Association of plasma aflatoxin with persistent detection of oncogenic human papillomaviruses in cervical samples from Kenyan women enrolled in a longitudinal study

BACKGROUND

Cervical cancer is caused by oncogenic human papillomaviruses (HR-HPV) and is common among Kenyan women. Identification of factors that increase HR-HPV persistence is critically important. Kenyan women exposed to aflatoxin have an increased risk of HR-HPV detection in cervical specimens. This analysis was performed to examine associations between aflatoxin and HR-HPV persistence.

METHODS

Kenyan women were enrolled in a prospective study. The analytical cohort for this analysis included 67 HIV-uninfected women (mean age 34 years) who completed at least two of three annual study visits and had an available blood sample. Plasma aflatoxin was detected using ultra-high pressure liquid chromatography (UHPLC)-isotope dilution mass spectrometry. Annual cervical swabs were tested for HPV (Roche Linear Array). Ordinal logistic regression models were fitted to examine associations of aflatoxin and HPV persistence.

RESULTS

Aflatoxin was detected in 59.7% of women and was associated with higher risk of persistent detection of any HPV type (OR = 3.03, 95%CI = 1.08-8.55, P = 0.036), HR-HPV types (OR = 3.63, 95%CI = 1.30-10.13, P = 0.014), and HR-HPV types not included in the 9-valent HPV vaccine (OR = 4.46, 95%CI = 1.13-17.58, P = 0.032).

CONCLUSIONS

Aflatoxin detection was associated with increased risk of HR-HPV persistence in Kenyan women. Further studies, including mechanistic studies are needed to determine if aflatoxin synergistically interacts with HR-HPV to increase cervical cancer risk.

Association of Plasma Aflatoxin With Persistent Detection of Oncogenic Human Papillomaviruses in Cervical Samples From Kenyan Women Enrolled in a Longitudinal Study

Background Cervical cancer is common among Kenyan women and is caused by oncogenic human papillomaviruses (HR-HPV). Identification of factors that increase HR-HPV persistence is critically important. Kenyan women exposed to aflatoxin have an increased risk of cervical HR-HPV detection. This analysis was performed to examine associations between aflatoxin and HR-HPV persistence. Methods Kenyan women were enrolled in a prospective study. The analytical cohort for this analysis included 67 HIV-uninfected women (mean age 34 years) who completed at least two of three annual study visits and had an available blood sample. Plasma aflatoxin was detected using ultra-high pressure liquid chromatography (UHPLC)-isotope dilution mass spectrometry. Annual cervical swabs were tested for HPV (Roche Linear Array). Ordinal logistic regression models were fitted to examine associations of aflatoxin and HPV persistence. Results Aflatoxin was detected in 59.7% of women and was associated with higher risk of persistent detection of any HPV type (OR = 3.03, 95%CI = 1.08-8.55, P = 0.036), HR-HPV types (OR = 3.63, 95%CI = 1.30-10.13, P = 0.014), and HR-HPV types not included in the 9-valent HPV vaccine (OR = 4.46, 95%CI = 1.13-17.58, P = 0.032). Conclusions Aflatoxin detection was associated with increased risk of HR-HPV persistence in Kenyan women. Further studies are needed to determine if aflatoxin synergistically interacts with HR-HPV to increase cervical cancer risk.

The East Africa Consortium for human papillomavirus and cervical cancer in women living with HIV/AIDS

