Human papillomavirus update with a particular focus on cervical disease

Sexually Transmitted Infection Risks and Symptoms Heightened Among Female Sex Workers who Started Selling Sex Before the Age of 18 in Five Cities in Cameroon

Many adolescents under 18 years old who sell sex are at elevated risk for sexually transmitted infection (STI) acquisition, which may persist into adulthood. There has been limited study of the burden of the risks and vulnerabilities among women who started selling sex as adolescents across Sub-Saharan Africa. In this study, a Adult female sex workers (FSW) recruited through respondent-driven sampling in five cities in Cameroon from December 2015 to October 2016 completed a questionnaire and human immunodeficiency virus (HIV) and syphilis testing. Multivariable logistic regression analysis controlling for age was used to identify factors associated with reporting selling sex before age 18. Selling sex before age 18 was reported by 11.5% (256/2,220) of FSW. Initiation of selling sex as an adolescent was positively associated with experiencing dysuria (adjusted odds ratio [aOR]:1.50, 95% confidence interval [CI]:1.08-2.10) or genital warts (aOR:1.78, 95% CI:1.08-2.94) and negatively associated with prior recent testing for HIV (aOR:0.71, 95% CI:0.53-0.96) or STIs (aOR:0.65, 95% CI:0.44-0.96). Consistent condom use with clients was negatively associated with early initiation of selling sex (aOR:0.58, 95% CI:0.42-0.80), while experience of recent sexual violence was positively associated with early initiation (aOR:1.74, 95% CI:1.15-2.63). There were no independent significant differences in HIV (24.5%) or syphilis (8.3%) prevalence. Given the limited use of HIV and STI testing services by women who sold sex as adolescents, the prevalence of forced sex, condomless sex, and STI symptoms were high. Programs serving FSW should more vigorously aim to serve adolescents and adults who began selling sex early.

Comparison of four different human papillomavirus genotyping methods in cervical samples: Addressing method-specific advantages and limitations

Since human papillomavirus (HPV) is recognized as the causative agent of cervical cancer and associated with anogenital non-cervical and oropharyngeal cancers, the characterization of the HPV types circulating in different geographic regions is an important tool in screening and prevention. In this context, this study compared four methodologies for HPV detection and genotyping: real-time PCR (Cobas® HPV test), nested PCR followed by conventional Sanger sequencing, reverse hybridization (High + Low PapillomaStrip® kit) and next-generation sequencing (NGS) at an Illumina HiSeq2500 platform. Cervical samples from patients followed at the Family Health Strategy from Juiz de Fora, Minas Gerais, Brazil, were collected and subjected to the real-time PCR. Of those, 114 were included in this study according to the results obtained with the real-time PCR, considered herein as the gold standard method. For the 110 samples tested by at least one methodology in addition to real-time PCR, NGS showed the lowest concordance rates of HPV and high-risk HPV identification compared to the other three methods (67-75 %). Real-time PCR and Sanger sequencing showed the highest rates of concordance (97-100 %). All methods differed in their sensitivity and specificity. HPV genotyping contributes to individual risk stratification, therapeutic decisions, epidemiological studies and vaccine development, supporting approaches in prevention, healthcare and management of HPV infection.

Epidemiological evidence and association of human papillomavirus with esophageal cancer in northeastern Thailand: a case-control study

Recently, epidemiological evidence of high-risk human papillomavirus (hrHPV) and its association with the increasing risk of esophageal cancer (EC) have been described. However, the involvement of such a virus in the pathogenesis of EC is still inconclusive in the literature. Therefore, our objective was to clarify the epidemiology of HPV infections in primarily diagnosed EC cases and validate this correlation with hospital-based control patients using a retrospective study with a case-control model. Here, we reported that the overall prevalence of HPV DNA was statistically associated with an increased risk of EC (OR, 3.3; 95% CI, 2.5-4.3). Interestingly, a history of gastroesophageal reflux disease (GERD) was constituted and significantly associated with HPV prevalence (adjusted OR, 4.6; 95% CI, 2.2-9.5). Furthermore, our meta-analysis in public databases also indicated that the combined OR and 95% CI between HPV infection and EC risk were 3.31 and 2.53-4.34, respectively, with significant heterogeneity (I₂ = 78%). Variations in the geographic study, tissue type, and detection method remain potential predictors of heterogeneity. In addition, publication bias and sensitivity analysis were not observed, and the results exhibited stable outcomes. Collectively, we specify the recent epidemiological evidence in a validation of the distributed HPV, which might be statistically associated with an increased risk of EC. However, additional high-quality studies with larger sample sizes are needed to further verify the link between HPV and EC.

Human papillomavirus (HPV) types 16 and 18 infection and esophageal squamous cell carcinoma: a systematic review and meta-analysis

OBJECTIVE

The human papillomavirus (HPV) is implicated in the pathogenesis of several cancers among humans. The role of HPV as one of the etiological agents in esophageal carcinogenesis is partially unknown. We assessed whether the available evidence supports the association of HPV with risk and prognosis in patients with esophageal squamous cell carcinomas (ESCCs).

DESIGN

For this systematic review and meta-analysis, PubMed, Embase, Cochrane Library, and SCOPUS were searched up to February 2021. The included studies were prospective or retrospective studies that evaluated the incidence, risk, and prognosis of HPV-16/18-related ESCCs in adult subjects. The primary outcome was the incidence rate of ESCC in HPV-16/18 carriers. Secondary outcomes included the risk of ESCCs compared with healthy HPV-16/18 carriers (expressed as odds ratios [ORs] with 95% confidence intervals [CIs]) and the survival of HPV + versus HPV- ESCCs.

RESULTS

The search identified 1649 unique citations, of which 145 met the inclusion criteria and were included in the pooled analysis (16,484 patients). The pooled HPV prevalence in ESCCs was 18.2% (95% CI 15.2-21.6%; P < 0.001). A significantly increased ESCC risk was associated with HPV infection (OR = 3.81; 95% CI 2.84-5.11; P < 0.001). Main limitation were methods of HPV detection (DNA only), race of populations included (mainly Asiatic countries) and lack of adjustment for other prognostic factors.

CONCLUSIONS

The findings suggest that HPV-16/18 is detectable in about 1 on 5 cases of ESCC with different prevalences across the world. It is moderately but significantly associated with a diagnosis of ESCC. Further epidemiological studies are needed to confirm and increase the current knowledge of the subject.

