Role of P16(INK4a) expression in identifying CIN2 or more severe lesions among HPV-positive patients referred for colposcopy after abnormal cytology

BACKGROUND: p16 is strongly overexpressed in dysplastic cervical cells because of the transforming activity of the E7 oncogene of all high-risk human papillomavirus (HR-HPV) types and may be easily revealed by immunochemistry: p16 may, therefore, be considered a surrogate marker for the activated oncogene expression of HR-HPV in dysplastic cervical cells. METHODS: HPV and p16(INK4a) testing were performed in a consecutive series of 283 patients with abnormal cytology referred to colposcopy assessment or follow-up. Triage of patients to colposcopy by HPV or HPV and p16 testing was simulated, and the relative sensitivity, specificity, and positive predictive value (PPV) of HPV and p16 testing for > CIN2 lesions was determined as well as the cost balance of the two triage types. RESULTS: Compared to current protocol, triage by HPV testing reduced the number of colposcopies by 44.2%, but also reduced the > CIN2 detection rate by 10.7%, and was associated with a cost of euro 54.16 per assessed woman and of euro 613.20 per > CIN2 detected. Compared with current protocol, triage by HPV and p16 testing combined reduced the number of colposcopies by 73.1%, but reduced > CIN2 detection rate by 21.5%, and was associated with a cost of euro 54.73 per woman assessed and of euro 704.09 per > CIN2 detected. CONCLUSIONS: Triage by HPV and p16 improves considerably the PPV of diagnostic assessment, but decreases > CIN2 detection rate, and is associated with substantially higher costs. Further decrease of molecular immunochemistry testing due to technological progress may allow HPV and p16 testing to become a cost effective procedure in the future.     

The role of cyclins and cyclins inhibitors in the multistep process of HPV-associated cervical carcinoma

BACKGROUND: Human papillomavirus (HPV) types 16 and 18 are associated with cervical carcinogenesis. This is possibly achieved through an interaction between HPV oncogenic proteins and some cell cycle regulatory genes. However, the exact pathogenetic mechanisms are not well defined yet. METHODS: We investigated 110 subjects (43 invasive squamous cell carcinoma (ISCC), 38 CIN III, 11 CIN II, 18 CIN I) confirmed to be positive for HPV16 and/or 18 as well as 20 normal cervical tissue (NCT) samples for abnormal expression of cyclin D1, cyclin E, CDK4, cyclin inhibitors (p21 (waf), p27, p16 (INK4A)) and Ki-67 using immunohistochemistry and differential PCR techniques. RESULTS: There was a significant increase in the expression of Ki-67, cyclin E, CDK4, p16 (INK4A) (p=0.003, 0.001, 0.001) and a significant decrease in p27 (Kip1) from NCT to ISCC (p=0.003). There was a significant correlation between altered expression of p27 (KIP1) and p16(INK4A) (p<0.001), cyclin D1 and CDK4 (p=0.001), cyclin E and p27 (Kip1) (p=0.011) in all studied groups. In ISCC, there was significant relationship between standard clinicopathological prognostic factors and high Ki-67 index , increased cyclin D1 and cyclin E, reduced p27 (Kip1) and p21 (waf). CONCLUSION: 1) Aberrations involving p27 (KIP1), cyclin E, CDK4 and p16 (INK4A) are considered early events in HPV 16 and 18-associated cervical carcinogenesis (CINI & II), whereas cyclin D1 aberrations are late events (CINIII & ISCC) 2) Immunohistochemical tests for p16 (INK4A) and cyclin E could help in early diagnosis of cervical carcinoma 3) Only FIGO stage, cyclin D1, p27 (Kip1) and Ki-67 are independent prognostic factors that might help in predicting outcome of cervical cancer patients.     