The East Africa Consortium was formed to study the epidemiology of human papillomavirus (HPV) infections and cervical cancer and the influence of human immunodeficiency virus (HIV) infection on HPV and cervical cancer, and to encourage collaborations between researchers in North America and East African countries. To date, studies have led to a better understanding of the influence of HIV infection on the detection and persistence of oncogenic HPV, the effects of dietary aflatoxin on the persistence of HPV, the benefits of antiretroviral therapy on HPV persistence, and the differences in HPV detections among HIV-infected and HIV-uninfected women undergoing treatment for cervical dysplasia by either cryotherapy or LEEP. It will now be determined how HPV testing fits into cervical cancer screening programs in Kenya and Uganda, how aflatoxin influences immunological control of HIV, how HPV alters certain genes involved in the growth of tumours in HIV-infected women. Although there have been challenges in performing this research, with time, this work should help to reduce the burden of cervical cancer and other cancers related to HIV infection in people living in sub-Saharan Africa, as well as optimized processes to better facilitate research as well as patient autonomy and safety. KEY MESSAGESThe East Africa Consortium was formed to study the epidemiology of human papillomavirus (HPV) infections and cervical cancer and the influence of human immunodeficiency virus (HIV) infection on HPV and cervical cancer.Collaborations have been established between researchers in North America and East African countries for these studies.Studies have led to a better understanding of the influence of HIV infection on the detection and persistence of oncogenic HPV, the effects of dietary aflatoxin on HPV detection, the benefits of antiretroviral therapy on HPV persistence, and the differences in HPV detections among HIV-infected and HIV-uninfected women undergoing treatment for cervical dysplasia by either cryotherapy or LEEP.

A community-based approach to cervical cancer prevention in western Kenya: An AMPATH feasibility project

Objectives

Centralized programs have been ineffective in reducing the burden of cervical cancer among Kenyan women. A community-based pilot study was initiated to screen Kenyan women for cervical cancer and to vaccinate their children against human papillomavirus (HPV).

Methods

Women were educated about cervical cancer prevention at community meetings. Women then provided self-collected vaginal swabs for oncogenic HPV testing using the Roche Cobas Assay. All women were then referred to the local clinic for Visual Inspection with Acetic Acid (VIA). Women were offered the quadrivalent HPV vaccine for their children if and when it became available for the study.

Results

Women in western Kenya were invited to participate in community meetings. A total of 200 women were enrolled: 151 (75.5%) were HIV-uninfected and 49 (24.5%) were HIV-infected; the median age for all women was 42 years. High-risk (HR)-HPV types were detected in 49 of swabs from all 200 participants (24.5%) including 20.5% of HIV-uninfected women and 36.7% of HIV-infected women (P = .022). VIA was performed on 198 women: 192 had normal examinations and six had abnormal examinations. Five cervical biopsies revealed two cases of CIN 2 and one CIN 3. Although all mothers were willing to have their children (N = 432) vaccinated, the HPV vaccine could not be delivered to Kenya during the study period.

Conclusions

Kenyan women were willing to attend community meetings to learn about prevention of cervical cancer, to provide self-collected vaginal swabs for HPV testing, to travel to the Webuye Clinic for VIA following the collection of swabs, and to have their children vaccinated against HPV. HR-HPV was prevalent, especially in HIV-infected women. As a result of this pilot study, this community-based strategy to prevent cervical cancer will be continued in western Kenya.

Can Salivary Innate Immune Molecules Provide Clue on Taste Dysfunction in COVID-19?

Emerging concerns following the severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) pandemic are the long-term effects of coronavirus disease (COVID)-19. Dysgeusia in COVID-19 is supported by the abundant expression of the entry receptor, angiotensin-converting enzyme-2 (ACE2), in the oral mucosa. The invading virus perturbs the commensal biofilm and regulates the host responses that permit or suppress viral infection. We correlated the microbial recognition receptors and soluble ACE2 (sACE2) with the SARS-CoV2 measures in the saliva of COVID-19 patients. Data indicate that the toll-like receptor-4, peptidoglycan recognition protein, and sACE2 are elevated in COVID-19 saliva and correlate moderately with the viral load.

Longer duration of anti-retroviral therapy is associated with decreased risk of human papillomaviruses detection in Kenyan women living with HIV

OBJECTIVE

A longitudinal study was conducted among women living with HIV in Kenya to determine if duration of anti-retroviral (ART) usage altered detection and persistence of oncogenic (high-risk) human papillomaviruses (HR-HPV).

METHODS

Women living with HIV without cervical dysplasia were enrolled at a cervical cancer screening clinic. Three cervical swabs, HIV viral loads, and CD4 cell counts were obtained at enrollment and at two annual visits. HPV genotyping was performed on swabs (Roche Linear Array). Linear regression models assessed effects of ART duration on HR-HPV detection and persistence.