The Diagnostic and Therapeutic Challenge of Anal Intraepithelial Neoplasia

PURPOSE OF REVIEW

No single modality of care serves as the defined best practice for the treatment of anal intraepithelial neoplasia (AIN). This review aims to present the common treatment modalities germane to AIN while considering evolving evidence.

RECENT FINDINGS

AIN affords an opportunity to evaluate and treat patients before the development of invasive diseases. Efforts to screen for AIN have yielded mixed results. The major available pharmacotheraputic and surgical options offer efficacious options to reduce the bioburden of disease but can be met with high levels of recurrent disease. None affords a predictably durable response in severe disease. Vaccination as primary prevention will likely reduce the overall upward trend in AIN. Evidence suggests vaccination also affords improvement in recurrent disease. Early evidence reveals potential benefit in multimodal approaches to control AIN. Valuable data is anticipated from the phase III, randomized ANCHOR study evaluating the management of high-grade AIN in HIV +patients.

Human Papillomavirus Vaccination Uptake in Canada: A Systematic Review and Meta-analysis

Human papillomavirus (HPV) is the most commonly sexually transmitted infection in the world and the primary cause of cervical cancer. Canada introduced publicly funded HPV vaccination programs in 2006. The objectives of this study are twofold and aim to (1) determine the levels and (2) examine the various factors influencing vaccine uptake among the general Canadian population. A literature search was conducted on seven databases, followed by screening, methodological quality review (using modified Newcastle-Ottawa Scale), and data extraction. Pooled meta-analysis and a subgroup analysis were conducted stratifying by a number of variables (age, sex, type of program, and method of payment) determined apriori. A total of 718 peer-reviewed articles were initially identified with 12 remaining after screening and underwent methodological quality review. HPV vaccination uptake in Canada varied from 12.40% (95% confidence interval [CI] 6.77–20.26) to 88.20% (95% CI 85.72–90.39). The pooled random effects model showed the HPV vaccination uptake to be 55.92% (95% CI 44.87–66.65). The subgroup analysis showed that vaccination uptake was 66.95% (95% CI 55.00–77.89) in participants ≤ 18 years as compared to 13.58% (95% CI 10.93–16.46) in participants > 18 years. Uptake for females was higher 57.23% (95% CI: 45.40–68.66) when compared to that of 47.01% (95% CI: 0.82–97.75) in males. HPV vaccine uptake among school-based programs was 69.62% (95% CI 57.27–80.68) as compared to 18.66% (95% CI 6.66–34.92) for community-based programs. Vaccination uptake for publicly funded programs was significantly higher 66.95% (95% CI 55.00–77.89) when compared to 13.58% (95% CI 10.92–16.46) for programs where participants had to pay out of pocket. To prevent infections and reduce the burden of HPV-related diseases (including cervical cancer), communities should be made aware and encouraged to vaccinate their children. There is a documented need to direct effort and focus interventions toward improving HPV vaccination uptake in Canada.

CRISPR/Cas9-mediated knockout of c-REL in HeLa cells results in profound defects of the cell cycle

Cervical cancer is the fourth common cancer in women resulting worldwide in 266,000 deaths per year. Belonging to the carcinomas, new insights into cervical cancer biology may also have great implications for finding new treatment strategies for other kinds of epithelial cancers. Although the transcription factor NF-κB is known as a key player in tumor formation, the relevance of its particular subunits is still underestimated. Here, we applied CRISPR/Cas9n-mediated genome editing to successfully knockout the NF-κB subunit c-REL in HeLa Kyoto cells as a model system for cervical cancers. We successfully generated a homozygous deletion in the c-REL gene, which we validated using sequencing, qPCR, immunocytochemistry, western blot analysis, EMSA and analysis of off-target effects. On the functional level, we observed the deletion of c-REL to result in a significantly decreased cell proliferation in comparison to wildtype (wt) without affecting apoptosis. The impaired proliferative behavior of c-REL-/- cells was accompanied by a strongly decreased amount of the H2B protein as well as a significant delay in the prometaphase of mitosis compared to c-REL+/+ HeLa Kyoto cells. c-REL-/- cells further showed significantly decreased expression levels of c-REL target genes in comparison to wt. In accordance to our proliferation data, we observed the c-REL knockout to result in a significantly increased resistance against the chemotherapeutic agents 5-Fluoro-2'-deoxyuridine (5-FUDR) and cisplatin. In summary, our findings emphasize the importance of c-REL signaling in a cellular model of cervical cancer with direct clinical implications for the development of new treatment strategies.

Imiquimod for anogenital warts in non-immunocompromised adults

BACKGROUND

30% of people with anogenital warts (AGW) have spontaneous regression of lesions but there is no way to determine whether a specific lesion will remain. There are a wide range of options available for treating people with AGW and selection is based on clinician's experience, patient preferences and adverse effects. The imiquimod could offer the advantages of patient-applied therapies without incurring the limitations of provider-administered treatments.

OBJECTIVES

To assess the effectiveness and safety of imiquimod for the treatment of AGW in non-immunocompromised adults.

SEARCH METHODS

We searched the Cochrane Sexually Transmitted Infections Group Specialized Register (15 April 2014), CENTRAL (1991 to 15 April 2014), MEDLINE (1946 to 15 April 2014), EMBASE (1947 to 15 April 2014), LILACS (1982 to 15 April 2014), World Health Organization International Clinical Trials Registry (ICTRP) (15 April 2014), ClinicalTrials.gov (15 April 2014), Web of Science (2001 to 15 April 2014) and OpenGrey (15 April 2014). We also handsearched conference proceedings, contacted trial authors and reviewed the reference lists of retrieved studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing the use of imiquimod with placebo, any other patient-applied or any other provider-administered treatment (excluding interferon and 5-fluorouracil which are assessed in other Cochrane Reviews) for the treatment of AGW in non-immunocompromised adults.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for inclusion, extracted data and assessed risk of bias. We resolved any disagreements through consensus. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

