Platelet-Rich Plasma (PRP) and Adipose-Derived Stem Cell (ADSC) Therapy in the Treatment of Genital Lichen Sclerosus: A Comprehensive Review.

Lichen sclerosus (LS) is a chronic inflammatory dermatosis mostly localized in the genital area, characterized by vulvar alterations that can severely impact a patient's quality of life. Current treatment modalities often provide incomplete relief, and there is a need for innovative approaches to manage this condition effectively. Platelet-rich plasma (PRP) and adipose-derived stem cells (ADSCs) have emerged as potential regenerative therapies for LS, offering promising results in clinical practice. This comprehensive review explores the utilization of PRP and ADSC therapy in the treatment of genital LS, highlighting their mechanisms of action, safety profiles, and clinical outcomes. PRP is a blood product enriched in growth factors and cytokines, which promotes tissue regeneration, angiogenesis, and immune modulation. ADSC regenerative potential relies not only in their plasticity but also in the secretion of trophic factors, and modulation of the local immune response. Numerous studies have reported the safety of PRP and ADSC therapy for genital LS. Adverse events are minimal and typically involve mild, self-limiting symptoms, such as transient pain and swelling at the injection site. Long-term safety data are encouraging, with no significant concerns identified in the literature. PRP and ADSC therapy have demonstrated significant improvements in LS-related symptoms, including itching, burning, dyspareunia, and sexual function. Additionally, these therapies enable many patients to discontinue the routine use of topical corticosteroids. Several studies have explored the efficacy of combining PRP and ADSC therapy for LS. In combination, PRP and ADSCs seem to offer a synergistic approach to address the complex pathophysiology of LS, particularly in the early stages. The use of PRP and ADSC therapy for genital lichen sclerosus represents a promising and safe treatment modality. These regenerative approaches have shown significant improvements in LS-related symptoms, tissue trophism, and histological features. Combination therapy, which harnesses the synergistic effects of PRP and ADSCs, is emerging as a preferred option, especially in early-stage LS cases. Further research, including randomized controlled trials and long-term follow-up, is warranted to elucidate the full potential and mechanisms of PRP and ADSC therapy in the management of genital LS. These regenerative approaches hold great promise in enhancing the quality of life of individuals suffering from this challenging condition.

Human papilloma virus-16-specific CD8+ T-cell expansions characterize different clinical forms of lichen planus and not lichen sclerosus et atrophicus.

Lichen planus (LP) is a cutaneomucosal chronic inflammatory disease characterized by a CD8+ cytotoxic T-lymphocytes (CTL) infiltrate. In erosive oral LP, we found HPV16-specific activated CTL in lesions, supporting a pathogenic contribution of HPV16. Here, we investigated whether a similar scenario occurs in other clinical forms of LP and in lichen sclerosus et atrophicus (LSA), another chronic disease also affecting the mucosa and/or the skin. Blood CTL from LP and LSA patients expressed significant higher levels of granzyme B, perforin and CD107a proteins than healthy donors. Expansions of TCRVß3+ CTL, with presence of TCR clonotypes identical to those previously detected in erosive oral LP, were found both in blood and mucosal/skin lesions of LP, and not of LSA patients. These expansions were enriched with HPV16-specific CD8+ T-cells as shown by their recognition of the E711-20 immunodominant epitope. In LSA patients, the peripheral repertoire of CTL was oligoclonal for TCRVß6+ CTL. Finally, although patients with LP and LSA have developed antibodies against HPV16 capsid L1, antibodies against HPV16 E6 were only observed in patients with LP. Overall, our data collectively suggest an involvement of HPV16-specific CTL in different clinical forms of LP, not only in erosive oral LP, while a different scenario operates in LSA.

Human beta defensin levels and vaginal microbiome composition in post-menopausal women diagnosed with lichen sclerosus.

