Prognostic significance of the detection of human papilloma virus L1 protein in smears of mild to moderate cervical intraepithelial lesions

Use of Cap Analysis Gene Expression to detect human papillomavirus promoter activity patterns at different disease stages

Transcription of human papillomavirus (HPV) genes proceeds unidirectionally from multiple promoters. Direct profiling of transcription start sites (TSSs) by Cap Analysis Gene Expression (CAGE) is a powerful strategy for examining individual HPV promoter activity. The objective of this study was to evaluate alterations of viral promoter activity during infection using CAGE technology. We used CAGE-based sequencing of 46 primary cervical samples, and quantitatively evaluated TSS patterns in the HPV transcriptome at a single-nucleotide resolution. TSS patterns were classified into two types: early promoter-dominant type (Type A) and late promoter-dominant type (Type B). The Type B pattern was more frequently found in CIN1 and CIN2 lesions than in CIN3 and cancer samples. We detected transcriptomes from multiple HPV types in five samples. Interestingly, in each sample, the TSS patterns of both HPV types were the same. The viral gene expression pattern was determined by the differentiation status of the epithelial cells, regardless of HPV type. We performed unbiased analyses of TSSs across the HPV genome in clinical samples. Visualising TSS pattern dynamics, including TSS shifts, provides new insights into how HPV infection status relates to disease state.

Utility of human papillomavirus L1 capsid protein and HPV test as prognostic markers for cervical intraepithelial neoplasia 2+ in women with persistent ASCUS /LSIL cervical cytology

Objective: Efficient and highly predictive biomarkers reflecting the prognosis of persistent atypical squamous cells of unknown significance(ASCUS) and low grade squamous intraepithelial lesion(LSIL)s are unavailable and need to be developed urgently. We aimed to develop a predictive model for diagnosis of cervical intraepithelial neoplasia(CIN)2+ by analyzing the immunocytochemical expression of the HPV L1 capsid protein in patients with persistent ASCUS and LSIL with a high risk of HPV infection. Methods: Cervical cytology samples comprising (70 ASCUS and 215 LSIL Pap smears) were analyzed. Immunocytochemical identification of the HPV L1 capsid protein in cervical cytology samples was performed. Expression levels of HPV L1 capsid protein in cervical cytology samples were measured, and the correlation between HPV L1 expression and cervical pathologic diagnosis was evaluated. The risk for CIN2+ was calculated using the results of immunocytochemistry and the HPV DNA test. Results: Negative results for HPV L1 immunochemistry test were more frequently observed in CIN2+, and expression of the HPV L1 capsid protein was higher in CIN1 or cervicitis (Fisher's exact test, p<0.05). Diagnosis rates for CIN2+ were highest for the combination of HPV L1 capsid protein immunocytochemistry, cytology and HPV test when compared with other combinations (Akaike information criterion (AIC): 191.7, Schwarz criterion(SC): 206.3, p<0.001). Conclusion: Absence of HPV L1 capsid expression and presence of HPV type 16 or 18 infection are reliable predictors of progression to CIN2+ in patients showing persistent ASCUS and LSIL.

Immunohistochemistry and Polymerase Chain Reaction for Detection Human Papilloma Virus in Warts: A Comparative Study

Background

Immunohistochemistry and polymerase chain reaction (PCR) are the most widely used methods for the detection of viruses. PCR is known to be a more sensitive and specific method than the immunohistochemical method at this time, but PCR has the disadvantages of high cost and skilled work to use widely. With the progress of technology, the immunohistochemical methods used in these days has come to be highly sensitive and actively used in the diagnostic fields.

Objective

To evaluate and compare the usefulness of immunohistochemistry and PCR for detection human papilloma virus (HPV) in wart lesions.

Methods

Nine biopsy samples of verruca vulgaris and 10 of condyloma accuminatum were examined. Immunohistochemical staining using monoclonal antibody to HPV L1 capsid protein and PCR were done for the samples. DNA sequencing of the PCR products and HPV genotyping were also done.

Results

HPV detection rate was 78.9% (88.9% in verruca vulgaris, 70.0% in condyloma accuminatum) on immunohistochemistry and 100.0% for PCR. HPV-6 genotype showed a lower positivity rate on immunohistochemistry (50.0%) as compared to that of the other HPV genotypes.

