Detection of TS polyomavirus DNA in tonsillar tissues of children and adults: Evidence for site of viral latency

Background: The trichodysplasia spinulosa-associated polyomavirus (TSPyV), a recently discovered species of the family Polyomaviridae, is associated with development of trichodysplasia spinulosa (TS), a rare follicular skin disease of immunocompromised individuals. The viral seroprevalence in the general population is ~70%, with little known of its route of transmission, latency, or primary infection site. Objectives: We aimed to determine whether the viral DNA is detectable in tonsillar tissue of constitutionally healthy individuals, and what the corresponding antiviral seroreactivities are. Study design: We tested 229 matched pairs of tonsillar tissue biopsies and serum samples from asymptomatic donors for TSPyV DNA by real-time quantitative PCR with primer pairs and Taq-Man probes targeting the VP1 and LT genes. The sera were studied by enzyme immunoassay (EIA) for TSPyV-VP1-IgG and the PCR-positive individuals also for -IgM and -IgG-avidity. Results: TSPyV DNA was detectable in 8 (3.5%) of 229 tonsillar tissues, and in none of the corresponding sera. TSPyV IgG seroprevalence among children was 39% and among adults 70%. Each of the 8 PCR-positive subjects had antiviral IgG of high avidity but not IgM. Conclusions: TSPyV PCR positivity of tonsillar samples of individuals with long-term immunity provides the first evidence of TSPyV in tonsils and suggests lymphoid tissue as a latency site of this emerging human pathogen.