Vulvar Epithelium Research Articles

Developmental origin of vaginal epithelium

The developmental origin of vaginal epithelium has been controversial for nearly a century, with speculation that vaginal epithelium originates from the Müllerian duct, Wolffian duct, and/or urogenital sinus. None of these possibilities have been definitively proven or disproven by direct scientific data. To define precisely the origin of vaginal epithelium, epithelial cells of the Müllerian duct, Wolffian duct, or urogenital sinus were fluorescently labeled in mouse embryos by crossing tdTomato-EGFP dual-reporter transgenic mice with transgenic mouse lines that express Cre-recombinase in each type of epithelium. In embryos and newborn mice, the vagina consisted of fused Müllerian ducts plus the sinus vagina of urogenital sinus origin. However, the proportion of the sinus vagina was significantly reduced as the Müllerian vagina grew caudally. By postpartum day 7, the Müllerian vagina extended to the caudal end of the body, whereas the sinus vagina remained only at the junction between the vagina and perineal skin. As the vagina opened in puberty, urogenital sinus epithelium was detected only in the vulva, but not in the vagina. Additionally, from embryo to adult stages, residual Wolffian duct epithelium was present in the dorsolateral stromal wall of the vagina, but not within vaginal or vulvar epithelium. In conclusion, adult mouse vaginal epithelium is derived solely from Müllerian duct epithelium.

Phylogenetic conservation of the cell-type-specific Lan3-2 glycoepitope in Caenorhabditis elegans

The biological function of a cell-type-specific glycosylation of an adhesion molecule belonging to the L1CAM immunoglobulin superfamily was previously determined in the nervous system of the embryonic leech, Hirudo medicinalis. The Lan3-2 glycoepitope is a surface marker of sensory afferent neurons and is required for their appropriate developmental collateral branching and synaptogenesis in the CNS. The chemical structure of the Lan3-2 glycoepitope consists of beta-(1,4)-linked mannopyranose. Here, we show the conservation of the cell-type-specific expression of this mannose polymer in Caenorhabditis elegans. The Lan3-2 glycoepitope is expressed on the cell surface of a subset of dissociated embryonic neurons and, in the adult worm, by the pharyngeal motor neuron, M5, and the chemosensory afferents, the amphids. Additionally, the vulval epithelium expresses the Lan3-2 glycoepitope in late L4 larvae and in adult hermaphrodites. To investigate proteins carrying this restrictively expressed glycoepitope, worm extract was immunoaffinity purified with Lan3-2 monoclonal antibody and Western blotted. A polyclonal antibody reactive with the cytoplasmic tail of LAD-1/SAX-7, a C. elegans member of the L1CAM family, recognizes a 270 kDa protein band while Lan3-2 antibody also recognizes a 190 kDa glycoform, its putative Lan3-2 ectodomain. Thus, in C. elegans, as in leech, the Lan3-2 epitope is located on a L1CAM homologue. The cell-type-specific expression of the Lan3-2 glycoepitope shared by leech and C. elegans will be useful for understanding how cell-type-specific glycoepitopes mediate cell-cell interactions during development.

Sarcomatoid squamous cell carcinoma of the vulva expressing smooth muscle actin and S100 protein

Vulvar sarcomatoid squamous cell carcinoma has been rarely reported. Case report and immunohistochemistry. The author herein reports a peculiar vulvar tumor. An 87-year-old woman with hypertension presented with a vulvar tumor, and admitted to our hospital. Gross examination showed an elevated tumor measuring 3 × 4 × 5 cm in the vulva near the urethra. An excisional biopsy was taken, and it showed proliferation and invasion of malignant spindle cells (70% in area) and malignant polygonal cells (30% in area). There were gradual transitions between vulvar squamous epithelium and these malignant tumor cells. Immunohistochemically, the malignant sarcomatoid cells (spindle and polygonal cells) were positive for cytokeratins, epithelial membrane antigen, vimentin, α-smooth muscle actin, S100 protein, and p53 protein. They were negative for melanosome, CD34, CD68, myoglobin, and CD45. Ki-67 labeling was 63%. A pathological diagnosis of sarcomatoid squamous cell carcinoma expressing smooth muscle antigen and S100 protein was made. The patient developed lung metastasis 2 months later, and suddenly died of unknown cause. A rare case of vulvar sarcomatoid squamous cell carcinoma expressing S100 protein and α-smooth muscle actin is reported.