RESULTS

Seventy-seven women, median age 38 years, completed three study visits and were included in the analysis. The mean time from HIV diagnosis to enrollment was 9.6 years (SD 3.9 years). The mean ART duration was 6.2 years (SD 3.1 years). Most women had undetectable HIV viral loads and CD4 cell counts above 500 cells/L. Each additional year of ART use reduced the likelihood of detection of HR-HPV by 10-15% and persistent detection of A9 HR-HPV by 20%.

CONCLUSION

Among Kenyan women living with HIV, longer duration of ART use was associated with significantly reduced risk of all detection and persistent detection of HR-HPV.

Persistence of oncogenic and non-oncogenic human papillomavirus is associated with human immunodeficiency virus infection in Kenyan women

OBJECTIVES

Cervical cancer is caused by persistent infection with oncogenic, or "high-risk" types of human papillomaviruses, and is the most common malignancy in Kenyan women. A longitudinal study was initiated to investigate factors associated with persistent human papillomavirus detection among HIV-infected and HIV-uninfected Kenyan women without evidence of cervical dysplasia.

METHODS

Demographic/behavioral data and cervical swabs were collected from HIV-uninfected women (n = 82) and HIV-infected women (n = 101) at enrollment and annually for 2 years. Human papillomavirus typing was performed on swabs (Roche Linear Array). Logistic regression models of human papillomavirus persistence were adjusted for demographic and behavioral characteristics.

RESULTS

HIV-infected women were older and less likely to be married and to own a home and had more lifetime sexual partners than HIV-uninfected women. All HIV-infected women were receiving anti-retroviral therapy at enrollment and had satisfactory CD4 cell counts and HIV viral loads. One- and two-year persistent human papillomavirus detection was significantly associated with HIV infection for any human papillomavirus, high-risk human papillomavirus, International Agency for the Research on Cancer-classified high-risk human papillomavirus, and non-oncogenic "low-risk" human papillomavirus.

CONCLUSION

Persistent detection of oncogenic and non-oncogenic human papillomavirus was strongly associated with HIV infection in Kenyan women with re-constituted immune systems based on satisfactory CD4 cell counts. In addition to HIV infection, factors associated with an increased risk of human papillomavirus persistence included a higher number of lifetime sex partners. Factors associated with decreased risk of human papillomavirus persistence included older age and being married. Further studies are needed to identify the immunological defects in HIV-infected women that allow human papillomavirus persistence, even in women receiving effective anti-retroviral therapy. Further studies are also needed to determine the significance of low-risk human papillomavirus persistence in HIV-infected women.

Evaluation of the Performance of a Point-of-Care Test for Chlamydia and Gonorrhea

IMPORTANCE

Rates of chlamydial and gonococcal infection continue to increase in the United States, as do the associated costs of untreated infections. Improved diagnostic technologies that support testing and treating in 1 clinical visit are critical to advancing efforts to control the rates of chlamydial and gonococcal infection.

OBJECTIVE

To evaluate the clinical performance of a point-of-care (POC) molecular diagnostic assay for the detection of chlamydia and gonorrhea.

DESIGN, SETTING, AND PARTICIPANTS

A noninterventional, cross-sectional clinical study was conducted from September 18, 2018, through March 13, 2019, at sexually transmitted infection (STI), HIV, family planning, and obstetrics and gynecology clinics where STI screening is routine, using a convenience sample and comparing commercially available assays with a new 30-minute POC assay. Patients included were those eligible for STI screening or diagnostic testing who had not taken antibiotics effective against chlamydia or gonorrhea within the previous 28 days. Four vaginal swab samples were collected from women and a first-catch urine sample was obtained from men.

MAIN OUTCOMES AND MEASURES

A composite infection status was used to classify participants as infected if 2 or more comparator results were positive, as not infected if 2 or more comparator samples were negative, and as unevaluable if 1 result was invalid and the other 2 results did not agree with each other.

