KNOWN HPV TYPES HAVE NO ASSOCIATION WITH KERATOACANTHOMAS

Certain HPV types have been linked to the genesis and development of p remalignent and malignant skin diseases, There have been several contr adictory reports on the role of HPV infections in the development of k eratoacanthomas (KAs). To further study the involvement of HPVs in the aetiology of KAs, we investigated paraffin-embedded specimens of 80 b iopsies of KAs for the presence of HPV 1, 2, 3, 4, 5, 7, 26, 37, 38, 4 7 and 59 DNA by in situ hybridization (ISH) with biotinylated probes u nder high stringency conditions (Tm-10 degrees C). Every fourth biopsy specimens was also examined by polymerase chain reaction (PCR) with c onsensus primers targeting the HPV E1 and L1 regions, The positive cas es were further studied by direct DNA sequencing. All specimens proved to be negative for all HPV DNAs studied by ISH. Three out of 20 cases produced in positive PCR amplifications when consensus primers target ing the L1 region were used, However, the same samples remained negati ve with general primers targeting the E1 region, The DNA sequence anal ysis of the PCR-positive products showed a 76% homology with HPV type 17. Our results suggest that the known HPV types are unlikely to have any role in the aetiology of KAs.