Human beta defensins (hBDs) may play an important role in the progression of lichen sclerosus (LS), due to their ability to induce excessive stimulation of extracellular matrix synthesis and fibroblast activation. The genetic ability of the individual to produce defensins, the presence of microbes influencing defensin production, and the sensitivity of microbes to defensins together regulate the formation of an ever-changing balance between defensin levels and microbiome composition. We investigated the potential differences in postmenopausal vaginal microbiome composition and vaginal hBD levels in LS patients compared to non-LS controls. LS patients exhibited significantly lower levels of hBD1 (p = 0.0003), and significantly higher levels of hBD2 (p = 0.0359) and hBD3 (p = 0.0002), compared to the control group. The microbiome of the LS patients was dominated by possibly harmful bacteria including Lactobacillus iners, Streptococcus anginosus or Gardnerella vaginalis known to initiate direct or indirect damage by increasing defensin level production. Our observations highlight that correcting the composition of the microbiome may be applicable in supplementary LS therapy by targeting the restoration of the beneficial flora that does not increase hBD2-3 production.

Elastophagocytosis and interstitial granulomatous infiltrate are more common in extragenital vs genital lichen sclerosus.

BACKGROUND: Genital and extragenital lichen sclerosus (LS) share similar histopathologic features. A recent small series documented elastophagocytosis uniquely in extragenital LS. We evaluated a larger series of LS for elastophagocytosis, elastic fiber loss, and other histopathologic features. We evaluated matrix metalloproteinase (MMP) expression to determine if these proteins play an etiologic role. METHODS: Genital (n = 42) and extragenital (n = 41) LS biopsies were examined for histopathologic features, elastic fiber alteration (Verhoeff van Gieson staining), and MMP-2 and MMP-9 expression (immunohistochemistry). RESULTS: Elastophagocytosis and an interstitial granulomatous pattern were significantly more common in extragenital LS than genital LS (43.9% vs 4.7% and 56.1% vs 9.5%). Extragenital LS had mild/focal elastic fiber loss (43.9%), while genital LS had moderate (61.9%) or marked (19%) loss. MMP-9 was diffusely expressed in histiocytes in both types of LS (genital 97.5%; extragenital 100%). Weak MMP-2 expression was seen in genital (58%) and extragenital (55%) LS. CONCLUSIONS: Extragenital LS, but not genital LS, frequently exhibits elastophagocytosis and interstitial granulomatous infiltrate, and these patterns could contribute to elastic fiber destruction in extragenital LS. While MMP-2 and MMP-9 expression are common in LS, expression did not significantly differ depending on anatomic site and thus is unlikely to explain observed histopathologic differences.

Insights into the Pathophysiology of Urethral Stricture Disease due to Lichen Sclerosus: Comparison of Pathological Markers in Lichen Sclerosus Induced Strictures vs Nonlichen Sclerosus Induced Strictures.

PURPOSE: We evaluated the pathophysiology of lichen sclerosus and nonlichen sclerosus urethral stricture disease by comparing protein expression related to inflammation, cell cycle disruption, oxidative stress, hormone receptor status and infection. MATERIALS AND METHODS: Tissue samples were collected from the urethral strictures of 81 patients undergoing urethroplasty. Clinical and demographic data were obtained by chart review. After identifying areas pathognomonic for lichen sclerosus a tissue microarray was created with cores from each sample and immunohistochemistry was performed. RESULTS: Patients had similar baseline demographics and comorbidities. Of the 81 strictures 58 were and 23 were not due to lichen sclerosus. Lichen sclerosus strictures were significantly longer and showed higher levels of inflammation. The proportion of T cells which stained positive for CD8 was significantly higher in strictures due to lichen sclerosus (50% vs 13%, p = 0.004). CCL-4 was expressed significantly more in strictures due to lichen sclerosus (76% vs 42%, p = 0.01). Several other inflammatory markers were only found in strictures due to lichen sclerosus. Block-like p16, a surrogate for high risk human papillomavirus infection, and varicella zoster virus were found only in lichen sclerosus urethral stricture disease samples, although both were rare. Epstein-Barr virus RNA was found in significantly more lichen sclerosus samples (37% vs 10%, p = 0.024). CONCLUSIONS: To our knowledge this is the first study to evaluate protein expression in lichen sclerosus urethral stricture disease. These strictures demonstrate increased inflammation compared to nonlichen sclerosus urethral strictures. Markers of oxidative stress, cell cycle dysregulation and the androgen receptor do not appear to be uniquely associated with lichen sclerosus urethral stricture disease. Positive staining for several viruses in samples of lichen sclerosus urethral stricture disease suggests a possible infectious etiology.