Hand2 Regulates Extracellular Matrix Remodeling Essential for Gut-Looping Morphogenesis in Zebrafish

Extracellular matrix (ECM) remodeling is critical for organogenesis, yet its molecular regulation is poorly understood. In zebrafish, asymmetric migration of the epithelial lateral plate mesoderm (LPM) displaces the gut leftward, allowing correct placement of the liver and pancreas. To observe LPM migration at cellular resolution, we transgenically expressed EGFP under the control of the regulatory sequences of the bHLH transcription factor gene hand2. We found that laminin is distributed along the LPM/gut boundary during gut looping, and that it appears to become diminished by the migrating hand2-expressing cells. Laminin diminishment is necessary for LPM migration and is dependent on matrix metalloproteinase (MMP) activity. Loss of Hand2 function causes reduced MMP activity and prolonged laminin deposition at the LPM/gut boundary, leading to failed asymmetric LPM migration and gut looping. Our study reveals an unexpected role for Hand2, a key regulator of cell specification and differentiation, in modulating ECM remodeling during organogenesis.

Diagnosis of Vulvar Lesions by Non-Invasive Optical Analysis: A Pilot Study

A procedure that could allow an early in vivo and non-invasive detection of vulvar lesions would be extremely useful. We tested an innovative optical method (Optiprobe), which uses a harmless, visible light source for the in vivo, on-line detection of minimal alterations in the structure of vulvar epithelium. A group of 3 female volunteers without gynecological symptoms were first screened to evaluate optical properties of normal vulvar tissue. Next, a group of 16 patients undergoing gynecological examination for vulvar lesions was evaluated by the Optiprobe at suspected sites before these sites were biopsied for histological analysis. Adjacent, non-involved sites were also measured to provide internal controls. Histological analysis of the biopsies identified one case that did not show obvious alterations, 4 cases of high-grade vulvar intraepithelial neoplasia (VIN), 5 cases of vulvitis, and 6 cases of lichen sclerosis (LS).The optical properties of the VIN cases were significantly different from those of controls, due to a decrease in the absorption spectra and an increase in the scattering spectra. In contrast, a significant increase in the absorption spectra and a decrease in the scattering spectra were observed in the cases of vulvitis. In the LS cases, the absorption spectra were as in controls, whereas the scattering spectra were significantly decreased. We conclude that the Optiprobe provides a useful tool for a rapid and non-invasive detection of vulvar alterations. The method should contribute to reduce the number of biopsies and to facilitate the long-term follow-up of vulvar lesions.

Syndrome des vestibulites vulvaires : étude anatomoclinique de 14 cas

Vulvar vestibulitis syndrome (VVS) is one of the most frequent causes of superficial dyspareunia in young women. VVS has a pronounced psychological impact. The results of pathological studies published thus far are controversial. Fourteen women with VVS were included in this study and underwent vestibular biopsy. Vulvar biopsies were taken from the orifice of Bartholin's gland. The biopsy samples were stained with a standard stain and PAS and 25 serial sections were prepared for each specimen. The mean patient age was 26 years and VVS had been present for a mean 30 months. Extensive inflammation of mononuclear cells was observed in the vulvar chorionic epithelium. This inflammation was seen mainly around the minor vestibular glands. Mild exocytosis of lymphocytes was noted in the vestibular glands and ducts. Most studies concerning this disease report chronic inflammation of the vulvar vestibular mucosa. This inflammation is seen mainly around the minor vestibular glands. We report the same pattern in our study. Moreover, we observed some exocytosis into the epithelium of minor vestibular glands and the excretory duct. This aspect has not been reported to date, further supporting the individual nature of this entity.

