Human papillomavirus 16 and 18 infection of the uterine cervix in women with different grades of cervical intraepithelial neoplasia (CIN)

Cervicovaginal microbiome and natural history of HPV in a longitudinal study

BACKGROUND

Human papillomavirus (HPV) infection is one of the most common sexually transmitted infections. However, only a small percentage of high-risk (HR) HPV infections progress to cervical precancer and cancer. In this study, we investigated the role of the cervicovaginal microbiome (CVM) in the natural history of HR-HPV.

METHODS

This study was nested within the placebo arm of the Costa Rica HPV Vaccine Trial that included women aged 18-25 years of age. Cervical samples from two visits of women with an incident HR-HPV infection (n = 273 women) were used to evaluate the prospective role of the CVM on the natural history of HR-HPV. We focus specifically on infection clearance, persistence, and progression to cervical intraepithelial neoplasia grade 2 and 3 (CIN2+). The CVM was characterized by amplification and sequencing the bacterial 16S V4 rRNA gene region and the fungal ITS1 region using an Illumina MiSeq platform. OTU clustering was performed using QIIME2. Functional groups were imputed using PICRUSt and statistical analyses were performed using R.

RESULTS

At Visit 1 (V1) abundance of Lactobacillus iners was associated with clearance of incident HR-HPV infections (Linear Discriminant Analysis (LDA)>4.0), whereas V1 Gardnerella was the dominant biomarker for HR-HPV progression (LDA>4.0). At visit 2 (V2), increased microbial Shannon diversity was significantly associated with progression to CIN2+ (p = 0.027). Multivariate mediation analysis revealed that the positive association of V1 Gardnerella with CIN2+ progression was due to the increased cervicovaginal diversity at V2 (p = 0.040). A full multivariate model of key components of the CVM showed significant protective effects via V1 genus Lactobacillus, OR = 0.41 (0.22-0.79), V1 fungal diversity, OR = 0.90 (0.82-1.00) and V1 functional Cell Motility pathway, OR = 0.75 (0.62-0.92), whereas V2 bacterial diversity, OR = 1.19 (1.03-1.38) was shown to be predictive of progression to CIN2+.

CONCLUSION

This study demonstrates that features of the cervicovaginal microbiome are associated with HR-HPV progression in a prospective longitudinal cohort. The analyses indicated that the association of Gardnerella and progression to CIN2+ may actually be mediated by subsequent elevation of microbial diversity. Identified features of the microbiome associated with HR-HPV progression may be targets for therapeutic manipulation to prevent CIN2+.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00128661.

Correlation of human papillomavirus and adeno-associated virus 2 infection in cytology with Korean women

The purpose of our prospective study was to investigate the prevalence of adeno-associated virus (AAV) and human papillomavirus (HPV) 16 and/or HPV 18 infection in Korean women with normal cervical smears and those with HPV-associated cervical intraepithelial neoplasia (CIN) and cancer in cytobrush samples, and to evaluate the correlation between AAV 2 and HPV 16 and/or HPV 18 infection. AAV 2 was detected in CIN I (9.7%), CIN II (20%), CIN III (22.8%), and cancer (10%). HPV 16 was detected in CIN I (42%), CIN II (55%), CIN III (54.3%), and cancer (70%). HPV 18 was detected in CIN I (51.6%), CIN II (50%), CIN III (62.8%), and cancer (43.3%). HPV 16 or HPV 18 was detected in CIN I (18.3%), CIN II (80%), CIN III (71.4%), and cancer (80%). In normal and HPV-infected group, AAV 2 DNA was detected in 16.3% and 4.4% of samples, respectively. HPV 16 was detected in 10.2% of normal patients and in 44.4% of HPV-infected patients, and HPV 18 was detected in 12.2% of normal patients and in 40% of HPV-infected patients. HPV 16 or HPV 18 was detected in 18.3% of normal patients and in 57.7% of HPV infection. The correlation between AAV 2 and HPV 16 was statistically significant in normal and CIN I/II group only, and AAV 2 and HPV 16 and/or HPV 18 showed no correlation. Therefore, the correlation between AAV and HPV were not statistically significant. These data support the previous reports that AAV might not be associated with cervical tumorigenesis.