Conclusion

Immunohistochemistry for HPV L1 capsid protein showed comparable sensitivity for detection HPV. Considering the high cost and great effort needed for the PCR methods, we can use immunohistochemistry for HPV L1 capsid protein with the advantage of lower cost and simple methods for HPV detection.

Natural history of high-grade cervical intraepithelial neoplasia: a review of prognostic biomarkers

The natural history of high-grade cervical intraepithelial neoplasia (CIN) is largely unpredictable and current histopathological examination is unable to differentiate between lesions that will regress and those that will not. Therefore, most high-grade lesions are currently treated by surgical excision, leading to overtreatment and unnecessary complications. Prognostic biomarkers may differentiate between lesions that will regress and those that will not, making individualized treatment of high-grade CIN possible. This review identifies several promising prognostic biomarkers. These biomarkers include viral genotype and viral DNA methylation (viral factors), human leukocyte antigen-subtypes, markers of lymphoproliferative response, telomerase amplification and human papillomavirus-induced epigenetic effects (host factors) and Ki-67, p53 and pRb (cellular factors). All identified biomarkers were evaluated according to their role in the natural history of high-grade CIN and according to established criteria for evaluation of biomarkers (prospective-specimen-collection, retrospective-blinded-evaluation [PROBE] criteria). None of the biomarkers meets the PROBE criteria for clinical applicability and more research on prognostic biomarkers in high-grade CIN is necessary.

Immunohistochemical expression of p16 and HPV L1 capsid proteins as predictive markers in cervical lesions

PURPOSE

Human papilloma virus (HPV) infection is the most important cause of cervical cancer, but only 2 % of cervical HPV infections will develop into cervical cancer. p16 INK4A has been introduced as a marker for HPV infection in cervix. HPV L1 capsid protein is also known to be associated with the productive phase of HPV infection; however, expression pattern in different HPV-associated cervical lesion and its correlation to p16 expression is not still well understood. The authors aimed to elucidate the relationship between L1 and p16 expression in cervical lesions.

METHODS

Immunohistochemical studies using antibodies against L1 capsid and P16 proteins were carried out on 89 paraffin-embedded tissue samples including 11 low-grade cervical intraepithelial neoplasias (CIN), 11 high-grade CINs, 20 cervical squamous cell carcinomas (SCC), eight cervical adenocarcinomas and 39 normal cervical tissues as a control group.

RESULTS

L1 capsid protein was positive in 63.6 % of low-grade CINs and 9.1 % of high-grade CINs; while none of the cervical SCCs, adenocarcinomas or normal cervical tissues showed this marker. In contrast, p16 protein was positive in 81.8 % of low-grade CINs, 90.1 % of high-grade CINs, 90 % of SCCs, 75 % of adenocarcinomas and 10.25 % of normal cervical tissues (p value < 0.001).

CONCLUSION

Despite the presence of interobserver variation in the histopathologic interpretation of cervical lesions, in more instances definite diagnosis is made by routine histopathological examination and these ancillary tests are supportive in follow-up of the patient.

Viral and cellular biomarkers in the diagnosis of cervical intraepithelial neoplasia and cancer

Cervical cancer arises from cells localized in the ectoendocervical squamocolumnar junction of the cervix persistently infected with one of about 13 human papillomavirus (HPV) genotypes. The majority of HPV infections induces low grade squamous epithelial lesions that in more than 90% of cases spontaneously regress and in about 10% eventually progress to high grade lesions and even less frequently evolve to invasive cancer. Tumor progression is characterized by (1) increased expression of E6 and E7 genes of high risk HPVs, known to bind to and inactivate p53 and pRb oncosuppressors, respectively; (2) integration of viral DNA into host genome, with disruption of E2 viral genes and host chromosomal loci; and (3) molecular alterations of key regulators of cell cycle. Molecular markers with high sensitivity and specificity in differentiating viral infections associated with cellular abnormalities with high risk of progression are strongly needed for cervical cancer screening and triage. This review will focus on the analysis of clinical validated or candidate biomarkers, such as HPV DNA, HPV E6/E7 mRNA, HPV proteins, p16(INK4a) and Ki67, TOP2A and MCM2 cellular factors, and DNA methylation profiles, which will likely improve the identification of premalignant lesions that have a high risk to evolve into invasive cervical cancer.