The presence of persistent high-risk hpv genotypes in dysplastic cervical lesions is associated with progressive disease: Natural history up to 36 months

To evaluate the clinical significance of HPV genotyping for the prediction of progressive cervical intraepithelial neoplasia (CIN) in women with cytomorphologically abnormal smears, a prospective, blind, non-intervention study was performed. A total of 342 patients screened with cytomorphologically abnormal cervical smears were monitored every 3–4 months by cervical cytology, colposcopy and HPV testing using PCR. Women with progressive CIN disease were defined as patients developing lesions with a colposcopic impression of CIN III over more than 2 quadrants or resulting in a cytological smear equivalent to Pap 5. These patients were subsequently treated according to standard procedures. If any doubt arose about the true status of the patients (n = 75) these patients were censored and biop-sied. The mean follow-up time was 16.5 months (range 3–36 months). Nineteen women showed progressive CIN disease and all appeared to be continuously HPV-positive from the start of the study. At biopsy, all these patients were histologically classified as CIN III. Seventeen of these women were positive for high-risk HPV types. Two cases were classified as still unidentified HPV. No progression was seen in the absence of HPV DNA or in the presence of low-risk HPV types. In life-table analysis the cumulative rate of progressive, histologically verified CIN disease was 17% after 36 months. Further analyses showed that other risk factors such as age, sexarche, number of sexual partners or smoking hardly influenced the effect of HPV on progression. The results show that the continuous presence of high-risk HPV types in women with cytomorphologically abnormal smears is a strong marker for progressive CIN disease. © 1995 Wiley Liss. Inc.     

p16INK4a Immunoprofiles of Squamous Lesions of the Uterine Cervix–Implications for the Reclassification of Atypical Immature Squamous Metaplasia

p16^INK4a immunoprofiles of non-precancerous and dysplastic squamous cervical lesions were defined and applied to the reclassification of atypical immature squamous metaplasia (AIM). The immunoexpression of cytokeratin 17 (CK 17) in AIM was also evaluated. Totally, 295 cervical cone biopsies representing squamous metaplasia, reactive changes, koilocytosis, flat condyloma, CIN I, CIN II, CIN III and AIM were subjected to p16^INK4a immunohistochemistry. AIM cases were analyzed using CK 17 antibody. Typical p16^INK4a immunoprofiles for the metaplastic, LSIL/HPV and HSIL phenotypes were recorded and used for the categorization of AIM into particular phenotype groups. Results were correlated with CK 17 immunoexpression. All CIN II and CIN III lesions, all but one case of CIN I and all flat condylomas overexpressed p16^INK4a. Other non-precancerous lesions, including koilocytosis, were predominantly negative. Contrary to the sporadic and focal immunostaining, diffuse positivity was associated with the dysplastic features of the lesion. CIN II and CIN III were characterized by a diffuse, strong/weak, full-thickness staining, whereas CIN I showed a heterogeneous diffuse/focal, weak/strong, lower half positivity. One third of AIM lesions may be reclassified as HSIL, one third as LSIL/HPV and one third shows metaplastic phenotype. All AIM cases with metaplastic and LSIL/HPV phenotypes expressed CK 17 diffusely, whereas focal positivity slightly prevailed in AIM with HSIL phenotype. We conclude that p16^INK4a immunohistochemistry is a supporting method for the differential diagnosis of cervical lesions, which may be especially useful for the reclassification of AIM. The efficacy of CK 17 immunohistochemistry seems to be controversial for these purposes.     

Combined human papillomavirus DNA and human papillomavirus-like particle serologic assay to identify women at risk for high-grade cervical intraepithelial neoplasia

The objective of this study was to assess the utility of a second generation human papillomavirus (HPV) virus-like particle (VLP)-based ELISA as an adjunct to HPV DNA testing to identify women at risk for high-grade cervical intraepithelial neoplasia (CIN). Participants provided blood, cervical samples and interviewer-obtained questionnaire information. HPV VLPs for types 16, 18, 33, 45 and 52 were produced using a baculovirus expression system. These highly purified VLPs were used in a polymer-based ELISA test. Cases with biopsy-confirmed CIN (CIN I, n = 237; CIN II, n = 56; CIN III, n = 48) and controls (n = 351) with normal Pap smears were tested for HPV DNA by PCR and serologic response to multiple oncogenic HPV VLPs. 258/341 (76%) of cases and 230/351 (65.5%) of control patients had any type of HPV VLP antibody (OR = 1.63, 95% CI 1.16-2.30). More cases were seropositive than controls for each individual HPV type (p < 0.001 for HPV types 16, 18, 33 and 45; p = 0.06 for HPV 52). Reactivity to an increasing number of different HPV type-specific VLPs are associated with high-grade CIN independent of HPV DNA status. HPV VLP assays may be useful as an adjunct to HPV DNA testing in a subset of patients that needs to be defined by further studies.     

