Search tips
Search criteria

Results 1-5 (5)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
Document Types
1.  Accuracy and Cost-Effectiveness of Cervical Cancer Screening by High-Risk HPV DNA Testing of Self-Collected Vaginal Samples 
Estimate the accuracy and cost-effectiveness of cervical cancer screening strategies based on high-risk HPV DNA testing of self-collected vaginal samples.
Materials and Methods
A subset of 1,665 women (18-50 years of age) participating in a cervical cancer screening study were screened by liquid-based cytology and by high-risk HPV DNA testing of both self-collected vaginal swab samples and clinician-collected cervical samples. Women with positive/abnormal screening test results and a subset of women with negative screening test results were triaged to colposcopy. Based on individual and combined test results, five screening strategies were defined. Estimates of sensitivity and specificity for cervical intraepithelial neoplasia grade 2 or worse were calculated and a Markov model was used to estimate the incremental cost-effectiveness ratios (ICERs) for each strategy.
Compared to cytology-based screening, high-risk HPV DNA testing of self-collected vaginal samples was more sensitive (68%, 95%CI=58%-78% versus 85%, 95%CI=76%-94%) but less specific (89%, 95%CI=86%-91% versus 73%, 95%CI=67%-79%). A strategy of high-risk HPV DNA testing of self-collected vaginal samples followed by cytology triage of HPV positive women, was comparably sensitive (75%, 95%CI=64%-86%) and specific (88%, 95%CI=85%-92%) to cytology-based screening. In-home self-collection for high-risk HPV DNA detection followed by in-clinic cytology triage had a slightly lower lifetime cost and a slightly higher quality-adjusted life expectancy than did cytology-based screening (ICER of triennial screening compared to no screening was $9,871/QALY and $12,878/QALY, respectively).
Triennial screening by high-risk HPV DNA testing of in-home, self-collected vaginal samples followed by in-clinic cytology triage was cost-effective.
PMCID: PMC2898894  PMID: 20592553
cervical cancer; screening; hpv; self-collect; cost-effectiveness
2.  Baseline human papillomavirus type 16 and 18 DNA load and persistence of the type-specific infection during a 2-year follow-up 
The Journal of infectious diseases  2009;200(11):1789-1797.
Studies of viral load-related persistence of human papillomavirus (HPV) infection are rare, with inconsistent results reported.
Study subjects were 741 and 289 women who were positive for HPV16 and HPV18, respectively, at enrollment into in the ASCUS-LSIL Triage Study and who returned one or more times for HPV testing during a biannual 2-year follow-up. Baseline HPV16 and HPV18 copies per nanogram of cellular DNA were measured by real-time polymerase chain reaction.
Women with, compared to without, persistent infection at month 6 had higher viral load at enrollment (P<0.001 for HPV16; P=0.01 for HPV18). The association of per 1 log10-unit increase in viral load with the first 6-month persistence of HPV16 or HPV18 was statistically significant among women with multiple types at enrollment (OR=1.53, 95% CI, 1.29–1.82 for HPV16; OR=1.35, 95% CI, 1.09–1.68 for HPV18) but not among those with mono-type infections (test for interaction between viral load and coinfection: P=0.002 for HPV16; P=0.34 for HPV18). Among women who continued to be positive at month 6, 12, or 18, persisting for another 6 months was unrelated to baseline viral load.
Higher viral load of prevalent HPV16 or HPV18 infection was associated with short- but not long-term persistence.
PMCID: PMC2783915  PMID: 19848609
Human Papillomavirus; Viral Load; Persistence
3.  Longer-term efficacy of a prophylactic monovalent human papillomavirus type 16 vaccine 
Vaccine  2009;27(41):5612-5619.
We conducted an extended follow-up study (March 2006 – May 2008) to assess the longer-term efficacy of a prophylactic monovalent human papillomavirus (HPV) type 16 L1 virus-like particle vaccine in women (n = 290) who had enrolled in a randomized controlled trial of this vaccine during October 1998 – November 1999 in Seattle and remained HPV-16 DNA negative during the course of that trial. During the extended follow-up period, none of the vaccine recipients was found to be infected with HPV-16 or developed HPV-16-related cervical lesions; among placebo recipients, 6 women were found to be infected with HPV-16 (vaccine efficacy [VE] = 100%; 95% confidence interval [CI]: 29% – 100%) and 3 women developed HPV-16-related cervical lesions (VE = 100%; 95% CI: <0% – 100%). Approximately 86% of vaccine recipients remained HPV-16 competitive Luminex immunoassay seropositive at an average of 8.5 years of follow-up. During the combined original trial and extended follow-up period, 20 and 22 women developed any cervical lesion regardless of HPV type among the vaccine and placebo recipients, respectively (VE = 15%; 95% CI: <0% – 56%). The results suggest that this monovalent HPV-16 vaccine remains efficacious through 8.5 years after its administration.