MIB1 expression in basal cell layer: a diagnostic tool to identify premalignancies of the vulva

Lichen sclerosus, high-grade usual vulvar intraepithelial neoplasia (VIN) and differentiated VIN have a different malignant potential. The objective of this study was to quantify the proliferative activity in the basal region of the epithelium of vulvar premalignancies. Furthermore, we investigated whether MIB1 expression in the basal region of vulvar epithelium can be helpful in diagnosing differentiated VIN, which may be hard to discern from normal epithelium. MIB1 was used to immunohistochemically visualise proliferating cells within formalin-fixed, paraffin-embedded, archival tissue sections of different vulvar premalignancies (N=48) and normal vulvar epithelium (N=16). Automatic digital image analysis software was developed to quantify the proliferating fraction in different parts of the epithelium (MIB1 positivity index). MIB1 expression differed among the various vulvar premalignancies; a MIB1-negative basal cell layer was a distinct feature of normal vulvar epithelium. No MIB1-negative basal cell layer was noted in differentiated VIN or other vulvar premalignancies. Owing to this negative cell layer, the MIB1 proliferation index in normal vulvar epithelium was significantly lower than in vulvar premalignancies. In conclusion, MIB1 expression can be a helpful tool in diagnosing a premalignancy and has additional value especially to distinguish differentiated VIN neoplasia from normal vulvar epithelium, but cannot explain the differences in malignant potential.

Do Langerhans cells play a role in vulvar epithelium resistance to squamous cell carcinoma?

Introduction:Langerhans cells (LCs) are a very important part of the skin immune system.Materials and Methods:Skin biopsies taken from 13 women after the removal of vulvar squamous cell carcinoma (SCC) who had not been treated earlier for any vulvar diseases were investigated. The control group consisted of 12 women who underwent a plastic surgical operation of the vulva region. Immunohistochemical staining was performed on formalin-fixed, paraffin-embedded tissues samples using antihuman CD1a antibody (NCL-CD1a-235, Novocastra).Results:This study showed a large decrease in LCs in vulvar SCC.Conclusions:It is postulated that the reduction in the number of LCs may be one of the reasons for a higher tendency of carcinogenesis in the vulvar region. Their role as a main element of the skin immune system in the initiation of this process needs further investigation. It is possible that research on LCs in the skin will cast a new light on their role and even contribute to the prophylaxis and treatment of skin and mucosa carcinomas.

C. elegansEVI1 proto-oncogene, EGL-43, is necessary for Notch-mediated cell fate specification and regulates cell invasion

During C. elegans development, LIN-12 (Notch) signaling specifies the anchor cell (AC) and ventral uterine precursor cell (VU) fates from two equivalent pre-AC/pre-VU cells in the hermaphrodite gonad. Once specified, the AC induces patterned proliferation of vulva via expression of LIN-3 (EGF) and then invades into the vulval epithelium. Although these cellular processes are essential for the proper organogenesis of vulva and appear to be temporally regulated, the mechanisms that coordinate the processes are not well understood. We computationally identified egl-43 as a gene likely to be expressed in the pre-AC/pre-VU cells and the AC, based on the presence of an enhancer element similar to the one that transcribes lin-3 in the same cells. Genetic epistasis analyses reveal that egl-43 acts downstream of or parallel to lin-12 in AC/VU cell fate specification at an early developmental stage, and functions downstream of fos-1 as well as upstream of zmp-1 and him-4 to regulate AC invasion at a later developmental stage. Characterization of the egl-43 regulatory region suggests that EGL-43 is a direct target of LIN-12 and HLH-2 (E12/47), which is required for the specification of the VU fate during AC/VU specification. EGL-43 also regulates basement membrane breakdown during AC invasion through a FOS-1-responsive regulatory element that drives EGL-43 expression in the AC and VU cells at the later stage. Thus, egl-43 integrates temporally distinct upstream regulatory events and helps program cell fate specification and cell invasion.

Langerhans cells in vulvar lichen sclerosus and vulvar squamous cell carcinoma

Langerhans cells (LCs), specializing in antigen presentation, are a very important part of the skin immune system (SIS). Skin biopsies from 22 women with vulvar lichen sclerosus (LS): 15 patients with early and 7 with the late stage of the disease, were evaluated. Five women with vulvar squamous cell carcinoma (SCC) were also examined. The control group consisted of 9 women who underwent plastic surgery of the vulvar region. Immunohistochemical staining was performed on formalin-fixed paraffin-embedded tissues samples using antihuman CD1a antibody (NCL-CD1a-235, Novocastra). Increased numbers of LC stainings were present in early LS, whereas decreased numbers of these cells were present in late LS and in SCC compared with the control group. This study showed that dysregulation of the SIS may lead to suppression of LCs in the vulvar epithelium and may be one of the reasons for a higher tendency for carcinogenesis in the vulvar region.

