人乳头瘤病毒与皮肤Bowen病的相关性

目的 探讨人乳头瘤病毒(HPV)与皮肤Bowen病发病的相关性.方法 41例皮肤Bowen病患者皮损以及48例健康对照皮肤,采用多对引物,应用巢式PCR进行HPV DNA检测,同时应用半定量PCR进行病毒定量,对HPV DNA阳性标本进一步采用原位杂交方法分析组织内病毒的分布状况.结果 41例皮肤Bowen病患者皮损HPV DNA阳性检出率为12%(5例),其中黏膜型3例(2例HPV16,1例HPV33),病毒定量相当于101～103拷贝,原位杂交显示在多数肿瘤细胞核中有广泛阳性表达,而肿瘤邻近的正常组织无信号表达;皮肤型2例(HPV27和HPV76各1例),原位杂交均无阳性表达.此外,对照组中有1例检出HPV DNA,属于疣状表皮发育不良相关型HPV23,检出率为2.1%,与皮肤Bowen病皮损中HPV检出率比较,差异无统计学意义.2例患者皮肤型病毒定量较低,与正常对照组中检出的1例HPV23相似,均相当于10-2～10-3拷贝.结论 某些皮肤Bowen病的发病与黏膜型HPV密切相关.     

巢式PCR方法检测非生殖器部位Bowen病HPV DNA

目的 建立一种巢式ＰＣＲ方法,探讨HPV DNA在非生殖器部位Bowen病中的检出率。方法 巢式PCR方法,用5对不同引物包括CN1FR、CN2FR、CN3FR、CN4FR以及CN5FR进行扩增。结果 通过ClustalX软件,将所设计的每对引物与已知HPV亚型的碱基序列逐一相比较,得知改良设计的引物可以使69种HPV亚型得到扩增,包括黏膜型HPV、皮肤型 HPV以及疣状表皮发育不良相关性 HPV;PCR反应体系的敏感度在10-2～10-3拷贝之间。41例非生殖器部位Bowen病的组织标本中,5例HPV DNA阳性,其中高危黏膜型3例（2例HPV16,1例HPV33）,皮肤型2例（HPV27和HPV76各1例）。结论 改良的巢式PCR方法具有较高的敏感性、特异性,部分非生殖器部位Ｂowen病发病与黏膜高危型ＨＰＶ感染相关。     

Human papillomavirus and extragenital in situ carcinoma

BACKGROUND: The relation between human papillomavirus (HPV) and extragenital Bowen's disease (BD) is controversial. METHODS: This study used in situ hybridisation to evaluate the rate of HPV in extragenital cutaneous BD and investigated possible relations with immune status and exposure of skin to light. RESULTS: HPV DNA was detected in 58% of 69 samples from 50 patients. The percentage of HPV detection was not significantly higher in exposed (55%) than unexposed areas (65%), and no difference in HPV rate was found between immunosuppressed and immunocompetent patients. CONCLUSION: Thus, this study confirms the high rate of HPV detection in extragenital cutaneous BD and suggests that there is no apparent relation concerning exposed areas and immune status.     

Detection of human papillomavirus in cutaneous extragenital Bowen's disease in immunocompetent patients