RESULTS

Swab samples from 1523 women (median age, 27 years [interquartile range, 17-37 years]), 817 (53.6%) of whom presented with symptoms, and 922 men (median age, 29 years [interquartile range, 17-41 years]), 308 (33.4%) of whom were symptomatic, were tested. For chlamydia, sensitivity of the new POC assay was 96.1% (95% CI, 91.2%-98.3%) for women and 92.5% (95% CI, 86.4%-96.0%) for men. For gonorrhea, sensitivity estimates were 100.0% (95% CI, 92.1%-100.0%) for women and 97.3% (95% CI, 90.7%-99.3%) for men. For chlamydia, specificity of the new POC assay was 99.1% (95% CI, 98.4%-99.5%) for women and 99.3% (95% CI, 98.4%-99.7%) for men. For gonorrhea, specificity estimates were 99.9% (95% CI, 99.5%-100%) for women and 100% (95% CI, 95.5%-100%) for men. Non-laboratory-trained personnel performed 94.8% of all tests (2318 of 2445) during the study.

CONCLUSIONS AND RELEVANCE

This study suggests that self-obtained vaginal swab samples were associated with performance equivalent to laboratory-based molecular diagnostics, which can support use of this POC assay in many settings. The availability of an easy-to-use, rapid (30-minute) molecular test for accurate detection of chlamydia and gonorrhea has the power to facilitate testing and treatment in a single patient visit for these STIs.

Detection and Concentration of Plasma Aflatoxin is Associated with Detection of Oncogenic Human Papillomavirus in Kenyan Women

BACKGROUND

Cervical cancer is common in Kenyan women. Cofactors in addition to infection with oncogenic human papillomavirus (HPV) are likely to be important in causing cervical cancer, as only a small percentage of HPV-infected women will develop this malignancy. Kenyan women are exposed to dietary aflatoxin, a potent carcinogen and immunosuppressive agent, which may be such a co-factor.

METHODS

Demographics, behavioral data, plasma, and cervical swabs were collected from 88 HIV-uninfected Kenyan women without cervical dysplasia. HPV detection was compared between women with or without plasma AFB1-lys and evaluated in relation to AFB1-lys concentration.

RESULTS

Valid HPV testing results were available for 86 women (mean age 34.0 years); 49 women (57.0%) had AFB1-lys detected and 37 (43.0%) had none. AFB1-lys detection was not associated with age, being married, having more than secondary school education, home ownership, living at a walking distance to health care ≥60 minutes, number of lifetime sex partners, or age of first sex. AFB1-lys detection and plasma concentrations were associated with detection of oncogenic HPV types.

CONCLUSIONS

AFB1-lys-positivity and higher plasma AFB1-lys concentrations were associated with higher risk of oncogenic HPV detection in cervical samples from Kenya women. Further studies are needed to determine if aflatoxin interacts with HPV in a synergistic manner to increase the risk of cervical cancer.

Comparison of HPV detection in HIV-infected and HIV-uninfected Kenyan women with or without cervical dysplasia

e17015

Background: Cervical cancer, a malignancy caused by human papillomavirus (HPV) infection, is the most common malignancy in women living in sub-Saharan African countries including Kenya. HIV co-infection accelerates the natural course of cervical cancer. To determine the specific HPV type distribution in HIV-infected women compared to HIV-uninfected women, with and without evidence of cervical dysplasia. Methods: Demographic information, behavioral data, and a cervical swab were collected from women 18 and 45 years of age, HIV-infected or HIV-uninfected, who presented for cervical cancer screening at Moi Referral and Teaching Hospital in Eldoret, Kenya. Women were triaged based on the presence or absence of cervical dysplasia. HPV testing was performed using the Roche Linear Array Assay. Results were compared between women with or without HIV co-infection and between those with or without cervical dysplasia, using Chi-square tests or Fisher’s exact tests. Results: 223 women had normal VIAs. All had HPV testing, 221 had valid results: 115 HIV-infected women (mean age 37 years) and 106 HIV-uninfected (mean age 33 years). 175 women had abnormal VIAs. 143 women had HPV testing performed, 140 had valid results: 70 HIV-infected women (mean age 38.5 years) and 70 HIV-uninfected (mean age 31.3 years). Greater than 90% of all HIV-infected women in both projects were receiving anti-retroviral therapy at enrollment. HPV of any type was detected in 48% of all women with normal VIA vs. 61% of women with abnormal VIA (P = 0.018). High risk (HR)-HPV was detected in 38% of all women with normal VIA vs. 51% of all women with abnormal VIA (P = 0.012). HIV-uninfected women with normal VIA had significantly lower detection of all HPV (P = 0.026), high risk-HPV (P = 0.018), IARC high risk-HPV (P = 0.047), A9 types (P = 0.050), and individual types HPV 16 (P = 0.0274), HPV 18 (P = 0.007), and HPV 51 (P = 0.009) than HIV-uninfected women with abnormal VIA. Among HIV-infected women, there was no difference in detection of any group of HPV types or individual types with respect to VIA results. Conclusions: HIV-uninfected women without cervical dysplasia had lower detection of oncogenic HPV than HIV-uninfected women with dysplasia. In contrast, HPV detection did not differ among HIV-infected women between those with or without cervical dysplasia. In addition, VIA appears to lack specificity for HPV-associated cervical dysplasia, as 39% of women with abnormal VIA examinations did not have any HPV detected, and 49% of women with abnormal VIA examinations did not have any HR-HPV detected.