Validation of p16INK4a as a marker of oncogenic human papillomavirus infection in cervical biopsies from a population-based cohort in Costa Rica.

Due to the high prevalence of cancer-associated types of human papillomavirus (HPV) and the poorly reproducible histologic classification of low-grade lesions, identifying infected women at highest risk for cancer prior to neoplastic progression remains a challenge. We therefore explored the utility of p16INK4a immunostaining as a potential diagnostic and prognostic biomarker for cervical neoplasia using paraffin-embedded tissue blocks (punch biopsies and loop electrosurgical excision procedures) obtained from women referred to colposcopy during the enrollment phase of the Guanacaste Project (1993 to 1994). All blocks from 292 women selected by HPV status (HPV negative, nononcogenic HPV positive, or oncogenic HPV positive) and representing the diagnostic spectrum of the population [normal to precancer: cervical intraepithelial neoplasia (CIN) 3] were immunostained for p16INK4a using the p16INK4a research kit based on the monoclonal antibody clone E6H4 (MTM Laboratories, Heidelberg, Germany). For CIN3, the sensitivity of diffuse p16INK4a immunostaining was 100% and the specificity was 95%. For CIN2, the sensitivity and specificity for diffuse staining were 81.1% and 95.4%, respectively. Generalized to the 10,000-woman cohort, this translated to positive predictive value and negative predictive value of 13.9% and 100% for CIN3, respectively, and 20.4% and 99.7% for CIN2 or CIN3, respectively. Of women with an initial diagnosis of less than CIN2 for whom follow-up data for up to 5 to 7 years were available, 44% with diffuse staining developed persistent infection (CIN2 or CIN3). Whereas our data support the diagnostic potential for p16INK4a, further prospective studies with detailed follow-up determining the prognostic capacity of this marker are needed.     

Combined p16INK4a and human papillomavirus testing improves the prediction of cervical intraepithelial neoplasia (CIN II-III) in Thai patients with low-grade cytological abnormalities

Thailand is in the process of developing a national cervical screening program. This study examined p16INK4a staining and HPV prevalence in abnormal cervical samples with atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LSIL), to evaluate the efficacy of combined HPV and p16INK4a detection to predict CIN II-III. Totals of 125 ASCUS and 87 LSIL cases were re-evaluated by Pap test and cervical cells of ASCUS and LSIL cases were prepared on slides for p16INK4a detection by immunocytochemistry. HPV genotyping of DNA extracts was performed by GP5+/6+ PCR and reverse line blot hybridization. Histopathologic tests were performed to identify cervical lesion. Total of 212 cases were diagnosed to normal (20), ASCUS (112), LSIL (78) and HSIL (2). HPV was detected in ASCUS (49/112, 43.8%), LSIL (60/78, 76.9%) and HSIL (2/2, 100%) cases. The majority of HPV positive samples typed for high-risk HPV. 55.7% (107/192) of abnormal cases (ASCUS, LSIL and HSIL) were positive p16INK4a. For the 111 HPV DNA positive cases, 34 of 49 (69.4%) ASCUS cases and 49 of 60 (81.7%) LSIL cases were p16INK4a positive. 140 biopsies were taken and histological classified: CIN negative (65 cases), CIN I (56 cases) and CIN II-III (19 cases). HPV DNA detection predicted CIN II-III with sensitivity and specificity of 84% and 49%, whereas p16INK4a staining showed higher sensitivity (89.5%) and specificity (56.2%). The prediction of CIN II-III was significantly better by combination of positive HPV DNA and p16INK4a with 93.8% sensitivity and 59.2% specificity. Detection of HPV DNA combined with p16INK4a in cervical cells can predict CIN II-III and may improve the screening diagnosis of Thai women at risk for CIN II-III or cancer.     