HPV L1 detection discriminates cervical precancer from transient HPV infection: a prospective international multicenter study

The benefits of cytology-based cervical cancer screening programs in reducing morbidity and mortality are well recognized. Especially, overtreatment of human papillomavirus (HPV) high-risk positive early dysplastic lesions may have a negative impact on reproductive outcomes for fertile women. To optimize the clinical management an objective standard is needed to distinguish precancer that requires treatment, from spontaneously resolving HPV infections. In the current study, we examined the prognostic relevance of HPV-L1 capsid protein analysis with Cytoactiv in an international prospective multicenter study including 908 HPV high-risk positive early dysplastic lesions (LSIL/HSIL) during a follow-up period of 54 months. The clinical end points of the study were histologically confirmed CIN3+ as progression, CIN1/2 for stable disease and repeated negative Pap smears as spontaneous clinical remission. The difference of the clinical outcome of HPV-L1-negative and HPV-L1-positive cases was statistically highly significant (P-value<0.0001) independent of the classification as mild dysplasia (LSIL) and moderate dysplasia (HSIL). Of the HPV-L1-negative HPV high-risk positive mild/moderate dysplasias 84% progressed to CIN3, as compared with only 20% of the HPV-L1-positive cases. The data from our study show that HPV-L1 detection allows to identify transient HPV infections and precancerous lesions within the group of HPV high-risk positive early dysplastic lesions. The high progression rate of HPV-L1-negative mild and moderate dysplasia emphasizes the precancerous nature of these lesions. A close follow-up with colposcopy and histological evaluation is advisable and removal of these lesions should be considered. The low malignant potential of HPV-L1-positive cases, however, indicates transient HPV infection, justifying a watch and wait strategy with cytological follow-up, thus preventing overtreatment especially for women in their reproductive age.

Human papillomavirus testing versus repeat cytology for triage of minor cytological cervical lesions

BACKGROUND

Atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intra-epithelial lesions (LSIL) are minor lesions of the cervical epithelium, detectable by cytological examination of cells collected from the surface of the cervix of a woman.Usually, women with ASCUS and LSIL do not have cervical (pre-) cancer, however a substantial proportion of them do have underlying high-grade cervical intra-epithelial neoplasia (CIN, grade 2 or 3) and so are at increased risk for developing cervical cancer. Therefore, accurate triage of women with ASCUS or LSIL is required to identify those who need further management.This review evaluates two ways to triage women with ASCUS or LSIL: repeating the cytological test, and DNA testing for high-risk types of the human papillomavirus (hrHPV) - the main causal factor of cervical cancer.

OBJECTIVES

Main objective To compare the accuracy of hrHPV testing with the Hybrid Capture 2 (HC2) assay against that of repeat cytology for detection of underlying cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) or grade 3 or worse (CIN3+) in women with ASCUS or LSIL. For the HC2 assay, a positive result was defined as proposed by the manufacturer. For repeat cytology, different cut-offs were used to define positivity: Atypical squamous cells of undetermined significance or worse (ASCUS+), low-grade squamous intra-epithelial lesions or worse (LSIL+) or high-grade squamous intra-epithelial lesions or worse (HSIL+).Secondary objective To assess the accuracy of the HC2 assay to detect CIN2+ or CIN3+ in women with ASCUS or LSIL in a larger group of reports of studies that applied hrHPV testing and the reference standard (coloscopy and biopsy), irrespective whether or not repeat cytology was done.

SEARCH METHODS

We made a comprehensive literature search that included the Cochrane Register of Diagnostic Test Accuracy Studies; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (through PubMed), and EMBASE (last search 6 January 2011). Selected journals likely to contain relevant papers were handsearched from 1992 to 2010 (December). We also searched CERVIX, the bibliographic database of the Unit of Cancer Epidemiology at the Scientific Institute of Public Health (Brussels, Belgium) which contains more than 20,000 references on cervical cancer.More recent searches, up to December 2012, targeted reports on the accuracy of triage of ASCUS or LSIL with other HPV DNA assays, or HPV RNA assays and other molecular markers. These searches will be used for new Cochrane reviews as well as for updates of the current review.