Aberrant expression of α-dystroglycan in cervical and vulvar cancer

Objectives. Cervical and vulvar cancers develop through well-defined precursor lesions but their exact pathogenesis is still unknown. The dystroglycan complex is a transmembrane glycoprotein that forms a continuous link from the extracellular matrix to the actin cytoskeleton. Deregulated expression of dystroglycan has been reported in human malignancies and related to tumor differentiation and aggressiveness. In this study, expression of dystroglycan was evaluated in the multistep cervical and vulvar tumorigenesis. Methods. Expression of the dystroglycan complex was evaluated by immunostaining in lesions representing different stages of vulvar and cervical tumorigenesis using a monoclonal antibody which recognizes carbohydratic epitopes on the α-dystroglycan subunit. Results. α-dystroglycan was constantly detected in normal cervical epithelium with a mean percentage of positive cells higher than 80%. A progressive significant reduction in the mean percentage of positive cells was observed in low (67%) and high grade SIL (14%) and in invasive carcinomas (2.6%) of the cervix. In cancers, no differences were observed in terms of percentage of positive cells when cases were stratified according with either tumor grade or stage. A progressive significant reduction in the mean percentage of positive cells was also observed from normal vulvar epithelium (90%) to VIN1 (66%), VIN2 (28%) and invasive vulvar carcinomas (22%). No significant decrease in the α-dystroglycan staining was observed in squamous cell hyperplasia lesions (85%) while lichen sclerosus displayed a percentage of positive cells (47%) significantly lower than normal epithelium. Conclusions. Detection of α-dystroglycan is frequently lost in human cervical and vulvar tumorigenesis and further studies are warranted to verify whether evaluation of this molecule might serve as marker of risk progression of preneoplastic lesions and to better understand its significance in terms of cancer development.

Cyclooxygenase-2 (COX-2) Immunostaining Does Not Correlate With the Degree of Vulvar Neoplasia

ObjectiveThe cyclooxygenase-2 (COX-2) enzyme is up-regulated in inflammatory and neoplastic conditions. In the last decade, its biological role has been investigated in various pre-invasive and invasive cancers with the hope that it can serve as a target for cancer prevention and treatment. MethodsWe evaluated the expression of COX-2 in vulvar biopsies to determine its relationship to the degree of dysplasia. COX-2 expression was studied by immunohistochemistry in 62 consecutive vulvar biopsies divided into four diagnostic groups. Group 1 included inflamed vulva (n=14); group 2, vulvar intraepithelial neoplasia (VIN) I and VIN II (n=20); group 3, VIN III and carcinoma in situ (n=18); and group 4, invasive squamous cell carcinoma (n=10). Representative sections were immunostained using polyclonal anti-COX-2 antibodies at concentration 1:25 without pretreatment. Immunostaining was scored according to the proportion of positive epithelial cells in the vulvar mucosa as 0 (no positive cells), 1(<5% positive), 2 (6–50% positive), or 3 (>50% positive). ResultsMean immunostaining scores were 1.6, 1.4, 0.7, and 1.2 for groups 1, 2, 3, and 4, respectively. Scores were different between the groups (χ2=9.908, cpu=0.019) as shown by Cochran-Mantel-Haenszel statistical analysis (modified ridit scores), but did not correlate with age or the degree of dysplasia. The strongest staining for COX-2 was in the inflammatory group. ConclusionCOX-2 staining in inflamed, dysplastic, and malignant vulvar epithelium is variable but, as shown in this study, does not correlate with the degree of vulvar dysplasia or malignancy.