Ten RCTs (1734 participants) met our inclusion criteria of which six were funded by industry. We judged the risk of bias of the included trials as high. Six trials (1294 participants) compared the use of imiquimod versus placebo. There was very low quality evidence that imiquimod was superior to placebo in achieving complete and partial regression (RR 4.03, 95% CI 2.03 to 7.99; RR 2.56, 95% CI 2.05 to 3.20, respectively). When compared with placebo, the effects of imiquimod on recurrence (RR 2.76, 95% CI 0.70 to 10.91), appearance of new warts (RR 0.76, 95% CI 0.58 to 1.00) and frequency of systemic adverse reactions (RR 0.91, 95% CI 0.63 to 1.32) were imprecise. We downgraded the quality of evidence to low or very low. There was low quality evidence that imiquimod led to more local adverse reactions (RR 1.73, 95% CI 1.18 to 2.53) and pain (RR 11.84, 95% CI 3.36 to 41.63).Two trials (105 participants) compared the use of imiquimod versus any other patient-applied treatment (podophyllotoxin and podophyllin). The estimated effects of imiquimod on complete regression (RR 1.09, 95% CI 0.80 to 1.48), partial regression (RR 0.77, 95% CI 0.40 to 1.47), recurrence (RR 0.49, 95% CI 0.21 to 1.11) or the presence of local adverse reactions (RR 1.24, 95% CI 1.00 to 1.54) were imprecise (very low quality evidence). There was low quality evidence that systemic adverse reactions were less frequent with imiquimod (RR 0.30, 95% CI 0.09 to 0.98).Finally, two trials (335 participants) compared imiquimod with any other provider-administered treatment (ablative methods and cryotherapy). There was very low quality of evidence that imiquimod did not have a lower frequency of complete regression (RR 0.84, 95% CI 0.56 to 1.28). There was very low quality evidence that imiquimod led to a lower rate of recurrence during six-month follow-up (RR 0.24, 95% CI 0.10 to 0.56) but this did not translate in to a lower recurrence from six to 12 months (RR 0.71, 95% CI 0.40 to 1.25; very low quality evidence). There was very low quality evidence that imiquimod was associated with less pain (RR 0.30, 95% CI 0.17 to 0.54) and fewer local reactions (RR 0.55, 95% CI 0.40 to 0.74).

AUTHORS' CONCLUSIONS

The benefits and harms of imiquimod compared with placebo should be regarded with caution due to the risk of bias, imprecision and inconsistency for many of the outcomes we assessed in this Cochrane Review. The evidence for many of the outcomes that show imiquimod and patient-applied treatment (podophyllotoxin or podophyllin) confer similar benefits but fewer systematic reactions with the Imiquimod, is of low or very low quality. The quality of evidence for the outcomes assessing imiquimod and other provider-administered treatment were of very low quality.

Primary prophylactic human papillomavirus vaccination programs: future perspective on global impact

Of the 40 types of human papillomavirus that can infect the mucosal epithelium, four types can now be prevented using prophylactic vaccination. Two of these types (high-risk types 16 and 18) cause 70% of cervical cancers, a proportion of other genital cancers and a subset of head and neck cancers. The low-risk types 6 and 11 cause 90% of genital warts and the disease recurrent respiratory papillomatosis. Thus, if primary HPV vaccination programs can be implemented effectively, the potential for a reduction in global disease burden is great. This article considers the current issues and challenges in delivering primary HPV vaccination programs effectively and the likely impact of the vaccines in both the near and more distant future.

Human papillomavirus in adolescents: lessons learned from decades of evaluation

Knowledge regarding the natural history of human papillomavirus (HPV) infection and its clinical sequelae in adolescents has increased significantly over the last decade; as a result, there have been world-wide recommendations for less aggressive Pap screening and management of cervical dysplasias in young women. It is important that adolescent health providers understand these issues, as knowledge of HPV and its sequelae in the Australian community is limited, despite the introduction of a national immunisation programme. Parents and young women have expressed a desire for further information to make informed choices. This paper reviews the natural history of HPV infection in adolescents and the evidence behind new conservative guidelines for cervical screening, plus prophylactic vaccination in young women.

A recombinant cottontail rabbit papillomavirus genome for ectopic expression of genes in cells infected with virus in vivo

The objective of this study was to construct a cottontail rabbit papillomavirus (CRPV) genome that would co-express a gene of choice and the viral genome simultaneously. Using this construct, the effects of the ectopic expression of diverse viral or cellular genes on PV-infected cells can be examined to elucidate which genes are essential for tumor formation. CRPV-pLAIIdelXba1, which lacks the major portion of L2 (designated the XbaI fragment), has been previously shown to fully retain the ability to induce tumors, and this ability was confirmed in this study. Insertion of the XbaI fragment in an antisense orientation did not change the efficiency of tumor induction. An SV40 overexpression cassette that originated from pSG5 and contains a more diverse multiple cloning site (MCS) was cloned into CRPV-Xba1-mcs, a CRPV genome based on CRPV-pLAIIdelXba1 that contains an additional MCS inserted via XbaI digestion. Additionally, the L1 ATG initiation codon of this construct, designated CRPV-Xba1-oe-WT, was mutated to avoid unnecessary L1 protein expression, which produced the CRPV-Xba1-oe-L1mut construct. Injection of these constructs into two New Zealand White rabbits and monitoring of tumor growth for two to six months showed that CRPV-Xba1-oe-WT induced tumors at 1/10 and 1/10 of the injection sites in two animals, while the control injections in each rabbit induced tumors at 3/10 and 4/10 injection sites, respectively. However, CRPV-Xba1-oe-L1mut induced tumors at 3/10, 6/10, 7/12 and 11/12 sites in four injected animals, and the control injections induced tumor growth in these animals at 6/10, 10/10, 12/12 and 12/12 of the injected sites, respectively. Thus, CRPV-Xba1-oe-L1mut could potentially be used to conduct overexpression experiments in vivo that can be used to measure the negative or positive influences of ectopically expressed foreign or HPV genes on tumor growth.

Papillomaviruses and herpesviruses: who is who in genital tumor development of free-ranging Atlantic bottlenose dolphins (Tursiops truncatus)?

The number of studies addressing neoplasia in marine mammals has recently increased, giving rise to concern whether such lesions could be reflective of an emerging infectious disease. Eight species-specific viruses, seven papillomaviruses (PVs) and two herpesviruses (HVs) have separately been shown to be associated with genital tumors in Atlantic bottlenose dolphins (Tursiops truncatus, Tt): TtPV1-6, as well as HVs provisionally assigned the names DeHV4 and -5 (Delphinid HVs). A definite causal role of these viruses in cell transformation remains to be demonstrated. Concurrent PV- and HV-infection has never been reported in marine mammals. DNA extractions from biopsies of genital tumors derived from 15 free-ranging Atlantic bottlenose dolphins were selected for molecular examination. Polymerase chain reaction (PCR) analyses revealed the presence of DeHV4, while a serological screening using an antibody-based TtPV enzyme-linked immunosorbent assay (ELISA) demonstrated previous and/or current infection of the HV-positive dolphins with at least one TtPV type. Therefore, care must be taken when drawing conclusions about viral causalities in tumor development, since the "hit and run" and other mechanisms have been described for types of both viral families. This study presents the first evidence of marine mammals having a history of PV- as well as HV-infection and discusses the disputed effects of viral co-infection.