SELECTION CRITERIA

Studies eligible for inclusion in the review had to include: women presenting with a cervical cytology result of ASCUS or LSIL, who had undergone both HC2 testing and repeat cytology, or HC2 testing alone, and were subsequently subjected to reference standard verification with colposcopy and colposcopy-directed biopsies for histologic verification.

DATA COLLECTION AND ANALYSIS

The review authors independently extracted data from the selected studies, and obtained additional data from report authors.Two groups of meta-analyses were performed: group I concerned triage of women with ASCUS, group II concerned women with LSIL. The bivariate model (METADAS-macro in SAS) was used to assess the absolute accuracy of the triage tests in both groups as well as the differences in accuracy between the triage tests.

MAIN RESULTS

The pooled sensitivity of HC2 was significantly higher than that of repeat cytology at cut-off ASCUS+ to detect CIN2+ in both triage of ASCUS and LSIL (relative sensitivity of 1.27 (95% CI 1.16 to 1.39; P value < 0.0001) and 1.23 (95% CI 1.06 to 1.4; P value 0.007), respectively. In ASCUS triage, the pooled specificity of the triage methods did not differ significantly from each other (relative specificity: 0.99 (95% CI 0.97 to 1.03; P value 0.98)). However, the specificity of HC2 was substantially, and significantly, lower than that of repeat cytology in the triage of LSIL (relative specificity: 0.66 (95% CI 0.58 to 0.75) P value < 0.0001).

AUTHORS' CONCLUSIONS

HPV-triage with HC2 can be recommended to triage women with ASCUS because it has higher accuracy (significantly higher sensitivity, and similar specificity) than repeat cytology. When triaging women with LSIL, an HC2 test yields a significantly higher sensitivity, but a significantly lower specificity, compared to a repeat cytology. Therefore, practice recommendations for management of women with LSIL should be balanced, taking local circumstances into account.

HPV-based Tests for Cervical Cancer Screening and Management of Cervical Disease

Current cervical cancer screening programs are changing due to the development of tests that detect the presence of human papillomavirus (HPV), the cause of cervical cancer. These tests are more sensitive than cytology-based methods for detecting cervical precancer and a negative test offers long-term assurance that cervical cancer will not develop and therefore longer screening intervals can be achieved. In screening programs, HPV-based tests have been approved to triage women with equivocal cytology results and as a primary testing method in conjunction with cytology. HPV-based tests also have a role in determining risk of recurrence after treatment for cervical precancer as well as in surveillance for vaccine-related changes in HPV genotype prevalence.

Immunohistochemical detection of human papillomavirus capsid proteins L1 and L2 in squamous intraepithelial lesions: potential utility in diagnosis and management

While cervical cancer screening relies on cervical cytology and high-risk human papillomavirus (HPV) detection, the histologic diagnosis, and specifically lesion grade, is the main parameter that drives clinical management of screen-positive women. Morphologically diagnosed squamous intraepithelial lesions (SIL/CIN) regress spontaneously in more than half of the cases, but identifying those likely to persist and progress is not currently possible based upon morphology. Lack of major capsid protein L1 expression has been suggested as a feature in progressive lesions, whereas expression of the minor capsid protein L2 has not been extensively evaluated. The goal of this study is to evaluate immunohistochemical expression of L1 and L2 in SILs in correlation with lesion grade. A total of 150 cervical specimens with SILs were selected based on HPV 16 or HPV 18 detection by Q-PCR. These included 89 low-grade SILs (LSIL/CIN 1) and 123 high-grade SILs (75 HSIL/CIN 2 and 48 HSIL/CIN 3). More than one lesion/grade was identified in 53 specimens. The presence and grade of SIL was determined by a panel of pathologists. Capsid protein expression was assessed by immunohistochemistry using MAB 837 for L1 and RG-1 for L2. Lesions of different grades in the same specimen were scored separately. Expression of capsid proteins was detected in 34/89 (40%) LSIL/CIN 1, 5/75 (6%) HSIL/CIN 2 and none of 48 HSIL/CIN 3. L1 and L2 were co-expressed in the same area of the lesion in 22 cases. In addition, L1 alone was expressed in 6 lesions and L2 alone in 11 lesions. Among the cases with multiple lesion grades in the same specimen, none with HSIL/CIN 3 expressed capsid proteins in any portion/grade of the lesion. HPV capsid proteins are expressed almost exclusively in LSIL/CIN 1 and rarely in HSIL/CIN 2. Additional studies are warranted to examine lack of L1 and L2 expression in LSIL/CIN 1 as a predictor of persistence or progression to HSIL/CIN 3, the precursor of cervical cancer.