Association of detection of aflatoxin in plasma of Kenyan women with increased detection of oncogenic HPV

5530

Background: Cervical cancer is the leading cause of cancer-related deaths among women living in Africa. Only a small proportion of HPV-infected women develop cervical cancer and other cofactors may increase a woman’s risk of developing cervical cancer. Aflatoxin, a potent carcinogen and immunosuppressive agent, is produced by fungi that contaminate corn and other staple foods in sub-Saharan Africa. Women who ingest aflatoxin may be more likely to have persistent infections with oncogenic HPV type. Methods: Demographics, behavioral data, plasma, and cervical swabs were collected from HIV-uninfected women 18 and 45 years of age who presented for cervical cancer screening at Moi Referral and Teaching Hospital (Eldoret, Kenya) and had normal VIA examination. HPV testing was performed on cervical swabs using the Roche Linear Array Assay. Aflatoxin-albumin adduct (AFB1-lys) was detected and quantified in plasma. The association of plasma AFB1-lys detection and concentration and the detection of HPV was examined. Results: Sufficient plasma was available from 88 HIV-uninfected women and was transported to the U.S. for aflatoxin testing. Valid HPV testing results were available for 86 of these women (mean age 34.0 years); 49 women (57.0%) had detectable AFB1-lys and 37 (43.0%) had no detection. Substantial variation existed in plasma AFB1-lys concentrations among the 49 women (range 0.02 to 0.21 pg/µL). Detection of AFB1-lys was not associated with age, and other behavioral factors such as number of lifetime partners, marital status and age at first sex. AFB1-lys detection was associated with detection of A9 HPV types (HPV 16, 31, 33, 35, 52, and 58) as a group in cervical swabs (p = 0.029) as well as A9 types excluding HPV 16 (p = 0.020), but not with individual A9 types, A7 HPV types (such as HPV 18), or low-risk HPV types. A concentration dependent association of AFB1-lys was seen with detection of A9 HPV types as a group (p = 0.009), non-HPV 16 A9 types (p = 0.005), and HPV 52 (p = 0.042), but not with the A7 HPV types. Conclusions: AFB1-lys was detected in 57% of HIV-uninfected Kenyan women without cervical dysplasia. AFB1-lys-positive women were more likely than AFB1-lys-negative women to have oncogenic HPV A9 types detected. Higher plasma AFB1-lys concentrations were associated with increased likelihood of oncogenic HPV A9 type detection. Further studies are needed to determine if chronic exposure to aflatoxin interacts with HPV infection (and possibly HIV co-infection) to modulate the risk of cervical cancer in women in Kenya and other developing countries.

A cross-sectional analysis of factors associated with detection of oncogenic human papillomavirus in human immunodeficiency virus-infected and uninfected Kenyan women

Background

Cervical cancer is caused by oncogenic human papillomaviruses (HPV) and is one of the most common malignancies in women living in sub-Saharan Africa. Women infected with the human immunodeficiency virus (HIV) have a higher incidence of cervical cancer, but the full impact on HPV detection is not well understood, and associations of biological and behavioral factors with oncogenic HPV detection have not been fully examined. Therefore, a study was initiated to investigate factors that are associated with oncogenic HPV detection in Kenyan women.

