Brahim Qadadri

A Longitudinal Study of Genital Human Papillomavirus Infection in a Cohort of Closely Followed Adolescent Women

BACKGROUND We performed a study to better characterize the natural history of genital human papillomavirus (HPV) infection in a cohort of closely followed adolescent women. METHODS A cohort of 60 adolescent women was followed over a 2.2-year period, on average. A median of 41.5 self-collected vaginal and clinician-obtained cervical swabs were obtained from each subject. RESULTS HPV was detected in 45.3% of all adequate specimens, by use of a polymerase chain reaction/reverse blot strip assay. Oncogenic--or high-risk (HR)--HPV types were detected in 38.6% of specimens, and nononcogenic--or low-risk (LR)--types were detected in 19.6% of specimens. During the entire study period, 49 of 60 subjects tested positive for HPV (cumulative prevalence, 81.7%). The most frequently detected HR types were HPV types 52, 16, and 59. Infections with multiple HPV types were common. The median duration of persistence of a specific HPV type was 168 days, and HR types were more persistent than LR types. Abnormal cervical cytological results occurred in 37% of the adolescent women and were significantly associated with HR HPV infection. CONCLUSIONS The cumulative prevalence of HPV infection in sexually active adolescent women is extremely high, involves numerous HPV types, and frequently results in cervical dysplasia.

Distribution of human papillomavirus types in cervicovaginal washings from women evaluated in a sexually transmitted diseases clinic.

Background Women evaluated for sexually transmitted diseases (STDs) may be at increased risk for human papillomavirus (HPV) infection, a condition associated with cervical dysplasia. The distribution of HPV types in such a population is unknown. Goal The goal was to determine the prevalence of HPV infection, the distribution of HPV types, and the type distribution in relation to cervical dysplasia in women in an STD clinic. Study Design Cervicovaginal lavage and Papanicolaou smear specimens were obtained from 295 women. Lavage specimens were analyzed for HPV by polymerase chain reaction/reverse blot strip assay. Results Cervical cytologic findings were abnormal for 19.7% of women. HPV DNA was detected in 49.2% of women (high-risk HPV in 42.4%). HPV positivity correlated with the degree of cytologic abnormality. In women with dysplasia, HPV types 16, 66, 83, 56, 52, and 59 were commonly detected. Specimens containing abundant HPV DNA occurred most often in women with dysplasia. Conclusions HPV infection was common in women attending an STD clinic. Numerous individual HPV types were associated with cervical dysplasia, including “low-risk” types.

Human papillomavirus infection and its association with cervical dysplasia in Ecuadorian women attending a private cancer screening clinic

Women living in Latin American countries bear a disproportionate burden of cervical cancer, a condition caused by infection with the human papillomavirus (HPV). We performed a study in Santa Elena, Guayas (currently Santa Elena Province), Ecuador, to determine how often HPV could be detected in women attending a private cancer screening clinic. Participants underwent a Pap test, and vaginal and cervical swabs were performed for HPV testing by the polymerase chain reaction (PCR). Each participant completed a verbally administered survey. The mean age of 302 participants was 37.7 years (range 18 to 78 years). The majority of cervical and vaginal specimens contained sufficient DNA to perform PCR. Overall, 24.2% of the participants had either a cervical or vaginal swab that tested positive for HPV. In general, there was a good correlation between the HPV types detected in the cervical and vaginal swabs from the participants, but vaginal swabs were more likely to contain HPV DNA than were cervical swabs. The high-risk HPV types 16, 52, 58, and 59 and the low-risk HPV types 62, 71, 72, and 83 were the most frequently detected HPV types. The number of lifetime sexual partners was positively associated with detection of any HPV type, detection of oncogenic HPV, and abnormal Pap smears. Further studies are needed to determine if these results are representative of all Ecuadorian women and to determine if cervical cancers in Ecuadorian women are caused by the same HPV types found in the swab specimens obtained in this study.

Human papillomavirus detection and typing in thin prep cervical cytologic specimens comparing the Digene Hybrid Capture II Assay, the Roche Linear Array HPV Genotyping Assay, and the Kurabo GeneSquare Microarray Assay

Three methods for the detection of HPV DNA were compared in cervical cytologic specimens: the Digene Hybrid Capture II Assay (HC), the Roche Linear Array HPV Genotyping Assay (LA) and the Kurabo GeneSquare Microarray (GS). The main goals of the study were to correlate cytology with HPV detection and to determine agreement between assay pairs for HPV detection. Thin-prep Pap smears were performed and supernates were tested by HC, LA, and GS. For specimens reacting with the HPV 52/33/35/58 probe in the LA assay, type-specific PCR was performed for HPV types 52, 33, 35, or 58. Binomial proportions and kappa coefficients were calculated for agreement between assays. Cytology results and supernatant were available for 202 subjects. HPV detection increased with worsening cytologic abnormality in all three assays. For all cytologic groups, LA and GS detected more HPV (all and oncogenic) than HC. However, for detection of oncogenic HPV types represented in all three assays, differences between assays were less pronounced. The highest agreement was between LA and GS. In four of 12 specimens reacting with the HPV 52/33/35/58 probe in the LA assay but deemed HPV 52-LA-negative using an algorithm provided by the manufacturer, the presence of HPV 52 was confirmed using type-specific HPV 52 PCR. All four of these specimens were also GS-positive for HPV 52.