Nitrative and oxidative DNA damage in cervical intraepithelial neoplasia associated with human papilloma virus infection

Recently, it was proposed that inflammation plays an integral role in the development of human papilloma virus (HPV)-induced cervical cancer. The present study sought to examine if 8-nitroguanine, a mutagenic nitrative DNA lesion formed during inflammation, contributes to cervical carcinogenesis. We obtained biopsy specimens from 30 patients with cervical intraepithelial neoplasia (CIN)1 (n = 9), CIN2 (n = 10), CIN3 (n = 6) and condyloma acuminatum (n = 5). We used immunohistochemistry to detect the formation of 8-nitroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), an oxidative DNA lesion, and compared it with the expression of the cyclin-dependent kinase inhibitor p16, which is considered to be a biomarker for cervical neoplasia. Double immunofluorescence labeling revealed that 8-nitroguanine and 8-oxodG were colocalized in cervical epithelial cells. Samples from CIN2-3 patients, most of whom were infected with high-risk HPV subtypes, exhibited significantly more intense staining for 8-nitroguanine than those with condyloma acuminatum. 8-Nitroguanine and 8-oxodG immunoreactivities correlated significantly with the CIN grade. We observed the expression of inducible nitric oxide synthase in epithelial and inflammatory cells from CIN lesions. Proliferating cell nuclear antigen was expressed specifically in dysplastic epithelial cells, but not in those of condyloma acuminatum. There were no statistically significant differences in p16 expression between CIN and condyloma acuminatum samples. These results suggest that high-risk HPV types promote inducible nitric oxide synthase-dependent DNA damage, which leads to dysplastic changes and carcinogenesis; in contrast, p16 appears to be merely a marker of HPV infection. Thus, 8-nitroguanine is a more suitable and promising biomarker for evaluating the risk of inflammation-mediated cervical carcinogenesis than p16.     

New markers for cervical dysplasia to visualise the genomic chaos created by aberrant oncogenic papillomavirus infections

Extensive research over the past 20 years provided strong evidence that persistent infections with high risk type human papillomaviruses (HR-HPVs) cause cervical cancer. However, depending on their age, more than 20% of normal women are infected with these viruses and only very few develop clinically relevant dysplastic lesions or even cancer. During an acute HPV infection, expression of viral genes, in particular the viral E6 and E7 oncogenes is restricted to differentiated epithelial cells, which lost the capability to replicate their genomes and are therefore at no further risk for acquiring functionally relevant mutations upon genotoxic damage. High grade cervical dysplasia, however, is initiated by deregulated expression of viral oncogenes in replicating epithelial stem cells. Here, the E6-E7 gene products submerge control of the cell cycle and mitotic spindle pole formation through complex interactions with various cellular protein complexes and induce severe chromosomal instability. The detailed molecular analysis of these interactions allowed to define new biomarkers for dysplastic cervical cells. E7 for example induces increasing expression of the cyclin dependent kinase inhibitor p16(ink4a) in dysplastic cells. This can be used to identify dysplastic cells in histological slides, cytological smears or samples taken for biochemical analyses with an yet unmet fidelity. Detection of specific viral mRNAs derived from integrated HPV genomes in advanced precancers can be used to identify lesions with a particularly high risk for progression into invasive carcinomas (APOT assay). These new markers will result in a modified classification of cervical precancers and improved screening assays. Here, we review the basic concept and potential clinical applications of these new developments.     

