Human papillomavirus typing and viral gene expression analysis for the triage of women with abnormal results from papanicolaou test smears to colposcopy.
BACKGROUND
A cascade of molecular tests for human papillomavirus (HPV), as a follow-up to Papanicolaou test screening, could eliminate unnecessary colposcopy. Tests based on detection of HPV E6 messenger RNA (mRNA) are already being used as screening tools, but there is a good biological rationale for expecting that an increase in the relative amounts of HPV E6 mRNA in cervical samples may better predict cancerous transformation.


OBJECTIVE
To compare some of the available diagnostic methods and our novel method of relative quantification (RQ) of HPV gene expression for the effective triage of women with abnormal results from Papanicolaou tests to colposcopy.


METHODS
Sensitivities, specificities, and likelihood ratios were calculated for repeat Papanicolaou test smears, HPV DNA polymerase chain reactions, HPV genotyping, HPV-16 E6 mRNA detection, and the RQ of HPV-16 E6 mRNA calibrated to cellular RNA and DNA levels and standardized to viral load.


RESULTS
Human papillomavirus genotype in combination with a repeat Papanicolaou test can be used to categorize most women (96%) with cervical intraepithelial neoplasia of grade 2 or higher for colposcopy while eliminating 44% of women with cervical intraepithelial neoplasia 1 or less. The presence of HPV-16 E6 mRNA (P < .001) and RQ of HPV-16 E6 mRNA (P < .001) displayed significant median differences among the various grades of cervical intraepithelial neoplasia. Further testing of women who are positive for HPV-16 demonstrated that the RQ of E6 mRNA has diagnostic potential when combined with Papanicolaou testing in populations with higher disease prevalence.


CONCLUSIONS
The RQ of HPV E6 mRNA and HPV genotype could be useful in a cascade of diagnostic testing designed to refer women with findings of cervical abnormalities for colposcopy or treatment while reducing triage numbers.
Department of Chemistry and Biochemistry, University of Regina, Regina, Saskatchewan, Canada. nantonis@health.gov.sk.ca
Nick A
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Antonishyn
Greg B
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Horsman
Rod A
RA
Kelln
Alberto
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Severini
D014408:Biomarkers, Tumor / Q000378:metabolism; D003127:Colposcopy; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D005814:Genes, Viral / Q000235:genetics; D052162:Human papillomavirus 16 / Q000145:classification* / Q000235:genetics*; D006801:Humans; D009856:Oncogene Proteins, Viral / Q000235:genetics; D065006:Papanicolaou Test; D030361:Papillomavirus Infections / Q000473:pathology / Q000821:virology*; D011237:Predictive Value of Tests; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000032:analysis; D012097:Repressor Proteins / Q000235:genetics; D014218:Triage / Q000379:methods; D002578:Uterine Cervical Dysplasia / Q000473:pathology / Q000821:virology; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000821:virology; D014626:Vaginal Smears
D014408:Biomarkers, Tumor; D004279:DNA, Viral; C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D012333:RNA, Messenger; D012367:RNA, Viral; D012097:Repressor Proteins