The diagnostic performance of classical molecular tests used for detecting human papillomavirus

Cervical samples were evaluated for human papillomavirus (HPV) presence using the hybrid capture-2 (HC2) assay and the polymerase chain reaction (PCR) with three different primer sets (GP5+/6+, MY09/11 and pU1M/2R). PCR results were compared to HC2 and results of all assays were compared to cytological and colposcopy findings. Post-test probability was assessed in individual assays and test combinations. HPV-DNA prevalence was 36.5% with HC2 and 55.2% with PCR. MY09/11 detected HPV-DNA in 38% of samples, GP5+/6+ in 19.1% and pU1M/2R in 16.4%. pU1M/2R and HC2 had the highest concordance (75.31%, k=0.39 in the whole population; 74.1%, k=0.5 in women with abnormal cytology). pU1M/2R had the best diagnostic performance, including optimal post-test probabilities and cervical abnormality detection (individually or in a panel of tests). Women positive for pU1M/2R may be at higher risk of disease progression; the assay performance when combined with a Pap smear in cervical cancer screening programs should be evaluated.

Role of protein biomarkers in the detection of high-grade disease in cervical cancer screening programs

Since the Pap test was introduced in the 1940s, there has been an approximately 70% reduction in the incidence of squamous cell cervical cancers in many developed countries by the application of organized and opportunistic screening programs. The efficacy of the Pap test, however, is hampered by high interobserver variability and high false-negative and false-positive rates. The use of biomarkers has demonstrated the ability to overcome these issues, leading to improved positive predictive value of cervical screening results. In addition, the introduction of HPV primary screening programs will necessitate the use of a follow-up test with high specificity to triage the high number of HPV-positive tests. This paper will focus on protein biomarkers currently available for use in cervical cancer screening, which appear to improve the detection of women at greatest risk for developing cervical cancer, including Ki-67, p16^INK4a, BD ProEx C, and Cytoactiv HPV L1.

Correlation between immunocytochemistry of human papilloma virus L1 capsid protein and behavior of low-grade cervical cytology in Korean women

AIM

The aim of this study was to evaluate the behavior of low-grade squamous intraepithelial lesion (LSIL) in Korean women infected with human papillomavirus (HPV) in relation to the immunocytochemical detection of the HPV L1 capsid protein.

MATERIAL AND METHODS

From January 2006 to December 2007, a total of 353 immunocytochemistry tests were performed on specimens from HPV-infected patients with LSIL. Due to exclusions, the study population was reduced to 318. Subjects were monitored at 4-6 month intervals. The regression, persistence, and progression of the cytologic abnormalities of the 318 cases were compared with the results of HPV L1 capsid protein immunocytochemical detection.

RESULTS

Of the 137 patients negative for the HPV L1 capsid protein, 38 (27.7%) showed progression to high-grade lesions, 50 (36.5%) showed persistence, and 49 (35.8%) showed regression to normal cytological features. In contrast, of the remaining 181 patients positive for the HPV L1 capsid protein, 15 (8.3%) showed progression to high-grade lesions, 74 (40.9%) showed persistence, and 92 (50.8%) showed regression. The results of immunocytochemical testing for the HPV L1 capsid protein show a linear association with the progression or regression behavior of low-grade cervical cytology in patients infected with HPV (linear by linear association test, P<0.05).