INTRODUCTION: A specific link between human papillomavirus (HPV) types 16, 18, 31, and 33 and genital carcinomas and between HPV type 5 and cutaneous extragenital carcinomas in patients with epidermodysplasia verruciformis and renal transplant has been previously found. The aim of this prospective study was to detect HPV in cases of cutaneous extragenital Bowen's disease (BD) from non-immunosuppressed patients. PATIENTS AND METHODS: Twelve cases of cutaneous extragenital BD or Bowen's carcinoma (BC), seen in the period 1994-1996 and confirmed by histologic examination, were included in the study. Tissue sections were studied by in situ hybridization with a mixture of HPV DNA probes and specific HPV DNA probes. In addition, study on fresh materiel from 1995 included: Southern blot hybridization with various usual HPV probes (6, 11, 16, 18, 31, 33, 35, 39, 42), polymerase chain reaction (PCR) with hybridization using consensus HPV probes and probes specific for HPV types 6, 11, 16, 18 and 33. In positive samples with conventional PCR, in situ PCR with probes specific for HPV types 6/11 and 16 was performed on tissue sections. RESULTS: In situ hybridization was negative in all the cases. Southern blot hybridization was negative in our 9 studied cases. Three cases studied by consensus PCR were positive. PCR with specific HPV probes revealed positivity on two of these cases: HPV 6 in one, and HPV 16 in another. In situ PCR was positive with a mixed 6/11 HPV probe in the third positive consensus PCR case. DISCUSSION: Our study revealed the presence of HPV in 3 out of 12 cases of cutaneous extragenital BD and BC. HPV type 16, found in BC of skull, was the most usually found type in the literature. HPV types 6/11, detected in 2 cases, were rarely found in cutaneous extragenital BD and BC and these results are in favor of the oncogenic effect of these virus types. In our study, in situ hybridization and Southern blot hybridization were negative in all the cases; HPV was only found in 3 cases by conventional PCR and in 1 case by in situ PCR. The low range of detection of HPV in cutaneous extragenital BD may be due to the used methods, to difficulties related to sampling and/or to a low number of copies of the HPV genoma.     

Presence of high-risk mucosal human papillomavirus genotypes in primary melanoma and in acquired dysplastic melanocytic naevi

BACKGROUND: Some studies have shown that cutaneous and mucosal melanoma biopsy specimens harbour human papillomavirus (HPV), suggesting that this virus may play a role in development and progression of the tumour. OBJECTIVES: To investigate the presence of HPV DNA and the prevalence of different high-risk mucosal HPV genotypes in primary melanoma (PM) and in acquired dysplastic melanocytic naevi (ADMN). METHODS: Fifty-one PMs from 18 men and 33 women (median age 55.5 years), 33 ADMN from 15 men and 18 women (median age 35.1 years) and 20 control skin samples from nine men and 11 women (median age 43.5 years) were studied. All diagnoses were made after histological analysis. HPV DNA analysis was made using two different polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA) methods, namely MY-PCR and GP-PCR. RESULTS: Using GP-PCR, mucosal HPVs were detected in 14 PMs (27%; P = 0.0166) and eight ADMN (24%; P = 0.0367), while with MY-PCR, mucosal HPVs were found in 11 PMs (22%; P = 0.04) and five ADMN (15%; P not significant). All control skin samples were negative for mucosal HPVs with both DNA amplification procedures. CONCLUSIONS: Using our PCR-ELISA methods, the detection of mucosal high-risk HPV genotypes in 24% of precursor lesions (ADMN) and in 27% of PMs adds to the body of evidence indicating a colocalization of mucosal HPV and tumoral melanocytic pathologies.     

Oncogenic human papillomaviruses in extra-genital Bowen disease revealed by in situ hybridization]

BACKGROUND: The association between mucosal oncogenic human papillomaviruses (HPV) and bowenoid papulosis or genital Bowen's disease is well documented. In contrast this association with extra-genital Bowen's disease is poorly studied. The aim of this study was to detect oncogenic (16/18, 31/33/51) and non oncogenic (8/11) mucosal HPV using a in situ hybridization method in 28 skin biopsy specimens of extra-genital Bowen's disease.PATIENTS AND METHODS: Twenty-eight cases of extra-genital Bowen's disease seen in the period 1990-96 in the Dermatology department were included: 19 women and 9 men (mean age: 72 years). Bowen's disease locations were: hands and feet (8 cases), limbs (11 cases), face (8 cases), trunk (1 case). Blinded histopathologic examination confirmed the diagnosis of Bowen's disease and signs of HPV infection (koilocytosis). In situ hybridization was performed using three biotinylated probes detecting HPV types 6/11, 16/18, 31/33/51.RESULTS: Oncogenic HPV genoma was detected in 8 skin samples (28.6 p. 100). In all these cases, 16/18 probe was positive and in two cases, both 16/18 and 31/33/51 probes were positive; 4/8 Bowen's diseases of the extremities were positive for HPV. Koilocytes were found in 6/8 of skin samples with positive HPV detection.DISCUSSION: Mucosal oncogenic HPV are detected by in situ hybridization in 28.6 p. 100 of extra-genital Bowen's disease. In situ hybridization is an easier technique than Southern-Blot hybridization which is the gold standard. Five studies reported similar results and three studies reported different results that we discuss. A precise understanding of oncogenic HPV implication in the development of extra-genital Bowen's disease could lead to the development of new therapeutic strategies (topical cidofovir or imiquimod).     

