Astrid R. W. Schroder

Clinical performance of the APTIMA ® HPV Assay for the detection of high-risk HPV and high-grade cervical lesions

BACKGROUND Human papillomavirus (HPV) DNA testing is widely used in conjunction with Papanicolaou (Pap) testing in cervical cancer screening programs to improve the detection of high-grade lesions. While HPV DNA test sensitivity is good, an improvement in specificity is desired. Detection of HPV mRNA may improve specificity. The APTIMA HPV Assay detects the mRNA of 14 high-risk HPV types in liquid-based cytology specimens. OBJECTIVE To evaluate APTIMA HPV Assay performance for detection of high-risk HPV and high-grade cervical intraepithelial neoplasia (CIN) compared to Qiagens Hybrid Capture 2 HPV DNA (HC2) test. STUDY DESIGN Liquid Pap specimens were collected from 800 women referred to colposcopy and tested with the APTIMA HPV Assay and the HC2 test. Complete results were available for 753 subjects. A subset of samples (n = 393) were typed using Roches Linear Array HPV Genotyping Test. RESULTS Sensitivity and specificity for detection of high-risk HPV were >92% and 99% for the APTIMA HPV Assay and 93% and 82% for the HC2 test. Clinical sensitivity and specificity were 91% and >55% for detection of CIN 2+, and 98% and 53% for detection of CIN 3+ for the APTIMA HPV Assay; values for the HC2 test were 95% and 47% for CIN 2+, and 99% and 44% for CIN 3+. CONCLUSIONS The APTIMA HPV Assay is sensitive and very specific for detection of high-risk HPV. The APTIMA HPV Assay had similar clinical sensitivity for disease detection but higher clinical specificity than the HC2 test, which may improve patient management and reduce the cost of care.

Analytical characterization of the APTIMA® HPV Assay

BACKGROUND Human papillomavirus (HPV) testing has improved the sensitivity for the detection of cervical pre-cancer and cancer as compared to Pap testing. Several HPV tests are commercially available and most target the DNA from 13 or 14 high-risk HPV types. The APTIMA HPV Assay however, detects HPV E6/E7 mRNA from 14 high-risk types of HPV: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68. OBJECTIVE To determine the analytical performance characteristics of the APTIMA HPV Assay. STUDY DESIGN Analytical sensitivity, analytical specificity, reproducibility, and the effect of potentially interfering substances was determined for the APTIMA HPV Assay on both the DTS (semi-automated) and TIGRIS DTS (fully automated) systems. RESULTS The 95% detection limit for both systems was between 17 and 488 copies/reaction, depending on the HPV type. The assay did not cross-react with normal flora and opportunistic organisms that may be found in cervical samples, or low-risk HPV types. Spermicides, anti-fungal and anti-itch medications, whole blood, glacial acetic acid, and most lubricants did not interfere with assay performance. Those lubricants containing polyquaternium 15 did interfere with assay performance. Inter-instrument, inter-operator, inter-lot, and inter-run signal variability were <10% for >99% of the data. Intra-run variability was <15%, except for those samples with concentrations at or below the 95% detection limit of the assay. CONCLUSIONS Based upon the analytical sensitivity, analytical specificity, and low variability, the APTIMA HPV Assay showed excellent performance and robustness.