Disagreement in high-grade/low-grade intraepithelial neoplasia and high-risk/low-risk HPV infection: clinical implications for anal cancer precursor lesions in HIV-positive and HIV-negative MSM.

Anal condylomata are common in HIV-positive individuals and among men who have sex with men (MSM). Generally attributable to infection by low-risk human papillomaviruses (HPVs), condylomata are considered benign low-grade squamous intraepithelial lesions (SILs). However, anal condylomata have occasionally been linked to high-grade SIL and to oncogenic, high-risk HPVs. Here we describe the range of intraepithelial lesions and of the associated HPVs in heterosexual men and women and MSM. Perianal and anal condylomata were collected from 243 patients (56 heterosexual women, 61 heterosexual men and 126 MSM, including 41 HIV-positive MSM). We assessed lesion histology and HPV genotype. Prevalence estimates and Poisson models were used. Irrespective of HIV infection status, MSM showed a higher proportion of condylomata as high-grade SILs compared to heterosexual men/women. High-grade SILs were also more prevalent in anal than in perianal lesions in all patient groups. HIV-positive MSM exhibited increased prevalence ratio (4.6; 95% confidence interval 2.1-10.0) of perianal low-grade SILs containing only high-risk HPVs compared to HIV-negative MSM. In addition, more than 64% of anal SILs with a high-grade component, regardless of HIV infection, were exclusively associated with low-risk HPVs. In anal condylomata, both high-grade and low-grade SILs can be associated with high-risk and/or low-risk HPVs. Particularly, low-grade perianal SILs associated with high-risk HPVs were common in HIV-positive MSM, while presence of only low-risk HPVs in high-grade SILs were common in both MSM groups. Our findings sound a note of caution for the common clinical practice for the treatment of anal condylomata as benign lesions in MSM and HIV-positive patients.

Interlaboratory reproducibility and proficiency testing within the human papillomavirus cervical cancer screening program in Catalonia, Spain.

In Catalonia, a screening protocol for cervical cancer, including human papillomavirus (HPV) DNA testing using the Digene Hybrid Capture 2 (HC2) assay, was implemented in 2006. In order to monitor interlaboratory reproducibility, a proficiency testing (PT) survey of the HPV samples was launched in 2008. The aim of this study was to explore the repeatability of the HC2 assay's performance. Participating laboratories provided 20 samples annually, 5 randomly chosen samples from each of the following relative light unit (RLU) intervals: <0.5, 0.5 to 0.99, 1 to 9.99, and ≥10. Kappa statistics were used to determine the agreement levels between the original and the PT readings. The nature and origin of the discrepant results were calculated by bootstrapping. A total of 946 specimens were retested. The kappa values were 0.91 for positive/negative categorical classification and 0.79 for the four RLU intervals studied. Sample retesting yielded systematically lower RLU values than the original test (P<0.005), independently of the time elapsed between the two determinations (median, 53 days), possibly due to freeze-thaw cycles. The probability for a sample to show clinically discrepant results upon retesting was a function of the RLU value; samples with RLU values in the 0.5 to 5 interval showed 10.80% probability to yield discrepant results (95% confidence interval [CI], 7.86 to 14.33) compared to 0.85% probability for samples outside this interval (95% CI, 0.17 to 1.69). Globally, the HC2 assay shows high interlaboratory concordance. We have identified differential confidence thresholds and suggested the guidelines for interlaboratory PT in the future, as analytical quality assessment of HPV DNA detection remains a central component of the screening program for cervical cancer prevention.

Phylogenetically related, clinically different: human papillomaviruses 6 and 11 variants distribution in genital warts and in laryngeal papillomatosis.

Genital warts (GWs) and laryngeal papillomatosis (LP) are two usually benign pathologies related to infection with human papillomaviruses (HPVs), mainly HPV6 and HPV11. The aim of this work was to describe the genetic diversity of HPV6 and HPV11 isolates found in GWs and LPs, and to analyse the differential involvement of viral variants in either lesion. A total of 231 samples diagnosed as GWs (n = 198) or LP (n = 33) and caused by HPV6 or HPV11 monoinfections were analysed. The phylogenetic relationships of the retrieved viral sequences were explored. We have identified the long control region and the intergenic E2-L2 region as the two most variable regions in both HPV6 and HPV11 genomes. We have generated new HPV6 (n = 166) or HPV11 (n = 65) partial sequences from GWs and LPs lesions spanning both regions and studied them in the context of all available sequences of both types (final n = 412). Our results show a significant (p <0.01) differential presence of HPV6 variants among both pathologies, with HPV6 B variants being preferentially found in GW versus LP samples. No differential involvement of HPV11 variants was observed. Our findings suggest that different HPV6 variants may either show differential tropism or have different potential to induce lesions in different epithelia.