MiR-155-5p promotes fibroblast cell proliferation and inhibits FOXO signaling pathway in vulvar lichen sclerosis by targeting FOXO3 and CDKN1B.

Vulvar lichen sclerosis (VLS) is a chronic inflammatory skin disorder. Evidence is accumulating that microRNAs (miRNAs) exert crucial roles in initiation and development of a wide range of human diseases. MiR-155-5p has been frequently reported to be implicated in the tumorigenesis and progression of multiple types of cancers, however, its biological role in VLS remains unclear. This study aimed to explore the role of miR-155-5p in VLS and clarify the potential molecular mechanisms involved. In the present study, miR-155-5p was observed to be significantly upregulated in VLS tissues. Functional studies showed that miR-155-5p facilitated cell proliferation, accelerated cell cycle progression and inhibited forkhead box O (FOXO) signaling pathway in fibroblast cells. Mechanical studies demonstrated that miR-155-5p exerted its promoting effects on fibroblast cell proliferation via targeting both forkhead box O3 (FOXO3) and cyclin-dependent kinase inhibitor 1B (CDKN1B). Besides, Pearson's correlation analysis revealed that miR-155-5p expression was negatively correlated with the mRNA expression of FOXO3 and CDKN1B in VLS tissues. Taken together, our results indicate that miR-155-5p promotes fibroblast cell proliferation and inhibits FOXO signaling pathway by negative modulation of both FOXO3 and CDKN1B in VLS, and that miR-155-5p may be used to be a potential therapeutic target for VLS.

Interstitial Mycosis Fungoides With Lichen Sclerosus-Like Clinical and Histopathological Features.

Mycosis fungoides (MF) simulates a variety of dermatologic disorders histopathologically and clinically, well deserving the designation of a great mimicker. Interstitial MF is a rare, but well-recognized histopathological variant resembling the interstitial form of granuloma annulare or the inflammatory phase of morphea. From a clinical standpoint, MF can have a wide array of manifestations, including an anecdotal presentation with lesions clinically suggestive of lichen sclerosus (LS). We herein report a 25-year-old man with a history of patch-stage MF who later developed widespread LS-like lesions histopathologically consistent with interstitial MF. In some biopsies, additional features resembling LS were discerned. We think that our case might represent a unique variant of interstitial MF presenting with LS-like lesions. The diagnostic challenge arising from this uncommon presentation is discussed together with review of the literature.

Oral lichen sclerosus expressing extracellular matrix proteins and IgG4-positive plasma cells.

Lichen sclerosus (LS) is a mucocutaneous disease with uncommon oral involvement. The etiology is not yet well understood, but LS has been associated with autoimmune, genetic, and immunological factors. We report a 47-year-old man with LS that exhibited an asymptomatic white plaque with red patches on the maxillary alveolar mucosa extending to the labial mucosa. He had no other skin disease. Positive immunostaining for tenascin and scarcity of fibronectin suggested extracellular matrix reorganization. Elastin immunostaining indicated a reduction of elastic fibers. Immunoexpression of collagen IV in blood vessels and its absence in the epithelial basement membrane, together with diffuse MMP-9 immunoexpression, suggested altered proteolytic activity. Mast cell staining bordering areas of sclerosis indicated a possible role in the synthesis of collagen. IgG4 positivity in plasma cells suggested a role in the fibrogenesis. This is an unusual presentation of oral LS and we discuss immunohistochemical findings regarding cellular and extracellular matrix components.