Methods

Women without cervical dysplasia were enrolled in a longitudinal study. Data from enrollment are presented as a cross-sectional analysis. Demographic and behavioral data was collected, and HPV typing was performed on cervical swabs. HIV-uninfected women (n = 105) and HIV-infected women (n = 115) were compared for demographic and behavioral characteristics using t-tests, Chi-square tests, Wilcoxon sum rank tests or Fisher’s exact tests, and for HPV detection using logistic regression or negative binomial models adjusted for demographic and behavioral characteristics using SAS 9.4 software.

Results

Compared to HIV-uninfected women, HIV-infected women were older, had more lifetime sexual partners, were less likely to be married, were more likely to regularly use condoms, and were more likely to have detection of HPV 16, other oncogenic HPV types, and multiple oncogenic types. In addition to HIV, more lifetime sexual partners was associated with a higher number of oncogenic HPV types (aIRR 1.007, 95% CI 1.007–1.012). Greater travel distance to the clinic was associated with increased HPV detection (aOR for detection of ≥ 2 HPV types: 3.212, 95% CI 1.206–8.552). Older age (aOR for HPV 16 detection: 0.871, 95% CI 0.764–0.993) and more lifetime pregnancies (aOR for detection of oncogenic HPV types: 0.706, 95% CI, 0.565–0.883) were associated with reduced detection.

Conclusion

HIV infection, more lifetime sexual partners, and greater distance to health-care were associated with a higher risk of oncogenic HPV detection, in spite of ART use in those who were HIV-infected. Counseling of women about sexual practices, improved access to health-care facilities, and vaccination against HPV are all potentially important in reducing oncogenic HPV infections.

Redetection of human papillomavirus type 16 infections of the cervix in mid-adult life

PURPOSE

To assess whether HPV 16 originally detected in adolescent women can be redetected in adulthood.

METHODS

A convenience sample of 27 adult women with known HPV 16 detection during adolescence was assessed for HPV 16 redetection. A comparison of the long control region (LCR) DNA sequences was performed on some of the original and redetected HPV 16 isolates.

RESULTS

Median age at reenrollment was 27.5 years (interquartile range of 26.7-29.6). Reenrollment occurred six years on average after the original HPV 16 detection. Eleven of 27 women had HPV 16 redetected. Some of these HPV 16 infections had apparently cleared during adolescence. LCR sequencing was successful in paired isolates from 6 women; in 5 of 6 cases the redetected HPV 16 isolates were identical to those detected during adolescence, CONCLUSIONS: HPV 16 may be episodically detected in young women, even over long time periods. HPV 16 redetection with identical LCR sequences suggests low-level persistent infection rather than true clearance, although newly acquired infection with an identical HPV 16 isolate cannot be excluded. However, this study suggests that a new HPV 16-positive test in a clinical setting may not indicate a new infection.

Invasive cervical cancers in the United States, Botswana and Kenya: HPV type distribution and health policy implications

BACKGROUND

More deaths occur in African women from invasive cervical cancer (ICC) than from any other malignancy. ICC is caused by infection with oncogenic types of human papillomavirus (HPV). Co-infection with the human immunodeficiency virus (HIV) accelerates the natural history of ICC, and may influence the HPV type distribution. Because HPV vaccines are available, this malignancy is theoretically preventable, but the vaccines are largely type-specific in protection against infection. Data on specific HPV types causing ICC in African women is limited, and many studies utilized swab samples rather than actual cancer tissue. A previous study using archived, ICC tissue from women in Botswana identified an unusual HPV type distribution. A similar study was therefore performed in a second sub-Saharan country to provide additional information on the HPV type distribution in ICC.

METHODS

Archived, formalin-fixed, paraffin-embedded ICCs were acquired from women in the United States, Kenya, or Botswana. DNA was extracted and HPV genotyping performed by Roche Linear Array. HIV sequences were identified in ICCs by PCR.