Rate of vertical transmission of human papillomavirus from mothers to infants: relationship between infection rate and mode of delivery

Background

In contrast to consistent epidemiologic evidence of the role of sexual transmission of human papillomavirus (HPV) in adults, various routes may be related to HPV infection in infants. We have assessed the extent of HPV infection during the perinatal period, and the relationship between mode of delivery and vertical transmission.

Results

A total of 291 pregnant women over 36 weeks of gestation were enrolled with informed consent. Exfoliative cells were collected from maternal cervix and neonatal buccal mucosa. HPV infection and genotypes were determined with an HPV DNA chip, which can recognise 24 types. The HPV-positive neonates were re-evaluated 6 months after birth to identify the presence of persistent infection. HPV DNA was detected in 18.9 % (55/291) of pregnant women and 3.4 % (10/291) of neonates. Maternal infection was associated with abnormal cytology (p = 0.007) and primiparity (p = 0.015). The infected neonates were all born to HPV-positive mothers. The rate of vertical transmission was estimated at 18.2 % (10/55) which was positively correlated with maternal multiple HPV infection (p = 0.003) and vaginal delivery (p = 0.050), but not with labour duration and premature rupture of membranes. The rate of concordance of genotype was 100 % in mother-neonate pairs with vertical transmission. The neonatal HPV DNAs found at birth were all cleared at 6 months after delivery.

Conclusions

Vertical transmission of HPV DNA from HPV infected mother to the neonate increased when the infant was delivered through an infected cervix. However, the absence of persistent infection in infants at 6 months after delivery may suggest temporary inoculation rather than true vertical infection.

On the occasion of the 4th congress of infectiologists of bosnia and herzegovina with international participation

The 4th Congress of Infectiologists of Bosnia-Herzegovina with international participation was held in Konjic, on 30. May to 02. June 2012. In addition to the prominent infectious disease experts from almost all university centers in B&H, the teachers at medical schools in Bosnia-Herzegovina, infectious disease specialists who work in health institutions in B&H, this Congress was attended by infectious disease experts from Serbia (12 participants), Turkey (3 participants), Croatia (3 participants), Macedonia (3 participants), Germany (2 participants) and Montenegro (2 participants). Topics included: Infections of the skin, soft tissue and bones, Sepsis and endocarditis, Infectious diseases emergencies and pediatric infectology, Emerging and reemerging infectious diseases, Hospital infections, Sexualy transmitted diseases, Infectious diagnostic and therapeutic protocols. Participating invited speakers were following professors: Salih Hosoglu (Turkey), Hakan Leblebicioglu (Turkey), Resat Ozaras (Turkey), Karsten Plötz (Germany), Ilija Kuzman (Croatia), Bruno Baršić (Croatia), Goran Tešović (Croatia). In addition to experts in infectious diseases at this Congress, their works were presented by experts from other medical disciplines, but with infectious character issues (Professors: Sead Ahmetagić, Ismet Gavrankapetanović, Zora Vukobrat-Bijedić, Senija Rašić, Halima Resić, Adnan Kapidžić, Ivo Curić, Jelena Ravlija, Amela Begić, Izet Mašić, Sadeta Hamzić, and others). Some of the papers that were presented at this Congress have been published in extenso, in the Medical Archives and Materia Socio Medica. One part as abstracts (both journals are indexed in over 10 databases), and will be electronically available to the general scientific community in Bosnia-Herzegovina, Europe and worldwide. In this way, the Bosnian infectious disease experts, as a science and profession, will be worthily represented to the colleagues from other countries in the region and beyond.

The full-length isoform of human papillomavirus 16 E6 and its splice variant E6* bind to different sites on the procaspase 8 death effector domain

Human papillomavirus 16 is a causative agent of most cases of cervical cancer and has also been implicated in the development of some head and neck cancers. The early viral E6 gene codes for two alternatively spliced isoforms, E6(large) and E6*. We have previously demonstrated the differential effects of E6(large) and E6* binding on the expression and stability of procaspase 8, a key mediator of the apoptotic pathway. Additionally, we have reported that E6 binds to the FADD death effector domain (DED) at a novel E6 binding domain. Sequence similarities between the FADD and procaspase 8 DEDs suggested a specific region for E6(large)/procaspase 8 binding, which was subsequently confirmed by mutational analysis as well as by the ability of peptides capable of blocking E6/FADD binding to also block E6(large)/caspase 8 binding. However, the binding of the smaller isoform, E6*, to procaspase 8 occurs at a different region, as deletion and point mutations that disrupt E6(large)/caspase 8 DED binding do not disrupt E6*/caspase 8 DED binding. In addition, peptide inhibitors that can block E6(large)/procaspase 8 binding do not affect the binding of E6* to procaspase 8. These results demonstrate that the residues that mediate E6*/procaspase 8 DED binding localize to a different region on the protein and employ a separate binding motif. This provides a molecular explanation for our initial findings that the two E6 isoforms affect procaspase 8 stability in an opposing manner.

Comparison of human papillomavirus detection and typing by hybrid capture 2, linear array, DNA chip, and cycle sequencing in cervical swab samples

Although the Hybrid Capture II (HC II) assay can detect 13 high-risk human papillomavirus (HPVs), it does not yield any genotype-specific information. We evaluated the performance of 4 HPV DNA tests, namely, HC II, Linear Array (LA), DNA chip, and cycle sequencing for their capacity to detect the presence of high-risk HPV DNA and HPV-associated cervical lesions. Seventy-six women who were referred to the colposcopy clinic for abnormal cytology were enrolled. The women were examined using liquid-based cytology, colposcopy-directed biopsy, and HPV DNA tests. After DNA extraction from a single sample, HPV DNA tests were performed by all 4 methods on the same specimen. The LA test has higher HPV-positive rates than HC II for cervical intraepithelial neoplasia I (83.3% vs 61.1%; P < 0.01) and for cervical intraepithelial neoplasia II and more severe lesions (100.0% vs 80.0%; P < 0.01). The concordance between the DNA chip and LA tests was 89.5%, confirming substantial agreement (kappa coefficient = 0.73), and the concordance between HC II and the DNA chip was 80.3%, also showing substantial agreement (kappa coefficient = 0.738). The concordance for 15 high-risk HPV genotypes between LA and sequencing was 82.5% with a kappa value of 0.536. Furthermore, the LA test was more sensitive in the detection of high-grade cervical lesions than HC II (100% vs 92.3%, P < 0.01). The LA test showed superior sensitivity in the detection of clinically relevant HPV infections and has proven to be an accurate tool for identifying individual HPV types, especially in cases of multiple HPV infections.