高危型HPV负荷量和p16INK4A蛋白监测评估宫颈锥切术治疗CIN

[目的]评价高危型人乳头状瘤病毒HPV负荷量的检测和p16INK4A蛋白的表达在预测宫颈上皮内瘤变(CIN)宫颈锥切术后残存病变或复发中的意义.[方法]回顾性分析142例2008年10月至2010年12月因CIN行宫颈锥形切除术治疗患者的临床资料.所有患者均于宫颈锥形切除术前6个月以内和术后6～12个月进行HPV负荷量检测,并采用免疫组化方法检测HPV DNA阳性患者宫颈细胞中p16INK4A蛋白表达.[结果]宫颈锥切术前,随着CIN级别的上升,HPV负荷量以及p16INK4A蛋白表达均明显增强(P＜0.05).但在宫颈锥切术后,HPV负荷量和p16INK4A蛋白表达明显降低,宫颈锥切术前和术后两者之间差异有统计学意义(P＜0.05).[结论] HPV负荷量持续增高和p16INK4A蛋白持续呈强阳性是宫颈锥切术后发生残存病变或复发的高危因素,在监测HPV负荷量的同时检测p16INK4A蛋白的表达,对判断宫颈锥切术后发生残存病变或复发有重要意义.     

Identification of high-grade cervical dysplasia by the detection of p16INK4a in cell lysates obtained from cervical samples

BACKGROUND: Current cervical cancer screening approaches are based on cytology supplemented by human papillomavirus (HPV) testing in some settings. Whereas cytology is laborious and depends on the cytologists' experience, HPV testing has limited specificity when it is used to detect high-grade lesions. A dichotomous test to identify high-grade lesions with greater specificity may be a useful tool for cervical cancer screening. p16(INK4a) is a cell-cycle regulator that has demonstrated strong overexpression in cervical precancer cells and cervical cancer induced by the deregulated expression of HPV oncogenes. METHODS: The authors used a sandwich enzyme-linked immunosorbent assay (ELISA) to quantify the amount of solubilized p16(INK4a) protein in lysates that were prepared from cervical samples to detect high-grade cervical lesions. In total, 187 specimens that were obtained after sampling for conventional cytology in women who attended a cervical colposcopy clinic were analyzed. Seventy-six women underwent a biopsy, and 45 of those women showed histologically confirmed, high-grade cervical intraepithelial neoplasia. RESULTS: For 76 women with biopsy-proven diagnoses, receiver operating characteristic (ROC) analysis of different cutoff values showed an area under the ROC curve of 0.89 for the detection of high-grade cervical dysplasia. At a cutoff value of 8 U/mL, the sensitivity of the p16(INK4a) ELISA for detecting high-grade dysplastic cervical lesions was 96%. CONCLUSIONS: The data obtained in this study suggested that ELISA-based quantification of solubilized p16(INK4a) protein may have high sensitivity for detecting cervical precancer. Further population-based studies will be necessary to analyze the specificity and predictive values of p16(INK4a) protein quantification in cervical samples.     

Expression of p16(INK4a) in relation to histopathology and viral load of 'high-risk' HPV types in cervical neoplastic lesions

A total of 91 cervical archival biopsy series were analysed for the presence and viral load of 'high-risk' types of human papillomavirus (HR-HPV), and p16(INK4a) expression. The women had various degrees of CIN (cervical intraepithelial neoplasia). HPV 16 was the most prevalent type found, at 47% frequency. The frequency of HPV 16 increased with increasing immunoreactivity to p16(INK4a), from 39% to 44% at cases scored low to medium, to 65% at high reactivity. Thirty (33%) of the samples had negative p16(INK4a) analysis results, but were positive for HR-HPV. There was no significant correlation between viral load and the level of p16(INK4a) expression, while the grade of CIN correlated to such expressions. Thus, p16(INK4a) expression analysis yielded information which is consistent with results from the histopathology and might complement the HPV analysis in a clinical prognostic procedure in order to find women at risk for cervical cancer.     