CONCLUSION

Immunocytochemical detection of HPV L1 was significantly related with the biological patterns of LSIL in Korean women. Hence, immunocytochemistry for the detection of HPV L1 is beneficial in providing further information for LSIL.

HPV L1 capsid protein detection and progression of anal squamous neoplasia

The progression of cervical intraepithelial lesions to invasive cancer is associated with corresponding reductions in human papillomavirus (HPV) L1 capsid antigen (L1) expression. We sought to determine whether a similar loss of L1 occurs during anal carcinogenesis using immunohistochemistry on paraffin-embedded sections as well as INNO-LiPA HPV Genotyping (Innogenetics, Gent, Belgium) technology to determine HPV infection status. We analyzed 31 squamous cell carcinomas (SCCs), 26 SCCs in situ (SCC-IS), and 11 normal anal mucosae from 36 patients. High-risk HPV subtypes were detected in all patients. L1 nuclear staining was identified in 38% of SCC-IS; however, there was no detection in normal anal mucosae, SCC, or recurrent SCC. Of those SCC-IS associated with a concomitant invasive SCC, only 15% demonstrated nuclear L1 expression as compared to 62% of isolated SCC-IS (P = .02). Nuclear expression of L1 is lost in the progression of anal SCC-IS to SCC and may serve as a possible prognostic marker of enhanced malignant potential.

Diagnostic value of p16INK4A, Ki-67, and human papillomavirus L1 capsid protein immunochemical staining on cell blocks from residual liquid-based gynecologic cytology specimens

BACKGROUND

This study was conducted to evaluate the reliability and role of cell block preparations in the diagnosis of neoplastic and preneoplastic lesions of the cervix and to improve the value of cell block preparations in diagnosing and predicting the prognosis of cervical lesions through immunostaining of p16INK4A (p16), Ki-67, and human papillomavirus (HPV) L1 capsid protein (HPV L1).

METHODS

In total, 138 specimens were diagnosed on liquid-based cytology (LBC) and cell block preparations, and 63 specimens were subjected subsequently to tissue follow-up and immunostaining for p16, Ki-67, and HPV L1 on cell block sections.

RESULTS

In 42 specimens that were diagnosed as low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion (HSIL), and squamous cell carcinoma (SCC) on cell blocks, 38 specimens (90.5%) were confirmed by histopathologic reports, and there was slightly better than 81.6% agreement between LBC and tissue follow-up. Immunointensity and cells that were positive for p16 were enhanced according to increased pathologic grade and differed statistically between cervical intraepithelial neoplasia 1 (CIN-1) and CIN-2/CIN-3 as well as SCC. The positive rates of HPV L1 decreased gradually according to the severity of cervical neoplasia, and HPV L1/p16 expression patterns were related to the severity of cervical lesions.

CONCLUSIONS

The cell block preparation technique was complementary to LBC, and the authors concluded that the application of LBC combined with cell block preparations may improve the diagnostic accuracy of cytology. Immunostaining for p16 and Ki-67 on cell block preparations can help to improve the diagnostic accuracy of HSIL and SCC. A combined expression pattern of p16 and HPV L1 may serve as a valuable index for predicting prognosis and follow-up of cervical dysplastic lesions.

HPV vaccine protein L1 predicts disease outcome of high-risk HPV+ early squamous dysplastic lesions

Prediction of the clinical outcome of nonadvanced, early dysplastic lesions is one of the unresolved problems of cervical cancer screening programs. We examined the influence of human papillomavirus (HPV) L1 capsid protein detection in a randomized, prospective study of 187 high-risk HPV+ early dysplastic lesions during 36 to 46 months. The difference in the clinical outcome of the HPV L1- cases and the HPV L1+ cases was highly statistically significant (P < .0001) and independent of the classification of low-grade squamous intraepithelial lesion (mild dysplasia) and high-grade squamous intraepithelial lesion of the moderate dysplastic type. L1+ mild and moderate dysplasias, reflecting productive HPV infection, showed low malignant potential, justifying a wait-and-watch strategy to prevent overtreatment, especially in young women. L1- early dysplastic lesions, as nonproductive infections or precancerous lesions, have a high malignancy potential and close follow-up with colposcopy and histologic evaluation should be advised.