Human papilloma virus infection prior to coitarche

OBJECTIVE

The aim of our study was to determine the prevalence and the natural course of anogenital human papilloma virus (HPV) infections in girls prior to coitarche attending an outpatient gynecological unit.

STUDY DESIGN

Specimens were taken from the anogenital region of 114 unselected 4-15 year old girls who were referred consecutively for various gynecological problems.

RESULTS

Four girls were excluded because of sexual abuse. Low-risk HPV-deoxyribonucleic acid (DNA) was detected in 4 girls (3.6%) and high-risk HPV DNA in 15 children (13.6%). Two girls testing positive for HPV DNA had clinical apparent warts. After 1 year, 2 children had persistent high-risk HPV DNA, and in 1 case we found a switch from high-risk to low-risk HPV DNA.

CONCLUSION

Subclinical genital low- and high-risk HPV infections are common in girls without any history of sexual abuse or sexual activity. We found persistence of genital HPV infection in children, which could be a reservoir for HPV-associated diseases later in life.

The interaction between human papillomavirus type 16 and FADD is mediated by a novel E6 binding domain

High-risk strains of human papillomavirus, such as types 16 and 18, have been etiologically linked to cervical cancer. Most cervical cancer tissues are positive for both the E6 and E7 oncoproteins, since it is their cooperation that results in successful transformation and immortalization of infected cells. We have reported that E6 binds to tumor necrosis factor receptor 1 and to Fas-associated death domain (FADD) and, in doing so, prevents E6-expressing cells from responding to apoptotic stimuli. The binding site of E6 to FADD localizes to the first 23 amino acids of FADD and has now been further characterized by the use of deletion and site-directed mutants of FADD in pull-down and functional assays. The results from these experiments revealed that mutations of serine 16, serine 18, and leucine 20 obstruct FADD binding to E6, suggesting that these residues are part of the E6 binding domain on FADD. Because FADD does not contain the two previously identified E6 binding motifs, the LxxphiLsh motif, and the PDZ motif, a novel binding domain for E6 has been identified on FADD. Furthermore, peptides that correspond to this region can block E6/FADD binding in vitro and can resensitize E6-expressing cells to apoptotic stimuli in vivo. These results demonstrate the existence of a novel E6 binding domain.

Bottlenose dolphin (Tursiops truncatus) papillomaviruses: vaccine antigen candidates and screening test development

Papillomaviruses (PVs) have been shown as being the etiologic agents of various benign and malignant tumours in many vertebrate species. In dolphins and porpoises, a high prevalence of orogenital tumours has recently been documented with at least four distinct novel species-specific PV types detected in such lesions. Therefore, we generated the immunological reagents to establish a serological screening test to determine the prevalence of PV infection in Atlantic bottlenose dolphins [(Tursiops truncatus (Tt)]. Using the baculovirus expression system, virus-like particles (VLPs) derived from the L1 proteins of two TtPV types, TtPV1 and TtPV2, were generated. Polyclonal antibodies against TtPV VLPs were produced in rabbits and their specificity for the VLPs was confirmed. Electron microscopy and enzyme-linked immunosorbent assay (ELISA) studies revealed that the generated VLPs self-assembled into particles presenting conformational immunodominant epitopes. As such, these particles are potential antigen candidates for a TtPV vaccine. Subsequently, the VLPs served as antigens in initial ELISA tests using sera from six bottlenose dolphins to investigate PV antibody presence. Three of these sera were derived from dolphins with genital tumour history and showed positive PV ELISA reactivity, while the remaining sera from lesion-free dolphins were PV antibody-negative. The results suggest that the developed screening test may serve as a potential tool for determining PV prevalence and thus for observing transmission rates in dolphin populations as the significance of PV infection in cetaceans starts to unfold.

Prevalence of high-risk human papillomavirus types in Mexican women with cervical intraepithelial neoplasia and invasive carcinoma

Background

Prevalence of high risk (HR) human papillomavirus (HPV) types in the states of San Luis Potosí (SLP) and Guanajuato (Gto), Mexico, was determined by restriction fragment length-polymorphism (RFLP) analysis on the E6 ~250 bp (E6-250) HR-HPV products amplified from cervical scrapings of 442 women with cervical intraepithelial neoplasia and invasive carcinoma (280 from SLP and 192 from Gto). Fresh cervical scrapings for HPV detection and typing were obtained from all of them and cytological and/or histological diagnoses were performed on 383.

Results

Low grade intraepithelial squamous lesions (LSIL) were diagnosed in 280 cases (73.1%), high grade intraepithelial squamous lesions (HSIL) in 64 cases (16.7%) and invasive carcinoma in 39 cases (10.2%). In the 437 cervical scrapings containing amplifiable DNA, only four (0.9%) were not infected by HPV, whereas 402 (92.0%) were infected HR-HPV and 31 (7.1%) by low-risk HPV. RFLP analysis of the amplifiable samples identified infections by one HR-HPV type in 71.4%, by two types in 25.9% and by three types in 2.7%. The overall prevalence of HR-HPV types was, in descending order: 16 (53.4%) > 31 (15.6%) > 18 (8.9%) > 35 (5.6) > 52 (5.4%) > 33 (1.2%) > 58 (0.7%) = unidentified types (0.7%); in double infections (type 58 absent in Gto) it was 16 (88.5%) > 31 (57.7%) > 35 (19.2%) > 18 (16.3%) = 52 (16.3%) > 33 (2.8%) = 58 (2.8%) > unidentified types (1.0%); in triple infections (types 33 and 58 absent in both states) it was 16 (100.0%) > 35 (54.5%) > 31 (45.5%) = 52 (45.5%) > 18 (27.3%). Overall frequency of cervical lesions was LSIL (73.1%) > HSIL (16.7%) > invasive cancer (10.2%). The ratio of single to multiple infections was inversely proportional to the severity of the lesions: 2.46 for LSIL, 2.37 for HSIL and 2.15 for invasive cancer. The frequency of HR-HPV types in HSIL and invasive cancer lesions was 16 (55.0%) > 31 (18.6%) > 35 (7.9%) > 52 (7.1%) > 18 (4.3%) > unidentified types (3.6%) > 33 (2.9%) > 58 (0.7%).