Natural History of Multiple Human Papillomavirus Infections in Female Adolescents With Prolonged Follow-up

PURPOSE The aim of the study was to better characterize the natural history of human papillomavirus (HPV) infections in female adolescents. METHODS Female adolescents were enrolled in a longitudinal study. Self-vaginal samples were obtained every 3 months and tested for HPV. No participants received HPV vaccination. The findings for 40 female adolescents with the longest follow-up are reported in this study. RESULTS Average age at the time of enrollment was 15.2 years (range: 14-17; SD: .97). Mean duration of follow-up was 6.7 years (range: 4.4-9.2; SD: 1.2). In all, 32 participants (80%) reported being involved in sexual activity before their enrollment in the study; all reported being involved in sexual activity before enrollment; all reported being involved in sexual activity during follow-up. Baseline and cumulative prevalence of HPV among participants was 55% and 100%, respectively. During the study, each participant tested positive for a mean of 14 HPV types. Cumulatively, HPV 16 was detected in 29 of 40 participants (72.5%). Mean duration of high- and low-risk infections was 655.9 (median: 433) and 524.1 days (median: 334), respectively. CONCLUSION With prolonged follow-up, HPV infections with multiple types were found in all participants. Most had infection with HPV-16 or HPV-18, the oncogenic types represented in current vaccines, as well as infection with other oncogenic types. These data reinforce the importance of vaccine and non-vaccine strategies for prevention of HPV infections.

Low-level persistence of human papillomavirus 16 DNA in a cohort of closely followed adolescent women†

Most human papillomavirus (HPV) infections in young women become undetectable by standard assays after a few months. It is possible that many HPV infections do not actually clear, but persist at very low levels for years, becoming detected again later in life. The purpose of this study is to describe HPV 16 clearance, reappearance, and low‐level persistence in a cohort of adolescent women. Adolescent women (N = 66), not vaccinated against HPV, were recruited from 1998 to 2008 into a longitudinal study. Self‐collected vaginal samples were obtained quarterly and tested for HPV by Linear Array HPV Genotyping Test (LA‐HPV). To explore low‐level persistence, a type‐specific nested PCR for HPV 16 (TSN‐PCR‐16) was developed. Women with HPV 16 detected by LA‐HPV had their negative swabs retested with TSN‐PCR‐16. Forty‐two participants with HPV 16, followed for a mean of 6.3 years, were analyzed. Using LA‐HPV, the median duration of HPV 16 detection was 428 days (SD 852.5 days). TSN‐PCR‐16 detected HPV 16 during periods of LA‐HPV non‐detection in samples from many women. Using a combination of LA‐HPV and TSN‐PCR‐16 results, the median duration of HPV 16 detection was 1,022.5 days (SD 943.7 days). The durations of detection differed significantly between the two methods (P = 0.0042) with a mean difference of 434.5 days. In adolescent females, duration of HPV 16 detection was significantly longer when TSN‐PCR‐16 was combined with LA‐HPV. Some apparently cleared HPV 16 could be shown to persist at low levels using nested PCR. J. Med. Virol. 83:1362–1369, 2011.

Episodic detection of human papillomavirus within a longitudinal cohort of young women

Redetection of a type‐specific human papillomavirus (HPV) infection may represent reinfection. However, a growing body of literature suggests that reactivation of HPV is common and that episodic detection of a HPV infection may represent reactivation of a persistent virus. A cohort of prospectively followed adolescent women (N = 150), ages 14–17, was observed on average 6.4 years. The authors describe the redetection of 37 HPV types and associated factors of redetection of high‐risk (HR) and low‐risk (LR) types using Cox proportional hazard models. Of 1,248 HPV type‐specific infections, 286 (22.9%) were associated with redetection after apparent clearance. Chlamydia infections (HR = 1.99 [95%CI, 1.15–3.49]) and non‐condom use (HR = 1.1 [95%CI, 1.04–1.99]) were associated with increased redetection of HR‐HPV infections. Oral contraceptive pills (HR = 2.73 [95%CI, 1.52–4.90]) and number of sexual partners (HR = 1.44 [95%CI, 1.04–1.99]) were associated with increased redetection of LR‐HPV infections. Episodic detection of HPV is common for HR‐ and LR‐HPV types. This finding and identified factors or redetection have clinical implications and enhances the understanding of HPV natural history. J. Med. Virol. 87:2122–2129, 2015.