No evidence of human papillomavirus DNA in actinic keratosis

Human papillomaviruses (HPVs) are involved in premalignant and malignant skin diseases as well as in a variety of benign cutaneous and mucosal lesions. Actinic keratosis (AK) is a common premalignant disease. Its association with HPV infection has recently been evaluated in a few studies, but the results are contradictory. For further assessment of the role of HPVs in AK, a series of 100 paraffin-embedded biopsy specimens taken from subjects with AK were studied for the presence of HPV types 1, 2, 3, 4, 5, 7, 12, 15, 26, 36, 37 and 59 DNA using in situ hybridization (ISH) under high stringency conditions (Tm -10°C). All specimens were definitely negative for all biotinylated HPV DNA probes tested. One-fifth of the specimens were studied using the polymerase chain reaction (PCR) with general primers to confirm the negative results. All cases were also negative in the PCR. Our results suggest that HPVs are not directly involved in the aetiology of AK.     

HPV-associated diseases

Nearly 200 distinct human papilloma viruses (HPVs) have now been recognized, and each is associated with a specific set of clinical lesions. They are associated with a spectrum of diseases, from benign verrucae vulgares and condylomata acuminata to the malignancies of the cervix, vulva, anus, and penis. Disease associated with HPV can be divided into skin and mucosal lesion of the genital and extragenital regions. The relationship between HPV and nonmelanoma skin cancer (NMSC) is important clinically, because NMSC is the most common form of malignancy among fair-skinned populations. HPVs have also been detected in skin tags, lichen sclerosus, seborrheic keratoses, actinic keratoses, epidermal cysts, psoriatic plaques, and plucked hairs, but cutaneous HPV can be found on healthy skin.     

Detection of human papillomavirus type 56 DNA, belonging to a mucous high-risk group, in hair follicles in the genital area of a woman no longer suffering from viral warts

BACKGROUND: Human papillomaviruses (HPVs) parasitize human epithelium, but it is not clear where they reside when they do not cause apparent infection. Hair follicles are important candidates as reservoirs. OBJECTIVES: A patient reported previously by us as having perianal warts caused mainly by HPV 56, demonstrated hair follicles in her genital area which bulged a little from the surface and appeared somewhat enlarged. We therefore examined whether DNA of HPV 56, a member of the mucous high-risk group, might be detectable in these structures. METHODS: We obtained plucked hairs and performed an examination by polymerase chain reaction and subsequent reverse-phase dot blot hybridization (PCR-RDBH) and in situ hybridization (ISH). RESULTS: Strong positive signals were obtained not only with PCR-RDBH but also with ISH. CONCLUSIONS: Hair follicles in the genital area might serve as reservoirs for HPVs belonging to the mucous high-risk group.     