The Association of Molecular Biomarkers in the Diagnosis of Cervical Pre-Cancer and Cancer and Risk Factors in Senegalese

Background: Cervical intraepithelial neoplasia (CIN) grading is subjective and affected by substantial rates of discordance among pathologists. Although recent studies have suggested that p16INK4a may be a useful surrogate biomarker of cervical neoplasia, Ki-67 and human papillomavirus testing have also been shown to be useful in detecting neoplasia. The purpose of this study was to determine the expression of p16INK4a and Ki-67 in cervical neoplasia and its correlations with cofactors. Methods: The study involved 69 patients with and without cervical neoplasia who underwent colposcopic directed biopsy. On each patient, two samples were taken; the first was used for immunohistochemistry and the second for molecular testing, using HPV16and18 genotyping Real-Time PCR Kit. Results: The study revealed the expression level of p16INK4a and Ki-67 in a descending order, from invasive squamous cell carcinoma (SCC), CIN2/3, CIN1 and non-dysplastic lesions. Correlations showed an association between the staining of p16NK4a and Ki-67 with the increase of age (OR: 1.79 (95%IC: 0.49 – 6.55), p = 0.037) and marital status (OR: 0.17 (95%IC: 0.04 – 0.68), p = 0.003). We found that the expressions of p16INK4a and Ki-67 were significantly different between invasive SCC vs non-dysplasia (OR: 44.57 (95%IC: 4.91 – 403.91), p <0.0001). The study showed significant correlation between HPV 16and18 infection with p16 INK4a and Ki-67 expression (OR: 0.13 (95%IC: 0.03 – 0.52), p <0.0001). Strong expression of p16INK4a and Ki-67 were observed in invasive squamous cell carcinoma, moderate staining was found in CIN2/3, weak staining in CIN1 and normal histology. Conclusion: Our findings indicate that p16INK4a and Ki-67 expressions associated strongly with cervical pathology. Therefore, p16/Ki-67 could be considered as a suitable biomarker for cervical cancer screening, particularly in HPV-based screening programs.     

Evaluation of a new p16(INK4A) ELISA test and a high-risk HPV DNA test for cervical cancer screening: results from proof-of-concept study

p16(INK4a), a cell cycle regulation protein, accumulates in abnormal epithelial cells infected with high-risk human papilloma virus (HPV). In immunostaining studies, p16(INK4a) has shown potential as a marker of high grade cervical intraepithelial neoplasia (CIN) and invasive cervical cancer. To evaluate its potential use in cervical cancer screening, we conducted a feasibility study to compare the performance of a new enzyme linked immunosorbant assay (ELISA) for p16(INK4a) (mtm laboratories, Heidelberg, Germany) to that of the Hybrid Capture 2 (hc2) test for high-risk HPV DNA for the detection of CIN3. Three hundred and nineteen women were referred from Western Washington Planned Parenthood clinics for colposcopy examination and cervical biopsy because of abnormal Pap test results. Cervical samples were obtained from study participants for p16(INK4a) ELISA, liquid-based cytology and hc2. The order (first and second) for obtaining samples for cervical cytology and p16(INK4a) ELISA changed with every other subject. Concentrations of p16(INK4a) protein were higher when the sample was taken before the cytology. The sensitivity of p16(INK4a) ELISA (concentration > or = 8 units/ml) taken as first sample was 90.0% for CIN3, and the sensitivity of HC2 taken as a second sample was 85%. In the same group, the specificity of p16(INK4a) ELISA (46.9%) was slightly better than hc2 (35.4%) Results from this proof-of-concept study suggest that p16(INK4a) ELISA has a similar sensitivity and slightly better specificity for CIN3 compared to hc2. These findings support proceeding with a larger study with samples from a population of women presenting for routine cytology screening.     