Galectin-3 and CD1a-Positive Dendritic Cells Are Involved in the Development of an Invasive Phenotype in Vulvar Squamous Lesions

In this study, the expression patterns of Galectin-3 (Gal-3) and the frequency of infiltrating CD1a positive dendritic cells (DCs) were determined in 82 cases of vulvar tissues, consisting of normal squamous epithelia (NE, N = 10), vulvar condylomas (VC, N = 24), high grade vulvar intraepithelial neoplasias (HG-VIN, N = 26) of common type, and invasive keratinizing squamous cell carcinomas (SCC, N = 22) by a standard immunohistochemical method using monoclonal antibodies to investigate their differential expression in vulvar squamous dysplasia and infiltrating carcinomas with an emphasis on neoplastic transformation and progression. Gal-3 expression was cytoplasmic, nuclear or membranous in NE, VCs, and HG-VINs, with negative or weak and occasionally moderate reactivities. In SCCs, exclusively cytoplasmic staining patterns with moderate or strong reactivity in 59% of cases were observed (p < 0.0001, chi-square test); Gal-3 expression was not related with stage, grade, and recurrence. The frequency of CD1a positive DCs increased from NE and VCs to highest numbers in HG-VINs, was lowest in SCCs (p < 0.0001, ANOVA), and was not related with stage and grade, but with recurrence in SCCs (p = 0,048, t-test). This study indicates that qualitative and quantitative changes of Gal-3 immunoexpression and infiltration by CD1a positive DCs in vulvar NE, VCs, and HG-VIN lesions, respectively, compared with SCCs play a role in the development of an infiltrative phenotype, and may provide adjunctive criteria in the diagnosis of invasion of vulvar squamous epithelia.

Expression of the CDK inhibitor p27kip1 and oxidative DNA damage in non-neoplastic and neoplastic vulvar epithelial lesions

Vulvar cancer represents an important medical problem worldwide whose incidence is increasing at an alarming rate in young females. Several factors have been linked to vulvar cancer development, but its exact pathogenesis remains to be determined. Vulvar tumorigenesis proceeds through intermediate dysplastic lesions, known as vulvar intraepithelial neoplasias, frequently associated with non-neoplastic epithelial disorders of the vulva, such as lichen sclerosus and squamous cell hyperplasia. In this study, the expression of the CDK inhibitor p27Kip1 and the extent of endogenous oxidative DNA damage were evaluated in vulvar specimens, including normal tissues, lichen sclerosus, squamous cell hyperplasia, vulvar intraepithelial neoplasias and invasive squamous cell carcinomas. We found that p27Kip1 was constantly expressed in normal vulvar epithelium cells while a progressive significant reduction in the percentage of p27Kip1-positive cells was observed in vulvar intraepithelial neoplasias (77%) and in invasive carcinomas (64%). Mean percentage of positive cells in invasive carcinomas, but not in vulvar intraepithelial neoplasias, was also significantly lower than squamous cell hyperplasia lesions (78%) while lichen sclerosus displayed a percentage of positive cells (45%) significantly lower than both vulvar intraepithelial neoplasias and invasive carcinomas. 8-hydroxydeoxyguanosine (8-OHdG) is considered a sensitive biomarker for oxidative stress. We observed a progressive significant increase in the levels of 8-OHdG and in the percentage of positive cells from normal vulvar epithelium to vulvar intraepithelial neoplasias (25%) and to invasive carcinomas (64%). Squamous cell hyperplasia displayed an intermediate percentage of positive cells comparable to vulvar intraepithelial neoplasias 2 but significantly higher than vulvar intraepithelial neoplasias 1 and lower than invasive carcinomas. Lichen sclerosus staining was significantly lower than carcinomas but higher than vulvar intraepithelial neoplasias and squamous cell hyperplasia. These results demonstrate that expression of p27Kip1 is downregulated while oxidative DNA damage increases from early non-neoplastic epithelial alterations through vulvar intraepithelial neoplasias to invasive vulvar carcinomas. Thus, both parameters might play an important role in the development of this cancer and their study might contribute to our understanding of human vulvar carcinogenesis.

FOS-1 Promotes Basement-Membrane Removal during Anchor-Cell Invasion in C. elegans

Cell invasion through basement membranes is crucial during morphogenesis and cancer metastasis. Here, we genetically dissect this process during anchor-cell invasion into the vulval epithelium in C. elegans. We have identified the fos transcription factor ortholog fos-1 as a critical regulator of basement-membrane removal. In fos-1 mutants, the gonadal anchor cell extends cellular processes normally toward vulval cells, but these processes fail to remove the basement membranes separating the gonad from the vulval epithelium. fos-1 is expressed in the anchor cell and controls invasion cell autonomously. We have identified ZMP-1, a membrane-type matrix metalloproteinase, CDH-3, a Fat-like protocadherin, and hemicentin, a fibulin family extracellular matrix protein, as transcriptional targets of FOS-1 that promote invasion. These results reveal a key genetic network that controls basement-membrane removal during cell invasion.

