Prevalence of polyomaviruses BK, JC, SV40, KI, and WU in non-malignant tonsil specimens

Aim.The recently described polyomaviruses KI and WU have been detected in respiratory samples, stools, tonsils, and blood, particularly in immunocompromised conditions, although little is known about tissue tropism. Herein we investigated the occurrence of KIV and WUV in non-malignant tonsillar specimens by Real-time quantitative PCR; the presence of polyomaviruses BK, JC and SV40-DNA was also evaluated. Methods. Twenty-nine non-malignant tonsil specimens obtained from children and adults admitted for tonsillectomy were prospectively studied. Real-time quantitative TaqMan PCR for polyomaviruses KI, WU, BK, JC, and SV40 were performed. Results. KI-DNA was positive in 2/29 tonsillar specimens (6.9%), while BK- DNA, JC-DNA, SV-40 DNA, and WU-DNA sequences were not identified. Conclusion. Few studies have investigated the prevalence of polyomaviruses in tonsil specimens, with varying results, and data are particularly scant as regards the newly discovered KIV and WUV. Two major questions remain to be definitely answered at this regard: the possibility that human tonsils represent the initial site of infection and/or a latency site and the biological and clinical meaning of KIV and WUV in different contexts and groups of patients, in that it is not clear whether they are simple bystanders or play a role in tonsil disease.