Conclusion

Ninety percent of the women included in this study were infected by HR-HPV, with a prevalence 1.14 higher in Gto. All seven HR-HPV types identifiable with the PCR-RFLP method used circulate in SLP and Gto, and were diagnosed in 99.3% of the cases. Seventy-one percent of HR-HPV infections were due to a single type, 25.9% were double and 2.7% were triple. Overall frequency of lesions was LSIL (73.1%) > HSIL (16.7%) > invasive cancer (10.2%), and the ratio of single to multiple infections was inversely proportional to severity of the lesions: 2.46 for LSIL, 2.37 for HSIL and 2.15 for invasive cancer. The frequency of HR-HPV types found in HSIL and invasive cancer was 16 (55.0%) > 31 (18.6%) > 35 (7.9%) > 52 (7.1%) > 18 (4.3%) > unidentified types (3.6%) > 33 (2.9%) > 58 (0.7%). Since the three predominant types (16, 31 and 18) cause 77.9% of the HR-HPV infections and immunization against type 16 prevents type 31 infections, in this region the efficacy of the prophylactic vaccine against types 16 and 18 would be close to 80%.

Cellular binding partners of the human papillomavirus E6 protein

The high-risk strains of human papillomavirus (HR-HPV) are known to be causative agents of cervical cancer and have recently also been implicated in cancers of the oropharynx. E6 is a potent oncogene of HR-HPVs, and its role in the progression to malignancy has been and continues to be explored. E6 is known to interact with and subsequently inactivate numerous cellular proteins pivotal in the mediation of apoptosis, transcription of tumor suppressor genes, maintenance of epithelial organization, and control of cell proliferation. Binding of E6 to these proteins cumulatively contributes to the oncogenic potential of HPV. This paper provides an overview of these cellular protein partners of HR-E6, the motifs known to mediate oncoprotein binding, and the agents that have the potential to interfere with E6 expression and activity and thus prevent the subsequent progression to oncogenesis.

Prevention, diagnosis, and treatment of cervical cancer

This article reviews the current data on human papillomavirus as the cause of most cervical cancer cases, data on the recently approved human papillomavirus vaccines, and updated information concerning the Bethesda System for interpretation of Papanicolaou test results. Current recommendations for surgical treatment, concurrent chemotherapy, and radiation therapy and recent advances in systemic therapy for advanced or metastatic cervical cancer are reviewed.

Prevalence of human papillomavirus DNA in cholesteatomas

Cholesteatomas show histomorphological features like papillary growth and koilocytosis, which are characteristic of lesions induced by human papillomaviruses (HPV). Two previous studies investigating the possible role of HPV in the development of cholesteatoma had detected HPV-6 and HPV-11 DNA with a prevalence differing from 3 to 36%. The aim of the presented study was to evaluate the prevalence of different HPV types in cholesteatomas using a sensitive detection system for HPV DNA. Twenty-nine biopsies from cholesteatomas were screened for HPV DNA with a 2-step broad-spectrum PCR (PCR and nested PCR). HPV-positive products were directly sequenced by means of a cycle sequencing approach. Sensitivity of the applied broad-spectrum PCR was 0.1 copy/genome. One out of 29 biopsies showed a positive signal on the nested PCR level. Considering the low prevalence (1/29 biopsies) of detected HPV DNA in cholesteatomas, infections with common HPV types are unlikely to be a causative factor.

Oral inosiplex in the treatment of cervical condylomata acuminata: a randomised placebo-controlled trial

Conventional therapies for human papillomavirus infection aim to remove clinically apparent lesions, while latent infection may remain, representing a threat for transmission and carcinogenesis. The use of a systemic agent may more effectively control the virus. We conducted a randomised placebo-controlled study to investigate the efficacy and safety of oral inociplex in the treatment of cervical condylomata acuminata (CA) that had been resistant to conventional therapies. Thirty-eight white European women, aged 20-43 years, with genital warts of the cervix, refractory to at least one conventional therapy, were randomly assigned to receive either inosiplex, 50 mg/kg daily peros for 12 weeks (group 1), or placebo (group 2). Of the 17 evaluable group 1 women, 4 responded to the treatment completely, 7 responded partially and 6 did not respond. Of the 19 group 2 women, none responded to the treatment completely, 3 responded partially and 16 did not respond. The therapeutic difference between women receiving active and placebo therapy was statistically significant (chi(2)= 6.69, P < 0.01) and remained significant when an intention-to-treat analysis was performed (chi(2)= 7.69, P < 0.01). None of the complete responders experienced recurrence during the 12-month follow up. Adverse effects were mild and resolved upon completion of therapy. Compared with placebo, inosiplex showed considerable efficacy with insignificant and reversible adverse effects and without recurrences. Inosiplex may represent an efficacious and safe alternative systemic form of therapy for cervical genital warts.

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.

Genital warts in children: what do they mean?

Human papillomaviruses (HPVs) are a diverse family of viruses, of which 30-40 genotypes specifically infect the genital tract. Genital HPVs are largely transmitted sexually, with most infections being asymptomatic and transient. In contrast, persistent infection with oncogenic genotypes in a minority is a strong risk factor, for subsequent development of high grade dysplasia, the precursor lesion to cervical neoplasia, which generally occurs after a long latency period. It is unknown whether there is a disease correlate in children chronically infected with oncogenic HPVs. Low risk HPV genotypes 6 and 11 are the primary cause of condylomata acuminata, although in children non-genital genotypes are also found in a proportion, with the mode of transmission being either perinatal, horizontal, or sexual. The finding of asymptomatic HPV DNA in children, and correlation with live virus, infectivity, or disease is unclear. Long term follow up for children with anogenital warts is recommended, although there are no longitudinal studies available to clarify whether they are at risk of developing carcinoma in young adulthood.