Human Papillomavirus Infection and p16INK4a Protein Expression in Vulvar Intraepithelial Neoplasia and Invasive Squamous Cell Carcinoma

Vulvar intraepithelial neoplasia (VIN) is defined histopathologically by distinctive abnormalities of cellular maturation and differentiation. The purpose of this study was to investigate the functional properties of VIN related to expression of p16(INK4a) protein as well as to detection of human papillomavirus (HPV) type 16 by real-time polymerase chain reaction (RT-PCR) analysis. A total of 49 vulvar biopsy samples were examined by hematoxylin-eosin staining from benign/reactive lesions, condyloma acuminatum, VIN, and invasive squamous cell carcinoma (SCC). JC8 mouse monoclonal antibodies were used that recognize p16(INK4a) epitope at a dilution of 1:25. The reaction pattern for p16(INK4a) was graded in each sample between 0 and 3+. RT-PCR analysis of formalin-fixed paraffin-embedded sections determined positivity for HPV type 16. p16(INK4a) immunoreactivity was different in VIN 1, VIN 2, VIN 3, and squamous cell carcinoma. Strong expression of p16(INK4a) protein was observed in 92% (22 of 24) of VIN 2 and VIN 3 lesions and 100% (4 of 4) of invasive SCCs. Two (67%) of 3 VIN 2 lesions, 17 (81%) of 21 VIN 3 lesions, and 4 (100%) of 4 SCCs were positive for HPV type 16 by PCR analysis. Two (20%) of 10 VIN 1 lesions were immunoreactive for p16(INK4a), with only 1 lesion positive for HPV type 16. No p16(INK4a) immunoreactivity was observed in any of the benign/reactive and condyloma acuminatum lesions. In addition, none of the benign/reactive or condyloma lesions were positive for HPV type 16 by RT-PCR analysis. Upregulation of INK4a gene occurs in vulvar carcinogenesis. p16(INK4a) is not a sensitive marker for differentiation of benign vulvar squamous epithelium from condyloma acuminatum or VIN 1 lesions because most VIN 1 lesions are p16(INK4a) negative. Expression of p16(INK4a) may aid in the diagnosis of HPV-related lesions and as such may be of value as a surrogate marker in the diagnosis of vulvar premalignant and malignant lesions.

Caenorhabditis elegans syndecan (SDN-1) is required for normal egg laying and associates with the nervous system and the vulva.

In Caenorhabditis elegans, the identification of many enzymes involved in the synthesis and modification of glycosaminoglycans (GAGs), essential components of proteoglycans, has attained special attention in recent years. Mutations in all the genes that encode for GAG biosynthetic enzymes show defects in the development of the vulva, specifically in the invagination of the vulval epithelium. Mutants for certain heparan sulfate modifying enzymes present axonal and cellular guidance defects in specific neuronal classes. Although most of the enzymes involved in the biosynthesis and modification of heparan sulfate have been characterized in C. elegans, little is known regarding the core proteins to which these GAGs covalently bind in proteoglycans. A single syndecan homologue (sdn-1) has been identified in the C. elegans genome through sequence analysis. In the present study, we show that C. elegans synthesizes sulfated proteoglycans, seen as three distinct species in western blot analysis. In the sdn-1 (ok449) deletion mutant allele we observed the lack of one species, which corresponds to a 50 kDa product after heparitinase treatment. The expression of sdn-1 mRNA and sequencing revealed that sdn-1 (ok449) deletion mutants lack two glycosylation sites. Hence, the missing protein in the western blot analysis probably corresponds to SDN-1. In addition, we show that SDN-1 localizes to the C. elegans nerve ring, nerve cords and to the vulva. SDN-1 is found specifically phosphorylated in nerve ring neurons and in the vulva, in both wild-type worms and sdn-1 (ok449) deletion mutants. These mutants show a defective egg-laying phenotype. Our results show for the first time, the identification, localization and some functional aspects of syndecan in the nematode C. elegans.

