Reproducibility of HPV DNA Testing by Hybrid Capture 2 in a Screening Setting

Within a large Italian randomized trial on new technologies for cervical canc+er screening involving 7 laboratories with different levels of experience, an intralaboratory and interlaboratory quality control program for human papillomavirus (HPV) DNA testing by Hybrid Capture 2 (HC2; Digene, Gaithersburg, MD) was implemented. To monitor the hybridization and detection steps, target samples containing purified, concentration-defined, HPV DNA were introduced in each test run. Only 3 of 1,024 showed a mistake in a positive vs negative classification with a 1 relative light unit (RLU)/positive control specimen (PC) ratio cutoff. To monitor the preanalytic steps (particularly denaturation), blinded specimens (33 collected in PreservCyt [Cytyc, Boxborough, MA] and 36 in Specimen Transport Medium [STM, Digene]) were centrally prepared, divided into aliquots, and sent to each laboratory. The multiple-rater κ scores for negative (<1 RLU/PC), low-positive (1 to <11 RLU/PC), and high-positive (≥11 RLU/PC) samples, respectively, were 0.91, 0.60, and 0.69 with PreservCyt and 0.93, 0.87, and 0.90 with STM. Our data showed high reliability and reproducibility with HC2, with κ values higher for STM than ThinPrep (Cytyc) samples.