Assessment of the presence of mucosal human papillomaviruses in malignant melanomas using combined fluorescent in situ hybridization and chemiluminescent immunohistochemistry

BACKGROUND: The vast majority of studies aimed at detecting human papillomavirus (HPV) DNA in skin cancer have used sensitive polymerase chain reaction (PCR) methods but the PCR technique, despite its high sensitivity, is not suitable to ascertain whether (i) the presence of HPV can be related only to few cells harbouring the virus, (ii) the presence of HPV is due to a tumour surface contamination and (iii) the presence of HPV is localized in cancer cells, rather than in normal keratinocytes present in the tumour biopsy. In a recent work we have found mucosal high-risk (HR) HPV genotypes in primary melanoma by PCR. OBJECTIVES: To localize mucosal HR-HPV nucleic acids and tumoural melanocytic marker in the same sections of primary melanoma samples in order to understand the relationship between HPVs and melanoma cells. METHODS: We have developed a very sensitive method that combines an enzyme-amplified fluorescent in situ hybridization (ISH) for the detection of HPV nucleic acids (types 16 and 18) with a chemiluminescent immunohistochemistry (IHC) method for the detection of the tumoural melanocytic marker HMB-45 sequentially in the same section. Digital images of fluorescent ISH and chemiluminescent IHC were separately recorded, assigned different colours and merged using specific software for image analysis. RESULTS: The combined fluorescent ISH and chemiluminescent IHC demonstrated a sharp colocalization (in the range 60-80%) of HPV nucleic acids and melanoma marker inside the same sections of melanoma biopsies, with a strong specificity and sensitivity. CONCLUSIONS: The strong colocalization of mucosal HR-HPV nucleic acids and HMB-45 melanocytic marker emphasized that viral nucleic acids were specifically present in melanoma cells and supported a possible active role of HPV in malignant melanoma.     

Human papillomavirus type 58 in Bowen's disease of the elbow

Human papillomavirus (HPV) can be detected in skin lesions of Bowen's disease, particularly on the fingers, and its genotype is associated with mucosal/genital types of HPV. We report herein an 85-year-old woman who had HPV-associated Bowen's disease on her elbow. HPV-58 DNA was detected in the lesion by polymerase chain reaction with restriction fragment length polymorphism and by Southern blot hybridization. In situ hybridization revealed numerous hybrid cells in the nuclei of the upper epidermis and stratum corneum of Bowen's disease. A high-risk type of mucosal HPV-58 DNA is associated with Bowen's disease in this case, suggesting that HPV-related Bowen's disease is not always restricted to genital or finger lesions.     

Detection and sequences of human papillomavirus DNA in nongenital seborrhoeic keratosis of immunopotent individuals

BACKGROUND: The etiology of seborrhoeic keratosis (SK) is unknown. Its clinical and histopathological similarities to verrucae vulgaris and condyloma acuminatum prompted us to examine whether human papillomavirus (HPV) is present in SK lesions. In the present study, HPVs were frequently detected from genital lesions or hair follicle in immunocompromised host. OBJECTIVE: We analyzed 104 nongenital SK specimens diagnosed by clinical and histopathological examinations for HPV DNA in immunopotent individuals. METHOD: We analyzed SK specimens for HPV DNA using in situ hybridization (ISH), polymerase chain reaction (PCR), Southern blot hybridization, and sequencing of viral DNA of PCR-amplified fragments. And we also examined virion, which is the capsid protein of HPV in ISH-positive specimens by immunochemical examination. We identified eight mucosal and two cutaneous type HPVs. RESULT: ISH revealed that 30 of 104 (28.8%) SK samples contained HPV DNA. All ISH-positive specimens were demonstrated virion in the nuclei of the epidermal keratinocytes. PCR analysis showed that 87 (83.7%) samples contained HPV-18, 81 (77.9%) HPV-6, and 73 (70.2%) contained both HPV-18 and -6. The incidence of HPV-1 (7.7%) and HPV-2 (14.4%) was relatively low. All 20 normal controls were negative for HPV DNA by ISH but seven were positive by PCR sequencing. CONCLUSION: Our results suggest that HPV, possibly coinfection with HPV-6 and -18 and unknown type(s) of HPV, plays an important role in the pathogenesis of SK.     

Expression of cell-cycle proteins p53, p21 (WAF-1), PCNA and Ki-67 in benign, premalignant and malignant skin lesions with implicated HPV involvement.