RESULTS

HPV types 16 or 18 (HPV 16/18) were identified in 93.5 % of HPV-positive ICCs from the U.S., 93.8 % from Kenya, and 61.8 % from Botswana (p < 0.0001). Non-HPV 16/18 types were detected in 10.9 % of HPV-positive cancers from the U.S., 17.2 % from Kenya, and 47.8 % from Botswana (p < 0.0001). HIV was detected in 2.2, 31.5, and 32.4 % from ICCs from the U.S., Kenya, or Botswana, respectively (p = 0.0002). The distribution of HPV types was not significantly different between HIVinfected or HIV-uninfected women. The percentages of ICCs theoretically covered by the bivalent/quadrivalent HPV vaccines were 93.5, 93.9, and 61.8 % from the U.S., Kenya and Botswana, respectively, and increased to 100, 98, and 77.8 % for the nanovalent vaccine.

CONCLUSIONS

HPV 16/18 caused most ICCs from the U.S. and western Kenya. Fewer ICCs contained HPV 16/18 in Botswana. HIV co-infection did not influence the HPV type distribution in ICCs from African women from the two countries. Available HPV vaccines should provide protection against most ICCs in the U.S. and Kenya. The recently developed nanovalent vaccine may be more suitable for countries where non-HPV 16/18 types are frequently detected in ICC.

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

BACKGROUND

Cervical cancer is the primary cause of cancer-related deaths in women living in Botswana.

METHODS

Paraffin-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.

RESULTS

HPV 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.

CONCLUSION

This 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.

Association of HPV types 6, 11, 16, and 18 DNA detection and serological response in unvaccinated adolescent women

Antibodies directed against the human papillomavirus (HPV) L1 protein are detected in approximately 70% of individuals with HPV infections. The factors associated with a serological response are not characterized. It is hypothesized that the HPV viral load, duration of detection, or both would be associated with seropositivity in adolescent women. Adolescent women (n = 117), ages 15-17 at enrolment were followed for a mean of 6.2 years. Quarterly vaginal swabs (mean 22 per participant) were used to identify HPV 6, 11, 16, or 18 DNA (Roche PCR/Linear Array). Type-specific HPV infection was defined as ≥2 positive assays. To approximate viral load, Roche PCR/Linear Array test strips were scored visually based on the strength of signal relative to beta-globin controls. Sera collected near the end of study were tested by cLIA. Regression models were fit to assess associations between strength of signal (as represented by mean and cumulative strength of signal), duration of HPV detection, seropositivity, and serotiter. Detection of HPV DNA was associated with seropositivity for four types combined and for types 6, 16, and 18. Overall, 70.1% of DNA positive episodes were associated with type-specific seropositivity. The cumulative HPV DNA signal strength during periods of HPV detection for types 6, 11, 16, and 18 combined was associated with seropositivity (OR = 1.21, 95% CI 1.02-1.44 P = 0.026). No other HPV DNA predictors were found to be associated with seropositivity or serotiter.

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.

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.

The human papillomavirus type 11 E1--E4 protein is a transglutaminase 3 substrate and induces abnormalities of the cornified cell envelope

The human papillomavirus (HPV) E1--E4 protein is detected in the cytoplasm of differentiated keratinocytes, near the cornified cell envelope. HPV does not induce lysis of the infected keratinocyte, and the normally durable cornified cell envelope that forms during keratinocyte differentiation would seemingly inhibit viral egress. HPV infection induces abnormalities of the cornified cell envelope, but the exact mechanisms involved are not well understood. We tested whether the HPV 11 E1--E4 protein, which co-localizes the cell envelope and co-purifies with cell envelope fragments, could serve as an in vitro substrate for transglutaminases. We found evidence of E1--E4 cross-linking by endogenous transglutaminases in an in situ assay using frozen sections of human foreskin, and in addition, E1--E4 protein was cross-linked by recombinant transglutaminase 3 (but not transglutaminase 1) in an in vitro cross-linking assay. We also tested whether expression of E1--E4 in differentiated keratinocytes would induce morphologic alterations of cornified cell envelopes. Differentiated keratinocytes expressing E1--E4 were disorganized and pleomorphic compared to control cells, and cell envelopes purified from E1--E4-expressing cells were small, fragmented, and rough bordered compared to the round, smooth bordered cell envelopes from control cells. We conclude from these in vitro experiments that the E1--E4 protein is cross-linked by transglutaminase 3, and that E1--E4 expression in differentiated keratinocytes induces morphologic abnormalities of the cornified cell envelope.