Searching for pathogenic gene functions to cervical cancer

OBJECTIVES

Molecular pathology of cervical cancers associated with human papillomavirus (HPV) infection is presently unclear. In an effort to clarify this issue, we investigated gene expression profiles and pathogenic cellular processes of cervical cancer lesions.

METHODS

Tissues of 11 patients (invasive cancer stages Ib-IIIa) were investigated by a cDNA microarray of 4700 genes, hierarchical clustering and the Gene Ontology (GO).

RESULTS

We identified 74 genes showing a more than 2-fold difference in their expression in at least 8 out of 11 patients. Among these, 33 genes were up-regulated, in contrast, 41 genes were down-regulated. The gene expression profiles were classified into mutually dependent 345 function sets, resulting in 611 cellular processes according to the GO. The GO analysis showed that cervical carcinogenesis underwent complete down-regulation of cell death, protein biosynthesis, and nucleic acid metabolism. Also, genes belonging to nucleic acid binding and structural molecule activity were significantly down-regulated. In contrast, significant up-regulation was shown in skeletal development, immune response, and extracellular activity.

CONCLUSIONS

These data suggest that the regulated genes and cellular processes could be further used for predicting prognosis and diagnosis of cervical cancer patients, and further investigation and functional characterization of the identified genes is warranted.

Evaluation of adenoassociated virus 2 and human papilloma virus 16 and 18 infection in cervical cancer biopsies

OBJECTIVE

Protective roles of adenoassociated virus (AAV) 2 in cervical tumorigenesis are controversial. In an effort to clarify this issue, we tested prevalence of AAV 2 and human papillomavirus (HPV) infection in cervical lesions and adjacent normal tissues.

METHODS

Tissues of cervical intraepithelial neoplasm (CIN) I (20 patients), CIN II (24 patients), CIN III (25 patients), and invasive cancer (23 patients) were investigated by microdissection and PCR using HPV-16-, HVP-18-, and AAV-2-specific primers.

RESULTS

AAV 2 was detected in 11 out of 20 CIN I (55%), 21 out of 24 CIN II (84.5%), 13 out of 25 CIN III (52%), and 12 out of 23 invasive cancer cases (52.2%). However, HPV 16 was detected in none out of 20 CIN I, 2 out of 24 CIN II (8.3%), 6 out of 25 CIN III (24%), and 6 out of 23 invasive cancer cases (26.1%). HPV 18 was detected in 1 case in CIN II (4.2%) and 2 cases in CIN III (8%). In 92 perilesional normal tissues, AAV 2 was detected in 53 cases (57.6%), displaying 25% of CIN I, 83.3% of CIN II, 52% of CIN III, and 65.2% of invasive cancer.

CONCLUSION

The differences in AAV 2 prevalence are not significant between CIN and normal tissues. However, differences in HPV 16 are significant in CIN III and invasive cancer, as compared to CIN I, CIN II, and normal, suggesting no significant correlation between AAV 2 and cervical cancer. Thus, these results support the notion that AAV 2 is not associated with cervical tumorigenesis.

How should we grade CIN?

How should we grade CIN? The grading of cervical intraepithelial neoplasia (CIN) is problematic. CIN represents a morphological continuum, but biopsies displaying this lesion are classified into two (e.g. Bethesda) or three grade categories, sometimes with poor reproducibility. There are also difficulties in reliably distinguishing low-grade CIN from its reactive simulants. Because of problems with inter- and intra-observer disagreement in the grading of CIN and the diagnosis of low-grade lesions, three expert contributions were commissioned to address the question 'how should we grade CIN?'.