A series of 120 biopsies from benign (verruca vulgaris and keratoacanthoma), premalignant (actinic keratosis and extragenital Bowen's disease) and malignant (squamous cell carcinoma) skin lesions were studied immunohistochemically for the expression of cell-cycle proteins p53, p21 (WAF-1), PCNA and Ki-67. The presence of human papillomavirus (HPV) DNA in these samples had been analysed previously using in situ hybridization (ISH) and PCR. Moderate to intense expression of both PCNA and Ki-67 was present in most of the lesions studied. PCNA staining was extensive in the epidermis underneath the layers where abundant HPV DNA staining was shown in HPV DNA-positive verrucas. In keratoacanthomas, p21 and PCNA expression remained low, despite intense p53 expression. In actinic keratosis, only half of the specimens showed overexpression of p53 associated with moderate or intense expression of PCNA. In extragenital Bowen's lesions, all these cell-cycle markers were overexpressed, but in squamous cell carcinomas, they were heterogeneously expressed and showed no correlation with tumour differentiation. Our results suggest a mechanism by which HPV can reactivate the host genes (leading to cell proliferation) to support its own DNA replication. Also p21 might start keratinocyte differentiation in areas where HPV DNA replication starts. Cell proliferation remained active in actinic keratosis and Bowen's lesions, emphasizing the precancer character of these lesions in contrast with the benign nature of keratoacanthoma and verruca vulgaris.     

Vulval intraepithelial neoplasia and periungual Bowen's disease concordant for mucosal (HPV-34) and epidermodysplasia verruciformis (HPV-21) human papillomavirus types

Human papillomavirus (HPV) infection is associated with genital malignancy and specific cutaneous malignancies. We report a case of an HPV-associated concurrent vulval intraepithelial neoplasia and periungual Bowen's disease in a young immunocompetent Afro-Caribbean woman with no known risk factors for either disease. HPV genotyping studies detected multiple alpha and beta papillomaviruses with concordance for HPV-34 [a high-risk (HR) mucosal type], and HPV-21 [an epidermodyslasia verruciformis (EV) type] in both vulval and finger tissue. Although the HR-mucosal viruses detected are likely to have a pathogenic role in vulval intraepithelial neoplasia, this is the first report of concordance for EV HPV types in both genital and nongenital skin premalignancies. This case, in the context of accumulating epidemiological and experimental data in cutaneous SCC, raises the question of whether EV HPV may contribute to vulval malignancy, and further study is merited.     

Cutaneous manifestations of human papillomaviruses: a review

Human papillomaviruses (HPVs) are small DNA viruses of the papovavirus family, with more than 100 types already described. Their importance in human disease cannot be overemphasized because these agents are among the most common pathogens in cutaneous infectious diseases and are very important in a subset of predominantly, but not exclusively, genital squamous-cell carcinomas. HPVs can be associated with a variety of cutaneous as well as mucosal manifestations. Some types of HPVs are associated with increased risk of epithelial malignancies; these have been divided into low-risk and high-risk types based on their oncogenic potential. Clinical and histological features of HPV infection vary according to individual susceptibility (e.g., immunosuppressed patients), site of involvement, and type of HPV implicated. The histological features of HPV infection are very easy to identify on sections stained with hematoxylin and eosin. However, many findings usually associated with HPV infection are entirely non-specific. Additional current diagnostic methods for identification of HPV in tissues include techniques based on the detection of viral DNA; namely, in-situ hybridization and polymerase chain reaction (PCR). This article reviews the main clinical and histopathological cutaneous manifestations of HPV infection, including common warts, plantar warts, plane warts, condyloma acuminatum, Bowenoid papulosis, and epidermodysplasia verruciformis. Emphasis is placed on the clinical and histological features of these various manifestations, including a brief discussion about the routinely used laboratory methods for detecting HPV in tissues.     

