Cellular subsets and epithelial ICAM-1 and HLA-DR expression in human papillomavirus infection of the vulva.

Cryostat sections of 20 clinical condylomata of the vulva induced by human papillomavirus and 5 normal control biopsies were examined using immunohistochemistry. The results indicated that in vulvar papillomavirus infection the intraepithelial Langerhans' cells showed abnormal morphology and a significantly lower density than controls. CD1a positive Langerhans' cells were also observed in dermis of condylomata, suggesting an abnormal epithelial traffic of dendritic cells. T lymphocytes with a mean CD4/CD8 ratio of 0.25 and a mean density of 267 +/- 59 cells/mm2 of epithelial section were the main cellular infiltrate in vulvar papillomavirus infection. Most of the T cells were HLA-DR negative. Those condylomata with moderate to severe mononuclear infiltrate showed leucocyte function antigen 1 positive T cells forming small clusters in the lower epithelial half around the ICAM-1 positive keratinocytes. Vulvar warts also showed epithelial areas with overlapped ICAM-1 and HLA-DR expression. Scattered T gamma-delta and B lymphocytes, macrophages and NK cells were observed among the cells of the dermal infiltrate of vulvar condylomata.