Differential expression of connective tissue growth factor and extracellular matrix proteins in lichen sclerosus.

BACKGROUND: The histopathology of lichen sclerosus (LS) suggests abnormalities in extracellular matrix (ECM) composition. OBJECTIVES: We aimed to investigate the expression pattern of ECM proteins and related growths factors and Smad signal transducers in LS as compared with healthy skin. METHODS: To assess the expression of decorin, biglycan, versican, perlecan, fibronectin, dermatopontin, extracellular matrix protein 1 (ECM-1), matrix metalloproteinase 1, tissue inhibitor of metalloproteinase 1, connective tissue growth factor (CTGF), transforming growth factor ß1, and Smad-3 protein, real-time RT-PCR and immunohistochemistry were performed on skin specimens obtained from the genital region of healthy subjects (n = 10) as well as LS patients (n = 26). RESULTS: Median mRNA as well as mean protein expression of biglycan, versican, fibronectin, and ECM-1 was significantly higher in LS when compared with healthy controls. Both mRNA and protein CTGF expression observed in LS was significantly higher than in controls. CTGF mRNA expression significantly correlated with mRNA expression of biglycan, versican and fibronectin. CONCLUSIONS: Expression of ECM proteins (e.g. proteoglycans, ECM-1) and CTGF is altered in LS. TGF-ß/Smad-3 independent up-regulation of CTGF may induce accumulation of ECM proteins and maintain fibrosis in chronic LS.

Gene expression profiling in male genital lichen sclerosus.

Male genital lichen sclerosus (MGLSc) has a bimodal distribution in boys and men. It is associated with squamous cell carcinoma (SCC). The pathogenesis of MGLSc is unknown. HPV and autoimmune mechanisms have been mooted. Anti extracellular matrix protein (ECM)1 antibodies have been identified in women with GLSc. The gene expression pattern of LSc is unknown. Using DNA microarrays we studied differences in gene expression in healthy and diseased prepuces obtained at circumcision in adult males with MGLSc (n = 4), paediatric LSc (n = 2) and normal healthy paediatric foreskin (n = 4). In adult samples 51 genes with significantly increased expression and 87 genes with significantly reduced expression were identified; paediatric samples revealed 190 genes with significantly increased expression and 148 genes with significantly reduced expression. Concordance of expression profiles between adult and paediatric samples indicates the same disease process. Functional analysis revealed increased expression in the adult and child MGSLc samples in the immune response/cellular defence gene ontology (GO) category and reduced expression in other categories including genes related to squamous cancer. No specific HPV, autoimmune or squamous carcinogenesis-associated gene expression patterns were found. ECM1 and CABLES1 expression were significantly reduced in paediatric and adult samples respectively.

Cell cycle regulation and proliferation in lichen sclerosus.

INTRODUCTION: Genital lichen sclerosus (LS) is considered a potential precursor lesion of squamous cell carcinoma. We aimed to investigate the expression pattern of cell cycle regulators, tumour suppressor proteins and proliferation markers in genital LS as compared to extragenital LS (ELS) and healthy controls (HC). METHODS: In order to assess the expression of minichromosome maintenance protein 3 (MCM3), MCM7, Ki-67, cyclin D1, cyclin E, p16, p21, and p53, immunohistochemistry and immunofluorescence were performed on skin specimens obtained from the genital region of LS patients (short-standing LS, n=19; long-standing LS, n=15), patients with ELS (n=10), and HC (n=8). RESULTS: Median protein expression of MCM3 and Ki-67 was significantly higher in LS when compared to ELS and HC. In patients with long-standing LS, the expression profiles of MCM3 and Ki-67 significantly correlated. Moreover, long-standing LS lesions showed significantly increased expression of p53 when compared to short-standing LS, ELS, and HS. Immunoreactivity of MCM7, p16, p21, cyclin D1 and cyclin E did not significantly differ between the groups. CONCLUSIONS: Tumour suppressor proteins such as p53 are significantly overexpressed in genital LS when compared to extragenital disease and healthy skin. The significant p53 overexpression, particularly in long-standing genital lesions, may reflect the increased risk of malignant transformation and/or oxidative stress associated with LS. Moreover, we have demonstrated that proliferation markers such as Ki-67 and MCM3 are significantly up-regulated in genital LS as compared to controls. With regard to cell cycle regulation and proliferation rates, ELS significantly differs from its genital counterpart.