Differential presence of Papillomavirus variants in cervical cancer: an analysis for HPV33, HPV45 and HPV58.

BACKGROUND: Certain human papillomaviruses (HPVs) are the causative agents of cervical carcinomas in humans. The identification of the link between infection and cancer has resulted in the successful establishment of clinical strategies such as screening or vaccination programs, aiming to prevent this pathology. More than 150 different HPVs have been described and classified and the large majority of them are not related to cancer. The genus Alphapapillomavirus encompasses many PVs, some of which are identified in humans as oncogenic, according to the epidemiological connection between infection and cervical cancer. Variants of some of these "high-risk" HPVs may have an increased involvement in cervical cancer, although definitive data are still wanting. The aim of the present work was to analyze the presence of HPV33, HPV45 and HPV58 variants in cases of cervical cancer. METHODS: Samples from cervical lesions in the context of different cervical cancer surveys were analyzed for presence of HPV DNA. Samples positive for HPV33, HPV45 or HPV58 DNA were selected and the E6/E7 genes were amplified and sequenced. The phylogenetic relationships of these sequences were inferred using an evolutionary placement algorithm and accordingly classified at the variant level. RESULTS: All viral E6/E7 sequences were successfully placed in the classification schemes of the corresponding viruses. For HPV33 (n=23), 45 (n=61) or 58 (n=29), the distribution of variants found in cases of cervical cancer is not a random sample of the corresponding diversity. In all three HPVs, the respective A variants were more prevalent in the viral DNA-positive cases of cervical cancer analyzed. This is the first study trying to discern the phylogenetic connection between variants of the oncogenic HPV33, 45 and 58, and squamous cell carcinoma of the cervix.

High prevalence of human papillomavirus 16 in penile carcinoma.

In order to analyze the incidence and prevalence of Human Papillomavirus (HPV) in penile carcinoma, we studied 49 patients with penile carcinoma. Formalin-fixed, paraffin-embedded tissue samples were collected from 64 samples of penile carcinoma from the Hospital General Universitario (Albacete, Spain). Cases were histologically classified and the polymerase chain reaction (PCR) method was used to detect the presence of HPV. Two sets of consensus primers were used, the My09/My11, and the GP5+/GP6+. All positive cases were sequenced in order to establish the implicated genotype. Our results showed that 38 of the 49 cases were positive for HPV (77,5%). HPV16 appeared in 32 (84,2 %) of the 38 positive cases and HPV18 in 4 (10,5%). Our data demonstrate that the My09/My11 primers are more sensitive than GP5+/GP6+ primers, although the combination of the two sets of primers notably increased the total number of HPV positive cases detected.

The immunohistochemical expression of CD34 in human hair follicles: a comparative study with the bulge marker CK15.

BACKGROUND: Anti-CD34 antibodies label the bulge region of mouse hair follicles. However, in human hair follicles, CD34 immunoreactivity is found in the outer root sheath below the bulge zone. The immunohistochemical staining of CD34 in catagen and telogen follicles has not been evaluated. AIMS: To characterize the expression of CD34 immunoreactivity at different stages of the hair cycle in human terminal hair follicles, and to compare the immunostaining pattern of CD34 with that of CK15, used here as a marker of the bulge region. METHOD: Serial vertical sections of human hair follicles in anagen, catagen and telogen phases were immunostained with anti-CD34 (QBEnd 10) and anti-CK15 (LHK15 and C8/144B) antibodies. Double-labelling immunofluorescence was also performed. RESULTS: The catagen and telogen follicles studied did not show CD34 immunoreactivity in the outer root sheath. The location of CD34 and CK15 immunoreactivity in anagen follicles reveals a different staining pattern: CD34-positive cells are located in the outer root sheath below the attachment zone of the arrector pili muscle, whereas CK15-positive cells are located in the outer root sheath above the attachment zone of the arrector pili muscle. CONCLUSIONS: Only anagen human hair follicles show CD34 immunoreactivity. CD34 and CK15 recognize different types of cells or cells at different stages of differentiation.