Human papillomavirus in cervical screening and vaccination

Recent decades have witnessed a reduction in the incidence of cervical cancer in countries where screening programmes have achieved broad coverage. The recognized importance of high-risk HPV (human papillomavirus) infection in the aetiology of cervical cancer may introduce a role for HPV DNA testing in cervical screening programmes. Positive HPV DNA tests indicate women at risk of cervical cancer with greater sensitivity, but reduced specificity, compared with exfoliative cytology. Combining HPV testing with cytology may be useful in the triage of minor cytological abnormalities into those requiring referral to colposcopy (HPV positive) compared with those who can be safely managed by cytological surveillance (HPV negative). With its high sensitivity and high-negative-predictive value, HPV testing may also be useful for predicting treatment failure, since residual disease is very unlikely in the event of a negative HPV test. Ultimately, prevention is better than cure, and the advent of HPV prophylactic vaccines may obviate the need for population-based cervical screening programmes in the future. A multivalent vaccine administered to adolescents prior to the onset of sexual activity and boosted at regular intervals throughout their sexually active life may provide protection against type-specific HPV infection, malignant precursors and invasive cervical disease. Several large randomized placebo-controlled trials have been conducted with promising results. For those generations of women already exposed to high-risk HPV infection, therapeutic vaccines may offer advantages over conventional treatment, although much work still needs to be done.

Gynaecological cancer surgery

Cancers of the female genital tract account for a significant proportion of cancers in women. Surgery plays a major role in the management of these patients. As a single modality, it provides definitive treatment for early-stage cancers and contributes to the management of patients with advanced cancers as part of multimodality treatment. Surgery can involve relatively simple procedures, such as wide local excision for microinvasive lesions of the vulva. However, for more advanced cancers, such as metastatic ovarian cancer, surgery can be very complex indeed, at times requiring resection of non-gynaecological organs, such as small or large bowel. Extensive surgical training and experience is needed to successfully manage patients with these challenging conditions, and this has resulted in the development of the subspecialty of gynaecological oncology. This chapter discusses the place of surgery in the treatment of individual gynaecological cancers.

Therapeutic vaccination with papillomavirus E6 and E7 long peptides results in the control of both established virus-induced lesions and latently infected sites in a pre-clinical cottontail rabbit papillomavirus model

This study was performed to test the therapeutic efficacy of overlapping long E6 and E7 peptides, containing both CD4+ T-helper and CD8+ CTL epitopes, on CRPV-induced lesions, which is an appropriate pre-clinical model for HPV diseases, including recurrent respiratory papillomatosis (RRP). Therapeutic peptide vaccination was able to significantly control wart growth (p < 0.01) and abrogate latent CRPV infection (p = 0.0006) compared to controls. Vaccination was associated with a T(H)1 T cell response, as suggested by a strong DTH skin test, antigen-specific proliferation of PBMC and a minimal IgG antibody response. Thus, this study shows promise for treatment of RRP by vaccination with long peptides.

Rel/Nuclear factor-kappa B apoptosis pathways in human cervical cancer cells

Cervical cancer is considered a common yet preventable cause of death in women. It has been estimated that about 420 women out of the 1400 women diagnosed with cervical cancer will die during 5 years from diagnosis. This review addresses the pathogenesis of cervical cancer in humans with a special emphasis on the human papilloma virus as a predominant cause of cervical cancer in humans. The current understanding of apoptosis and regulators of apoptosis as well as their implication in carcinogenesis will follow. A special focus will be given to the role of Rel/NF-kappaB family of genes in the growth and chemotherapeutic treatment of the malignant HeLa cervical cells emphasizing on Xrel3, a cRel homologue.

Stem cell origin of cancer and differentiation therapy

Our forefathers in pathology, on observing cancer tissue under the microscope in the mid-19th century, noticed the similarity between embryonic tissue and cancer, and suggested that tumors arise from embryo-like cells [Recherches dur le Traitement du Cancer, etc. Paris. (1829); Editoral Archiv fuer pathologische Anatomie und Physiologie und fuer klinische Medizin 8 (1855) 23]. The concept that adult tissues contain embryonic remnants that generally lie dormant, but that could be activated to become cancer was later formalized by Cohnheim [Path. Anat. Physiol. Klin. Med. 40 (1867) 1-79; Virchows Arch. 65 (1875) 64] and Durante [Arch. Memori ed Osservazioni di Chirugia Practica 11 (1874) 217-226], as the "embryonal rest" theory of cancer. An updated version of the embryonal rest theory of cancer is that cancers arise from tissue stem cells in adults. Analysis of the cellular origin of carcinomas of different organs indicates that there is, in each instance, a determined stem cell required for normal tissue renewal that is the most likely cell of origin of carcinomas [Lab. Investig. 70 (1994) 6-22]. In the present review, the nature of normal stem cells (embryonal, germinal and somatic) is presented and their relationships to cancer are further expanded. Cell signaling pathways shared by embryonic cells and cancer cells suggest a possible link between embryonic cells and cancer cells. Wilm's tumors (nephroblastomas) and neuroblastomas are presented as possible tumors of embryonic rests in children. Teratocarcinoma is used as the classic example of the totipotent cancer stem cell which can be influenced by its environment to differentiate into a mature adult cell. The observation that "promotion" of an epidermal cancer may be accomplished months or even years after the initial exposure to carcinogen ("initiation"), implies that the original carcinogenic event occurs in a long-lived epithelial stem cell population. The cellular events during hepatocarcinogenesis illustrate that cancers may arise from cells at various stages of differentiation in the hepatocyte lineage. Examples of genetic mutations in epithelial and hematopoietic cancers show how specific alterations in gene expression may be manifested as maturation arrest of a cell lineage at a specific stage of differentiation. Understanding the signals that control normal development may eventually lead us to insights in treating cancer by inducing its differentiation (differentiation therapy). Retinoid acid (RA) induced differentiation therapy has acquired a therapeutic niche in treatment of acute promyelocytic leukemia and the ability of RA to prevent cancer is currently under examination.

