamma-human herpesviruses (HHVs) and their potential mutual influences at their natural portal of entry, quantitative polymerase chain reaction (qPCR) assays were applied to adenoids and tonsils obtained from 30 children. DNA of Epstein-Barr virus (EBV), cytomegalovirus (CMV), HHV-6, HHV-7, and HHV-8 was detected in adenoids, tonsils, or both of 24 (80%), 19 (63%), 23 (77%), 23 (77%), and 0 (0%) children, respectively. EBV, CMV, HHV-6, and -7 localized in both adenoids and tonsils from 92%, 37%, 52%, and 70% of children, respectively, with the virus detectable by qPCR. The amount of EBV was 2-10-fold higher than of other HHVs and correlated in autologous organs (P=0.01) as did the amount of HHV-7 (P=0.002). The amount of CMV correlated with the HHV-6 amount in adenoids (P= 0.028) and tonsils (P= 0.007), and with the amount of HHV-7 in adenoids (P < 0.01). Levels of HHV-6 DNA were lower in adenoids with detectable CMV DNA than in adenoids without detectable CMV DNA (P=0.0062). Inversely, CMV and HHV-7 levels were higher in adenoids with than in adenoids without detectable EBV DNA (P=0.019 and P=0.039, respectively).Thus, beta- and gamma-HHV exhibit distinct distribution behaviors in Waldeyer's ring organs and seem to interact. This may be of medical importance in immunocompromised hosts who are likely to reactivate HHVs causing severe morbidity and death.