KI and WU Polyomavirus detection in tonsils of immunocompetent patients

Abstract

The Polyomaviruses KI and WU have been identified in 2007 in nasopharyngeal aspirates of patients with acute respiratory tract infections.They have been further isolated in faecal samples, lymphoid tissue, bronchoalveolar lavages and blood, although their pathological associations, molecular epidemiology and tissue tropism are still not widely known.The aim of this study was to determine the presence of KIV and WUV in tonsillar tissue of immunocompetent patients to assess whether the tonsils may represent a site of infection and/or persistence.The presence of Polyomavirus BKV, JCV and SV40 was also evaluated. The presence of Polyomavirus KI,WU, BK, JC and SV40-DNA was evaluated in a prospective study on tonsillar samples obtained from 29 immunocompetent patients (adults and children undergoing tonsillectomy) by a commercially available Taqman Real-time quantitative PCR (BKV Q-PCR Alert Kit, Nanogen) and a home-made system (for KIV,WUV, SV40, JCV).The amplification conditions were optimized and standardized. KIV-DNA was detected in 2/29 (6.9%) tonsil tissue (obtained from an adult and a child), while WU, BK, JC and SV40 were negative in all cases. Our prevalence results are consistent with those reported in the literature on samples from the respiratory tract and lymphoid tissue such as tonsils. Further studies are needed to understand the significance of the presence of KIV in tonsil tissue and assess the possibility that the virus can establish latent and/or persistent infection at this level.