Vulvar lichen sclerosus and lichen planus are T-cell-mediated chronic skin disorders. Although autoimmunity has been suggested, the exact pathogenesis of these disorders is still unknown. Therefore, the aim of the current study was to investigate the molecular and immunological mechanisms critical to the pathogenesis of vulvar lichen sclerosus and lichen planus. By using gene expression profiling and real-time RT-PCR experiments, we demonstrated a significantly increased expression of the pro-inflammatory cytokines (IFNγ, CXCR3, CXCL9, CXCL10, CXCL11, CCR5, CCL4, and CCL5) specific for a Th1 IFNγ-induced immune response. In addition, BIC/microRNA-155 (miR-155)--a microRNA involved in regulation of the immune response--was significantly upregulated in lichen sclerosus and lichen planus (9.5- and 17.7-fold change, respectively). Immunohistochemistry showed a significant T-cell response, with pronounced dermal infiltrates of CD4(+), CD8(+), and FOXP3(+) cells. In conclusion, these data demonstrate an autoimmune phenotype in vulvar lichen sclerosus and lichen planus, characterized by increased levels of Th1-specific cytokines, a dense T-cell infiltrate, and enhanced BIC/miR-155 expression.

Human papillomavirus (HPV) infections may result in benign hyperplasia, caused by low-risk HPV types, or (pre)malignant lesions caused by high-risk HPV types. The molecular basis of this difference in malignant potential is not completely understood. Here, we performed gene profiling of different HPV infected vulvar tissues (condylomata acuminata (n 5 5), usual type vulvar intraepithelial neoplasia (uVIN) (n 5 9)) and control samples (n 5 14) using Affymetrix Human U133A plus 2 GeneChips. Data were analyzed using OmniViz V R , Partek V R and Ingenuity V R Software. Results were validated by real-time RT-PCR and immunostaining. Although similarities were observed between gene expression profiles of low-and high-risk HPV infected tissues (e.g., absence of estrogen receptor in condylomata and uVIN), high-risk HPV infected tissues showed more proliferation and displayed more DNA damage than tissues infected with low-risk HPV. These observations were confirmed by differential regulation of cell cycle checkpoints and by increased expression of DNA damage-biomarkers p53 and cH2AX. Furthermore, FANCA, FANCD2, BRCA1 and RAD51, key players in the DNA damage response, were significantly upregulated (p < 0.05). In addition, we compared our results with publicly available gene expression profiles of various other HPV-induced cancers (vulva, cervix and head-and-neck). This showed p16 INK4a was the most significant marker to detect a high-risk HPV infection, but no other markers could be found. In conclusion, this study provides insight into the molecular basis of low-and high-risk HPV infections and indicates two main pathways (cell cycle and DNA damage response) that are much stronger affected by high-risk HPV as compared to low-risk HPV.Worldwide, human papillomavirus (HPV) is the most common sexually transmitted infection, with an 80% life-time infection risk. 1 Fortunately, the majority of these HPV infections ($ 90%) are cleared within one to two years, without further consequences for the host. 2 Persistent infections, however, are a well-established risk factor for a large spectrum of epithelial lesions, ranging from benign hyperplasia, caused by low-risk HPV types, to (pre)malignant lesions caused by high-risk HPV types.The best known high-risk HPV related disorder is the second most common cancer in women, namely cervical cancer, with 500,000 new cases each year worldwide resulting in 250,000 deaths every year. 3 Persistent HPV infections have also been associated with other anogenital squamous cell carcinomas, including vulvar, vaginal, anal and penile cancers and their precursors. Furthermore, recent epidemiological, molecular and clinical evidence indicate that high-risk HPV (especially HPV type 16) accounts for the development of approximately 20-30% of squamous cell carcinomas of the head-and-neck. 4,5 The molecular basis of the difference in malignant potential between low-and high-risk HPV infections is not

Recently, we reported on the efficacy of imiquimod for treatment of usual type vulvar intraepithelial neoplasia (uVIN). A histologic regression of uVIN to normal tissue was observed in 58% of patients. As success of treatment is related to clearance of high-risk human papilloma virus (HPV), the aim of our study was to assess differences in immune cell counts and in the expression of p16 INK4a in VIN tissue before and after imiquimod treatment, in relation to HPV clearance and clinical response. Vulvar tissue samples taken prior to imiquimod treatment and 4 weeks after treatment were tested for the presence of HPV. Previously determined immune cell counts (CD1a, CD207, CD208, CD123/CD11c, CD94, CD4, CD8 and CD25/HLA-DR) in epidermis and dermis of 25 VIN patients and 19 healthy controls were completed with the counts for CD14 and CD68. The expression of p16 INK4a was investigated by immunohistochemistry in 15 patients. Before imiquimod treatment, both HPV cleared and HPV noncleared patients showed mainly in the dermis significantly upregulated immune cell counts compared to healthy controls. However, in patients that cleared HPV and showed histologic regression already 4 weeks after imiquimod treatment, immune cell counts and p16 INK4a expression were normalized. In conclusion, our data indicate that imiquimodinduced clearance of HPV results in normalization of counts for certain immune cells and is strongly correlated with histologic regression of the disease.Vulvar intraepithelial neoplasia (VIN) is a premalignant disorder that is classified into differentiated type VIN, which is associated with lichen sclerosus, and usual type VIN (uVIN), 1 which is caused by a persistent infection with a high-risk or oncogenic HPV (hrHPV, usually HPV-type 16, 18 or 33). 2 Over the last decades, the incidence of uVIN has increased, most likely due to a rise in the incidence of HPV infections. 3 Lifetime risk to become infected with HPV in western societies is around 80% and $40% of all sexually active, female adolescents are at least once infected with hrHPV. [4][5][6][7] When hrHPV persists (in less than 10% of cases), premalignant disorders of the anogenital tract, such as uVIN, can develop. 8-10 uVIN has invasive potential (10% of untreated cases will progress in 1-4 years) and needs to be treated proactively. 11,12 The host immune response is of critical importance in determining clearance or persistence of an HPV-infection. In natural life, during the early stages of a viral infection, CpGrich regions in the viral DNA are recognized by toll-like receptor (TLR) 7 and 9 on the cell surface of immature dendritic cells (DCs). Upon binding, TLRs activate kinase cascades eventually activating NFjB, which will result in the production of cytokines, adhesions molecules and other effectors of the innate immune response. 13 Other receptor and adhesion molecules at the DC surface can bind viral antigen and will internalize and digest the antigen, which is followed by expression on the cell membrane in major histocompatibility complex...

In case of a complete response, imiquimod is effective in the long-term. Furthermore, patients with a long-term complete response had a significantly better global quality of life than patients who recurred after imiquimod treatment.