Distinctive association of p16INK4a overexpression with penile intraepithelial neoplasia depicting warty and/or basaloid features: a study of 141 cases evaluating a new nomenclature.

From the pathogenic point of view, penile cancers may be grouped in human papillomavirus-related and unrelated tumors, each one of them with distinctive morphologic features. The former are predominantly composed of small, undifferentiated basaloid cells, with more or less prominent koilocytic changes, and the latter of keratinizing differentiated squamous cells. The same cellular types are observed in precancerous lesions. On the basis of these observations, we constructed a novel nomenclature for penile precancerous lesions and classified them as penile intraepithelial neoplasia (PeIN) of differentiated, warty, basaloid, and warty-basaloid types. The aim of this study was to test the usefulness of immunohistochemical p16 overexpression, considered as a surrogate for high-risk human papillomavirus infection, using this classification system. We pathologically evaluated 141 patients with PeIN, associated (123 cases) and unassociated (18 cases) with invasive cancer. Distribution of PeIN types was: differentiated, 72%; basaloid, 9%; warty-basaloid, 7%; warty, 4%; and mixed, 7%. There was a striking similarity in the morphology of in situ and invasive squamous cell carcinomas. Differentiated PeIN was commonly associated with usual, verrucous, papillary, and other low-grade keratinizing variants of squamous cell carcinoma whereas in basaloid and warty carcinomas the presence of in situ lesions with similar morphology was habitual. We evaluated p16 overexpression using a 4-tiered (0, 1, 2, and 3) pattern-based system. To properly distinguish differentiated PeIN from in situ lesions with warty and/or basaloid features only pattern 3, which requires full-thickness staining in all epithelial cells, was considered positive. Using this approach, there was a significant association of the negative patterns and differentiated PeIN and of the positive pattern and warty, basaloid, and warty-basaloid PeIN (P<0.0001). Basaloid variant had the strongest association. The sensitivity rate of p16 positivity for discriminating types of PeIN was of 82%, with a specificity of 100% and an accuracy of 95%. Lichen sclerosus was identified in 42 cases and their epithelial component was p16 negative in all cases. Although more studies are necessary to confirm these observations, p16 overexpression seems to be a useful tool for discriminating differentiated from warty, basaloid, and warty-basaloid PeIN.

Extragenital lichen sclerosus et atrophicus mimicking cutaneous T-cell lymphoma: report of a case.

Early lesions of lichen sclerosus et atrophicus (LSA) may present as a mild lichenoid tissue reaction, occasionally together with basilar epidermotropism, mimicking early cutaneous T-cell lymphoma, mycosis fungoides (MF) variant. We report a case of extragenital LSA in which both histological patterns were present in the same clinically homogenous and stable lesion. A 27-year-old man presented with a history of white atrophic plaques on the trunk. A biopsy of an abdominal lesion revealed epidermal thinning, a superficial perivascular lymphoid cell infiltrate with focal epidermotropism, mild nuclear atypia and perinuclear halos. Immunophenotyping showed decreased CD5 and CD7, with a slight predominance of CD8-positive T-lymphocytes. All these changes were suggestive of MF. However, a repeat biopsy 3 months later from the same stable plaque revealed features diagnostic of LSA. LSA mimicking early MF histologically has been reported in genital skin. Conversely, MF may clinically and histopathologically resemble LSA. With gene rearrangement studies, clonal proliferation may not be detected in early MF but has been reported to occur in LSA. Awareness of the histopathologic spectrum of LSA within a stable plaque is important to avoid a potential diagnostic pitfall, and should prompt a repeat biopsy.

