Human Papillomavirus (HPV) Detection in Keratotic Variants of Oral Lichen Planus: Negative Results in a Preliminary Open Study

Background During the last few decades, several researches have been identified HPV genomic sequences in Head Neck Squamous Cell Carcinomas (HNSCC) and in Oral Potentially Malignant Disorders (OPMD) hypothesizing a possible viral etiological role. However, the reported prevalence of HPV-DNA (varying from 0% to 100%) in these lesions result still very discordant. Objective Human papillomavirus (HPV) infection in Oral Lichen Planus (OLP) has been largely investigated but not so extensively with respect to its morphological/histopathological features. The possible influence of hyper-keratosis/parakeratosis in HPV detection for keratotic variants of OLP is here proposed and investigated. Materials and methods A total of 45 individuals with keratotic variants of OLP, clinically and histologically confirmed, were consecutively enrolled, before starting any treatment, and underwent oral brushing for HPV investigation. Viral DNA was extracted from oral brushed cells and HPV DNA researched by the combined use of the INNO-LiPA HPV Genotyping system (Innogenetics) and a PCR assay coupled with genome sequencing. Results None of cytological samples collected resulted HPV-positive. Conclusions In this preliminary study, oral HPV infection, investigated by means of a non-invasive oral sampling procedure and a standardized approach for HPV DNA detection, was not showed in any of the investigated cases. The presence of epithelial hyper-keratosis/parakeratosis in some variants of OLP could be a possible cause of impenetrability and/or difficult detection of the virus. Indeed, in case of keratotic variants of OLP, the possible potential false-negative results of HPV investigation by cytological procedure might be possible; on consequence, an alternative approach for viral detection (i.e. by histological sampling) should be considered.