Correlation of p16 and pRb expression with HPV detection in Bowen's disease

BACKGROUND: Bowen's disease is a form of cutaneous squamous cell carcinoma which may be caused by ultraviolet radiation, human papilloma virus (HPV) infection, or other causes. Although p16 over-expression is a surrogate marker of HPV E7-mediated catabolism of pRb in premalignant and malignant lesions of the cervical mucosa, the correlation of p16 and pRb expression with HPV detection in Bowen's disease has not been well characterized. METHODS: A retrospective study on formalin-fixed tissues was performed. Immunohistochemistry for p16 and pRb was performed on 32 cases. DNA was successfully extracted from 20 cases, and polymerase chain reaction was performed to amplify a highly conserved region of the HPV L1 open reading frame. RESULTS: Twenty-eight of 32 (88%) cases showed strong diffuse staining for p16 but were negative for pRb; two of 32 cases (6%) were negative for p16 but were diffusely positive for pRb; one case was strongly positive for both p16 and pRb, and one case was negative for both p16 and pRb. Three of 20 cases (15%) contained HPV DNA. All three of these cases showed strong p16 expression and lack of pRb staining. CONCLUSIONS: Most cases of Bowen's disease strongly express p16 but not pRb. In contrast to HPV-associated lesions of the cervical mucosa, p16 overexpression in cutaneous Bowen's disease appears to be unrelated to HPV status. The p16 overexpression in Bowen's disease may reflect disruption of the G1/S checkpoint, resulting in unregulated cell cycle progression.     

Immunohistochemical staining of p16 in squamous cell carcinomas of the genital and extragenital area

Background and objectivesPositive immunostaining for the tumor suppressor protein p16 is associated with the presence of mucosal or αsubtypes of human papillomavirus (HPV) in cervical and genital squamous cell carcinoma (SCC). The aim of this study was to determine whether p16 immunostaining is also associated with mucosal HPV in extragenital SCC.Material and methodsParaffin sections of lesions located in the genital region (8 genital warts, 3 intraepidermal SCCs, and 7 invasive SCCs) and extragenital area (29 intraepidermal SCCs corresponding to Bowen disease and 10 invasive SCCs) were stained for p16 by immunohistochemistry. Mucosal HPV was detected by polymerase chain reaction (PCR).ResultsIn the genital area, p16 immunostaining was negative in genital warts and positive in all 3 intraepidermal SCCs and 2 invasive SCCs (29%). Mucosal HPV was detected in 6 genital warts and 2 intraepidermal SCCs (100% after exclusion of 3 lesions that could not be analyzed by PCR) and in the 2 invasive SCCs that were positive for p16. In the extragenital area, 19 intraepidermal SCCs (95%) and 2 invasive SCCs (20%) were immunopositive for p16. Mucosal HPV was detected in 4 intraepidermal SCCs (p16 immunopositive) and 1 invasive SCC (p16 immunonegative). In intraepidermal SCCs, p16 immunostaining facilitated the identification of dermal microinfiltration or invasion of normal skin appendages.ConclusionsAccording to our results, unlike in genital SCCs, p16 immunopositivity is independent of the presence of HPV in extragenital SCCs. Compared with intraepidermal SCCs, the absence of p16 protein in invasive SCCs in the extragenital area would indicate progression of the disease.     

Premalignant lesions and cancers of the skin in the general population: evaluation of the role of human papillomaviruses