Downregulated CD44 and hyaluronan expression in vulvar intraepithelial neoplasia and squamous cell carcinomas.

OBJECTIVE: To investigate the expression of CD44 and hyaluronan in vulvar squamous cell carcinomas, vulvar intraepithelial neoplasia (VIN) and lichen sclerosus (LS) cases. DESIGN: Retrospective study. SETTING: Kuopio University Hospital in Finland. SAMPLES AND METHODS: A total of 18 vulvar squamous cell carcinomas, 22 VIN and 14 LS cases were studied by immunohistochemistry and histochemistry. Co-localization of these markers was also studied by dual fluorescence staining. MAIN OUTCOME MEASURES: Expression and cellular localization of CD44 and hyaluronan. RESULTS. In the normal squamous cell epithelium and in most LS samples, CD44 and hyaluronan were expressed homogeneously along plasma membranes with extensive co-localization. In carcinomas and VIN, both CD44 and hyaluronan were mostly irregular and without co-localization. In most VIN samples, CD44 was membranous, while hyaluronan was intracellular in 45% of the cases. CD44 showed both plasma membrane and intracellular localization in 39% of the carcinomas and in 94% of the cases hyaluronan was located only intracellularly. In LS, stromal hyaluronan staining was stronger than in carcinomas (p = 0.01). CD44 and hyaluronan staining was not associated with the grade of VIN, while there was good differentiation in carcinomas associated with preserved membranous CD44 (p = 0.012). Hyaluronan was not associated with the grade or stage of cancer. CONCLUSIONS: Differences in hyaluronan and CD44 expression in VIN and squamous cell carcinomas compared to normal epithelium suggest that they have a role in vulvar malignancy.

Effectiveness of photodynamic therapy in the treatment of lichen sclerosus: cell changes in immunohistochemistry.

BACKGROUND: Vulvar lichen sclerosus (LS) affects primarily women at postmenopausal age and its background remains unknown. One of the treatment modalities is photodynamic therapy (PDT). The aim was to investigate the efficacy of PDT in women with LS and the analysis of protein expression before and after PDT. MATERIAL AND METHODS: From 04.2006-01.2008 28 women, with LS underwent photodynamic diagnosis and next PDT: six-courses every second week with using 5-aminolevulinic acid (ALA) as a photosensitizer. Punch biopsies were taken before and after treatment and immunohistochemistry was done with Ki67,CD44,CD34 and CD3. RESULTS: Before PDT all patients suffered from pruritus and after in 89.3% the relief was noted. The histological examination showed that 35.7% patients hadn't LS after therapy completion. Anti-CD44 staining intensities was scored qualitatively - there were no statistical difference at the expression of protein CD44 in the epidermis (p>0.05) before and after therapy. Microvessel density was assessed at the hot spots, marked with anti-CD34. Statistical difference in AVD before and after therapy: (p<0.05). The staining intensity of Ki-67 didn't differ before and after PDT (p>0.05). The expression of CD3 on T lymphocytes showed statistical difference of the lymphocytic infiltration before and after PDT ( p<0.05). CONCLUSION: The immunohistochemical staining in vulvar LS showed increasing microvessel density and decreasing lymphocytic infiltration. There were a clinical, and less histological improvement in patients with LS. We suggest that the photodynamic therapy is an effective, alternative treatment in some but not all patients with LS. Therefore, further studies are needed.

Significant upregulation of antimicrobial peptides and proteins in lichen sclerosus.