The vulvar epithelium differs from the skin: implications for cutaneous testing to address topical vulvar exposures

Vulvar tissue is more permeable than exposed skin due to differences in structure, occlusion, hydration and susceptibility to friction. The safety assessment of products that contact the vulva should account for this potentially heightened permeability. Standard clinical patch tests may not sufficiently mimic vulvar exposures. Because testing on the vulva is not routinely feasible, we are investigating new and modified cutaneous test methods to increase the degree of conservatism of the safety assessment. To this end, we have 1) developed a method to assess chemical and frictional effects by means of repeated application to the popliteal fossa (the behind-the-knee test); 2) modified the quantitative risk assessment for the induction of allergic contact dermatitis; and 3) proposed a modified human repeat insult patch test for assessing materials intended for vulvar contact. Modification of the traditional 4-day, irritation patch test by using wet samples or compromized skin sites failed to enhance test sensitivity. Future studies will evaluate testing in subjects with heightened susceptibility to chemical and sensory irritation, in order to increase test sensitivity to chemical irritants. These approaches can be employed to augment the margin of safety when cutaneous test methods are applied to agents that contact the vulva.

Characterizing T-cell response in low-grade and high-grade vulval intraepithelial neoplasia, study of CD3, CD4 and CD8 expressions

Objective. The objective of our study was to compare immunocyte infiltrates in vulval epithelium from low-grade and high-grade vulval intraepithelial neoplasia (VIN) lesions to determine if difference in T-cell presence reflected the grade of VIN. Material and methods. Thirty-six vulval specimens were obtained from 24 patients who had previously undergone vulval biopsies for VIN, 14 high-grade diseases (VIN 3 with or without HPV) and 14 low-grade diseases (VIN 1 and VIN 2 with or without HPV). Eight samples of normal vulval tissue were selected from the excision margins of resected vulval biopsies. The lymphocyte surface markers included CD3 (Pan T-cell marker), CD4 (T helper cells), and CD8 (T cytotoxic cells). Each tissue section was visualized under high power magnification and cells were counted in 10 random areas at the dermo-epidermal junction. Results. A significantly higher number of total mean T lymphocytes were detected in VIN specimens compared to normal vulval tissue ( P = 0.002). In low-grade VIN, there were significantly more CD8 cells than CD4 when compared to high-grade VIN. This difference in CD4/CD8 ratio was significant ( P = 0.001). Conclusions. This study suggests that increased CD8 response in VIN is a feature of low-grade disease and we speculate that this may be a protective mechanism. In high-grade disease, both CD4 cells and CD8 cells are equally present with preservation of normal CD4/CD8 ratio.

Characterizing T-cell response in low-grade and high-grade vulval intraepithelial neoplasia, study of CD3, CD4 and CD8 expressions

Objective. The objective of our study was to compare immunocyte infiltrates in vulval epithelium from low-grade and high-grade vulval intraepithelial neoplasia (VIN) lesions to determine if difference in T-cell presence reflected the grade of VIN. Material and methods. Thirty-six vulval specimens were obtained from 24 patients who had previously undergone vulval biopsies for VIN, 14 high-grade diseases (VIN 3 with or without HPV) and 14 low-grade diseases (VIN 1 and VIN 2 with or without HPV). Eight samples of normal vulval tissue were selected from the excision margins of resected vulval biopsies. The lymphocyte surface markers included CD3 (Pan T-cell marker), CD4 (T helper cells), and CD8 (T cytotoxic cells). Each tissue section was visualized under high power magnification and cells were counted in 10 random areas at the dermo-epidermal junction. Results. A significantly higher number of total mean T lymphocytes were detected in VIN specimens compared to normal vulval tissue (P = 0.002). In low-grade VIN, there were significantly more CD8 cells than CD4 when compared to high-grade VIN. This difference in CD4/CD8 ratio was significant (P = 0.001). Conclusions. This study suggests that increased CD8 response in VIN is a feature of low-grade disease and we speculate that this may be a protective mechanism. In high-grade disease, both CD4 cells and CD8 cells are equally present with preservation of normal CD4/CD8 ratio.