To evaluate the role of human papillomaviruses (HPV) in the development of premalignant lesions and cancers of the skin in the general population, 314 biopsies obtained from 227 patients with benign neoplasms, premalignant lesions, and cancers of the skin and from 25 patients with squamous cell carcinoma of the lip were analyzed by Southern blot hybridization. DNA probes specific for various cutaneous and genital HPV types were used in hybridizations conducted under nonstringent or stringent conditions. HPV DNA sequences were only detected in eight specimens obtained from six patients: HPV 34 in one case of periungual Bowen's disease, HPV 36 and an as yet uncharacterized HPV in two cases of actinic keratosis, HPV 20 in one case of basal cell carcinoma, an as yet unrecognized HPV in one case of squamous cell carcinoma, and HPV 16 in one case of squamous cell carcinoma of the lip. None of the specimens of cutaneous horn and keratoacanthoma contained detectable HPV DNA. In contrast, HPV DNA sequences, mostly HPV 16, were detected in 13 of 23 cases of anogenital Bowen's disease and invasive Bowen's carcinoma. HPV DNA sequences were not detected in 90 cutaneous samples further analyzed by the polymerase chain-reaction technique, using amplification primers that contain conserved sequences among the genomes of HPV. These results strongly suggest that the known HPV types play only a minor role, if any, in skin carcinogenesis in the general population.     

Eccrine-centred distribution of human papillomavirus 63 infection in the epidermis of the plantar skin

BACKGROUND: The primary target cell of human papillomaviruses (HPVs) is an unsettled issue. Recent studies have suggested that the hair follicle is an important candidate as the reservoir of certain HPV types. However, little is known about the cells which serve as the target or the reservoir of HPVs in nonhairy palmoplantar skin. OBJECTIVES: To investigate whether the eccrine sweat gland, the only skin appendage in nonhairy palmoplantar skin, also serves as the target or the reservoir of HPVs. METHODS: HPV 63-induced warts were employed in this study, because the virus induces tiny warty lesions of a punctuate appearance in the plantar skin and shows peculiar intracytoplasmic inclusion bodies as a diagnostic histopathological marker of infection: this seemed to provide a useful model for the present study. Serial sections were obtained from the entire body of each biopsy specimen and were investigated histologically, immunohistochemically and using DNA-DNA in situ hybridization (ISH) for the histological localization of HPV 63 infection. RESULTS: On microscopy, HPV 63 histopathological changes were seen closely associated with eccrine ducts. Using ISH, HPV 63 DNA was detected not only in keratinocytes resident around acrosyringia but also in the uppermost portion of the eccrine dermal duct. A few keratinocytes harbouring HPV 63 DNA were also identified in acrosyringeal areas in the normal plantar skin adjacent to the wart lesions. CONCLUSIONS: On the basis of our results, it seems likely that HPV 63 targets keratinocytes resident in or around the eccrine ducts in the plantar skin. The results may also suggest that not only hair follicles but also eccrine ducts serve as reservoirs for certain HPV types, including HPV 63, especially in the nonhairy plantar skin.     

Human papillomavirus-DNA loads in actinic keratoses exceed those in non-melanoma skin cancers

Recent studies suggest a role of cutaneous human papillomaviruses (HPV) in non-melanoma skin cancer (NMSC) development. In this study viral DNA loads of six frequent HPV types were determined by quantitative, type-specific real-time-PCR (Q-PCR) in actinic keratoses (AK, n=26), NMSC (n=31), perilesional tissue (n=22), and metastases of squamous cell carcinomas (SCC) (n=8) which were previously shown to be positive for HPV5, 8, 15, 20, 24, or 36. HPV-DNA loads in AK, (partially microdissected) NMSC, and perilesional skin ranged between one HPV-DNA copy per 0.02 and 14,200 cell equivalents (median: 1 HPV-DNA copy per 344 cell equivalents; n=48). In 32 of the 79 HPV-positive skin biopsies and in seven of the eight metastases viral loads were even below the detection limit of Q-PCR. Low viral loads in NMSC were confirmed by in situ-hybridization showing only a few HPV-DNA-positive nuclei per section. Viral loads in SCC, basal cell carcinomas, and perilesional tissue were similar. But, viral loads found in AK were significantly higher than in SCC (p=0.035). Our data suggest that persistence of HPV is not necessary for the maintenance of the malignant phenotype of individual NMSC cells. Although a passenger state cannot be excluded, the data are compatible with a carcinogenic role of HPV in early steps of tumor development.