Identification of the novel KI Polyomavirus in paranasal and lung tissues.

KI is a novel polyomavirus identified in the respiratory secretions of children with acute respiratory symptoms. Whether this reflects a causal role of the virus in the human respiratory disease remains to be established. To investigate the presence of KIV in the respiratory tissue, we examined 20 fresh lung cancer specimens and surrounding normal tissue along with one paranasal and one lung biopsy from two transplanted children. KIV-VP1 gene was detected in 9/20 lung cancer patients and 2/2 transplanted patients. However, amplification of the sequence coding for the C-terminal part of the early region of KIV performed on the 11 positive cases was successful only in two malignant lung tissues, one surrounding normal tissue, and 1/2 biopsies tested. Phylogenetic analysis performed on the early region of KIV (including the four Italian isolates), BKV and JCV revealed the presence of three distinct clades. Within the KIV clade two sub-clades were observed. A sub-clade A containing the four Italian strains, and a sub-clade B comprising the Swedish and Australian isolates. Interestingly, the two Italian strains identified in normal tissue clustered together, whereas those detected in malignant tissue fell outside this cluster. In vitro studies are needed to investigate the transforming potential of KIV strains. Copyright 2009 Wiley-Liss, Inc.