Human papillomavirus type 59 immortalized keratinocytes express late viral proteins and infectious virus after calcium stimulation

Human papillomavirus type 59 (HPV 59) is an oncogenic type related to HPV 18. HPV 59 was recently propagated in the athymic mouse xenograft system. A continuous keratinocyte cell line infected with HPV 59 was created from a foreskin xenograft grown in an athymic mouse. Cells were cultured beyond passage 50. The cells were highly pleomorphic, containing numerous abnormally shaped nuclei and mitotic figures. HPV 59 sequences were detected in the cells by DNA in situ hybridization in a diffuse nuclear distribution. Southern blots were consistent with an episomal state of HPV 59 DNA at approximately 50 copies per cell. Analysis of the cells using a PCR/reverse blot strip assay, which amplifies a portion of the L1 open reading frame, was strongly positive. Differentiation of cells in monolayers was induced by growth in F medium containing 2 mM calcium chloride for 10 days. Cells were harvested as a single tissue-like sheet, and histologic analysis revealed a four-to-six cell-thick layer. Transcripts encoding involucrin, a cornified envelope protein, and the E1/E4 and E1/E4/L1 viral transcripts were detected after several days of growth in F medium containing 2 mM calcium chloride. The E1/E4 and L1 proteins were detected by immunohistochemical analysis, and virus particles were seen in electron micrographs in a subset of differentiated cells. An extract of differentiated cells was prepared by vigorous sonication and was used to infect foreskin fragments. These fragments were implanted into athymic mice. HPV 59 was detected in the foreskin xenografts removed 4 months later by DNA in situ hybridization and PCR/reverse blot assay. Thus, the complete viral growth cycle, including production on infectious virus, was demonstrated in the HPV 59 immortalized cells grown in a simple culture system.

Invasive cervical cancers from women living in the United States or Botswana: differences in human papillomavirus type distribution.

BackgroundCervical cancer is the primary cause of cancer-related deaths in women living in Botswana.MethodsParaffin-embedded blocks of formalin-fixed invasive cervical cancer specimens were identified from women living in the U.S. (n = 50) or Botswana (n = 171) from which DNA was extracted. Thin-section PCR was performed on each sample for HPV types and HIV. Comparisons were made between HPV types and groups of types identified in cancers.ResultsHPV DNA was identified in 92.0% of specimens from the U.S. containing amplifiable human DNA, and 79.5% of specimens from Botswana. HPV 16 was detected in 40 of 46 HPV-positive specimens (87.0%) from the U.S. vs. 58 of 136 (42.7%) from Botswana (p < 0.001). In contrast, non-HPV 16/18 types, all A9 species (HPV16, 31, 33, 35, 52, and 58), non-HPV 16 A9 (HPV 31, 33, 35, 52, and 58), HPV 18, all A7 types (18, 39, 45, 59, and 68) types were detected significantly more often in specimens from Botswana. The prevalence of non-HPV 18 A7 types did not differ significantly between the two groups. For specimens from Botswana, 31.6% contained PCR-amplifiable HIV sequences, compared to 3.9% in U.S. specimens. Stratifying the samples from Botswana by HIV status, HPV 31 was detected significantly more often in HIV-positive specimens. Other HPV types and groups of types were not significantly different between HIV-positive and HIV-negative specimens from Botswana.ConclusionThis study demonstrates that there may be important HPV type differences in invasive cervical cancers occurring in women living in the United States or Botswana. Factors in addition to HIV may be driving these differences.

DNA detection and seroprevalence of human papillomavirus in a cohort of adolescent women.

Objectives Human papillomavirus (HPV) infections are common in adolescent women, while the rare cancerous sequelae of HPV infections do not generally occur until the 4th or 5th decades of life. This prospective study of a cohort of adolescent women was performed to further our knowledge of the natural history of incident and prevalent HPV infections. Methods Self-vaginal swabs collected from high-risk, unvaccinated adolescent women in a longitudinal study were analysed for HPV DNA. Sera were collected at enrolment and later tested for HPV antibodies. Statistical analysis was performed to determine the HPV genotype distribution and duration of detection, and to determine rates of seropositivity and seroconversion for HPV types represented in the assays. Results 146 subjects (mean enrolment age=15.4 years; mean duration of follow-up=5.8 years) had samples adequate for analysis of HPV detection, and 95 of these subjects had paired sera available. The cumulative prevalence for high-risk and low-risk HPV types was 95.9% and 91.1%, respectively. HPV types 6, 11, 16 and 18 (HPV types represented in the quadrivalent vaccine) were found at some point in 40.4%, 6.2%, 48% and 24% of participants, respectively. Serological data confirmed exposure to these vaccine-covered types, as well as to other high-risk HPV types. Conclusions In this cohort of adolescent women, high- and low-risk HPV types were frequently detected, and serological data confirmed exposure in most subjects. The high-prevalence HPV types represented in the quadrivalent HPV vaccine further support vaccination of women at an age well before sexual debut.