BACKGROUND: Lichen sclerosus (LS) is a chronic inflammatory T cell-driven sclerotic skin condition in which skin barrier disruption frequently occurs. Inflamed and injured epithelia are a particularly rich source of antimicrobial peptides and proteins (AMPs). OBJECTIVES: We aimed to investigate for the first time the expression pattern of AMPs in lesions of LS as compared with healthy skin. METHODS: Twenty-four women with LS as well as 10 healthy women were included in the study. In order to assess the expression of human beta-defensin (hBD)-1, hBD-2, hBD-3, psoriasin (S100A7), the cathelicidin LL-37 and RNase 7, real-time reverse transcriptase-polymerase chain reaction and immunohistochemistry were performed on skin specimens obtained from lesional and healthy skin of the genital region, respectively. RESULTS: Median hBD-2 mRNA levels observed in LS were significantly higher than in controls (0.15 vs. 0.008; P = 0.0037). Moreover, psoriasin (98.2 vs. 28.1; P = 0.0052) mRNA expression was significantly higher in LS lesions as compared with controls. Significant differences in mRNA expression of hBD-2 and psoriasin were also confirmed by immunohistochemistry. For hBD-1, hBD-3, LL-37 and RNase 7, levels did not differ significantly or were significant only at the gene level but not protein level. CONCLUSIONS: We have demonstrated that hBD-2 and psoriasin expression levels in lesional skin of patients with LS are significantly increased when compared with healthy controls. Whether this observation simply reflects an innate defence response caused by an increased risk of local infection, or whether our data indicate a pathogenetic role of AMPs in LS, will be addressed in future studies.

Human papillomavirus-associated increase in p16INK4A expression in penile lichen sclerosus and squamous cell carcinoma.

BACKGROUND: Human papillomaviruses (HPVs) are sexually transmitted human carcinogens that may play a role in the oncogenesis of penile cancer. OBJECTIVES: To investigate the role of HPV infection and expression of the tumour suppressor protein p16INK4A in the pathogenesis of penile cancer. METHODS: By means of polymerase chain reaction amplification and reverse hybridization line probe assay to detect HPV infection, and immunohistochemical staining for p16INK4A and Ki67, we analysed 26 penile squamous cell carcinomas (SCCs) and 20 independent penile lichen sclerosus (LS) lesions from 46 patients. RESULTS: HPV DNA was found in 54% of penile SCCs and 33% of penile LS cases in single and multiple infections. High-risk HPV 16 was the predominant HPV type detected. No relationship between Ki67 expression and HPV infection was observed. Strong immunostaining for p16INK4A correlated with HPV 16/18 infection in both penile LS and penile SCC. In our penile SCC series the cancer margins were also associated with penile LS in 13 of 26 lesions, and HPV was detected in seven of the 13 SCC cases associated with LS and in six of the 11 SCC lesions not involving LS. CONCLUSIONS: Our study shows a high prevalence of HPV 16 and p16INK4A expression in penile lesions, consistent with an active role for HPV in interfering with the retinoblastoma pathway. High-risk HPV infection could be involved in the tumorigenic process in 50% of penile cancers, and the use of prophylactic HPV vaccines has the potential to prevent these cancers.

Detection of perforin and granzyme B mRNA expressing cells in lichen sclerosus.

Granzyme B and perforin messenger RNA (mRNA) expression has been shown to be a specific in vivo activation marker for cytotoxic cells. The aim of this study was to assess the contribution of cell-mediated cytotoxicity in the pathogenesis of lichen sclerosus. In situ hybridization and immunohistochemistry were performed on serial tissue sections of lesional skin biopsies and normal skin as control. Immunohistochemical staining showed that the cellular infiltrate of diseased skin consisted predominantly of T cells (CD3+) and some B cells (CD20+). Among T cells CD4+ and CD8+ cells were found in about equal numbers. In normal skin samples perforin and granzyme B mRNA expressing cells were only rarely found. In contrast, in biopsies from diseased skin a high percentage of infiltrating cells expressed mRNA for perforin and granzyme B. The perforin and granzyme B expressing cells were found in the dermal infiltrate and intraepidermally in close proximity to keratinocytes suggesting in situ activation of these cells. These findings provide evidence that cell-mediated cytotoxicity plays a significant role in tissue destruction in lichen sclerosus.

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.