Langerhans cells in human papillomaviruses types 6/11 associated laryngeal papillomas

Some studies have shown a reduced density of Langerhans cells (LCs) within epithelium infected by human papillomaviruses (HPV) types 16/18. However, data on a correlation between HPV types 6/11 infection and LCs have been missing. To solve this problem, we analysed 24 biopsy specimens of laryngeal papillomas, selected randomly, 20 multiple and 4 solitary. The presence of HPV 6 and 11 was proven by polymerase chain reaction (PCR) using 2 different sets of primers in 23 biopsy specimens. Abnormalities of the covering stratified squamous epithelium were graded according to the Kambic-Gale classification. LCs were immunohistochemically labelled with 2 different antibodies, CD1a and S100. Quantitative analysis was performed to determine the density of LC per mm2 in different grades of epithelial abnormalities covering laryngeal papillomas. Although no statistically significant differences in the mean number of LCs per mm2 of the cross-sectioned epithelium covering laryngeal papillomas were observed comparing simple, abnormal and atypical hyperplasia groups, the mean number of LCs per mm2 in laryngeal papillomas associated with HPV types 6/11 infection substantially exceeded that of the vocal cord surface epithelium in patients with chronic laryngitis.