PMCID: PMC2749988  PMID: 19647066
Human papillomavirus type 16; Prophylactic vaccines; Efficacy
4.  Human Papillomavirus Type 18 DNA Load and 2-Year Cumulative Diagnoses of Cervical Intraepithelial Neoplasia Grades 2–3 
The clinical relevance of the amount of human papillomavirus type 18 (HPV18) DNA in cervical tissue (ie, HPV18 DNA load) is unknown.
Study subjects were 303 women who were HPV18 positive at enrollment into the Atypical Squamous Cells of Undetermined Significance (ASC-US) and Low-Grade Squamous Intraepithelial Lesion (LSIL) Triage Study. HPV18 DNA load, expressed as copies of HPV18 per nanogram of cellular DNA, at enrollment was quantitatively measured. Subjects were followed up semiannually for a period of 2 years for detection of cervical intraepithelial neoplasia 2–3 (CIN2–3). A linear regression model was used to examine associations of CIN2–3 with HPV18 DNA load. All statistical tests were two-sided.
CIN2–3 was confirmed in 92 of 303 (30.4%) HPV18-positive women. Among women without CIN2–3, HPV18 DNA load was positively associated with increasing severity of cervical cytology at enrollment (Ptrend < .001). However, among those with CIN2–3, HPV18 DNA load was not associated with severity of cervical cytology at enrollment (Ptrend = .33). The ratios of geometric means of HPV18 DNA load at enrollment among women with CIN2–3, relative to those without, were 6.06 (95% confidence interval [CI] = 0.31 to 117.92) for those with normal cytology at enrollment, 0.50 (95% CI = 0.10 to 2.44) for those with ASC-US, 0.11 (95% CI = 0.03 to 0.46) for those with LSIL, and 0.07 (95% CI = 0.01 to 0.80) for those with high-grade squamous intraepithelial lesion (HSIL). After adjusting for age and coinfection with other high-risk HPVs, a statistically significant association of lower HPV18 DNA load with CIN2–3 was observed among women with LSIL or HSIL at enrollment (P = .02). Within the 2-year period, HPV18 DNA load was unrelated to the timing of CIN2–3 diagnosis. Overall results were similar when the outcome was CIN3.
HPV18 DNA load was higher for women with LSIL or HSIL at enrollment with no evidence of CIN2–3 during the 2-year follow-up period than it was for women with CIN2–3. Thus, testing for high levels of HPV18 DNA does not appear to be clinically useful.
PMCID: PMC2724855  PMID: 19176451
5.  Sequence Variation of Human Papillomavirus Type 16 and Measurement of Viral Integration by Quantitative PCR▿  
Journal of Clinical Microbiology  2008;47(3):521-526.
Given that the integration of human papillomavirus type 16 (HPV16) into the host genome occurs preferentially with the disruption of the E2 gene, a ratio of E2 to E7 gene copies is often used as a marker for integration. It is largely undetermined, however, whether ratio estimates are affected by HPV intratypic variations. We assembled four plasmid constructs, each containing a DNA fragment from an HPV16 European, Asian-American, African-1, or African-2 variant. These constructs and nine cervical swab samples were assayed by real-time PCR with two primer-probe sets for each gene: a specific set, fully complementary to the HPV16 prototype, and a degenerate set, incorporating degenerate bases at positions where nucleotides differed among the variants. The ratio of E2 to E7 gene copies for the European variant construct was close to 1, no matter which sets of primers and probes were used. While the ratios for the African-1 and Asian-American variant constructs remained close to 1 with the degenerate sets of primers and probes, the ratios were 0.36 and 2.57, respectively, with the specific sets of primers and probes. In addition, a nucleotide alteration at the position immediately following the 3′ end of the E2 forward primer binding site was found to be responsible for an underestimation of E2 gene copies for the African-2 variant construct. Similar patterns were found in nine cervical samples. In conclusion, mismatches between the primers and probes and their targets due to HPV16 intratypic variations would introduce errors in testing for integration; this situation can be sufficiently ameliorated by incorporating degenerate bases into the primers and probes.
PMCID: PMC2650947  PMID: 19116350

Results 1-5 (5)