HPV testing of biobanked liquid-based cytology - a validation study

Area of Science:

• Gynecologic Pathology
• Molecular Diagnostics
• Biomarker Analysis

Background:

• Liquid-based cytology (LBC) is widely used for cervical cancer screening.
• Biobanking of biological samples allows for retrospective analysis and biomarker discovery.
• Investigating the stability of biomarkers in biobanked samples is crucial for reliable diagnostic testing.

Purpose of the Study:

• To evaluate the feasibility of reanalyzing biobanked LBC vaginal samples for HPV DNA and mRNA.
• To assess the impact of biobanking on the sensitivity and specificity of HPV detection methods.
• To determine the concordance of HPV testing results before and after sample biobanking.

Main Methods:

• One hundred LBC samples (ASCUS or CIN1) were tested for HPV DNA and mRNA pre- and post-biobanking.
• Real-time PCR was used for HPV DNA analysis targeting E6/E7 genes of high-risk and low-risk HPV types, including a human control gene (HBB).
• The Aptima HPV assay was employed for mRNA analysis of 14 high-risk HPV types.

Main Results:

• Both HPV DNA (87% agreement) and mRNA (84% agreement) assays demonstrated good concordance between pre- and post-biobanking results.
• Sensitivity and specificity for HPV DNA were 0.85 and 0.95, respectively; for mRNA, they were 0.79 and 0.94.
• A statistically significant difference in positive results was observed post-biobanking (McNemar test, p < 0.004), with some loss of sensitivity but overall good concordance.

Conclusions:

• Biobanking of LBC vaginal samples provides a suitable platform for HPV DNA and mRNA testing.
• The findings support the extension of biobanking to other molecular analyses of vaginal samples.
• To ensure accurate results, a larger sample portion should be analyzed from biobanked specimens for reliable HPV detection.