Evaluation of cervical cone biopsies for coexpression of p16INK4a and Ki-67 in epithelial cells

Diffuse overexpression of p16(INK4a) in basal and parabasal cells of cervical epithelium is a hallmark of human papillomavirus-mediated transformation. Focal p16(INK4a) expression is occasionally observed in nondysplastic epithelium. In normal cells, expression of p16(INK4a) triggers cell cycle arrest. However, cells undergoing transformation in intraepithelial lesions actively proliferate. To prove that the different expression patterns of p16(INK4a) , i.e., focal versus diffuse, reflect biologically different entities, we hypothesized that p16(INK4a) -positive cells in epithelia displaying focal p16(INK4a) expression pattern do not coexpress proliferation-associated Ki-67 protein, while p16(INK4a) -positive cells in lesions with diffuse p16(INK4a) expression may do. A total of 138 cervical cone biopsies were stained for the expression of p16(INK4a) and Ki-67 using a primary antibody cocktail. All metaplastic lesions (n = 21) displayed focal staining for p16(INK4a) , and in all of these lesions p16(INK4a) -positive cells were found to be negative for Ki-67 expression. Diffuse expression of p16(INK4a) was observed in 12/21 (57.1%) cervical intraepithelial neoplasia (CIN) 1 lesions, all of them simultaneously showed Ki-67 immunoreactivity in a large proportion of p16(INK4a) -positive cells. Seventeen of 23 (73.9%) CIN2 lesions and all 27 (100%) CIN3/carcinoma in situ (CIS) as well as all 46 (100%) carcinoma cases displayed diffuse and combined expression of p16(INK4a) and Ki-67. Coexpression of Ki-67 and p16(INK4a) in the same cell is entirely restricted to cervical lesions displaying diffuse p16(INK4a) expression, whereas in lesions with focal p16(INK4a) expression, p16(INK4a) -expressing cells are negative for Ki-67. Thus, diffuse expression of p16(INK4a) reflects lesions with proliferation-competent cells, while p16(INK4a) -expressing cells associated with focal expression patterns are cell cycle arrested.     

Comparison of p16INK4a Immunocytochemistry with the HPV Polymerase Chain Reaction in Predicting High Grade Cervical Squamous Intraepithelial Lesions

Aim: To compare p16INK4a immunocytochemistry with the HPV polymerase chain reaction in predictinghigh grade cervical squamous intraepithelial lesions. Materials and Methods: This diagnostic case-control studywas conducted from January 2010 until December 2010. We obtained 30 samples, classified according to thedegree of cervical intraepithelial neoplasia (CIN): 11 samples for CIN 1, 9 samples for CIN 2, and 10 samples forCIN 3. HPV PCR, p16INK4a immunocytochemistry, and histopathological examination were performed on allsamples. Statistical analysis was conducted using SPSS 20.0. Results: In predicting CIN 2-3, we found p16INK4ato have similar specificity and positive predictive value as HPV PCR (95%, 97.2% vs 96.7%), but better sensitivity(87.5% vs 72.5%) and negative predictive value (82.1% vs 67.6%). The most prevalent types of high-risk HPVin our study were HPV 33, 35, 58, 52, and 16. Conclusions: p16INK4a has better diagnostic values than HPVPCR and may be incorporated in the triage of ASCUS and LSIL to replace HPV PCR. Genotype distribution ofHPV differs in each region, providing a challenge to develop HPV vaccines based on the epidemiology of HPVin that particular region.     

Nonisotopic human papillomavirus DNA typing of cervical smears obtained at the initial colposcopic examination

To determine the prevalence of human papillomavirus (HPV) infection in 401 patients attending colposcopy for the first time, scraped cervical cells were investigated using dot blot hybridization and biotinylated DNA probes to HPV 6 and 11 (low-risk types) and 16, 18, and 33 (high-risk types). The HPV DNA was isolated from 52% of patients (low-risk types = 4%, high-risk types = 48%). Seventy-five percent had a cervical intraepithelial neoplasia (CIN)-condyloma. Low-risk types were infrequent (7%) and high-risk types (41%) predominant in condyloma/CIN I lesions when converse rates were expected. As CIN I lesions harboring high-risk types are at some risk of progressing to a higher grade dysplasia, colposcopic examination and treatment of this subgroup would seem justified. As expected, high-risk types were statistically associated with increasing grades of dysplasia. This hybridization method identified typeable HPV DNA in 60% of patients with a CIN-condyloma, and highlighted a unique HPV profile for this patient cohort.