Depressed type 1 cytokine synthesis by superantigen-activated CD4+ T cells of women with human papillomavirus-related high-grade squamous intraepithelial lesions

Carcinoma of the cervix is causally related to infection with the human papillomavirus (HPV), and T cells play a pivotal role in the immune response of the host to rid itself of HPV infection. Therefore, we assessed the T-cell function of women with HPV-related cervical neoplasia against a superantigen, Staphylococcus enterotoxin B (SEB). Each woman provided a cervical brush specimen for HPV DNA testing and Papanicolaou (Pap) smears for the staging of cervical lesions. They also provided a blood specimen for determination of the ability of CD4(+) T and CD8(+) T cells to synthesize Th1 (interleukin-2 [IL-2], gamma interferon [IFN-gamma], and tumor necrosis factor alpha [TNF-alpha]) and Th2 (IL-10) cytokines in response to activation with SEB. Compared with control subjects with self-attested negative Pap smears, women with high-grade squamous intraepithelial lesions (HSIL) had significantly lower percentages of activated CD4(+) T cells that produced IL-2 (P = 0.045), IFN-gamma (P = 0.040), and TNF-alpha (P = 0.015) and a significantly lower percentage of activated CD8(+) T cells that produced IL-2 (P < 0.01). These data indicate that women with HPV-related cervical HSIL show a decrease in Th1 cytokine production by activated CD4(+) T cells and suggested that compromised T-helper functions may negatively impact the function of cytotoxic CD8(+) T cells.

HPV-16 L1 genes with inactivated negative RNA elements induce potent immune responses

Introduction of point mutations in the 5' end of the human papillomavirus type 16 (HPV-16) L1 gene specifically inactivates negative regulatory RNA processing elements. DNA vaccination of C57Bl/6 mice with the mutated L1 gene resulted in improved immunogenicity for both neutralizing antibodies as well as for broad cellular immune responses. Previous reports on the activation of L1 by codon optimization may be explained by inactivation of the regulatory RNA elements. The modified HPV-16 L1 DNA that induced anti-HPV-16 immunity may be seen as a complementary approach to protein subunit immunization against papillomavirus.

Human papillomavirus infections: diagnosis, treatment, and hope for a vaccine

HPV infections are common, with millions of Americans infected. Common gynecologic manifestations of HPV infection include genital warts and cervical neoplasia. The CDC recently issued guidelines for the treatment of genital warts. Gynecologists should be familiar with these therapies and their potential short-comings. A recently reported clinical trial has raised hopes that HPV and its sequelae may be prevented by vaccination.

Human papillomavirus testing methods

Testing for human papillomavirus (HPV) relies exclusively on techniques of molecular biology using nucleic acid probes. Tests for HPV using nucleic acid probes have been commercially available since the late 1980s, but early tests were cumbersome, involving the use of nucleic acid probes labeled with radioactive phosphorus (32P). These early HPV tests did not achieve widespread use because they did not detect all oncogenic HPV genotypes. The current commercial HPV detection kit, Digene's Hybrid Capture 2 kit, detects virtually all high-risk oncogenic HPV types, as well as most low-risk nononcogenic HPV genotypes. The Hybrid Capture 2 test format is a proprietary nucleic acid hybridization signal amplification system owned by Digene Corporation. Virtually all test formats for DNA sequence analysis are amenable to applications intended to detect and perhaps quantify the various HPV genotypes. These methods can involve direct hybridization with complementary DNA probes, such as Southern blotting or in situ hybridization, signal amplification, such as the Hybrid Capture 2 method or target nucleic acid amplification, most notably the polymerase chain reaction (PCR). Polymerase chain reaction has been used for HPV detection, genotyping, and viral load determination. General or consensus primer-mediated PCR assays have enabled screening for a broad spectrum of HPV types in clinical specimens using a single PCR reaction. Following amplification using consensus primers, individual HPV genotypes are identified using a variety of methods. Using consensus primers in a test format known as real-time quantitative PCR (RQ-PCR), it is possible to generate viral load (concentration) data from reaction curves generated by monitoring PCR reaction kinetics in real time.

Evaluation and application of a broad-spectrum polymerase chain reaction assay for human papillomaviruses in the screening of squamous cell tumours of the head and neck

OBJECTIVE

The results of studies analysing the prevalence of human papillomaviruses (HPVs) in squamous cell carcinomas of the head and neck region often vary depending on the different molecular biological methods applied. Focusing on the histomorphological criteria of HPV infections, the percentage of HPV-positive cancers should be higher than has been found in most studies. The aim of this study was to increase the detection spectrum of HPV polymerase chain reaction (PCR) screening using degenerate consensus primers.

MATERIAL AND METHODS

To increase the sensitivity of the assay to one copy of HPV DNA per cell, a two-step PCR was carried out. The products were directly sequenced by means of a cycle sequencing approach. Seventy biopsies from squamous cell carcinomas of the upper aerodigestive tract were screened using the primer system.

RESULTS

According to the PCR results, 0/2 carcinomas of the floor of the mouth or tongue, 7/16 biopsies of oropharyngeal cancers, 3/13 hypopharyngeal cancers, 13/34 squamous cell carcinomas of the larynx, 4/4 biopsies from carcinomas of the nasal cavity or paranasal sinuses and 1/1 squamous cell carcinoma of the parotid gland were positive.

CONCLUSION

This broad-spectrum PCR can effectively detect HPV in head and neck cancers.

Imiquimod

PURPOSE OF REVIEW

Imiquimod is the first member of a new class of immune response modifiers; it was first approved in 1997 for the topical treatment of external genital and perianal warts. It is an imidazoquinoline, a novel synthetic compound which is an immune response stimulator, enhancing both the innate and acquired immune pathways (particularly T helper cell type 1-mediated immune responses) resulting in antiviral, antitumour and immunoregulatory activities. The mechanism of action of imiquimod involves cytokine induction in the skin, which then triggers the host's immune system to recognize the presence of a viral infection or tumour, ultimately to eradicate the associated lesion.

RECENT FINDINGS

Imiquimod, a patient-applied topical 5% cream is clinically efficacious and safe in the management of condylomata acuminata and other warty manifestations of human papillomavirus infections. Although not licensed for use against other viral skin infections, preliminary data suggest imiquimod's success against molluscum contagiosum, caused by a poxvirus. Initial studies with imiquimod for the management of HPV-related intraepithelial dysplasias (bowenoid papulosis/vulvar intraepithelial neoplasia) as well as for ultraviolet-induced skin lesions such as actinic keratoses, Bowen's disease, and basal cell carcinomas show great promise in immunocompetent and immunosuppressed patients.

SUMMARY

In the future, imiquimod and newer generations of imidazoquinolines (resiquimod) require further investigation for potential clinical utility in treating other cutaneous and mucosal viral infections, dysplasias and neoplasia, as well as potential vaccine adjuvants.